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Landfill biomining is indeed a promising eco-friendly approach to sustainably manage and reclaim old dumpsites. Soil like fractions of < 8–10 mm size, also known as bioearth or good earth constitute a substantial part of the legacy waste. Detailed characterization is necessary to meet regulatory standards for the safe use of bioearth and minimize its environmental and human health impacts upon reuse. In this study, bioearth recovered from six different dumpsites of Tamil Nadu, India, constituted 1.2 to 9.1% of total organic carbon that can improve soil structure, water retention, and nutrient supply. Macronutrients which are regarded as main factors for plant growth namely nitrogen, phosphorous, and potassium ranged 800 to 9800 mg kg−1, 700 to 2800 mg kg−1, and 3100 to 5900 mg kg−1, respectively, and highlighted the suitability of bioearth for use as soil amendment upon nutrient enrichment. However, the presence of heavy metals like Cu (15.9 to 254.4 mg kg−1), Ni (34.5 to 62.1 mg kg−1), Cr (48.2 to 152.3 mg kg−1), Pb (58.5 to 123.7 mg kg−1), and Zn (75.4 to 464.2 mg kg−1), with Cr and Ni levels beyond the regulatory standards, higher pollution (Igeo, 0.6 to 3.6; EF, 0.1 to 5.5), and ecological risk indicator values (Er, 4.4 to 91.5; ERI, 67.6 to 224.3) suggested its unsuitability for certain types in reuses, especially in agricultural applications where it could pose risks to biota. Nevertheless, the human health risk indicator values (HQ and HI < 1) for bioearth showed that the current levels of metals are within the safe limits for human exposure. Pearson's correlation and principal component analysis uncovered close relationship between bioearth physicochemical properties and heavy metals. The current study highlights that bioearth from landfill mining presents an attractive option for reuse, the high levels of metals necessitate proper treatment like phytoremediation, chemical stabilization, thermal treatment, or soil washing before it can be safely utilized offsite. This ensures compliance with environmental and health safety standards, making the bioearth suitable for applications such as agriculture, landscaping, and land reclamation. [ABSTRACT FROM AUTHOR]

Impacts of the acid mine drainage (AMD) remediation are investigated on the largest gold mine in Latin America, located in the Dominican Republic. Geochemical analysis of suspended matter in water performed in 2022 on water bodies located downstream to the mine, namely, the Margajita River and Lake Hatillo, are compared with analyses made in 2007, before the AMD remediation. The results for the Margajita River show a strong decrease in heavy metal and metalloid concentrations in the dissolved phase for Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Sb, and Pb (between 89.1 and 99.9%) which is correlated with a pH neutralization (from a pH of 2 to 7.5). However, the concentrations of Cd and sulfate in the dissolved fraction remain higher than their environmental standard values, and a high concentration of K is also observed. High contributions in terms of mass are identified for Cs, Tl, Cd, and Li in the Margajita River. Concentrations of Al, Fe, Ni, Zn, and As in suspended sediments are higher than the environmental standard values in 2022. Modeling of the chemical speciation shows that the higher pH leads to the formation of suspended particles in the form of hydroxides and sulfates. The concentrations in suspended sediments are highly correlated between Margajita River and Lake Hatillo in 2022 for Fe, Cd, Li, and Ca (R2 between 0.9 and 0.99 with p ≤ 0.05). In Lake Hatillo, principal component analysis shows that invariant elements Fe, P, Ti, Zr, and Al are correlated, as they precipitate between the inlet and outlet of the lake. [ABSTRACT FROM AUTHOR]

Exposure to heavy metals from vegetable consumption poses a serious health risk to the Chinese population. The lack of knowledge on the overall status of vegetable contamination at the national level hinders the development of national regulations on preventing heavy metal exposure. To address this issue, the study presents an overview of heavy metal contamination in vegetables across China based on 96 peer-reviewed studies published over the past 20 years. The average concentrations of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn in the edible parts of vegetables are 3.7 ± 12.9, 1.6 ± 4.0, 4.3 ± 10.3, 18.6 ± 27.6, 164 ± 281, 4.5 ± 5.5, 7.7 ± 23.7, and 105 ± 283 mg kg−1 (dry weight), respectively. The associated daily exposures are 0.1–5.7, 0.1–1.7, 0.6–4.2, 4.1–20.5, 26–107, 0.7–3.0, 0.4–16.0, and 13–93 μg kg−1 d−1, respectively. General linear models explained 80%, 44%, 83%, 79%, 64%, 81%, 65%, and 55% of the total variance in As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn concentrations in vegetables, respectively, based on vegetable type and selected geological, meteorological, economic, and environmental factors. Agroforestry is the main source of heavy metal contamination, accounting for 3%–30% of the total variance in heavy metal concentrations in vegetables. Mining, smelting, refining, metalworking, and electrical equipment manufacturing are important source of As, Cr, Cu, Mn, Ni, and Pb, accounting for 7%–17% of the total variance. [ABSTRACT FROM AUTHOR]

The occurrence of chemical effluents in different water bodies is an emerging concern. However, the effect of laboratory effluents on the canal ecosystem in Bangladesh is largely unknown. In this study, we collected 10 components of the canal ecosystem including sediments, water, fish, crabs, snails, phytoplanktons, and weeds specifically from canals that directly receive laboratory effluents. We examined the occurrence of both the essential (Fe, Mn, Cu, and Zn) and toxic (Pb, Cd, Cr, Co, Ni, and As) metals as well as microplastics (MPs). Results explored that laboratory effluents strongly interact with the components of the canal ecosystem and enhance the abundance of toxic metals in the canal hydrosystem. Furthermore, diverse types of MPs including fibers, fragments, and microbeads were observed in all components of the canal ecosystem. Remarkably, our results unveiled that the co-occurrence of pollutants was more severe in benthic organisms like snails or crabs might be due to their omnivorous food habits. The cumulative pollutant accumulation was much higher in all components of the canal ecosystem indicating a greater ecological risk. Although the potential risk index (RI) or hazardous index (HI) from fish ingestion was found within acceptable limits, the biomagnification of pollutants due to repeated ingestions may have strong ecotoxicological impacts even at very low concentrations. [ABSTRACT FROM AUTHOR]

Although yerba mate has been known and used for hundreds of years, not all of its properties have been fully understood yet. Yerba mate is a source of many desirable substances, but it may also contain toxic metals and other substances that are harmful to health. Fifteen samples of yerba mate tea from three South American countries were analyzed. The content of Cr, Ni, and Cd was determined using the AAS technique, while the PHA's content was determined with the gas chromatography method. Our studies show that some of the analyzed substances present in Ilex paraguariensis may exceed their acceptable levels specified in European standards established for the given substances. All analyzed samples contained the determined metals, where the concentrations of individual elements ranged from 1.92 ± 0.38 to 0.12 ± 0.05 µg/g (for Cr), from 4.86 ± 0.28 to 1.72 ± 0.14 µg/g (for Ni), and from 0.0008 ± 0.000 to 0.0695 ± 0.0745 µg/g (for Cd). The total PAH content ranged from 0.064 to 0.585 mg/kg. Yerba mate samples from Brazil were characterized by a lower PAH content (0.064–0.254 mg/kg), compared with mate from Argentina and Paraguay (0.084–0.374 and 0.197–0.585 mg/kg, respectively). Pesticide residues were found only in samples from Argentina and Paraguay, while samples from Brazil did not contain those compounds. Only four active substances belonging to the group of herbicides, fungicides, and insecticides were detected, two of them not approved for use in the EU: chlorpyrifos and fenbuconazole. The most frequently detected compounds in yerba mate samples were pendimethalin (in four samples), fluazifop-p-butyl and fenbuconazole (detected in two samples), and chlorpyrifos (in one sample). [ABSTRACT FROM AUTHOR]

Vehicle electrification is an important means of reducing urban air pollution. However, vehicle electrification does not necessarily reduce particulate matter (PM2.5 and PM10) and heavy metals (HM) due to the increase in non-exhaust emissions. In this study, we established the emission inventories of PM2.5, PM10, and their associated heavy metals (PM2.5-HM and PM10-HM) from the on-road vehicles in the Xiamen-Zhangzhou-Quanzhou metropolitan area in southeastern China between 2015 and 2060. In the base year 2021, brake wear emissions account for 66.6% of PM2.5-HM and 76.9% of PM10-HM, much higher than the contributions of exhaust emissions to PM2.5-HM (12.4%) and PM10-HM (6.2%). Light-duty passenger vehicles, heavy-duty trucks, and light-duty trucks are the three main contributors to PM and HM. HM emissions have a high emission density in urban areas. In the business-as-usual (BAU) scenario, HM emissions continue to increase from 2021 to 2060 due to the combined effects of the stricter emission standards and the growth of vehicle population, while the health risk of HM shows an initial decrease and then an increasing trend. Compared with BAU, moderate and aggressive electrification scenarios show a significant reduction in PM2.5-HM emissions between 2030 and 2060, but not in PM10-HM emissions. Further increases in vehicle electrification will bring forward the peak of PM2.5-HM emissions, with the potential to reduce adverse health effects. In the process of vehicle electrification, the reduction of heavy metal emissions from the braking system should be prioritized in order to effectively reduce traffic pollution. [ABSTRACT FROM AUTHOR]

