Search

• A stack-up micro electrochemical device was developed based on the carbon paper electrode. • Cobalt-based MOFs and gold nanoparticles improved the metal ion absorption and electron diffusion. • Sensitive simultaneous determination of Pb2+ and Cd2+ achieved the subnanogram LODs. A portable device is conducive to the on-site detection of heavy metal ions at trace level in food and the prevention of related food safety issues. In this work, an electrochemical device stacked up with flat electrodes was developed for the detection of Pb2+ and Cd2+. The top layer of the device is a carbon paper as working electrode, which is modified with amino functionalized cobalt-based metal-organic framework and gold nanoparticles. The bottom layer was constructed with the carbon counter electrode and Ag/AgCl reference electrode, and a punched sample cell (Φ = 8 mm) was in the middle. The proposed method could simultaneously determinate Pb2+ and Cd2+ via anodic stripping voltammetry with the detection limit of 7.0 × 10−2 ng mL−1 and 1.1 × 10−2 ng mL−1, and was applied in real food samples (drinking water, juice, tea, grain, fruits, vegetables, liver and aquatic products) with the recovery of 91.2–105.4 % and 90.2–111.2 %, respectively. [ABSTRACT FROM AUTHOR]

Heavy metal pollution has become increasingly prominent, and bioremediation of heavy metal polluted areas is urgently needed. Broussonetia papyrifera is a pioneer tree species for vegetation restoration in the tailings area, while its molecular mechanism of heavy metal adaptation is not clear. Here, we report that a R2R3 MYB from B. papyrifera (BpMYB1) is involved in Cd accumulation by controlling the down-stream genes and mineral accumulation. Overexpression of BpMYB1 in B. papyrifera resulted in a significant increase in Cd accumulation and multiple gene transcription. Among the up-regulated genes, BpMYB1 could bind to ferrochelatase (BpFC2), basic helix-loop-helix transcription factor bHLH93 (BpbHLH93), and basic leucine zipper transcription factor bZIPs (BpbZIP1 , BpbZIP-CPC1) by recognizing TATCCAOSAMY (TATCCA) motif and related promoter segments. Further investigations revealed that overexpression of BpbZIP1 promotes the absorption of Cd, BpMYB1 regulate Cd uptake in plant relating to Fe accumulation without Fe-deficiency pathway via recognizing the downstream BpbHLH93 and involving in PCs biosynthetic pathway via recognizing the target BpFC2. Moreover, the Cd response effect mediated by BpMYB1 was boosted by interacting with a DELLA protein BpGAI1, a vital member of GA signaling. These results provide new insights into the molecular feedback mechanisms underlying BpMYB1-BpGAI1 controlled Cd uptake in plants, which will benefit for phytoremediation of Cd polluted soil. [Display omitted] • BpMYB1 overexpression benefits for Cd enrichment and tolerance of B. papyrifera. • BpMYB1 could regulate the transcription of multiple genes in Cd stress response. • The Cd stress response of BpMYB1 involves in the gibberellin-dependant signaling. • BpMYB1 could recognize downstream genes of BpFC2 , BpbHLH93 , BpbZIP1 , BpbZIP-CPC1. • BpFC2 , BpbHLH93 , BpbZIP1 , BpbZIP-CPC1 overexpression improves plant Cd uptake. [ABSTRACT FROM AUTHOR]

[Display omitted] • A three-electrode system for cadmium detection with paper-based channels. • Detection areas and channels were created by forming a hydrophobic barrier on a paper using the wax. • Usage of 5 wt/wt% antimony precursor the carbon working electrode increased the sensitivity by 2.18 times. • The usage of a PET film decreased the price of the electrode, thereby rendering it suitable for disposable sensors. This paper describes the development of a heavy metal sensor with point-of-care detection for heavy metal detection based on paper channel. A heavy metal detection sensor using a three-electrode system was fabricated on the surface of PET by screen printing. The working electrode is made of carbon paste containing antimony precursors, the reference electrode is made of Ag/AgCl paste, and the auxiliary electrode is made of carbon paste. The fabricated three electrodes were designed to deliver target substance through a paper-based channel to allow very easy point-of-care detection. When measuring cadmium, the fabricated three electrodes showed the highest sensitivity when the antimony precursor concentration was 5 wt/wt%, which was about 2.18 times higher than that of the carbon paste electrode. The fabricated heavy metal sensor had a cadmium detection range of 20–2000 μg/L and a linear coefficient (R2) of 0.988 in the detection range of 20–500 μg/L. The developed paper channel-based heavy metal sensor can be fabricated at a very low cost and is expected to be applicable to other heavy metal detection applications. [ABSTRACT FROM AUTHOR]

Cadmium ion (Cd (II)) is a highly toxic heavy metal usually found in natural water. Exposure to Cd (II) can produce serious effects in human organs such as Itai-Itai disease. Therefore, the maximum allowance levels of Cd (II) in drinking water and herbal medicines imposed by the World Health Organization (WHO) are 3 μg L−1 and 300 μg kg−1, respectively. In this work, nitrogen-doped graphene quantum dots (N-GQDs) as a fluorescent sensor for Cd (II) determination was developed in both solution-based and paper-based systems. N-GQDs were synthesized from citric acid (CA) and ethylenediamine (EDA) via the hydrothermal method. The synthesized N-GQDs emitted intense blue fluorescence with a quantum yield (QY) of up to 80%. The functional groups on the surface of N-GQDs measured by FTIR were carboxyl (COO−), hydroxyl (OH−), and amine (NH 2) groups, suggesting that they could be bound to Cd (II) for complexation. The fluorescence intensity of N-GQDs was gradually enhanced with the increase of Cd (II) concentration. This phenomenon was proved to result from the fluorescence enhancement (turn-on) based on the chelation enhanced fluorescence (CHEF) mechanism. Under the optimum conditions in the solution-based and paper-based systems, the limits of detection (LODs) were found to be 1.09 and 0.59 μg L−1, respectively. Furthermore, the developed sensors showed relatively high selectivity toward Cd (II) over ten other metal cations and six other anions of different charges. The performance of the sensor in real water and herbal medicine samples exhibited no significant difference as compared to the results of the validation method (ICP-OES). Therefore, the developed sensors can be used as fluorescent sensors for Cd (II) determination with high sensitivity, high selectivity, short incubation time (5 min). As such, the paper-based strategy has excellent promising potential for practical analysis of Cd (II) in water and herbal medicine samples with a trace level of Cd (II) concentrations. [Display omitted] • Novel paper-based N-GQDs sensor for trace-level probing of Cd (II) was developed. • User-friendly probing involved chelation enhanced fluorescence (turn-on) mechanism. • Sensor had high selectivity toward Cd (II) over 16 other metal cations and anions. • Sensor offers simple fabrication, high sensitivity, and short incubation time. • Sensor was validated by ICP-OES and applicable for real water and medicine samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • A simple and easy approach for detecting Cd2+ in drinking water has been developed. • Ten percent of horseradish peroxidase inhibition (IC 10) was achieved with 0.1 ppb of cadmium ions. • The PADs platform allowed the detection of Cd2+ in a simple and eco-friendly approach. With the knowledge of the extent of damage caused by cadmium ions (Cd2+), it becomes imperative to detect the presence of Cd2+ in drinking water with a rapid, efficient, and selective analytical method. Herein, a facile and novel colorimetric method for detecting cadmium ions, based on the irreversible inhibition of horseradish peroxidase (HRP) enzyme was established. Alternatively, a low-cost and affordable paper-based analytical device integrated with a smartphone platform was further designed to visualize, on-site and quantitative detection of Cd2+. The method developed for Cd2+ detection is of great interest to ensure a rapid diagnosis of water quality. Under the optimal conditions, the limit of detection of cadmium ions was 0.1 ppb, which is much lower than the permissible limit of WHO (5 ppb) for human exposure. Interference measurements showed that the method exhibited good selectivity. The proposed method was successfully applied as a rapid screening for cadmium ions monitoring in drinking water. [ABSTRACT FROM AUTHOR]

• Cadmium phytoxicity: A potential threat to crop system. • Calcium signalling: A response to cadmium-phytotoxicity. • Nitric oxide: Significance in plant cadmium tolerance. • Ca2+ and NO crosstalk and its role in cadmium tolerance. Despite its known phytotoxicity, cadmium (Cd) is being added in most arable soils via different agricultural activities. Additionally, information is meager on the Cd-phytotoxicity mitigation strategies employing sustainable approaches. Essential plant nutrient calcium (Ca2+) and signaling molecule nitric oxide (NO) are known as the key regulators of plant biochemical and physiological processes under stress conditions. Though there exists a close functional synergism between Ca2+ and NO in plant stress tolerance, the role of either Ca2+ and/or NO has been explored in plant stress tolerance in isolated reports. Given this, in addition to briefly overviewing the availability, uptake, transport and toxicity (including impact on morpho-physiological traits, photosynthesis, oxidative stress, and genotoxicity), this paper aimed to highlight the general roles, transport, and signaling of Ca2+ and/or NO in plants, and appraises the literature available on their significance in improvements of plant growth, photosynthesis and control of oxidative stress under Cd stress. Effort was also made to present a crosstalk on Ca2+ and NO signaling, and the significance of its outcome in plant Cd-tolerance. [ABSTRACT FROM AUTHOR]