Due to their toxicity and permanence, heavy metals pose a significant threat as pollutants. Metals leach into soil from human activities including mining, manufacturing, and farming. Phytoremediation involves removing contaminants from soils using herbaceous plants and trees; it is a cost-effective, non-invasive, and aesthetically pleasing technique. The current research investigated the phytoremediation capacity of Cosmos bipinnatus in soil that had been polluted with chromium (Cr) along the Dravyavati River in Jaipur. The plant uptake of heavy metals was studied for 20, 40, 60, and 80 days of growth in pot and field experiments using atomic absorption spectrophotometry (AAS) to analyze residual heavy metal concentrations in the plant's shoots and roots. Chromium exhibited variation in total absorption by plants depending on the type of treatment. Using the translocation factor, it was observed that after 80 days in Nala soil 80% + wheat husk 20% (H2), the plant's capacity to absorb Cr was equivalent and considerably higher. Nola soil 80% + wheat husk 20%; H2, and Nala soil 70% + wheat husk 30%; H3 were among the treatments with TFs more than 1; however, the BCF values were all lower than 1. Additionally, root uptake was greater than shoot uptake. Thus, at H3 and H2 treatments, C. bipinnatus was determined to be an efficient phytoextractor for Cr, but at other concentrations, it acted as an excluder. [ABSTRACT FROM AUTHOR]

The potential of two different aquatic macrophytes, Azolla pinnata R.Br. and Lemna minor L., to treat livestock wastewater through phytoremediation was investigated. The physiological analysis includes the removal efficiency of manganese (Mn) from livestock wastewater by AAS. Morphological observation was performed by using a scanning electron microscope (SEM) and visual observation. RAPD analysis was applied to observe the DNA profile. It was observed that the removal efficiency of Mn was higher in L. minor with a 92% removal rate, while in A. pinnata RE, it was at a 77% rate. The higher removal rate of Mn by L. minor showed that plants had a significant impact on the removal of heavy metals, with a p ≤ 0.05. Retention time and the removal of heavy metals were found to be positively correlated. As early as 24 h after exposure to livestock wastewater (LW), the stomata on the leaves of A. pinnata and L. minor have both shrunk, and the root surfaces have shortened. According to the RAPD analysis, A. pinnata only shows an increase in band intensities and no polymorphism, whereas L. minor has 19% polymorphisms that indicate higher tolerance as hyperaccumulators. As a conclusion, L. minor showed no signs of necrosis and performed more efficiently as a hyperaccumulator in LW, with a higher removal efficiency. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different amounts of acid-activated attapulgite clay on soil environmental risks and ecotoxicity after incubation as a soil amendment. The experimental soil was alkaline clay soil with a pH of 7.54. The optimal addition and incubation times for the remediation of Cd-contaminated soil were determined. The results showed that the optimal period for Cd stabilization was 24 days, and the optimal addition amount was 8% (w/w). The addition of 8% attapulgite clay significantly reduced the bioavailable Cd concentration in soil. Water-Cd, DTPA-Cd, TCLP-Cd, and HCl-Cd reduced the bioavailable Cd concentration in the soil by 26.43%, 42.75%, 35.22%, and 25.89%, respectively. Meanwhile, the addition of 8% attapulgite clay converted the chemical speciation of exchangeable-Cd into residual-Cd, and the stabilizing component increased by 48% after 48 days. The ecological and environmental risk indices decreased significantly, reaching 10.89% and 4.22%, respectively. The pot experiment showed that attapulgite clay promoted corn growth while decreasing concentrations of Cd in aboveground parts and roots by 9.01–31.82% and 9.52–40.48%, respectively, and limited Cd transfer from roots to stems, minimizing its presence in edible portions as much as possible. The accumulation of heavy metals in the growth of corn plants was significantly and positively correlated with the bioavailability of Cd extracted from different extractants and exchangeable speciation, and significantly and negatively correlated with soil residual speciation. Attapulgite is a promising soil amendment that can effectively reduce ecological and environmental risks, reduce the ecological toxicity of Cd, and improve soil quality. [ABSTRACT FROM AUTHOR]

Zinc-extraction kiln slag is a hazardous solid waste rich in heavy metals. It is a great challenge to utilize it economically and harmlessly. This study aims to convert this zinc-extraction kiln slag (proportion of 50–60%) into solid-waste ceramics, by simultaneously utilizing other solid waste, fly ash, and desulfurization gypsum. By using X-ray diffraction, leaching experiments, and SEM analysis, the paper studied the solid-waste ceramics 'ability to solidify heavy metals. Under optimal conditions, C5 (zinc-extraction kiln slag, desulfurization gypsum, and fly ash with mass percentages of 60:20:20, at a sintering temperature of 1180 °C) shows an excellent performance with 43.02 MPa bending strength and 0.74% water absorption. The solidification ratios of Cr, Mn, Ni, Cu, and Zn were all exceed 97%. The main phases in the solid-waste ceramics were diopside and hematite. Diopside can efficiently solidify Zn, Mn, and Ni, while Cr and Cu can be solidified in the minor phase of spinel. During the sintering process, the ceramics produced the liquid phase, which promoted crystallization for solid solution of heavy metals and accelerated densification by elimination of pores. The ceramic system with diopside as the main phase not only shows excellent performance but also effectively solidifies heavy metals. Therefore, it is suitable for the resource utilization of metallurgical solid wastes containing heavy metals. [ABSTRACT FROM AUTHOR]

This study reports the first use of natural history museum ungulate specimens' (common fallow deer, bontebok, Arabian oryx, impala, Dall's sheep, water buffalo, and yak) hair as biomarkers for the determination of environmental trace element contamination and public exposure risk factor assessment. Morphological characteristics of the hair, like diameter and protein structure, were determined using optical microscopy and FTIR spectroscopy, respectively. The levels of thirty-nine (39) elements, sixteen (16) rare earth elements (REEs), and selected isotope ratios (52Cr/53Cr, 144Nd/146Nd, 147Sm/149Sm, 173Yb/172Yb, 206Pb/207Pb, and 206Pb/208Pb) in the hair samples were determined by ICP-MS analysis. A NIST 1643e standard reference material was analyzed for method validation to determine the accuracy of the developed elemental analysis method. The average hair diameter found in samples obtained from common fallow deer (193 ± 72 µm), bontebok (148 ± 48 µm), Arabian oryx (194 ± 40 µm), impala (88 ± 20 µm), Dall's sheep (240 ± 68 µm), water buffalo (139 ± 17 µm), and yak (139 ± 16 µm) were recorded. 27Al (1642 ± 1551 mg·kg−1), 44Ca (506 ± 272 mg·kg−1), 56Fe (730 ± 1391 mg·kg−1), 24 Mg (108 ± 57 mg·kg−1), 39 K (720 ± 1591 mg·kg−1), 28Si (1125 ± 1163 mg·kg−1), 23Na (10,223 ± 9824 mg·kg−1), and 66Zn (33 ± 25 mg·kg−1) have the highest concentrations detected in the hair samples. Potentially toxic elements and REEs have the lowest concentration in the hair samples. The detection of low concentrations of 75As, 111Cd, 59Co, 52Cr, 53Cr, 60Ni, Pb isotopes, and REEs in all hair samples suggests heavy metal contamination. The plausible sources of the detected elements in ungulate animal hair are likely due to dietary intake, anthropogenic activities, environmental contamination, specimens' preservation practices, or a combination of those sources. The figures of merit highlighted by a high correlation coefficient (R2 ≥ 0.9990), low limit of detection (as low as 1.00 × 10−7 mg·kg−1 for 140Ce), and high average percent recoveries (97.0 ± 11.5) of the NIST 1643e standard reference material analyses demonstrate the linearity, high sensitivity, and accuracy of the ICP-MS technique for elemental and isotopic analysis of hair samples. [ABSTRACT FROM AUTHOR]

Microplastics (MPs), degraded from plastic wastes, have drawn significant attention worldwide due to its prevalence and rapid transition. Contamination of freshwater with MPs has become an emerging global issue. Heavy metals (HMs), a prominent global pollutant, also garnered much attention due to their potential interaction with MPs, presenting a multifaceted environmental threat. The primary source of HM contamination in freshwater has been identified as mining sites. Additionally, the increasing use of plastic materials within mining areas raises concerns about MP release into the surrounding freshwater environments. Recent studies only provide information on the contamination of HMs status with MPs. However, studies on the mechanism responsible for MPs contamination from both external and internal sources of freshwater MPs and HMs are limited. The knowledge gaps in the deposition and fate of MPs in various mining situations and the possibility of combined impacts of heavy metals and MPs in the ecosystem raise ecological concerns. Here, we review the origins of MPs and HM pollution within mining sites and explore the potential combined detrimental impacts on plants and animal life. We found out that polystyrene (PS) and polyethylene (PE) have higher adsorption affinity to heavy metals, and the mingle toxic consequence of the MPs and HM can depend on the MP surface properties, pH, and salinity of the neighboring water solution. The Langmuir and Freundlich isotherm models enable the efficient design of adsorption systems. The Langmuir model describes single-layer adsorption at homogeneous sites, while the Freundlich model addresses multilayer adsorption on heterogeneous surfaces. The crucial mechanism of adsorption and desorption that underlies the occurrence of both MPs and heavy metals is a decisive matter in this issue. [ABSTRACT FROM AUTHOR]