• The addition of nickel ions to the co-precipitation can produce a new hydrotalcite adsorbent with a better structure (FeMnNi-LTH). • Lead and cadmium can be strongly adsorbed by FeMnNi-LTH during a broad pH range. • The adsorption of Pb and Cd by FeMnNi-LTH can theoretically reach 279.13 mg/g and 76.99 mg/g at 25 °C. • FeMnNi-LTH adsorbs heavy metal ions mainly through precipitation and surface complexation. This paper discusses the application of a layered triple hydroxide (FeMnNi-LTH) in removing Pb2+ and Cd2+ ions from aqueous solutions. The material was synthesized via co-precipitation, adhering to a molar ratio of 1:1:2 (Fe:Mn:Ni). It was characterized using FTIR, XRD, SEM and TEM. The results indicate that the synthesized material is classified as a hydrotalcite and exhibits a well-defined layered structure. Batch experiments were conducted to investigate the adsorption of Pb2+ and Cd2+ by FeMnNi-LTH, taking into account various factors such as coexisting ions, pH, temperature, adsorbent dosage, and contact time. The experimental results showed that the adsorption capacity of this material for Pb2+ and Cd2+ was 253.89 mg/g and 56.90 mg/g at 25 °C, respectively. Moreover, it exhibits a consistent high adsorption capacity across a broad pH range (pH 3–5.5). When cations coexist, they compete for adsorption sites in the following order: Zn2+ > Ca2+ > Mg2+ > Cd2+/Pb2+. Based on the calculated thermodynamic parameters, it is inferred that the adsorption process is endothermic and spontaneous. The adsorption mechanism, as analyzed by modeling and characterization, involves isomorphic substitution, surface complexation, precipitation, electrostatic attraction, and physical adsorption. The quantitative analysis of the adsorption mechanism revealed that FeMnNi-LTH primarily adsorbs Pb2+ and Cd2+ via precipitation and surface complexation. It was revealed by comparison with other adsorbents that the synthesized FeMnNi-LTH can be used for remediation of heavy metal pollution in water. [ABSTRACT FROM AUTHOR]

Heavy metals can adversely affect the growth and metabolic processes of plant. Arbuscular mycorrhizal (AM) fungi, which colonize the roots of most plants, may change the uptake and resistance to heavy metals by altering plant metabolism. But few published papers focused on how AM fungi enhanced plant tolerance to heavy metals at the metabolomics level. Therefore, our study incorporated LC-MS technology to explore the molecular mechanism by which AM fungi improved cadmium (Cd) tolerance of Bahia grass (Paspalum notatum) at the metabolomic scale. The results showed that AM fungi increased growth of Bahia grass, and enhanced its uptake and tolerance of Cd. Infection with AM fungi significantly raised the levels of both primary metabolites (amino acid, carbohydrate, organic acid, etc.) and secondary metabolites (such as terpenoids, phenolic compounds, and alkaloids), which in turn improved the photosynthesis efficiency, osmoregulation, and antioxidation defense of the plant, thereby enhancing the Cd tolerance of Bahia grass. Furthermore, under high concentration of Cd, both TCA cycle and lipid metabolism were generally suppressed, and AM fungi inoculation alleviated the effects and normalized the TCA cycle and lipid metabolism. In all, the metabolic alterations identified here provided insights into the mechanisms by which AM fungi enhanced plant tolerance to heavy metals. [Display omitted] • AM fungi altered the metabolism of Bahia grass and increased the tolerance to Cd. • AM fungi enhanced the buildup of primary metabolites, including amino acids. • Increased secondary metabolites by AM fungi ameliorated the harm of Cd to plant. • AM fungi restored the TCA cycle of plants to normal functioning under Cd stress. • AM fungi promoted lipid metabolism, thereby mitigating potential damages by Cd. [ABSTRACT FROM AUTHOR]

Water pollution, as the remarkable environmental remediation issue, is a today worldwide concern. Cadmium ion (Cd2+) as a hazardous water pollutant is seriously detrimental to human health, food safety, and ecological areas. Hence, we successfully designed a simple detection array for monitoring of ultra-low levels of Cd2+ ion by combining the advantages of aptamer as a high sensitive and selective sensing probe and zeolitic imidazolate framework-8 (ZIF-8) as a superior fluorescence quenching inducer. To have a portable and on-site detection assay, the aptamer biosensing array (aptasensor) was designed by using a paper-supported substrate. The basis of the designed paper-supported aptasensor was the specific complexation of Cd2+ with the aptamer strand, adsorption of fluorescein-labeled complementary (FAM-CP) strand on the ZIF-8 surface, and fluorescence quenching of FAM molecule after the leakage of the injected target solution on the sample zone of the paper substrate to the detection part. A linear relationship was obtained between the Mean Gray Value index, as a criterion for the fluorescence quenching, and the Cd2+ concentration in the range of 0.1–120 pM with a detection limit of 0.076 pM. The aptasensor could detect Cd2+ in the diverse real sample, including tap water, milk, coffee, and human blood serum. [Display omitted] • A simple fluorescent aptasensor was developed for monitoring of Cd2+ ion. • ZIF-8 as a fluorescence nanoquencher skeleton was utilized for the detection of Cd2+. • Cd2+ was sensitively determined as low as 0.076 pM. • Cd2+ was successfully detected in tap water, milk, coffee, rice, potato, and human blood serum. [ABSTRACT FROM AUTHOR]

[Display omitted] • GQDs-AuNCs ratiometric fluorescent sensor was prepared by electrostatic interaction. • The sensor was used to detect Cu2+ and Cd2+ in scallops. • The paper-based sensor can be used for semi-quantitative detection of Cu2+ and Cd2+. • The detection limits are 4.12 nM for Cu2+ and and 943 nM for Cd2+, respectively. Based on the electrostatic interaction, we constructed a ratiometric fluorescence nanomixture of graphene quantum dots-gold nanoclusters (GQDs-AuNCs) for the quantitative detection of Cu2+ and Cd2+. When Cu2+ or Cd2+ was added into the reaction system, the fluorescence of GSH-AuNCs at 565 nm can be quenched by Cu2+ and enhanced by Cd2+ while the intensity of N -GQDs at 403 nm stayed constant. Under the optimized conditions, the fluorescence intensity ratio (I 565 /I 403) of the GQDs-AuNCs system was proportional to the concentration of Cu2+ and Cd2+ in the range of 8×10−8 mol/L-6×10−6 mol/L and 1×10−6 mol/L-4×10−5 mol/L, respectively, with detection limits of 4.12×10−9 mol/L and 9.43×10−7 mol/L, respectively. In the presence of Cu2+ and Cd2+, the paper-based vision sensor would produce visible fluorescent color changes, which can be used for rapid detection on site. The method has been successfully applied to the determination of Cu2+ and Cd2+ in scallops with satisfactory results. [ABSTRACT FROM AUTHOR]

[Display omitted] • Garlic Se absorption and transportation were largely affected by Se speciation. • Organic Se was superior to inorganic Se in enriching Se and antagonizing Cd. • Bulb Se content treated with organic Se was about twice (or more) than inorganic Se. • Organic Se was significantly more effective in reducing Cd content than inorganic Se. • Se was mainly enriched in bulb, Cd was enriched in root under organic Se application. Currently, planting selenium-rich crops using inorganic selenium such as selenate and selenite is used to address human selenium deficiency problems. In this paper, besides the above two traditional inorganic selenium speciation, we chose a new organic selenium speciation of potassium selenocyanoacetate to investigate the different effects of selenium speciation on selenium absorption, selenium transformation and cadmium antagonism via foliar application. Planting experiments showed that the selenium content of garlic bulbs treated with organic selenium was 1.8–3.9 times higher than that of inorganic selenium. Additionally, the absorption and transformation efficiency of organic selenium in garlic was also the highest, reaching over 95 %. Importantly, it was noteworthy that the cadmium content in bulbs treated with organic selenium was significantly lower than the Chinese food safety standard (0.2 mg/kg). Hence, this study provides an efficient organic selenium speciation which is beneficial to meet human selenium requirements and ensure safe utilization of cadmium-contaminated soils. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a common heavy metal pollutant in the environment, and the widespread use of products containing Cd compounds in industry has led to excessive levels in the environment, which enter the animal body through the food chain, thus seriously affecting the reproductive development of animals. Related studies have reported that Cd severely affects spermatogonia development and spermatogenesis in animals. In contrast, the reproductive toxicity of Cd in males and its mechanism of action have not been clarified. Therefore, this paper reviewed the toxic effects of Cd on germ cells, spermatogonia somatic cells and hypothalamic-pituitary-gonadal axis (HPG axis) of male animals and its toxic action mechanisms of oxidative stress, apoptosis and autophagy from the perspectives of cytology, genetics and neuroendocrinology. The effects of Cd stress on epigenetic modification of reproductive development in male animals were also analyzed. We hope to provide a reference for the in-depth study of the toxicity of Cd on male animal reproduction. [ABSTRACT FROM AUTHOR]

The gut-brain axis is a crucial interface between the central nervous system and the gut microbiota. Recent evidence shows that exposure to environmental contaminants, such as heavy metals, can cause dysbiosis in gut microbiota, which may affect the gut-brain communication, impacting aspects of brain function and behavior. This systematic review of the literature aims to evaluate whether deleterious effects on brain function due to heavy metal exposure could be mediated by changes in the gut microbiota profile. Animal studies involving exposure to heavy metals and a comparison with a control group that evaluated neuropsychological outcomes and/or molecular outcomes along with the analysis of microbiota composition were reviewed. The authors independently assessed studies for inclusion, extracted data and assessed risk of bias using the protocol of Systematic Review Center for Laboratory Animal Experimentation (SYRCLE) for preclinical studies. A search in 3 databases yielded 16 eligible studies focused on lead (n = 10), cadmium (n = 1), mercury (n = 3), manganese (n = 1), and combined exposure of lead and manganese (n = 1). The animal species were rats (n = 7), mice (n = 4), zebrafish (n = 3), carp (n = 1) and fruit fly (n = 1). Heavy metals were found to adversely affect cognitive function, behavior, and neuronal morphology. Moreover, heavy metal exposure was associated with changes in the abundance of specific bacterial phyla, such as Firmicutes and Proteobacteria , which play crucial roles in gut health. In some studies, these alterations were correlated with learning and memory impairments and mood disorders. The interplay of heavy metals, gut microbiota, and brain suggests that heavy metals can induce direct brain alterations and indirect effects through the microbiota, contributing to neurotoxicity and the development of neuropsychological disorders. However, the small number of papers under review makes it difficult to draw definitive conclusions. Further research is warranted to unravel the underlying mechanisms and evaluate the translational implications for human health. [Display omitted] • This systematic review included 16 studies that exposed animals to Pb, Mn, Cd and Hg. • Heavy metal exposure affects gut microbiota, cognition, behavior & brain morphology. • Majors changes were in Firmicutes and Proteobacteria, albeit with conflicting results. • Gut dysbiosis due to heavy metals were correlated with mood and cognitive disorders. • Further research is essential to uncover mechanisms and health implications. [ABSTRACT FROM AUTHOR]