The current study investigated the enhancement of biomass in S. obliquus, using rice bran oil processing (RBOP) wastewater in different RBOP wastewater concentrations, while also aiming to produce biofuel and treat the wastewater simultaneously. The strain was grown in Blue Green-11 (BG11) media as well as RBOP wastewater at different wastewater concentrations with distilled water at 10%, 25%, 50%, 75%, and 100% under controlled experimental settings. The study findings demonstrated a notable enhancement in the characteristics of RBOP wastewater during a 16-day growth period. The 75% RBOP wastewater concentration demonstrated superior efficacy as a growth medium for producing biomass as well as lipids, among other wastewater concentrations. Accordingly, physicochemical parameters and heavy metal percent of the RBOP wastewater were assessed. The collected biomass was employed in the production of biodiesel, and the fatty acid methyl esters (FAME) were measured, along with an assessment of its characteristics. Physicochemical analysis indicated that S. obliquus was able to effectively decrease levels of nitrate, phosphate, sulfur, and chemical oxygen demand (COD) in RBOP wastewater. The heavy metal reduction percentages for iron (Fe), zinc (Zn), nickel (Ni), copper (Cu), and arsenic (As) were 69.43%, 72.94%, 72.99%, 90.49%, and 91.5%, respectively, following treatment with S. obliquus. FTIR indicated the existence of various functional groups (including alcohol, carboxylic acid) on the surface of the microalgal biomass. The FAME profile of S. obliquus exhibited a moderate level of saturated and unsaturated fatty acid content. S. obliquus demonstrated significant phycoremediation capabilities and potential for lipid production. This study has indicated that S. obliquus is a potential candidate for the treatment of wastewater. [ABSTRACT FROM AUTHOR]

Cadmium is a non-essential and toxic metal. Its presence in plants can have hazardous effects not only on the plants themselves but also on human health after consumption. A time-dependent experiment was conducted on nine accessions of A. paniculata (AP1, AP2, AP3, AP8, AP11, AP12, AP21, AP25, and CIM) in Cd-contaminated soil to understand the variability of Cd accumulation. The study examined the Cd uptake, translocation, antioxidant stress enzymes, ionic composition of root exudates, Cd bioavailability, and expression of transporter genes PCR, NRAMP, ABCC, HMA, and HIPP. Results demonstrated the lowest bio-concentration factor for Cd in AP1 and CIM (0.34–1.04). A significant increase in bio-concentration (6–37%), bioaccumulation (25–80%), and translocation (6–52%) of Cd was observed in nine accessions with time. However, AP1, AP8, AP11, and CIM demonstrated a significant decrease in bio-concentration (7–38%), bioaccumulation (14–50%), and translocation (8–45%) of Cd with time. The differential Cd uptake among the accessions was major associated with antioxidant enzyme activities, root exudates, Cd bioavailability, and biomass. The differential expression of Cd influx (ApNRAMP3 and ApNRAMP5) and efflux (ApPCR2, ApPCR6, ApPCR8, and ApPCR11) transporter genes was observed with time. According to the results, low accumulating accessions AP1, AP8, AP11, and CIM had higher biomass (10–46%) and lower Cd uptake (7–38%) than high accumulating accessions. These accessions also had minimal stress enzyme activities and a prevalence of cations in root exudates, which impeded Cd bioavailability (8–26%) and increased microbial biomass carbon (7–31%). The upregulation of ApPCR2, ApPCR6, ApPCR8, ApPCR11, ApHMA3, ApABCC3, ApABCC5, ApHIPP3.1, and ApHIPP3.2 while downregulation of ApNRAMP3, ApNRAMP5, and ApHMA1 genes further modulated Cd uptake and tolerance in low accumulating accessions. [ABSTRACT FROM AUTHOR]

Tree sparrow nestlings predominantly consume protein-rich insect larvae, making them vulnerable to environmental heavy metal contamination through the food web, potentially affecting their growth. Understanding the effects of heavy metals on the structure and function of the small intestine, the principal organ responsible for protein digestion and absorption, is therefore crucial. This study investigated tree sparrow nestlings at three developmental stages (3, 6, and 12 days old) in Liujiaxia (LJX), a comparatively unpolluted area, and Baiyin (BY), a heavy metal polluted area, to elucidate the factors and mechanisms by which heavy metals affect nutrient absorption. We compared heavy metal accumulation levels, structural integrity, and protein digestion and absorption functions of the duodenum, jejunum, and ileum. The increase of fluctuating asymmetry and decrease in body condition in tree sparrow nestlings were found to be associated with environmental heavy metal accumulation in the small intestine. Structural impairments of villi and crypts were observed in the duodenum and jejunum of tree sparrow nestlings at 3-, 6-, and 12-day-old in the polluted site BY. Conversely, structures related to the ileum were elevated, and the small intestine of nestlings at all stages exhibited abnormally elevated protein digestibility but diminished absorption of amino acids. However, there was no significant difference in small peptide absorption. These findings indicate that environmental heavy metal pollution impacts the structure of the small intestine in tree sparrow nestlings through the food chain and further affects their digestion and absorption function of proteins. [ABSTRACT FROM AUTHOR]

This research utilized tetraethylenepentamine-functionalized HY cubic zeolite as an adsorbent to effectively remove heavy metals from aqueous solutions. The adsorbent was characterized using FT-IR, XRD, TGA, FE-SEM, and EDS-MAP techniques. The synthesis aimed to optimize and evaluate the removal efficiency of Pb(II), Cr(III), Co(II), and Cu(II) from aqueous solutions by investigating key parameters, including initial pH, concentration, adsorbent dosage, and contact time. The results indicate that the highest adsorption capacities for each metal follow the order: Pb(II) > Cr(III) > Co(II) > Cu(II), with respective percentages of 99.7%, 98.2%, 95.1%, and 92.4%. Analysis of the batch systems reveals that the equilibrium data for Pb(II), Cr(III), Co(II), and Cu(II) align well with the Langmuir and Freundlich isotherms also show a good fit, with correlation coefficients (R2) higher than 0.9335 and 0.9478, respectively. The maximum adsorption capacities (181.82, 175.44, 169.49, and 158.73 mg/g) reflect the nature of the adsorption process. Kinetic studies for Pb(II), Cr(III), Cu(II), and Cu(II) yielded correlation coefficients (R2) higher than 0.9971. These high R2 values suggest that the experimental data closely fit a pseudo-second-order model, indicating a two-step adsorption mechanism. Heavy metal removal is attributed to ion exchange and chemisorption within the zeolite pores, involving interactions with nitrogen lone pairs. [ABSTRACT FROM AUTHOR]

Heavy metals such as lead and cadmium are prevalent in the environment. These are harmful to living beings even at lower concentrations as they persist in the body for years and lead to the development of severe diseases. Therefore, the present work was designed to develop a rapid and field-applicable cell-based assay for quick detection of lead and cadmium in biofluids using an RNA biomarker. The RNA biomarker was identified by analyzing the impact of these heavy metals on the gene expression of candidate genes using HepG2 cells. The results showed that the gene expression of AhR pathway-related genes, apoptosis-related genes, MAPK1, and HMOX1 were significantly increased after lead and cadmium treatments (P < 0.05). Interestingly, the gene expression of HMOX1 was increased linearly up to fivefold in a dose and time-dependent manner in the case of both heavy metals which also correlated with an increased secretion of bilirubin from the cells after 6 h treatment. Therefore, the RT-LAMP assay was developed for lead and cadmium toxicity using HMOX1. The positive amplification was visualized in the form of color change of HNB dye from violet to blue in 30 min. Additionally, standard curves were also prepared for the RT-LAMP color change after treatment with different concentrations of lead and cadmium for their quantification in unknown samples. The developed RT-LAMP assay was also validated using lead and cadmium-spiked milk samples. The ROC curve analysis showed 100% sensitivity and specificity for both heavy metals above their MRL value in infant milk substitutes and infant foods. This assay can be utilized for early detection of heavy metals in common food items such as milk. [ABSTRACT FROM AUTHOR]