A qualitative identification method of heavy metal cadmium concentration in peanut oil with microwave detection technology was presented. Initially, on the basis of national standards, the configured samples were classified into three categories: negative, which did not exceed the national standard; weak positive, which slightly exceeded the national standard; and strong positive, which far exceeded the national standard. Then, the obtained transmission index was subjected to data dimensionality reduction, using three feature dimensionality reduction methods, namely Principal component analysis (PCA) strategy, recursive feature elimination (RFE) algorithm, and RFE-PCA algorithm, respectively, and the dimensionality-reduced data were used as inputs to establish the random forest (RF) classification model, and the results showed that the three feature dimensionality reduction methods could achieve better prediction results. Among them, the RFE-PCA-RF model has the best prediction performance, at this time, the RFE algorithm retains 35 feature points and number of principal components (PCs) is 7. Next, the structure of RFE model is optimized, and the SVM-RFE-PCA-RF model is constructed by using support vector machines (SVM) as its weight allocator and the analysis of the results of its running 50 times reveals that the discriminative accuracy of the prediction set reaches 100% for 31 times, which meets the requirement of high-precision qualitative identification of three types of samples. Therefore, using microwave equipment for qualitative identification of cadmium content in peanut oil is feasible, and the SVM-RFE-PCA dimensionality reduction strategy proposed in this paper is also worth considering in the future. [Display omitted] • Detection of heavy metal cadmium transmission index in peanut oil by microwave detector. • A feature dimension reduction method based on SVM-RFE model is proposed. • Feature extraction algorithm is used to optimize the classification model. • This study used microwave detection to realize qualitatively analysis of cadmium in peanut oil. [ABSTRACT FROM AUTHOR]

• Juveniles of sea bream Sparus aurata were exposed to cadmium chloride for up to 120 days. • The effects of the exposure were evaluated on the hepatopancreas architecture. • In a time-dependent manner, cadmium was absorbed and stored within the tissue. • Severe morphological and functional damages were detected. • Cadmium induced endocrine disrupting effect on parenchyma. In recent decades, cadmium has emerged as an environmental stressor in aquatic ecosystems due to its persistence and toxicity. It can enter water bodies from various natural and anthropogenic sources and, once introduced into aquatic systems, can accumulate in sediments and biota, leading to bioaccumulation and biomagnification in the food chain. For this reason, the effects of cadmium on aquatic life remain an area of ongoing research and concern. In this paper, a multidisciplinary approach was used to assess the effects of long-term exposure to an environmental concentration on the hepatopancreas of farmed juveniles of sea bream, Sparus aurata. After determining metal uptake, metallothionein production was assessed to gain insight into the organism's defence response. The effects were also assessed by histological and ultrastructural analyses. The results indicate that cadmium accumulates in the hepatopancreas at significant concentrations, inducing structural and functional damage. Despite the parallel increase in metallothioneins, fibrosis, alterations in carbohydrate distribution and endocrine disruption were also observed. These effects would decrease animal fitness although it did not translate into high mortality or reduced growth. This could depend on the fact that the animals were farmed, protected from the pressure deriving from having to search for food or escape from predators. Not to be underestimated is the return to humans, as this species is edible. Understanding the behaviour of cadmium in aquatic systems, its effects at different trophic levels and the potential risks to human health from the consumption of contaminated seafood would therefore be essential for informed environmental management and policy decisions. [ABSTRACT FROM AUTHOR]

• We study the effects of an episode of extensive news coverage of cadmium contamination of rice in China in 2013. • The cadmium rice event reduced the incidence of joint or muscle pain (JMP) by 2% in Hunan Province. • Hunan residents switched away from unsafe drinking water sources such as surface water to deep groundwater, which contributed to the reduction in JMP incidence. • Hunan residents also reduced their consumption of rice in response to the event. • Strong evidence is in support of news and public information as supplemental approaches to formal environmental regulation. The paper studies the effects of news media coverage of the 2013 cadmium rice event in China on consumer health outcomes and avoidance behavior. A difference-in-differences analysis shows that the event caused a 2% decrease in the incidence of joint or muscle pain (JMP), a major health outcome of cadmium pollution, in high-cadmium-pollution regions relative to other regions. Individuals with higher income or with more access to traditional TV media or digital media experienced a greater level of JMP reduction. To defend against cadmium pollution, residents in cadmium-polluted regions switched their drinking water from unsafe sources such as surface water to the safe source of deep groundwater and significantly reduced their consumption of rice. Our findings demonstrate the importance of information provision as an informal approach to complement formal environmental regulation and the critical role of news media in environmental regulation and public health. [ABSTRACT FROM AUTHOR]

The studied materials, Cadmium (Cd2+) and Chromium (Cr3+) are highly toxic, and it focuses on investigating various environmental sources, such as industrial processes and waste water. When quantities of Cr3+ and Cd2+ exceed the allowable limit, biological toxicity and hazardous environmental pollution are unavoidable. In order to address this problem, we introduce 5-(5-(4-([2,2':6′,2″-terpyridin]-4′-yl) phenyl) thiophen-2-yl)-7,8,13,14-tetrahydrodibenzo [ a,i ] phenanthridine (TPTP), a dual-emission response chemosensor that employs a colorimetric and fluorescence turn-on approach for the rapid, sensitive, and discriminate detection of Cr3+ and Cd2+ ions. We created a newly designed luminous TPTP sensor based on intramolecular charge transfer (ICT). TPTP sensor probe specifically determined Cr3+ and Cd2+ ions with an immediate colour shift from cyan to green and orange in CH 3 CN: H 2 O (6:4) solvent solution. The permissible level set by the Environmental Protection Agency (EPA) of the United States for the presence of Cr3+ and Cd2+ ions in drinking water was higher than the detection level of 3.5 and 9.7 nM, by this sensor respectively. NMR titrations, HRMS, and theoretical calculation methods were employed to examine the accurate sensing processes of TPTP and complexes. This is an effective method of detecting Cr3+ and Cd2+ ions in an environmental system using a ratiometric methodology. In addition, TPTP was used to determine the concentration of Cr3+ and Cd2+ ions in natural water and food samples. Fluorescent bio-imaging studies revealed that the present sensor TPTP could identify Cr3+ and Cd2+ ions inside living HeLa cells. A paper kit analysis has been done on TPTP , which has a time-to-result of less than 1 s and offers a cost-effective assay. As a result, the platform offers portability. [Display omitted] • A ratiometric probe for Cd2+ and Cr3+ ions based on a thiophene-extended conjugate terpyridine with phenanthridine functionality has been developed. • The sensor TPTP has a good selectivity for detecting Cd2+ and Cr3+ ions and a low detection limit. • The sensing mechanism was confirmed by a 1H NMR titration experiment and a DFT calculation. • The probe worked well for fluorescent bio-imaging of the Cd2+ and Cr3+ ions in both living cells and real resources. [ABSTRACT FROM AUTHOR]

[Display omitted] • A method for rapid and accurate detection of cadmium content in saline soils is proposed. • The method is based on visible-near-infrared spectroscopy and machine learning. • We pre-processed the original reflection spectra using fractional order derivatives. • We constructed three-band spectral index by optimal band combination algorithm, and obtained the corresponding optimal band combinations. • We proposed the MSC-ELM model based on the two-hidden-layer extreme learning machine. Heavy metal pollution in saline-alkali land has a significant impact on the ecological environment and human health. Rapid and accurate inversion of cadmium (Cd) element content in the saline-alkali land is important for environmental protection, saline-alkali soil improvement and conversion of saline-alkali land to cultivated land. Using traditional chemical detection methods to detect the content of heavy metal elements requires a long testing time and has the drawback of high prices. In this paper, we select the saline-alkali land of Zhenlai County as the study area and combine visible-NIR spectroscopy with machine learning models to invert the Cd content in the saline-alkali land. We preprocess the original reflection spectra using fractional order derivatives (FOD), then construct six three-band spectral indices (TBIs) and obtain the corresponding optimal band combination parameters by the optimal band combination (OBC) algorithm. To address the shortcomings of two-hidden-layer extreme learning machine (TELM), this paper introduces new weight parameters among the nodes of the first hidden layer, further extends it to multiple layers on this basis, and proposes the MSC-ELM model. The improved model is compared with several models, such as random forest (RF), partial least squares (PLS) and extreme learning machine (ELM). And the model performance is analyzed and compared by introducing several performance indicators, such as root mean square error (RMSE) and the ratio of the performance to interquartile (RPIQ). The experimental results show that the FOD transformation can eliminate the baseline drift and reduce the spectral noise. The constructed TBIs can effectively enhance the correlation with Cd content relative to the original single band, reduce redundant information and enhance the spectral features. The MSC-ELM model achieves better performance metrics compared to the other models and obtains the optimal prediction performance. This study provides an accurate and rapid method for the detection of Cd content in saline soil, which is important for the improvement and ecological recovery of saline soil. [ABSTRACT FROM AUTHOR]