Natural based solutions, notably constructed/artificial wetland treatment systems, rely heavily on identification and use of macrophytes with the ability to tolerate multiple contaminants and grow for an extended period to reduce contamination. The potential to tolerate and remediate metal(loid) contaminated groundwater from an industrial site located in Flanders (Belgium) was assessed for 10 wetland macrophytes (including Carex riparia Curtis, Cyperus longus Baker, Cyperus rotundus L., Iris pseudacorus L., Juncus effusus L., Lythrum salicaria L., Mentha aquatica L., Phragmites australis Trin. ex Steud., Scirpus holoschoenus L., and Typha angustifolia L.). The experiment was conducted under static conditions, where plants were exposed to polluted acidic (pH ~ 4) water, having high level of metal(loid)s for 15 days. Plant biomass, morphology, and metal uptake by roots and shoots were analysed every 5 days for all species. Typha angustifolia and Scirpus holoschoenus produced ~ 3 and ~ 1.1 times more dried biomass than the controls, respectively. For S. holoschoenus, P. australis, and T. angustifolia, no apparent morphological stress symptoms were observed, and plant heights were similar between control and plants exposed to polluted groundwater. Higher concentrations of all metal(loid)s were detected in the roots indicating a potential for phytostabilization of metal(loid)s below the water column. For J. effusus and T. angustifolia, Cd, Ni, and Zn accumulation was observed higher in the shoots. S. holoschoenus, P. australis, and T. angustifolia are proposed for restoration and phytostabilization strategies in natural and/or constructed wetland and aquatic ecosystems affected by metal(loid) inputs. [ABSTRACT FROM AUTHOR]

The current study was conducted to identify the contamination of 10 toxic metals(loids) (mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn), copper (Cu), selenium (Se), nickel (Ni), arsenic (As) and aluminium (Al)) in the feathers of 15 raptor bird species, which tries to analyze the adverse effects, taxonomic affiliation, spatial distribution, habitat type, and effect of age. During 2020–2022, 476 feathers of 115 birds were collected and the primary feathers of each bird were sampled and an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to analyze the toxic metals(loids). It was found that there is a statistically significant difference between the concentration of metals(loids) and the studied birds (except for As) (p < 0.05). The highest average concentrations of Hg and Al in tawny owl (2.26 and 1184.75 mg/kg dry weight, respectively), Cu in spotted little owl (10.45 mg/kg), and Pb, Cd, Cr, Zn, Se, Ni, and As in pallid scops owl (5.44, 0.19, 3.93, 251.99, 4.84, 5.45, and 0.52 mg/kg, respectively) were observed. According to the threshold level of elements, the status of Pb, Cr, Ni, and Al can be reported as unfavorable. In the current project, there was a statistically significant difference between the concentration of Hg, Cr, and Ni in the studied birds and spatial distribution (p < 0.05). The pollution of birds in Khuzestan province with toxic elements was considerable and in all ten elements investigated, this province is among the first 5 provinces in terms of pollution. In the case of most of the investigated elements, namely Pb, Cd, Cr, Zn, As, and Ni, the highest concentration was related to the habitat of open grasslands (2.10, 0.04, 0.98, 64.66, 0.15, and 1.26 mg/kg, respectively). Regarding most of the studied elements, adult birds had the highest concentration, but elements such as Ni and As showed a reverse trend so that nestling birds had higher concentrations of Ni and As in their feathers. As a conclusion, tawny owl, spotted little owl, and pallid scops owl can be introduced among the important group of raptor birds as distinct indicators of environmental pollution. [ABSTRACT FROM AUTHOR]

A promising water treatment method involves using biomass-derived activated carbon (AC) to remove emerging pollutants from wastewater due to its adsorption capacity, cost-effectiveness, and sustainability. Notwithstanding, the existing literature lacks comprehensive studies that specifically focus on removing contaminants in water by comparing the effectiveness of adsorption and photocatalytic degradation methods. Additionally, there is not much emphasis on analyzing the combined processes of adsorption-photocatalytic degradation utilizing AC. Herein, this paper investigates the intricacies of adsorption-photocatalytic degradation mechanisms and contributing variables in the enhancement of performances using biomass-derived AC. Furthermore, this review paper presents a comprehensive examination of different biomass sources employed in the synthesis of AC. It also discusses the diverse techniques utilized for the fabrication of AC, including physical and chemical activation methods. Finally, the shortcomings and future prospects of biomass-derived AC have been addressed. This study offers significant insights for the development of future biomass-derived AC, with the goal of improving their efficiency and expanding their uses in wastewater treatment. [ABSTRACT FROM AUTHOR]

Bacteria assume a pivotal role in mitigating environmental issues associated with heavy metals, microplastics, and pesticides. Within the domain of heavy metals, bacteria exhibit a wide range of processes for bioremediation, encompassing biosorption, bioaccumulation, and biotransformation. Toxigenic metal ions can be effectively sequestered, transformed, and immobilized, hence reducing their adverse environmental effects. Furthermore, bacteria are increasingly recognized as significant contributors to the process of biodegradation of microplastics, which are becoming increasingly prevalent as contaminants in marine environments. These microbial communities play a crucial role in the colonization, depolymerization, and assimilation processes of microplastic polymers, hence contributing to their eventual mineralization. In the realm of pesticides, bacteria play a significant role in the advancement of environmentally sustainable biopesticides and the biodegradation of synthetic pesticides, thereby mitigating their environmentally persistent nature and associated detrimental effects. Gaining a comprehensive understanding of the intricate dynamics between bacteria and anthropogenic contaminants is of paramount importance in the pursuit of technologically advanced and environmentally sustainable management approaches. [ABSTRACT FROM AUTHOR]

Amphibians are continuously exposed to pollutants and anthropogenic stressors in their natural habitats, representing a significant challenge to their survival. This study aimed to quantify the extent of DNA damage caused by chronic industrial and agrochemical surface water pollution in wild populations of the marsh frog (Pelophylax ridibundus). The observed genotoxic effects on the marsh frog DNA, manifesting as abnormalities in erythrocyte nuclei, micronuclei, and DNA strand breaks, demonstrate a clear cause-and-effect relationship with surface water parameters, heavy metals, metalloids, and pesticides. The most prevalent nuclear abnormalities observed were notched and blebbed nuclei and nuclear buds, indicative of chromosomal instability. The significant correlation between cadmium, lead, and copper contamination and the increased frequency of DNA breakage in the marsh frogs from the industrial site indicates that heavy metal contamination has a higher genotoxic potential than pesticide contamination. These findings underscore the vulnerability of amphibians inhabiting heavy metal-contaminated wetlands to genotoxic stress due to their lower tolerance to environmental genotoxins. Therefore, using in situ assays to detect erythrocyte nuclear abnormalities and DNA damage in P. ridibundus could serve as a reliable indicator of environmental quality and provide early detection of anthropogenic pollution. [ABSTRACT FROM AUTHOR]

Imported waste paper and recycled pulp may contain pollutants, posing potential environmental risks to the ecosystem of China. This study examined the presence and distribution patterns of heavy metals, phthalate esters (PAEs), and adsorbable organic halogens (AOX) in recycled pulp and production wastewater after various recycling processes of three typical restricted types of imported waste paper. The results indicated that the concentration ranges of heavy metals, PAEs, and AOX in the three types of imported recycled waste paper were 21.61–40.38 mg/kg, 15.35–27.88 mg/kg, and 19.21–57.72 mg/kg, respectively. The comparative analysis with the initial waste paper demonstrated a reduction in heavy metal content in the recycled pulp by 17.80–49.75%, PAEs by 65.42–90.55%, and AOX by 32.80–42.34%. The average concentrations of these pollutants in wastewater were 0.85–1.66 mg/L, 27.28–59.86 mg/L, and 1.15–3.34 mg/L, respectively. Chromium and lead were identified as the primary heavy metals present in the waste paper. Following pulping, No. 1 and No. 2 met the arsenic and lead levels specified in the "Reuse Fiber Pulp" standard (GB/T24320-2021), whereas No. 3 met these criteria after de-inking only. The main PAEs detected in the waste paper were dibutyl phthalate and di(2-ethylhexyl) phthalate, most of which were removed during the pulping stage. Significantly higher levels of AOX were observed in No. 2 and No. 3 than in No. 1, with a minimal impact on AOX removal from the pulp during the recycling process. [ABSTRACT FROM AUTHOR]