In order to enhance the removal of cadmium from phosphoric acid, it is imperative to explore novel resources that may be utilized for the development of highly effective and environmentally sustainable adsorbents. Cellulose beads are composed of naturally occurring polysaccharide fibers and find extensive utilization across several industrial sectors and applications. Within this framework, this research paper presents a green and simple method for producing porous cellulose beads using date palm fibers as the preferred raw material. The innovation lies in immersing the obtained cellulose beads in a Polyvinyl fluoride (PVDF)/ N , N -dimethylformamide (DMF) suspension as a coating polymer with different concentrations (2.5, 5, 10 %) to maintain their stability in an acidic environment. The surface of cellulose/PVDF beads were subjected to multiple characterizations like Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), size distribution then pH stability confirming that the coating has been perfectly achieved and conserved well the shape of the beads. The coated cellulose/PVDF-2.5 % underwent evaluation by the process of batch adsorption experiments while different parameters were varied including contact time (5, 10, 20, 30, 60, 90 min), temperature (25, 35, 45 and 55 °C), and adsorbent mass (20, 40, 60, 80 and 100 mg). The obtained ICP data showed that the adsorption rate of Cd (II) from phosphoric acid medium decreased while increasing both temperature from 25 to 55 °C and contact time from 5 to 90 min while adding more adsorbent dosage from 20 to 100 mg enhanced the removal percentage. The cellulose/PVDF-2.5 % was more effective with an adsorption capacity equal to 3.4998 mg/g at optimal conditions including 25 °C as the temperature after 5 min as contact time and by adding a mass 100 mg of the biosorbent while the pH = 2 of the solution is maintained the same. The examined material's adsorption processes proved to be exothermic and non-spontaneous, and it proved that the pseudo-second-order model provided the best match for the cellulose/PVDF-2.5 % beads kinetics data. Furthermore, the cellulose beads exhibited exceptional reusability for up to four repeated cycles without undergoing desorption. The present study offers a viable approach for producing environmentally sustainable biomass-derived adsorbents. Additionally, the study validates the potential of cellulose/PVDF beads as an intriguing material for phosphoric acid decadmiation. [ABSTRACT FROM AUTHOR]

• There are no generally agreed criticality concepts and list of critical materials. • The suggested global criticality concept addresses the availability of materials. • Criticality concepts should prioritise long-term sustainability over politics. • All critical materials carry severe long-term sustainability risks to the economy. The demand for raw materials, in particular, for those classified as critical materials, has increased considerably due to the ongoing energy transition and the corresponding surge in the use of renewable energy technologies. In this context, this review paper analyses literature on reserves, resources, and production data of critical materials, which are required for the energy transition, to understand the connection between the present criticality definition and long-term sustainability. The link to long-term sustainability was studied by applying bell curve production projections. The analysis shows that the present criticality concept and classification is predominantly a reflection of a short-term local political construct, which may be consumption- or production-driven, or a mixture of both, depending on the classifying country. Based on material databases and the corresponding logistic production bell curves, severe limitations of primary supply could emerge from materials, such as antimony, cadmium, chromium, cobalt, copper, indium, molybdenum, nickel, silver, and zinc within two decades. Furthermore, all studied materials are projected eventually to be severely critical. Thus, local efforts will likely have a limited capability to effectively address the long-term risk associated with the production and use of critical materials. Moreover, without concerted global effort, the present criticality concept may not be effective in addressing even the short-term supply bottleneck, particularly for the accelerating energy transition, that it aspires to address. Hence, applying the criticality concept at the global level carries special potential to mitigate the supply risk by mobilising all stakeholders based on a well-informed understanding of materials flows. [ABSTRACT FROM AUTHOR]

In this growing age of population,agriculture plays a significant role by providing food and employment to millions of people. But to meet the growing need of food day by day the demand of fast and quality plant production becomes a must. Fertilization is one of such activities which are people accustomed to do for this purpose from a very long time. But the excessive uses of chemical fertilizers are showing negative influence on the environmental and public health. The paper mainly focuses on how the excessive use of chemical fertilizers are affecting the soil health as well as the water bodies by accumulating heavy metals (HMs) and other chemical elements present in them and the possible remediation measures.In adequate levels, all heavy metals are hazardous. However, some of them e.g., arsenic (As), lead (Pb) and Cadmium (Cd) are of particular relevance due to their environmental concentrations. The paper also provides a comprehensive discussion of the sources, uses, toxicity, and remediation of these particular HMs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluorescence hyperspectral technology is applied to Cd stress concentration classification. • Wavelet principal component analysis is proposed for data dimensionality reduction. • The paper achieves high-precision classification of Cd stress categories. The feasibility of fluorescence hyperspectral technology to classify lettuce leaves under different heavy metal pollutant cadmium stress was discussed and demonstrated, and the wavelet principal component analysis (WPCA) algorithm was proposed to effectively reduce the dimensionality of the data in this paper. The fluorescence hyperspectral images of 1250 lettuce leaves with 5 cadmium (Cd) stress categories (contrast check, low pollution, light pollution, medium pollution and severe pollution) were obtained by fluorescence hyperspectral imaging instrument. In addition, the results of atomic absorption spectrometry showed that the Cd content in lettuce leaves increased with the increase of Cd stress concentration. Taking the entire lettuce leaf as the region of interest, the ROI fluorescence hyperspectra of the lettuce leaf was obtained through mask processing. Then, WPCA was used to reduce the dimensionality of the fluorescence hyperspectral data with different wavelet basis function including db4, db5, db6, sym5 and sym7. Support vector machine (SVM) and cuckoo search optimization support vector machine (CS-SVM) models were set up based on WPCA dimensionality reduction data. Besides, the classification accuracy rate of WPCA-CS-SVM model for Cd stress lettuce leaves was higher than that of WPCA-SVM model. Among them, the WPCA-CS-SVM model based on the third layer decomposition of the sym7 wavelet basis function had the best performance, the accuracy of the calibration set and the prediction set were 99.79% and 94.19%, and the modeling time was only 465.32 s. WPCA algorithm combined with fluorescence hyperspectral technology could effectively realize the classification of lettuce leaves under different Cd concentration stress. [ABSTRACT FROM AUTHOR]

Nanomaterials with enzyme-like catalytic features (nanozymes) find wide use in analytical sensing. Apart from catalytic characteristics, some other interesting functions coexist in the materials. How to combine these properties to design multifunctional nanozymes for new sensing strategy development is challenging. Besides, in nanozymes it is still a challenge to conveniently control the catalytic process, which also hinders their further applications in advanced biochemical analysis. To remove the above barriers, here we design a light-controllable multifunctional nanozyme, namely manganese-inserted cadmium telluride (Mn–CdTe) particles, that integrates oxidase-like activity with luminescence together, to achieve the fluorometric/colorimetric dual-mode detection of toxic mercury ions (Hg2+) at ambient pH. The Mn–CdTe exhibits a light-triggered oxidase-mimicking catalytic behavior to induce chromogenic reactions, thus enabling one to start or stop the catalytic progress easily via applying or withdrawing light irradiation. Meanwhile, the quantum dot material can exhibit bright photoluminescence, which provides the fluorometric channel to sense targets. When Hg2+ is introduced, it rapidly leans toward Mn–CdTe through electrostatic interaction and Te–Hg bonding and induces the aggregation of the latter. As a result, the luminescence of Mn–CdTe is dynamically quenched, and the masking of active sites in aggregated Mn–CdTe leads to the decrease of light-initiated oxidase-mimetic activity. According to this principle, a new fluorometric/colorimetric bimodal method was established for Hg2+ determination with excellent performance. A 3D-printed portable platform combining paper-based test strips and an App-equipped smartphone was further fabricated, making it possible to achieve in-field sensing of the analyte in various matrices. [ABSTRACT FROM AUTHOR]

• Phosphogypsum slag-based cementitious materials (PS) can synergistic solidify/stabilize Cd. • The main hydrates of PS solidifying/stabilizing Cd are ettringite and C-S-H. • The stabilization mechanism is the lattice replacement of Ca2+ by Cd2+ and the formation of Cd(OH) 2. The phosphogypsum slag-based cementitious material (PS), a type of low-carbon cementitious materials, showed its potential in solidifying heavy metals. This paper is aimed to investigate the efficiency of PS in immobilising heavy metal cadmium (Cd) and explore the solidification mechanism. In the study, the PS specimens doped with different Cd(NO 3) 2 content (0–1.0% by weight) were prepared and the solidification efficiency was determined by leaching test. Moreover, the mechanism of solidification of Cd in PS were explored by characterising hydration behaviour of Cd-substituted PS by XRD, TGA, NMR, FTIR and SEM-EDS. The results showed that the best performance was observed in Cd mixed PS with 50% slag, 45% phosphogypsum and 5% lime, which showed a compressive strength of 37.3 MPa and a metal leaching concentration of 0.134 µg/L. The ettringite and C-S-H were observed as the main hydration products of PS system. Moreover, it was found that Cd was bound to the phases of sulfoaluminate and silicate and substituted to Ca2+ in the crystal structure or Cd(OH) 2 being trapped by C-S-H, the substitution and trapping of which lead to a shortening of the average chain length of C-S-H and delay the hydration process of the Cd-doped PS system. [ABSTRACT FROM AUTHOR]

Cadmium is a typical heavy metal ion. Long-term exposure to cadmium can lead to diseases like renal tubular dysfunction and bone degeneration. Therefore, it is necessary to develop efficient separation methods and detection techniques for cadmium ions. In this paper, adsorption enrichment was combined with detection to rapidly detect cadmium ions in water. Cadmium ion imprinted polymers (Cd(II)-IIPs) were prepared by bulk polymerization using Cd(II) as template ion, itaconic acid (IA) as functional monomer, ethylene dimethacrylate (EGDMA) as cross-linker, 4-(2-pyridylazo)-resorcinol (PAR) as chromogenic ligand, and azobisisobutyronitrile (AIBN) as initiator. The preparation conditions were optimized and the prepared Cd(II)-IIPs were characterized by Fourier transform infrared spectroscopy (FT-IR), solid-state 13C nuclear magnetic resonance (13C NMR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS). In the adsorption experiment, the adsorption equilibrium was reached within 10 min in a solution of pH 7.0, and the saturation adsorption capacity of IIPs and NIPs were 50.542 mg·g−1 and 33.762 mg·g−1, respectively. The Cd(II)–IIPs exhibited selectivity for Cd(II) ions in the presence of Ni(II), Fe(II), Co(II), Cu(II), and Pb(II) ions; and after eight adsorption–desorption cycles, the adsorption capacity of Cd(II)-IIPs retained > 90%. In addition, the detection performance of the Cd(II)-IIPs was investigated by digital image colorimetric (DIC) and ultraviolet spectrophotometric methods; the detection limits were 1.46 and 1.74 μg·L−1, respectively, and the quantitative detection range was 8–100 μg·L−1. The Cd(II)-IIPs exhibited excellent adsorption properties and an obvious color gradient variation, which could be used for quantitative colorimetric detection over a range of concentrations. • A novel Cd(II) ion imprinted polymer was synthesized by bulk polymerization. • The adsorption equilibrium was reached within 10 min in a solution of pH 7.0. • The maximum saturation adsorption capacity was 50.542 mg·g− 1. • The prepared Cd(II)-IIPs show good selectivity, stability and reusability. • The prepared Cd(II)–IIPs could be used for semi-quantitative colorimetric detection. [ABSTRACT FROM AUTHOR]