The Schiff base chelating ligands; (E)-2-(3,3-dimethoxy-2-oxa-7,10-diaza-3-silaundec-10-en-11-yl)phenol (L1), (E)-N-(2-((pyridine-2ylmethylene)amino)ethyl)-3-(trimethoxysilyl)propan-1-amine (L2) and (E)-N-(2-((thiophen-2-ylmethylene)amino)ethyl)-3-(trimethoxysilyl)propan-1-amine (L3) were immobilized on Fe3O4 magnetic nanoparticles (MNPs) and utilized in the extraction of Cr(VI), Cd(II) and Pb(II) metal cations from aqueous solutions. The compounds synthesized, denoted as L1@ Fe3O4, L2@Fe3O4, and L3@Fe3O4, were characterized using FT-IR spectroscopy, TEM-SEM, VSM, and BET/BHJ techniques for analysis of functional groups, surface morphology, magnetic properties, and degree of porosity of the adsorbents, respectively. BET/BHJ technique confirmed the mesoporous nature of the compounds as their pore diameters ranged between 15 and 17 nm. The initial optimization conditions of pH, adsorbent dosage, initial metal concentration, and contact time on adsorption were studied using L1@ Fe3O4. The optimum efficiencies recorded were 68% and 46% for Cr(VI) and Cd(II), respectively, obtained at pH 3, and a metal concentration of 20 ppm while an efficiency of 99% was recorded for Pb(II) cations at pH 7 and a metal concentration of 100 ppm. Compounds L2@Fe3O4 and L3@ Fe3O4 were also used in the extraction of metal cations from aqueous solution and gave efficiencies of 22%, 56%, and 78% for L2@ Fe3O4 and 19%, 90%, and 59% using L3@ Fe3O4 for Cr(VI), Cd(II), and Pb(II), respectively. The maximum adsorption capacities of L1@ Fe3O4 for Cr(VI), Cd(II), and Pb(II) cations were obtained from the Langmuir isotherm as 32.84, 41.77, and 450.45 mg/g, respectively. The experimental data was analyzed using pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich kinetic models. Both linear and non-linear forms of kinetic isotherms; Langmuir, Freundlich, Redlich-Peterson, and Temkin were utilized to investigate the nature of adsorption on L1@Fe3O4. The mechanistic studies deduced that the Langmuir isotherm and pseudo-second-order kinetic model better described the adsorption process both yielding high correlation coefficient values (R2 > 0.98). [ABSTRACT FROM AUTHOR]

Heavy metals (HMs) contamination has gained much attention due to its high degree of toxicity for living organisms. Therefore, different techniques are underway to eradicate HMs from the environment. Among the biological techniques, phytoremediation is a suitable method, but owing to the slow rate and chance of HMs penetration into the food chain, alternative techniques are needed to reduce their phytotoxicity, and biochar is one of them. Due to the diverse characteristics, biochar immobilizes HMs in the soil by improving soil pH, ion exchange, electrostatic interactions, complexation, precipitation, surface adsorption, and microbial activation. Thereby, amendment of biochar in the HMs-contaminated soils reduces HMs toxicity to plants and limits their penetration into the food chain. In contrast, some biochars have also been studied to induce metal availability in soils and subsequently its uptake by plants. This dual role of biochar depends on the feedstock of biochar, incineration temperature, and the rate of application. Moreover, biochar treatments enhance plant growth under HMs stress by improving nutrient availability, water retention capacity, scavenging of reactive oxygen species, and photosynthetic efficiency. Owing to the beneficial characteristics of biochar in HMs-contaminated sites, the number of publications has tremendously increased. Additionally, the plant species and the types of HMs that have been tested frequently under biochar treatments in these articles have been studied. Overall, the current study would help in understanding the mechanisms of how biochar influences phytoremediation of HMs and improves plant growth in HMs-polluted soils and the current scenario of the available literature. [ABSTRACT FROM AUTHOR]

The letter comments on a study that prepared P-type zeolite from coal fly ash for adsorption of heavy metals like Cr3+, Ni2+, and Co2+. The research focused on understanding the thermodynamics of the adsorption process, revealing an enthalpy-entropy compensation phenomenon. By analyzing the data, a predictive model was developed to estimate the adsorption of other heavy metals onto the zeolite. The study suggests that the zeolite may effectively remove heavy metals like In, Mo, Zn, As, and Fe, contributing to environmental safety. [Extracted from the article]

Heavy metal (HM) toxicity is a serious concern across the globe owing to their harmful impacts on plants, animals, and humans. Zinc oxide nanoparticles (ZnO-NPs) have gained appreciable attention in mitigating the adverse effects of abiotic stresses. The exogenous application of ZnO-NPs induces tolerance against HMs by improving plant physiological, metabolic, and molecular responses. They also interact with potential osmolytes and phyto-hormones to regulate the plant performance under HM stress. Moreover, ZnO-NPs also work synergistically with microbes and gene expression which helps to withstand HM toxicity. Additionally, ZnO-NPs also restrict the uptake and accumulation of HMs in plants which improves the plant performance. This review highlights the promising role of ZnO-NPs in mitigating the adverse impacts of HMs in plants. In this review, we explained the different mechanisms mediated by ZnO-NPs to counter the toxic effects of HMs. We also discussed the interactions of ZnO-NPs with osmolytes, phytohormones, and microbes in mitigating the toxic effects of HMs in plants. This review will help to learn more about the role of ZnO-NPs to mitigate HM toxicity in plants. Therefore, it will provide new insights to ensure sustainable and safer production with ZnO-NPs in HM-polluted soils. [ABSTRACT FROM AUTHOR]

In light of the increasing water scarcity and the need for sustainable waste management, the use of landfill leachate for irrigation has emerged as both a solution and a concern, posing potential risks to soil health and plant vitality. This study examined the multifaceted impacts of leachate irrigation on the soil characteristics, plant growth, and enzymatic activities of Medicago sativa (M. sativa). By exposing alfalfa to different concentrations of leachate, we assessed the influence on heavy metal accumulation, physiological parameters, and enzyme functions. The physicochemical profile of the leachate indicated that the pH was within acceptable limits, but the chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and concentrations of lead (Pb) and aluminum (Al) exceeded regulatory standards. Morphological parameters exhibited dual effects: stimulation at lower leachate doses and inhibition at higher leachate doses. Our findings show that soil acts as a buffer, reducing heavy metal uptake by plants. Enzymatic activities, including catalase, peroxidase, and succinate dehydrogenase, fluctuated significantly at higher leachate concentrations, indicating stress responses. This research underscores the interplay between leachate irrigation, plant physiology, and soil health, emphasizing sustainable management to optimize plant growth and minimize environmental impacts. It also stresses refining leachate application protocols to preserve soil and ecosystem health. [ABSTRACT FROM AUTHOR]

The present study aims to measure the values of metal pollutants in the dust of schools in Mashhad metropolis, determine the source of metal pollution, evaluate the degree of pollution, assess the health risk (carcinogenicity/non-carcinogenicity) and evaluate the potential ecological risk. For this purpose, after measuring the concentration of metals using an inductively coupled plasma-mass spectrometer, from various indices including Geoaccumulation Index (Igeo), Pollution Load Index (PLI), Contamination Factors (CF), Potential Ecological Risk Index (PERI), Enrichment Factor (EF), and Health Risk Indices such as Hazard Quotient (HQ), Hazard Index (HI), Carcinogenic Risk (CR) were used. The average concentrations of iron, arsenic, cadmium, chromium, copper, nickel, lead, vanadium and zinc (Fe, As, Cd, Cr, Cu, Ni, Pb, V and Zn) were 6361.50, 5.96, 0.59, 61.89, 37.13, 61.31, 28.93, 25.64 and 142.00 µg g−1, respectively. Based on CF, PLI and Igeo indices, most of the findings for the studied elements were at the low pollution level. The results also showed that the most likely origin of the studied metals was anthropogenic sources. The results of PERI indices showed that potential ecological risk at only one of the collection sites. In contrast, a high ecological risk was obtained for Cd. Hazard Index values were below safe levels for all studied elements. CR levels for elements were also classified as negligible and acceptable or tolerable risk, although the highest CR value for Cr indicated possible harm to humans. The findings showed the need for more attention and continuous monitoring of the concentration of metals, especially chromium, to announce a possible warning and prevent their harmful effects. It should be noted that the present study is the first research with mentioned objectives in Mashhad city and also in Khorasan Razavi province. [ABSTRACT FROM AUTHOR]

Owing to increasing levels of potentially toxic metals in road dust, air pollutants suspended in the air, pose significant health risks due to rapid, unplanned urbanization and industrialization. This study investigated the pollution status and health risks of trace metals (i.e., Cr, Cd, Ni, Cu, and Pb) in road dust collected from 16 locations across six land-use categories in Eskişehir, Türkiye, including residential, roadside, traffic, tram stations, and car industrial areas. The analysis of trace metals revealed distinct types of urban pollution based on these functional areas. In areas with heavy traffic, high concentrations of the elements, especially Zn, Cr, and Ni, would indicate significant toxic metal pollution. The overall contamination was evaluated using three indices: enrichment factor (EF 0.45–65.75), geo-accumulation index (Igeo − 2.50–4.18), and pollution index (PI 0.27–27.22). Human health risks of potentially toxic trace metals in urban road dust were evaluated for children and adult groups based on hazardous index (HI) and total cancer risk (TCR). The health risk assessments revealed that children (mean HIchildren 8.62E − 01; TCRchildren 6.99E + 04) are more vulnerable to toxic metal exposure than adults (mean HIadults 1.01E − 01; TCRadults 3.01E + 04), with ingestion being the primary exposure route over dermal contact and inhalation. In conclusion, we have captured the interaction between road dust and health risks, especially for children. [ABSTRACT FROM AUTHOR]

The management of cadmium-rich sludges, which are pollutant residues from the phosphorus industry, including the valorization of these sludges through the selective recovery of heavy metals, is a promising prospect. However, there is still a need to develop recovery methods that are both optimized for efficiency, cost-effectiveness, and environmentally friendly. This study aims to enhance cadmium extraction from the polymetallic sludge by optimizing the processes of sulfuric acid (SA) leaching and sodium sulfide precipitation. Key parameters including SA concentration, temperature, solid/liquid ratio, and stirring velocity were optimized to maximize the heavy metals extraction. Over 90% of the Cd and Zn present in the sludge were successfully extracted. Subsequently, investigates the selective precipitation of metal sulfide from acidic leachates (pH < 2), focusing particularly on cadmium. Through the optimization of chemical precipitation parameters (Na2S concentration, temperature, and reaction time), more than 99% of the cadmium was selectively recovered as CdS. The precipitates underwent analysis for mineralogy, chemistry, purity, and particle size. XRD analyses indicated CdS formation in "Greenockite" and "Hawleyite" forms, confirmed by SEM-EDS data, revealing fine powder consisting of micro and nanoparticles (< 0.5 µm) with varied spherical shapes. [ABSTRACT FROM AUTHOR]

Discharge of acidic wastewater from mining activities (acid mine drainage (AMD)) is a major global environmental and public health issue. Although several approaches, including chemical precipitation and membrane technology, have been developed to treat AMD, adsorption has emerged as the most promising technology due to its cost-effectiveness and efficacy. Despite the wide adoption of adsorption in treating AMD, the evolution of research in this area remains poorly understood. To address this gap, a bibliometric analysis of the most recent literature involving the application of adsorption in AMD remediation was conducted by merging datasets of articles from Scopus (1127) and the Web of Science Core Collection (1422), over the past decade (2013–2022). This analysis revealed a yearly increase of 11% in research publications, primarily contributed by China, the United States, and South Africa. Keyword analysis revealed that natural schwertmannites and their transformations, activated carbon, zeolites, and clay minerals, are the most extensively employed adsorbents for the removal of common metals (arsenic, chromium, iron, manganese, among others). The findings underscore the need for future focuses on recovering rare earth elements, using nanoparticles and modified materials, pursuing low-cost, sustainable solutions, integrating hybrid technologies, pilot-scale studies, exploring circular economic applications of AMD sludges, and inter-continental collaborations. These insights hold significant future implications, serving as a valuable reference to stakeholders in the mining industry. [ABSTRACT FROM AUTHOR]

This paper reports a comprehensive study of Theobroma cacao pericarp (TCP) residues, which has been prepared, characterized, and tested as an inexpensive and efficient biosorbent of Cr(VI) from aqueous solutions. The maximum adsorption capacity of TCP obtained at optimal conditions (pH = 2, dose = 0.5 g L−1, C0 = 100 mg L−1) was qmax = 48.5 mg g−1, which is one of the highest values reported by the literature. Structural and morphological characterization has been performed by FTIR, SEM/EDX, and pHPZC measurements. FTIR analysis revealed the presence of O–H, –NH, –NH2, C = H, C = O, C = C, C–O, and C–C functional groups that would be involved in the Cr(VI) biosorption processes. The experimental equilibrium data of biosorption process were successfully fitted to non-linear Langmuir (R2 = 0.95, χ2 = 11.0), Freundlich (R2 = 0.93, χ2 = 14.8), and Temkin (R2 = 0.93, χ2 = 14.7) isotherm models. Kinetics experimental data were well adjustment to non-linear pseudo-2nd (R2 = 0.99, χ2 = 2.08)- and pseudo-1st-order kinetic models (R2 = 0.98, χ2 = 2.25) and also to intra-particle Weber-Morris (R2 = 0.98) and liquid film diffusion (R2 = 0.99) models. These results indicate that Cr(VI) biosorption on heterogeneous surfaces as well as on monolayers of TCP would be a complex process controlled by chemisorption and physisorption mechanisms. The thermodynamic results indicate that the Cr(VI) biosorption on TCP is a feasible, spontaneous, and endothermic process. TCP can be regenerated with NaOH and reused up to 3 times. [ABSTRACT FROM AUTHOR]

Microplastics (MP) pollution is a pressing concern in today's marine environments. MPs can significantly affect marine ecosystems by altering nutrient and pollutant dynamics. This review analyses the existing literature to investigate interactions between MPs and micronutrients/pollutants, specifically trace and toxic metals in marine environments. It explores the adsorption of metals onto MP surfaces, emphasizing kinetics, isotherms, and underlying mechanisms of the process. The review highlights the potential consequences of MPs on the biogeochemical cycles of trace and toxic metals, emphasizing disruptions that could result in metal toxicity, metal limitations, reduced bioavailability, and adverse effects on primary productivity in marine ecosystems. It further underscores the need for future research to unravel the wide-ranging implications of MPs on trace and toxic metal cycling in marine ecosystems and their broader environmental impacts. [ABSTRACT FROM AUTHOR]

The co-contamination of dyes and heavy metal ions often used as mordants poses potential risks to environment and public health, and is a challenging problem that needs to be solved in water treatment. Meanwhile, improving the solid–liquid separation capability of adsorbents is of great significance for the application of adsorption technology. Herein, amidation modified hollow composite microspheres were prepared using hollow glass microsphere (HGM) as matrix through hydrolysis and condensation of silane coupling agent (A-1100) and subsequent amidation reaction. The material (HGMNE) not only exhibited good adsorption performance for DB86 and Ni2+ but also had stable self-floating capability. The adsorption of DB86 by HGMNE is mainly carried out by the electrostatic interaction between positively charged quaternary amine nitrogen and negatively charged DB86, while the adsorption of Ni2+ is achieved by the carboxyl group in EDTA group through complexation interaction to adsorb Ni2+ to form Ni complex. This research not only is devoted to the utilization of HGMNE to achieve the co-removal of DB86 and Ni2+ and flexible self-floating solid–liquid separation but also verifies the feasibility and applicability of the modification method of introducing organic adsorption functional groups through amidation reaction, so as to expand the preparation path of HGM-based adsorbents. [ABSTRACT FROM AUTHOR]

A comparative study between fertigation and spraying procedures in terms of the status of Cadmium (Cd) and Arsenic (As) in greenhouse cucumber was conducted as a two-factor split plot based on a randomized complete block design with three replications at the Soil and Water Research Institute, Karaj, Iran in 2023. The main and sub-factors were respectively fertigation and spraying that were used in two levels [the maximum permissible concentration of Cd and As in granular triple super phosphate fertilizer (25 ppm Cd and 50 ppm As) and the minimum permissible concentration of these metals in granular triple super phosphate fertilizer (5 ppm Cd and 5 ppm As)]. Spraying was done in three modes (spraying of leaves, leaves and fruit, and fruit). On average, the results showed that the order of the concentration of Cd in plant tissues (DW) was as leaf (0.284 mg/kg) > fruit peel (0.102 mg/kg) > fruit peel + flesh (0.054 mg/kg) > fruit flesh (0.044 mg/kg). This order for As was as leaf (0.608 mg/kg) > fruit flesh (0.127 mg/kg) > fruit peel + flesh (0.109 mg/kg) > fruit peel (0.072 mg/kg). Based on the measurements, the spraying procedure accumulated more amounts of Cd and As in the fruit (i.e., peel + flesh) than the fertigation procedure. In general, it is concluded that under soilless culture, the status of heavy metals in plant tissues of greenhouse cucumber is related to the nature of the metal, the organ exposed to the metal, and the fertilization procedure. Because there is the risk of contamination of vegetables grown in the areas fertigated and sprayed with poor-quality nutrient solutions in terms of the content of heavy metals, the frequency of fertigation and spraying needs to be monitored continuously for the quality of the vegetables cultivated in greenhouses. [ABSTRACT FROM AUTHOR]

The development of heavy metals, particularly chromium (Cr)-tolerant crop cultivars, is hampered due to lack of understanding of the mechanisms behind Cr stress tolerance. In this study, two Brassica napus cultivars, ZS758 and ZD622, were compared for Cr stress resistance by using the chlorophyll a fluorescence technique and biochemical characteristics. In both cultivars, Cr stress dramatically decreased PSII and PSI efficiency, biomass accumulation, and antioxidant enzyme levels. Although, cultivar ZS758 showed reduction in oxidative stress by decreasing the production of reactive oxygen species (ROS) in terms of reduced H2O2 and MDA content and increased enzymatic activities of key antioxidants enzymes including SOD, APX, CAT, and POD activities that play a crucial role in the regulation of numerous transcriptional pathways involved in oxidative stress responses. Higher non-photochemical quenching (NPQ) and QY were found in tolerant ZS758 cultivar under Cr stress, indicating that tolerant cultivar had a greater capacity to preserve PSII activity under Cr stress by enhancing heat dissipation as a photo-protective component of NPQ. Lower PSI activity and electron transfer from PSII were confirmed by lower PSI efficiency and higher donor end limitation of PSI in both rapeseed cultivars. The Cr concentration was greater in the ZD622 as compared to ZS758, which affected the mineral nutrients profile and damaged the cellular ultrastructure and related gene expression levels. However, current study suggest that cultivar ZS758 is more resistant to Cr stress than ZD622 due to improved metabolism and structural integrity and Cr stress tolerance that is linked with the increased PSII activity, NPQ, and antioxidant potential; these physiological characteristics can be exploited to select cultivars for Cr stress tolerance. [ABSTRACT FROM AUTHOR]