Adsorption kinetics are commonly modeled using pseudo-first order (PFO) and pseudo-second order (PSO) rate laws. Both models are formulated via differential equations whose coefficients are commonly treated as deterministic quantities, which are calculated from experimental data using regression techniques. In this paper, we propose a full randomization of both models by assuming that all the parameters of the PFO and PSO models are random variables with arbitrary densities. Then, we probabilistically solve both models by determining semi-explicit expressions of the first probability density functions of the corresponding solution stochastic processes, as well as the densities of the time until a fixed adsorbed amount of reactant has been reached for each model too. The analysis is conducted under very general assumptions and is based on extensive application of the so-called Random Variable Transformation (RVT) technique. Finally, we apply all the aforementioned theoretical findings to model the adsorption of cadmium ions onto tree fern, using real data. We compare the results obtained by the randomized PFO and PSO models, using a Bayesian and a randomized version of the least mean square method to assign reasonable densities to model parameters. After comparing the results, the PSO model is selected, and, we then show how the RVT technique can be applied to obtain further key information, such as the second probability density function, of the solution and the covariance function. • Full randomized PFO and PSO adsorption kinetic models are analyzed. • A complete statistical description of the adsorption capacity is given via the probability densities. • The Random Variable Transformation method is applied under very general assumptions. • Probability distributions of model parameters are estimated using two techniques. • Probabilistic theoretical results are applied to real-world chemical data. [ABSTRACT FROM AUTHOR]

This paper presents a new approach for the purification of 29% and 54% P 2 O 5 phosphoric acid contaminated with cadmium ions using synthesized lamellar material based on manganese (Na-MnO 2). The removal efficiencies of cadmium ions were 35 % and 31 % for 54% and 29% P 2 O 5 phosphoric acid. The kinetic and isotherm studies of cadmium adsorption were performed. After the phosphoric acid purification process, Na-MnO 2 material was characterized by XRD, SEM, and TGA-DTA. All the results enable the refinement of the final phase by the Rietveld method. A proposed mechanism of cadmium ion removal by Na-MnO 2 was given. The stability of the material was also controlled in the acid medium 29 % and 54 % P 2 O 5. The results confirmed that Na-MnO 2 material could be a potential sorbent for the efficient removal of heavy metals from phosphoric acid solutions. This simple process can be further developed and thus opens an avenue in the industrial sector to process larger quantities using high-performance materials based on manganese. Self-consistent ab initio calculations, based on DFT (Density Functional Theory) approach and using the FLAPW method (Full potential Linear Augmented Plane Wave), were performed to investigate both the electronic and magnetic properties of materials. [Display omitted] • New approach for the purification of phosphoric acid 29 % and 54 % P 2 O 5 by a lamellar material manganese oxide (Na-MnO 2). • The removal efficiencies of cadmium ions were higher for phosphoric acid 54 % P 2 O 5 than phosphoric acid 29 % P 2 O 5. • Na-MnO 2 material could be a potential sorbent for the efficient removal of heavy metals from phosphoric acid solutions. • Despite the acidity of the medium, the presence of phosphate ions in the phosphoric acid contribute to the improvement of the efficient removal of heavy metals. • FLAPW calculations were performed to investigate both electronic and magnetic structures to shed light on the Cd(II) adsorption effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • BCM-nZVI exhibit adsorption capacity of 134 mg·g−1 and Cd2+ removal rate of 99.96%. • Cd2+ in water treated by BCM-nZVI is below drinking water standards (5 μg·L-1). • BCM-nZVI can be stored stably for 120 days without loss of activity. • The adsorption mechanism by reducing toxic Cd2+ to non-toxic Cd0 is revealed. Cadmium (Cd2+) ions in drinking water are typical heavy metal contaminants, even trace amounts of Cd2+ can accumulate in the body, leading to serious irreversible damage to human bones and kidneys. Herein, we propose an effective and green strategy for the deep removal of trace Cd2+ from water by dispersed loading of nanoscale zero-valent iron (nZVI) onto bacterial cellulose membranes (BCM). BCM-nZVI can effectively remove Cd2+ from water in a wide pH range (5–8) with 99.96% removal rate. Freundlich isotherm model and the pseudo-second-order model reveal the adsorption process with a maximum adsorption capacity of 134.0 mg·g−1 at 30 °C. Impressively, the Cd2+ concentration in actual Cd2+ containing drinking water is below the target of 5 μg·L−1 (drinking water standard in China, USA and EU) after treated by the BCM-nZVI, and no additional pollutants are introduced. The excellent stability (stored stably for 120 days) and economic cost analysis ($75.6 m−3 for Cd2+ containing drinking water) of BCM-nZVI indicated they are viable for practical application in actual water treatment. Most importantly, the reduction reaction and mechanism study of BCM-nZVI revealed that the toxic Cd2+ is converted into non-toxic Cd0 assisted by the hydrated electrons and it has been systemically verified in our paper. This work sheds light on BCM-nZVI can be used as an ideal green material to removal Cd2+ in trace amounts of actual drinking water with high-efficiency, economical, environmentally friendly and has great potential for application in real environments. [ABSTRACT FROM AUTHOR]

Elemental impurities may occur in pharmaceutical products under different conditions. Impurity composition includes many types of species: metals and non-metals, which can be essentially toxic, due to their direct health damage potential, and those essential elements or compounds, which play a physiological role in the human body in defined levels. The essential ones may develop an illness profile or a non-desirable situation, since their concentrations exceed permitted and tolerable limits. Inorganic contamination in pharmaceuticals has been observed in several countries. A high number of reports on metal contamination in natural products, traditional eastern medicines, herbal medicines and medicinal plants have been presented, especially with lead, cadmium, mercury and arsenic. A simple explanation to this fact is mainly related to metal deposition in the soil, water contamination, fertilizer and pesticide poisoning. Synthetic products are faced to catalyst deposition, water contamination, glassware impurities, contaminated raw materials and excipients, as well as uncontrolled manufacturing processes. Several analytical methods have been developed and improved for years, allowing the application of better strategies to evaluate metal contamination in pharmaceutical products. Spectroscopy techniques are used by industries in routine investigations, and can also be improved to attend different types of matrices and materials. In Brazil, the Brazilian Pharmacopeia and National Health Surveillance Agency are the available guide and institution, respectively, onto which the investigation of elemental impurities is based. In the international scenario, The United States Pharmacopeia (USP), The European Pharmacopeia (EU), The European Medicine Agency (EMA) Guideline and The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use(ICH) Guideline are the four most important and complete manuals for the evaluation of impurities in pharmaceutical products, active pharmaceutical ingredients (APIs), raw materials and intermediates in the present days. A great amount of scientific research about inorganic impurities in pharmaceuticals has been conducted in recent years, but it still remains below the strategies of analytical applications due to the many possibilities of contamination. The continuous work on this theme, regulated by international agencies, is the best way to improve the quality of pharmaceutical products and to ensure safety in their use. The objective of this paper is to summarize spectroscopy techniques applied to inorganic evaluation in pharmaceuticals, considering the limits of element exposure to human beings reported by national and international references. [Display omitted] • Inorganic impurities in pharmaceutical products may cause hazardous effects to human health. • Analytical strategies for chemical elements determination in drugs were reported around the globe • There is a lack of concern about scientific research applied to inorganic impurities determination in pharmaceuticals samples. • Especially American, African and Asian natural products are not completely studied when it comes to chemical elements profile. [ABSTRACT FROM AUTHOR]

WRKY transcription factors (TFs) play an important role in regulating plant growth and responses to environmental stress. However, the molecular mechanism of WRKY to cadmium (Cd) stress is unclear, which prevents phytoremediation of Cd-contaminated soil from widely application. To determine the underlying mechanism, PyWRKY48 -overexpressing poplars were obtained (OE-32 and OE-67) to study the Cd tolerance and accumulation in poplars. Results showed that the Cd content in the aboveground part of the two transgenic poplar lines were 1.57 and 1.99 times higher than that of wild type (WT), and lateral roots, GSH, PCs content and GST activity increased significantly. RNA-seq. data about transgenic and WT poplars revealed that 2074 differentially expressed genes (DEGs) in roots, 4325 in leaves, and 499 in both tissues. And these DEGs were mainly concentrated in ABC transport protein (PaABC), heavy-metal binding protein (PaHIPP), and transportation and loading of xylem (PaNPF , PaBSP) proteins, and they enhanced Cd accumulation. Meanwhile, PyWRKY48 increased the Cd tolerance of transgenic poplars by up-regulating the expression of PaGRP , PaPER and PaPHOS , which encode cell wall proteins, antioxidant enzyme, and heavy metal-associated proteins, respectively. In addition, overexpression PyWRKY48 promoted poplar growth by increasing the chlorophyll a nd carotenoid content. This study generated PyWRKY48 -overexpressing poplars and functionally verified them in Cd-contaminated soil, to analyze the effects of the gene on poplar growth, Cd tolerance and Cd accumulation. RNA seq. data revealed that several genes are involved in Cd exposure. This may provide a strong molecular basis and new ideas for improving the phytoremediation efficiency of Cd-contaminated soils. Importantly, the transgenic poplars grew better and accumulated more Cd than the wild-type. Therefore, PyWRKY48 -overexpressing poplars could be considered useful for mitigating environmental pollution. • Overexpressed PyWRKY48 poplars grew better than the wild type. • Overexpressed PyWRKY48 poplars enhanced cadmium tolerance and accumulation. • PaABC , PaHIPP , PaNPF , PaBSP , etc. may involve in cadmium stress induced by PyWRKY48. [ABSTRACT FROM AUTHOR]

Medicinal plants have a wide range of uses worldwide. However, the quality of medicinal plants is affected by severe cadmium pollution. Cadmium can reduce photosynthetic capacity, lead to plant growth retardation and oxidative stress, and affect secondary metabolism. Medicinal plants have complex mechanisms to cope with cadmium stress. On the one hand, an antioxidant system can effectively scavenge excess reactive oxygen species produced by cadmium stress. On the other hand, cadmium chelates are formed by chelating peptides and then sequestered through vacuolar compartmentalization. Cadmium has no specific transporter in plants and is generally transferred to plant tissues through competition for the transporters of divalent metal ions, such as zinc, iron, and manganese. In recent years, progress has been achieved in exploring the physiological mechanisms by which medicinal plants responding to cadmium stress. The exogenous regulation of cadmium accumulation in medicinal plants has been studied, and the aim is reducing the toxicity of cadmium. However, research into molecular mechanisms is still lagging. In this paper, we review the physiological and molecular mechanisms and regulatory networks of medicinal plants exposed to cadmium, providing a reference for the study on the responses of medicinal plants to cadmium stress. [Display omitted] • Cadmium is a hazardous substance causing diseases such as cancer. • Medicinal plants are mightily affected by cadmium pollution. • Cadmium makes growth inhibition, reduces photosynthesis and vary active ingredients in medicinal plants. • Medicinal plants have evolved protective mechanisms for cadmium uptake and transportation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The concentration of Cd in the B.tomentipes samples varies considerably. • The relationship between Cd content and environmental factors was analyzed. • Eight machine learning models and four deep learning models were established. • 3DCOS, 3DCOS projection image and index image are first proposed based on 2DCOS. • Deep learning achieves fine-grained sampling site recognition based on small samples. This study proposed the necessity of identifying the sampling sites for Boletus tomentipes (B.tomentipes) in combination with cadmium content and environmental factors. Based on fourier transform mid-infrared spectroscopy (FT-MIR) preprocessing by 1st, 2nd, MSC, SNV and SG, five machine learning (ML) algorithms (NB, DT, KNN, RF, SVM) and three Gradient Boosting Machine (GBM) algorithms (XGBoost, LightGBM, CatBoost) were built. To avoid complex preprocessing, we construct BoletusResnet model, propose the concepts of 3DCOS, 3DCOS projected images, index images in addition to 2DCOS, and combine them with deep learning (DL) for classification for the first time. It shows that GBM has higher accuracy than ML and DL has better accuracy than GBM. The four DL models presented in this paper achieve fine-grained sampling sites recognition based on small samples with 100 % accuracy, and a computer application system was developed on them. Therefore, spectral image processing combined with DL is a rapid and efficient classification method which can be widely used in food identification. [ABSTRACT FROM AUTHOR]

Modified biochars has great potential for removing heavy metals from aquatic environments, but the removal of heavy metals by biochars is usually significantly affected by the co-presence of the macro amount of metal ions, such as Ca. Enhancing the ion exchange capacity of biochar by increasing its alkali metal content is a very prospective method to improve its selectivity. In this paper, MgO loaded biochar (MBC) was synthesized by co-pyrolysis of soybean straw and MgCl 2 ·6H 2 O for selective remove Pb and Cd from calcium-rich wastewater. MBC exhibited excellent selective adsorption performance for Pb and Cd in calcium-rich wastewater due to the successful loading of MgO. The adsorption capacities of MBC for Pb and Cd were 582.57 and 167.40 mg/g, and the removal efficiency of Ca below 2.5% with an initial concentration of 800 mg/L. The ion exchange capacities of Pb and Cd enhanced almost 27 and 23 times than BC. By analyzing the results of BET, XRD, SEM-EDS, XPS and FTIR, the adsorption mechanisms of MBC were mainly including ion exchange, precipitation with minerals, and interaction with oxygen-containing functional groups. The easy preparation method and high selective adsorption capacity makes MBC an ideal alternative for efficiently selective removal Pb and Cd from calcium-rich wastewater. [Display omitted] • MgO-loaded soybean straw biochars have high Pb/Cd and low Ca sorption capacity. • The adsorption capacity of MBC for Pb and Cd was 7 and 15 times than BC. • Ion exchange of MBC for Pb and Cd increased by 27 and 23 times. • MgO took part in the processes of ion exchange and precipitation with minerals. [ABSTRACT FROM AUTHOR]

Zero valent iron (Fe0) has been proven to be a highly efficient adsorption material for cadmium in wastewater. However, how to deal with Fe0 after cadmium adsorption, restricts its industrialization. In this paper, we attempted to desorb cadmium from the post-adsorption material (Fe Cd) through ammoniacal leaching and recycle the Fe0. Desorption experiments, Infrared and SEM-EDS results showed leaching with (NH 4) 2 SO 4 and NH 3 ·H 2 O can effectively desorb cadmium from Fe Cd. Based on Ultraviolet spectrum, solution chemistry and quantum chemical analysis, cadmium on Fe Cd can combine with free ammonia and form Cd-NH 3 complexes. Then the complexes are transferred into the leached solution, achieving the desorption of cadmium. Subsequently, cadmium in leached solution was precipitated into Cd(OH) 2 , a high-grade cadmium product. Finally, the cadmium adsorption capability of regenerated Fe0 was roughly investigated, and the results showed that it has a better capability for cadmium adsorption than initial Fe0, which further guaranteed the recycle of Fe0. [Display omitted] • The ammoniacal leaching could achieve efficient and selective desorption of cadmium from Fe Cd. • The buffer action of (NH 4) 2 SO 4 and NH 3 ·H 2 O could greatly improve the leaching rate and efficiency. • The coordination of Cd(Ⅱ) and ammonia molecules can occur spontaneously, promoting the desorption of cadmium from Fe Cd. • The cadmium on Fe Cd was leached into liquor in the form of [Cd(NH 3) m (H 2 O) n ]2+. • The cadmium transferred to leached solution could be precipitated into high-grade Cd(OH) 2 through adjusting pH. [ABSTRACT FROM AUTHOR]

• Soil Cd pollution assessment using soil active state as a tool. • Dynamic processes of soil absorption and desorption. • The coupled adsorption–desorption model is an optimized and corrected method for assessing total soil Cd contamination. The transfer rate and extent of cadmium (Cd) to groundwater and plants were controlled by soil adsorption and desorption processes, which directly affect agro-environment safety. Cd mobility shift is critical for the correct assessment of pollution vulnerability in different soil types. But the existing experimental methods and traditional quantitative prediction models are time-consuming and have a small scope of adaptation. In this paper, a coupling model of soil Cd adsorption and desorption was developed based on quantitative retention factors to explore the sensitivity of soil environmental factors for Cd pollution and quantify the spatial distribution pattern of Cd pollution vulnerability in highly heterogeneous soils in China. Results showed that: (1) The type of background electrolyte affected Cd adsorption and desorption capacity in soil solution. The performances of the single background electrolyte models (NaNO 3 , CaCl 2 , NaCl, KNO 3) are better than the mixed background electrolyte model. (2) The contribution values of adsorption and desorption models were compared by sensitivity analysis. (3) Vulnerable areas of soil Cd pollution with higher risk than expected were selected by using the adsorption–desorption coupling model in China, including Tibet Autonomous Region, Xinjiang Uygur Autonomous Region, northwestern Sichuan Province, southeastern Qinghai Province, Guangdong Province, Guangxi Province, and Yunnan Province. Our adsorption–desorption coupling model can be used as an assessment tool expressing the soil Cd pollution vulnerability based on the available state of Cd, which is expected to provide the quantitative scientific basis for the formulation of Cd quality standard systems and soil remediation measures for regional soil environment protection. [ABSTRACT FROM AUTHOR]

Some heavy metals in the environment may have estrogen-like activity, which probably lead to major diseases such as breast cancer. It is of great importance to establish new methods to evaluate the estrogen effect of heavy metals from multiple angles due to the complex mechanism of estrogen effect. In this paper, using MCF-7 cells as model, the electrochemical detection mechanism of the estrogen effect of heavy metal cadmium (Cd) was studied. The two electrochemical signals of MCF-7 cells derived from uric acid (0.30 V) and the mixture of guanine and xanthine (0.68 V) increased in a time and dose-dependent manner when MCF-7 cells induced by Cd, reaching the maximum at 96 h and 10−9 mol L−1. Further studies found that three purine metabolism pathways about de novo synthesis, salvage synthesis and decomposition metabolism were activated by the estrogen effect of Cd. The expression of PRPP amidotransferase in purine de novo synthesis pathway and HPRT in purine salvage synthesis pathway up-regulated, especially HPRT, which promoted cell proliferation together. Nevertheless, the expression of GDA and ADA, the key enzymes in purine decomposition metabolism pathway, up-regulated in a time and dose-dependent manner, which had same tendency with that of ERα, thereby increased the content of intracellular hypoxanthine, guanine, xanthine and uric acid, and enhanced electrochemical signals. [Display omitted] • Cd induced purine de novo and salvage synthesis, especially salvage synthesis. • Both purine de novo and salvage synthesis provided energy for cell proliferation. • Purine catabolism was induced by Cd in a time-dependent manner. • Purine metabolism induced by Cd enhanced electrochemical signals. [ABSTRACT FROM AUTHOR]

Biochar has a high specific surface area with abundant pore structure and functional groups, which has been widely used in remediation of cadmium or arsenic contaminated water and soil. However, the bottleneck problem of low-efficiency of pristine biochar in remediation of contaminated environments always occurs. Nowadays, the modification of biochar is a feasible way to enhance the performance of biochar. Based on the Web of science™, the research progress of modified biochar and its application in remediation of cadmium or arsenic contaminated water and soil have been systematically summarized in this paper. The main modification strategies of biochar were summarized, and the variation of physicochemical properties of biochar before and after modification were illustrated. The efficiency and key mechanisms of modified biochar for remediation of cadmium or arsenic contaminated water and soil were expounded in detail. Finally, some constructive suggestions were given for the future direction and challenges of modified biochar research. [Display omitted] • The physicochemical properties of different modified biochars exist differences. • The removal efficiency of Cd or As by biochar can be improved by modification. • Iron based biochar has great potential in remediation of Cd or As contaminated soil. [ABSTRACT FROM AUTHOR]