Eriocheir sinensis is the main aquaculture species in China. With the continuous expansion of the aquaculture scale, the demand for E. sinensis seedlings was also increased. The water used in breeding has well-nourished and its discharge into the sea posed significant risks. This study sampled the wastewater discharge points of the E. sinensis seedlings in Sheyang County, Jiangsu Province, and the areas far from the discharge points that were not affected in March and May 2023, respectively. A large number of antibiotic resistance genes (ARGs) were found in the sediment of the wastewater discharge area, and the highest ARG was sulfonamide ARG-sul1 using qPCR analysis, while ARGs were almost undetectable in the areas not affected by wastewater discharge. The 16S rRNA sequence analysis results showed that the main bacterial phyla at the wastewater discharge point were Bacteroidetes, Proteobacteria, and Thermodesulfobacteria. In the control point, the main bacterial phyla were Proteobacteria, Chlorobacterium, and Thermodesulfobacteria. There were significant differences in the composition of microbial communities between the two points, and the samples at the wastewater discharge point were more clustered and had higher similarity. The correlation network and redundancy analysis indicated that the phyla Bacteroidetes, Firmicutes, and Proteobacteria at the wastewater discharge points were positively correlated with most ARGs. The wastewater discharge had no effect on heavy metals from the two points. This study sets a foundation for future research by identifying key microbial taxa as potential ARG carriers and examining the interactions between microbial communities, ARGs, and heavy metals. [ABSTRACT FROM AUTHOR]

The influences of airborne trace elements in urban dust on element concentrations and functional traits of Tilia cordata were examined. For the present study, the unwashed and washed leaves of T. cordata were collected to assess the concentration of metals in Katowice City, Poland, from sites of different traffic intensity and industry activity. The content of Al, Cd, Cr, Cu, Fe, Mn, Pb, Zn, C, and N was measured. Additionally, a number of functional traits such as photosynthetic pigment content, specific leaf area (SLA), leaf dry matter content (LDMC), and diseased areas of the leaves were determined to assess the impact of the polluters on the physiology of the trees and their resources acquisition strategy. We hypothesized that the photosynthetic pigments of T. cordata will decrease with the traffic and industry intensity, and the traits related to the resources acquisition and stress resistance will shift into a more conservative strategy. The Principal Component Analysis and the Inverse Distance Weighting (IDW) interpolation method helped to identify that the Fe, Zn, Al, and Cr were related mainly to traffic intensification and Pb to industrial activities. The results indicate that Katowice is considerably polluted by Zn (up to 189.6 and 260.2 mg kg−1 in washed and unwashed leaves, respectively), Pb (up to 51.7 and 133.6 mg kg−1), and Cd (up to 2.27 and 2.43 mg kg−1) compared to other cities worldwide. Also, a reduction of approximately 27% in the photosynthetic pigments was observed at the high-traffic and industrial sites. The trees from the mainly affected areas with heavy traffic and industry tend to apply a conservative resources strategy with a decrement in SLA and an increment in LDMC. In contrast, the opposite trend was observed at the less affected sites (high SLA, low LDMC). The study showed that unfavourable urban conditions can trigger a plastic response on multiple levels. Knowledge of the possible paths of adaptation to urban conditions of different plant species is nowadays crucial to appropriate urban greenery planning. [ABSTRACT FROM AUTHOR]

This study investigates the adsorption of pollutants with different chemical structures; organic Naphtol Green B (NGB) dye and copper on a nanocomposite material with a hexagonal structure of the SBA-15 type. This research is divided into two main parts: the first carries out the synthesis of SBA-15 (Santa Barbra Amourphous) and its derivatives phases functionalized by 3-aminopropyl-triethoxylane (APTES) and calcined at 823 K. The second part presents the influence of the adsorption conditions on the adsorption efficiency of NGB dye and copper. High-resolution X-ray diffractogram (XRD) showed three distinct peaks characteristic of highly ordered mesoporous material. Nitrogen adsorption–desorption isotherm of SBA-15 at 77 K° is type IV typical of mesoporous materials. In addition, Fourier transform infrared spectroscopy (FT-IR) was also used in the characterization before and after the adsorption of the selected pollutants. At optimal conditions of pH 5.2, initial concentration of 50 mg/L, adsorbent dosage of 20 mg, and at adsorption time of 90 min the maximum removal of pollutants reached 76% and the adsorption capacity was 227.25 mg/g for NGB dye and 221.006 mg/g for copper. Furthermore, the adsorption kinetics followed the pseudo-second-order model, indicating that chemisorption was the dominant mechanism and the Sips isotherm model best described the adsorption data. Our research demonstrates that the SBA-15 material after modification is an effective adsorbent for removing effluents regardless of their different chemical structure (organic and inorganic). [ABSTRACT FROM AUTHOR]

In this work, biochars were used as adsorbents to remove Cu, Cd, and Zn ions in a real stabilized leachate from a controlled landfill. Oak fruit shells biochar (OFSBC) and date palm fibers biochar (DPFBC) were obtained by pyrolysis of oak fruit shells and date palm fibers at 700 °C and 400 °C, respectively. OFSBC and DPFBC showed well-developed structures and high specific surface areas (520.16 m2/g and 470.46 m2/g, respectively). Equilibrium adsorption of heavy metal ions on DPFBC and OFSBC occurred after 4 h and 2 h of stirring. The removal efficiencies of Cu, Cd, and Zn ions were 97.01%, 94.40%, and 80.59% with DPFBC and 90.10%, 88.33%, and 76.16% using OFSBC, respectively. The Avrami fractional order model was appropriate for describing kinetic adsorption. Increasing the dose of adsorbent improves heavy metal ion retention. Thermodynamic tests have proven the spontaneous and endothermic adsorption of these heavy metals. The electrostatic attraction, ion exchange, complexation, metal-π bending, and surface precipitation and pore filling were regarded as the most predominant heavy metal retention mechanisms from the landfill leachate onto the biochar surface. Separately, the DPFBC showed the best performance than OFSBC regarding the improvement of leachate quality. Chemical oxygen demand (COD), biological oxygen demand (BOD5), ammoniacal nitrogen (NH3-N), and phosphorus (P) were respectively removed at an efficiency of 53.57%, 29.17%, 36.07%, and 37.5%, respectively. Thus, the results allow highlighting that the adsorption on DPFBC and OFSBC can be an effective alternative in the practice of landfill leachate treatment. [ABSTRACT FROM AUTHOR]

Globally, the concentration of heavy metals and sediment toxicity analysis are significant liabilities to aquatic environments. This scrutiny outlines the sediment textures, heavy metals and toxicity status associated with environmental pollution indices in the core sediment of the Cauvery and Vettar estuaries, East coast of India. The impact of rapid industrialization, urbanization, harbour activities and agricultural activities influences on the twain estuary is a significant concern to designate the environment. The contamination status of the sediments affects the potential biodiversity, ecological risks and human health. A total of two core sediments were recovered from the Cauvery and Vettar estuaries in March 2023 to decipher the environmental pollution status. Meticulous observation of the textural studies underscores the prevalence of sand content in Cauvery, and Vettar sediments consist of predominate clay content and minor silt contents. Furthermore, the organic matter is augmented in the Vettar River due to the higher input of waste disposal, seaweeds and algae due to the surrounding landmass. Twain core sediments argue that heavy metal concentration is decreasing in order as Fe > Zn > Ni > Pb > Cu > Cr by using portable X-ray fluorescence (pXRF) spectrometry. Remarkable results of environmental pollution indices such as Igeo, Ef, Cf, Cd and mCd state very highly polluted, extreme enrichments, high contamination and very high degree of contamination. Furthermore, the potential ecological risk indices such as PLI, SQGs, and PERI argue polluted, medium to high toxicity and moderate adverse ecological risk to the estuarine regions. Statistical analysis of the heavy metal affirms the enrichment of Fe metals may derive from lithogenic and/or anthropogenic influences, and the other studied metals such as Cu, Ni, Zn, Pb and Cr may be influenced by the anthropogenic activities in the aspect of point and non-point pollution sources. This could result from both estuaries undergoing higher pollution, in which the Vettar estuary is a considerable environmental risk zone compared to the Cauvery river due to the impact of industrial effluents and rapid urbanization activities. This finding underscores the urgent need for enhanced estuarine sediment quality study and comprehensive assessment of sediment toxicity, regulating the beneficial acumen for the government to follow the suitable remediation on the embellish policy of river and marine environments. [ABSTRACT FROM AUTHOR]