[Display omitted] • SPR-based analysis has been applied in systems included BSA, Cd and CGA/CA /HPPA. • The presence of CGA, CA or HPPA reduced the structural change of BSA induced by Cd. • BSA-Cd-CGA system had a better effect than BSA-(Cd-CGA) system on BSA. • The degree of structural protection in BSA was as follows: CGA > CA > HPPA. • Site selective test showed that CGA might have competition on the binding of Cd to BSA. Chlorogenic acid (CGA) has attracted the interest of researchers because of its broad biological activity including antagonistic action against cadmium (Cd). While on the interaction between Cd and bovine serum albumin (BSA), the interferential impact of CGA and its intestinal microbial catabolites (caffeic acid (CA) and phloretic acid (HPPA)) remains unclear. A combined multispectral analysis, surface plasmon resonance (SPR), and docking studies have been carried out to analyze the above system in this paper. SPR and fluorescence quenching showed the presence of CGA, CA or HPPA could decrease the structural change of BSA induced by Cd2+, and the degree of reduction was as follows: CGA > CA > HPPA. Furthermore, CGA and its intestinal metabolites could produce competitive effect in the binding process of Cd2+ and BSA, and this competitive characteristic of phenolic acids is stronger than the chelation between Cd2+ and phenolic acids. [ABSTRACT FROM AUTHOR]

[Display omitted] This paper presents a novel chain model named soil–food–human (SFH) for clarifying the biogeochemical cascades among the triple challenges of cadmium contamination, food safety, and related public health effect. The model was developed based on the integration of spatial distribution pattern of soil environment and the biogeochemical process of cadmium in soil–rice–human health, and it was validated through a case study. In soil environment terms, SFH predicted the spatial distribution of soil properties with an average prediction accuracy of 82.28%. In food production terms, the SFH can identify the safe production zones for planting rice and unsafe area for adjusting cropping systems with a relative error of 39.41%. In food consumption terms, SFH mapped the high-resolution map of cadmium exposure dose, which gives a new solution to assess the food safety risks for self-sufficient populations. For the health effect of rice cadmium exposure, SFH simulated the spatiotemporal pattern of urinary cadmium based on toxicokinetic which revealed the health effect of rice cadmium exposure. The chain model provides a new insight in understanding the biogeochemical cascades between food production, food safety, and public health, making it possible to develop a comprehensive strategy to tackle cadmium pollution in soil–rice–human health system. [ABSTRACT FROM AUTHOR]

We report herein a new 4-Cyanobiphenyl-based Schiff base probe, BPC for efficient fluorometric detection of highly hazardous Cd2+ ions. BPC can sense Cd2+ through selective turn-on fluorescence responses in CH 3 CN/H 2 O (3:2, v/v; Tris-HCl, pH = 7.4) solution. The 1:1 complex formation between BPC and Cd2+ could block both isomerization of C N and excited-state intramolecular proton transfer (ESIPT) process and meanwhile enhance the molecular rigidity, resulting in chelating enhanced fluorescence (CHEF). The detection limit (10.5 nM) is lower than the WHO drinking water standard (26.7 μM), which renders BPC a likely candidate for sensing of Cd2+ ions in neutral aqueous media. The analytical applicability of BPC for Cd2+ has been tested on the test paper strips. In addition, BPC was applied to image Cd2+ in living HeLa cells and zebrafish. [Display omitted] • This study report a simple 4-cyanobiphenyl-based Schiff base probe (BPC) for Cd2+ ion. • BPC selectively detects Cd2+ ions as low as 10.5 nM. • The probe BPC is capable for imaging of Cd2+ in live Hela cells as well as n zebrafish. [ABSTRACT FROM AUTHOR]

• Extraction of metal ions: Ni(II), Cd(II) from black mass of waste Ni-Cd batteries. • Use of ILs, synergistic effects of a mixture of two ILs, ABS method, DESs and organophosphorous-based acids. • Derived extraction efficiencies using experimental data. The paper presents experiments with solid–liquid-liquid extraction of heavy metals from the "black mass" (BM) of waste batteries related to the recycling of nickel and cadmium, as well as cobalt (for several samples) from spent Ni-Cd batteries. The extraction and separation of Ni(II) and Cd(II) from the solid BM with Deep Eutectic Solvents (DESs) and other extractants dissolved in toluene or naphtha (kerosene) have been investigated in detail. It has been shown that the extraction efficiency of DESs, contrary to ionic liquids (ILs), is at the level of 30 wt% Ni(II) and 100 wt% Cd(II) from the BM, without the primary process of leaching with sulphuric acid. Solvent extraction has been proposed with two DESs (choline chloride + lactic acid and choline chloride + malonic acid), with ionic liquids (ILs): trihexyltetradecylphosphonium chloride [P 6,6,6,14 ][Cl] (Cyphos IL 101) and trihexyltetradecylphosphonium thiocyanate [P 6,6,6,14 ][SCN], and with organophosphorous-based acids (OPBAs) such as bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272) and di-(2-ethylhexyl) phosphoric acid (D2EHPA). Process factors such as extracting solvents and additives, solvent concentration, holding time, pH and liquid/solid, as well as organic/aqueous (O:A) ratios were studied. For all the systems, the extraction efficiency (E) and the distribution ratio (D) were specified. The metal content in the solid BM was analyzed by the SEM/EDS method and with the use of the UltraWAVE digestion system combined with an atomic absorption spectrometer (FAAS and FAES techniques). An inductively coupled plasma optical emission spectrometer (ICP-OES) was used to determine the concentration of metal ions in aqueous solutions and stripped organic solutions. [ABSTRACT FROM AUTHOR]

In-situ geophysical techniques based on electrical resistivity tomography were performed to determine the spatial and temporal distribution of heavy metals. This paper aimed to pursue a novel methodology consisting in combining electrical resistivity tomography measurements, soil chemical data, and statistical analysis to predict As and Cd distribution in paddy soils. The resistivity surveys were performed at 2 m depth in nine locations of Tolima district in Colombia. Chemical concentrations of both As and Cd were introduced in a standardization procedure to estimate their electrical resistivity values. Soil and fertilizers information were acquired to determine As and Cd input in the studied area. The laboratory standardization showed a direct linear regression for Cd and an inverse one for As. A high positive Spearman correlation between electrical resistivity and As / Cd content was determined, with 0.98 and 0.99 values, respectively. Results showed that As-like compounds were distributed mainly in shallower soil layers (0.45 m) and were characterized by lower electrical resistivity values (181–2318 Ω.m). On the contrary, Cd-like compounds were observed in a deeper profile (0.80 m) with higher electrical resistivity values (559–4879 Ω.m). This work underlies the utility of the combined geophysical techniques, soil chemical parameters and statistical analysis to improve the understanding of As and Cd dynamics and origin in topsoil, supporting the need of an agricultural management of paddy soils. [Display omitted] • ERT allowed estimating As and Cd-like compounds spatial distribution in topsoil. • High positive Spearman correlation between ρ A and As and Cd content. • ERT may help in decision making about heavy metals remedy in agricultural soils. [ABSTRACT FROM AUTHOR]

The pollution of heavy metals in aqueous solution has been paid considerable attention in the past several decades. Many researches focused on developing new materials or methods for removing heavy metals. The two-dimensional lamellar structure of molybdenum disulfide (MoS 2) has attracted extensive interest and was regarded as a potential material due to it has a large number of active sites. In this paper, a novel one-step hydrothermal method was proposed to prepare the MoS 2 /Bentonite composite material. The MoS 2 composed of many nano petals grew successfully in the pores of bentonite to form flower spheres, and the addition of bentonite can effectively avoid the agglomeration phenomenon of MoS 2 prepared by the hydrothermal method. Pseudo-second-order model was applied to describe the adsorption process, revealing the adsorption dominated by chemical adsorption. The dynamic model was in accord with the Langmuir model and the maximum adsorption capacity of Cd2+ was 89.45 mg/g. The excellent performance of MoS 2 /Bentonite made it have the tremendous application of removing heavy metal ions. [Display omitted] • MoS 2 /Bentonite was prepared by a facile one-step hydrothermal method. • The addition of bentonite can avoid the agglomeration phenomenon of MoS 2. • The performance of MoS 2 /Bentonite was superior to both pure MoS 2 and bentonite. • The adsorption characteristics were analyzed by kinetic model and isotherm model. • MoS 2 /Bentonite exhibited considerable adsorption capacity of Cd2+ from water. [ABSTRACT FROM AUTHOR]

The magnetization of CoFe 2 O 4 nanoparticles is often less than the bulk value of 3.6 μB (86 emu/g), corresponding to an inverse distribution of cations in the spinel structure. This paper investigated the Cd doping on cobalt ferrite nanoparticles' structural and magnetic properties. Cobalt ferrite nanoparticles doped with cadmium (Co 1-x Cd x Fe 2 O 4 , x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) were prepared by using hydrothermal method. X-ray diffraction (XRD) analysis confirmed cubic spinel structure, and the crystallite size is estimated at around 56–59 nm. Micrographs obtained by scanning electron microscopy (SEM) showed an average particle size of about 60 nm, which is in agreement with the XRD analysis. The absorption band ν 1 for samples obtained from the infrared spectrum (FTIR) varies from 586 up to 570 Cm-1 by Cd doping, indicating Cd's replacement on the tetrahedral site. Magnetization values of 71 and 81 emu/g are obtained for x = 0 and x = 0.1 samples, respectively. But the magnetization decreased as the amount of Cd doping further increased due to the decreasing superexchange interaction between tetrahedral and octahedral sites. The rearrangement of Fe3+ and Co2+ cations on tetrahedral and octahedral sites and spin disorder at the surface of nanoparticles can reduce the magnetization below the bulk value. The coercivity field (Hc) value of 1.1 kOe is obtained for the x = 0, and the Hc values decrease with Cd doping. This is due to the decreasing magnetocrystalline anisotropy by substituting cobalt with cadmium. • The cobalt ferrite nanoparticles doped with Cd ions are synthesized employing the hydrothermal method. • Micrographs obtained by FESEM showed spherical shapes for nanoparticles with an average particle size of about 60 nm. • The maximum magnetization (8 emu/g) was obtained in the sample with 10% Cd doping. • The coercivity field decreased with the doping of Cd. [ABSTRACT FROM AUTHOR]

[Display omitted] • High-gravity intensified electrodeposition for removing Cd2+ and recovering Cd. • The removal efficiency of Cd2+ and current efficiency were improved by high-gravity. • The electrodeposition time and energy consumption were reduced in high-gravity field. • The deposits structure was flaky and layered, and its mass was improved by 35.4%. Efficiently treating heavy metal wastewater are the goal that industries pursuit. A novel Multi-concentric Cylindrical Electrodes-Rotating Bed (MCCE-RB) which could provide high-gravity fields was proposed to enhance electrodeposition for efficient treatment of Cd-containing wastewater in this paper. Under the optimal operating conditions covering current density of 53.1 A m−2, wastewater circulation flowrate of 64 L h−1, high-gravity factor of 15, NaCl concentration of 0.2 mol L−1, initial pH value of 2, and initial Cd2+ concentration of 800 mg L−1, the removal efficiency of Cd2+ reached 99.4% after 120 min electrodeposition. Compared with the results of electrodeposition in normal gravity field, the removal efficiency of Cd2+, current efficiency and the mass of deposits were increased by 18.4%, 15.7% and 35.4%, respectively. The cell voltage, electrodeposition time and total energy consumption (E Total) were decreased by 21.7%, 42% and 21.2%, respectively. SEM, EDS, XRD and XPS analyses showed that the deposits were flaky and layered structure in high-gravity fields, avoiding the formation of dendrite in normal gravity field. The deposits were comprised of the mixture of Cd and Cd(OH) 2 , and the percent weight of elemental Cd was 91.29% in the high-gravity field which was 19.17% higher than that in normal gravity field. The purity of Cd was improved in the high-gravity field. These was ascribed to the depressed hydrogen evolution reaction, the removal of gas bubbles from the electrodes and the improvement in mass transport in the optimal high-gravity field. High-gravity intensified electrodeposition could serve as a clean, high efficient and low energy consumption method for treating heavy metal wastewater. [ABSTRACT FROM AUTHOR]

The paper presents a comparative analysis of the effect of structural and solvation factors on the spectral characteristics and lipophilicity of a series of iodo- and bromosubstituted zinc(II), cadmium(II), and boron(III) dipyrromethethenes. The studied chelates [ZnL 2 ], [CdL 2 ], and [BF 2 L] fluoresce in organic solvents solutions with a quantum yield from 1% to 50%, depending on their molecular structure and the solvent nature. It was noted that the high sensitivity of [ZnL 2 ] and [CdL 2 ] fluorescence to the presence of electron- and proton-donor solvents are due to the additional coordination of M···Solv or acid-base interactions ≥ N⋯H–Solv. It was found that [BF 2 L] have up to 1.5 times higher lipophilicity compared to [ZnL 2 ] with the same functional substitution. The hydrophobicity of 4,4′-dibromosubstituted luminophores is noticeably higher than that of 5,5′-dibromosubstituted analogs. The obtained results indicate the prospects for the development of new effective fluorescent markers and sensors of medium polarity based on halogen-substituted dipyrromethenates. • The spectral properties of halogenated Zn(II), Cd(II) and B(III) dipyrromethenates are compared. • The photo-physical properties of the [ZnL 2 ], [CdL 2 ] and [BF 2 L] are measured and computed. • The [ZnL 2 ] and [CdL 2 ] are endowed with high fluorescence sensitivity to the solvent nature. • Halogenation at 4- and 5-positions has a significant effect on photo-physical properties of the dyes. • The results are practical interest in the development of fluorescent markers and sensors of solvent polarity. [ABSTRACT FROM AUTHOR]

Prionace glauca is a top predator, prone to bioaccumulate trace elements, representing the most captured elasmobranch species for human consumption in Peru. Concentrations of cadmium and lead in the edible muscle tissue of the blue shark captured in the south Peruvian coastal waters and offshore north-central Chile were determined. The Cd and Pb levels varied between 0.004 and 0.014 and 0.004 and 0.03 mg kg−1, respectively. We found direct correlation of Cd concentration with the total length, nevertheless there was no clear relationship regarding sex, seasons, and capture areas. Both metals were below the safety limits for human consumption. The target hazard quotient (THQ) values suggest that its consumption does not represent a risk to the human health. In Peru, this is only the second paper that reports Cd and Pb in sharks. We recommend increasing the sampling by including larger sharks and in other regions of the Peruvian coastline. [Display omitted] • The blue shark is the most captured and consumed elasmobranch species in Peru. • Cd and Pb levels were below the maximum permissible limits for human consumption. • The highest level of Cd was recorded in the largest female, while Pb in the smallest. • Individuals above the minimum catch size (160 cm TL) had higher Cd levels. [ABSTRACT FROM AUTHOR]

As a byproduct of lead metallurgy, Cd-As-Pb-bearing dust, is a hazardous waste. This paper proposes a coprecipitation method for Cd and As removal and applies it to dust disposition. First, a thermodynamic analysis of the Cd2+-AsO 4 3−-H 2 O system was conducted, and the predominant areas of solid phase, including Cd 5 H 2 (AsO 4) 4 , Cd 3 (AsO 4) 2 and Cd(OH) 2 , were obtained at different molar ratios of cadmium to arsenic (n Cd /n As). Second, the effects of n Cd /n As ratio and pH on the precipitation behaviors of Cd and As were examined. The precipitated solids varied from Cd 5 H 2 (AsO 4) 4 •4H 2 O to Cd 3 (AsO 4) 2 •4H 2 O and then to amorphous Cd(OH) 2 with increasing pH. The morphology of solids transformed from cuboid to flake particles and then to fine agglomerated particles. Perfect removal of Cd and As can be achieved by generating Cd 5 H 2 (AsO 4) 4 •4H 2 O with molar ratios of n Cd /n As 1.25 at pH 5.5 or Cd 3 (AsO 4) 2 •4H 2 O with n Cd /n As 1.50 at pH 7.5. Finally, a method of H 2 O-H 2 O 2 leaching and Cd-As coprecipitation was proposed to treat Cd-As-Pb-bearing dust. The precipitation efficiencies of Cd and As were higher than 99.7%. This work improved a one-step method for removing toxic Cd and As from polymetallic dust and other materials. [Display omitted] • The solid phases in Cd2+-AsO 4 3−-H 2 O system were identified. • Cd and As coprecipitation can be achieved in the form of Cd 5 H 2 (AsO 4) 4 or Cd 3 (AsO 4) 2. • The precipitation degrees of Cd and As were higher than 99.7%. • A complete process was proposed for the disposition of Cd-As-Pb-bearing dust. [ABSTRACT FROM AUTHOR]

A promising electrode material, manganese dioxide (MnO 2), has been widely studied for capacitive deionization (CDI) desalination and recently researched for heavy metal removal. However, there are significant differences in the performance of MnO 2 in applications for heavy metal removal and desalination. In this paper, the mechanism for different electrochemical processes of Cd2+/Na+ ions on MnO 2 electrodes was comprehensively studied. MD simulations show that the diffusion performance of Cd2+ is much slower than that of Na+ in the presence of CdCl−, leading to a lower adsorption rate of Cd2+. Of the two ion storage mechanisms (capacitive and diffusion-controlled progress), capacitance contributions provided 65.6% of the total in the Na+ electrolyte, while diffusion-controlled progress contributed 55.2% in the Cd2+ electrolyte. For diffusion, tunnelling is the main storage mechanism for Na+; instead, Cd2+ undergoes a sequential surface redox process: (1) the combination of Cd2+ and O atoms from Mn-O-Mn results in the transition from Mn4+ to Mn3+, and (2) the H substitution reaction on Mn-O-H is generated from (1). Therefore, the adsorption capacity of Cd2+ is closely related to the chemical state of MnO 2 on the surface, which results in worse cycling stability than Na+. • The presence of CdCl+ reduces the migration of Cd2+ on the electrode surface. • Different faradaic processes are responsible for differences in the adsorption of Cd2+ and Na+. • The surface redox mechanism for Cd2+ in MnO 2 involves two processes. • The results of this study provide significant insights into the cation storage mechanism of MnO 2. [ABSTRACT FROM AUTHOR]

In this paper, a vibrating boron-doped diamond (BDD) electrode electroanalytical device and respective method for the analysis of ultralow concentrations of Cd(II) in water were studied. The enhanced mass transfer on the electrode surface was studied using Ru(NH 3) 6 Cl 3. Vibration with 133 Hz frequency enhanced the Ru(III) to Ru(II) reduction by 92.6% compared to a static electrode. The peak current of the anodic stripping voltammetry (ASV) method employed was increased by a factor of 5.3 and 4.7 for 10 and 30 μg L−1 Cd(II) concentrations, respectively, when a frequency of 200 Hz was used. A calibration plot with two linear regions was resolved between 0.01 and 1 μg L−1 and 1–30 μg L−1 with the LOD and LOQ of 0.04 μg L−1 and 0.12 μg L−1, respectively. The applicability of the device and the respective method in the analysis of real environmental samples was successfully verified by analysis of river samples and comparing the results with the ICP analysis presenting high reproducibility and trueness. According to the results of this research, the vibrating BDD electrode with the ASV method has excellent analytical performance without surface modification or regular replacement or polishing of the electrode surface. Combining the exceptional electrochemical and chemical properties of BDD with enhanced mass transfer and signal strength of vibrating electrodes makes the system especially suitable for on-site and online analysis of heavy metals. [Display omitted] • Novel vibrating analytical method for ultralow concentrations of Cd(II). • Accurate and reproducible analytical method without electrode modification. • LOD and LOQ for Cd(II) analysis were 0.04 μg L−1 and 0.12 μg L−1, respectively. • Applicability of the method was successfully verified by analysis of river samples. [ABSTRACT FROM AUTHOR]