Plastic has been known as an artificial polymer whereas environmental microplastics become a global concern. Microplastics are reported to cause immunotoxicity in humans through gut deposition and entering the bloodstream. This study is a comprehensive indication of the recent research on microplastic toxicity in the gastrointestinal system. We performed bibliographic analysis using VOS viewer software and analyzed the data received on microplastics and their impact on gut health which has grown exponentially since 2016. Recent findings also support microplastic toxicity in combination with heavy metals. The smaller particle size and other factors enhanced the adsorption ability of environmental contamination such as heavy metals on microplastic which increased their bioaccumulation. Such toxic complexes of heavy metals and microplastics are a concern to natural ecosystems and environmental biologists. Few reports also demonstrated the biofilm formation on microplastic surfaces which might cause greater environmental as well as human health risks. Notably, terms of determining the microplastics in human tissues through several analytical techniques are still limited to some extent. Future research should be focused on the quantification of microplastics in human tissues, the combined effect of microplastics with other contaminants, and their effects on pre-existing diseases. This study boosts understanding of the potential impacts of microplastic and nanoplastic toxicity in the human gastrointestinal system. [ABSTRACT FROM AUTHOR]

Heavy metal concentrations, which have increased continuously in the environment this century due to anthropogenic factors, severely threaten human and environmental health. Antimony (Sb) is one of the most toxic and harmful heavy metals in terms of human and environmental health. Therefore, the priority research subjects are monitoring the alteration of Sb pollution in the airborne and reducing pollution. This study was conducted to conclude the proper species to monitor and drop airborne Sb contamination on trees grown in Düzce, the 5th most polluted European city. This study examined samples taken from Pseudotsuga menziesii, Cupressus arizonica, Pinus pinaster, Picea orientalis, and Cedrus atlantica, and the Sb concentration changes based on tree species, route, tissue, and age range in the last 40 years were evaluated. The study hypothesizes that Sb concentration varies depending on (1) tree species, (2) direction, (3) plant tissue, and (4) age range, all confirmed in this study. In conclusion, the maximum concentrations were achieved in the outer bark and east (5.45 µg g−1) and north directions (6.72 µg g−1), with high traffic density. In addition, the mining and industrial places (sources of metal pollution) are not close to the study area. Therefore, it was concluded that traffic pollution was the primary source of Sb pollution in the study area. The study revealed that C. arizonica is the most suitable species for monitoring and reducing the change in Sb pollution because the highest Sb concentration (4.47 µg g−1) in wood (the largest organ) was obtained in C. arizonica. [ABSTRACT FROM AUTHOR]

In recent times, increased geogenic and human-centric activities have caused significant heavy metal(loid) (HM) contamination of soil, adversely impacting environmental, plant, and human health. Phytoremediation is an evolving, cost-effective, environment-friendly, in situ technology that employs indigenous/exotic plant species as natural purifiers to remove toxic HM(s) from deteriorated ambient soil. Interestingly, the plant's rhizomicrobiome is pivotal in promoting overall plant nutrition, health, and phytoremediation. Certain secondary metabolites produced by plant growth-promoting rhizobacteria (PGPR) directly participate in HM bioremediation through chelation/mobilization/sequestration/bioadsorption/bioaccumulation, thus altering metal(loid) bioavailability for their uptake, accumulation, and translocation by plants. Moreover, the metallotolerance of the PGPR and the host plant is another critical factor for the successful phytoremediation of metal(loid)-polluted soil. Among the phytotechniques available for HM remediation, phytoextraction/phytoaccumulation (HM mobilization, uptake, and accumulation within the different plant tissues) and phytosequestration/phytostabilization (HM immobilization within the soil) have gained momentum in recent years. Natural metal(loid)-hyperaccumulating plants have the potential to assimilate increased levels of metal(loid)s, and several such species have already been identified as potential candidates for HM phytoremediation. Furthermore, the development of transgenic rhizobacterial and/or plant strains with enhanced environmental adaptability and metal(loid) uptake ability using genetic engineering might open new avenues in PGPR-assisted phytoremediation technologies. With the use of the Geographic Information System (GIS) for identifying metal(loid)-impacted lands and an appropriate combination of normal/transgenic (hyper)accumulator plant(s) and rhizobacterial inoculant(s), it is possible to develop efficient integrated phytobial remediation strategies in boosting the clean-up process over vast regions of HM-contaminated sites and eventually restore ecosystem health. [ABSTRACT FROM AUTHOR]

Heavy metal stress poses a significant threat to the productivity of agricultural systems and human health. Silicon (Si) is widely reported to be very effective against the different heavy metal stresses in crops. According to reports, it can help plants that are under cadmium (Cd) and nickel (Ni) stress. The presented work investigated how silicon interacted in Cd- and Ni-stressed wheat and mitigated metal toxicity. A pot experiment was carried out in which wheat crop was irrigated with Cd- and Ni-contaminated water. Application of Cd and Ni-contaminated water to wheat significantly reduced the root and shoot growth parameters and physiological and biochemical factors while increasing the antioxidant enzymatic activity and bioaccumulation of Cd and Ni metal in shoot and root as compared to the control. Application of Si led to an improvement in physiological parameters, i.e., greenness of leaves, i.e., SPAD values (17% and 26%), membrane stability (26% and 25%), and growth parameters i.e., root surface area (42% and 23%), root length (81% and 79%), root dry weight (456% and 190%), root volume (64% and 32%), shoot length (41% and 35%), shoot dry weight of shoot (111% and 117%), and overall grain weight (62% and 72%) under Cd and Ni stress, respectively. It increased the activity of antioxidant activity (max. up to 20%) whereas decreased the metal bioaccumulation of Cd and Ni in the roots and shoot (max. up to 62%) of wheat. It was concluded that the application of Si potentially increases antioxidant activity and metal chelation resulting in decreased oxidative damage and reducing the effect of Cd and Ni stress on wheat which improves growth and physiological parameters as well as inhibits Cd and Ni inclusion in food chain under Cd and Ni toxicity reducing health risks associated with these metals. [ABSTRACT FROM AUTHOR]

The release of nickel "Ni(II)" into aquatic environments is of great concern because of environmental and health issues. Metal-organic frameworks (MOFs) are one of the most promising technologies for removing heavy metals from water. In this work, an octahedral Co-based MOF (Co-MOF) was synthesized with a high Ni(II) removal capacity (qmax of 1534.09 ± 45.49 mg g−1) in aqueous media. For the first time, the effect of Co-MOF alone and in co-exposure with Ni(II) on nitrifying microbial consortium was assessed using dynamic microrespirometry. A single concentration of Co-MOF had no significant effects on nitrifying microbial consortium, while the concentration of Ni(II) exerted non-competitive inhibition on the nitrifying microbial consortium with an IC50 of 1.67 ± 0.03 mg L−1. In addition, the theoretical speciation analysis showed a decrease of 40% of IC50 when the free Ni(II) concentration was considered. Co-exposure of Co-MOF and Ni(II) during the nitrifying process allowed us to conclude that Co-MOF is an effective adsorbent for Ni(II) and can be used to mitigate the inhibitory effects of nickel on nitrifying microbial consortia, which is crucial for maintaining the good operation of wastewater treatment and balance of nitrogen cycle. [ABSTRACT FROM AUTHOR]

Metals and their nanoparticles can induce toxicities that influence the survival of both microorganisms and macroorganisms. The current study reports on the impact of heavy metal pollution on the microbiome of estuarine and coastal sediments, where the settling and final remineralization of organic matter occur. Sediment samples collected from the Cochin estuary along the southwest coast of India and its adjacent coast showed high concentrations of cadmium (Cd) and zinc (Zn). The contamination factor (CF), calculated by comparing the concentration of metals in each station with that of shale value for Cd and Zn, ranged from 5.2 to 8.7 and 1.5 to 2.0 respectively, in the estuarine and coastal stations. Microbiome analysis revealed that bacteria were common across all stations but varied in relative abundance. Proteobacteria, Chloroflexi, Actinobacteria, Desulfobacteria, and Acidobacteria were the major bacterial phylum found in all stations. More than 70% of the bacteria were tolerant to 1 mM concentration of Cd. The findings of our study suggest that metal pollution can influence the microbiome of sediments in the estuaries and coasts. Bacteria with metal tolerance may dominate in polluted areas, but their participation in remineralization may be impaired, as evident in our previous reports. This impairment could ultimately influence the dynamics of the food web and the biogeochemical cycling of nutrients, necessitating further research. [ABSTRACT FROM AUTHOR]

The reuse of biomass waste has been gaining attention in adsorption processes to remove pollutants of emerging concern from water and wastewater. In this work, the potential of alginate-extracted macro-algae waste to uptake synthetic dyes and metal cations was evaluated in comparison with raw algae. In affinity assays, both materials were able to remove metal cations and cationic dyes up to maximum rates, and no significant removal was observed for an anionic dye in an acidic medium. Competition was observed in multi-component systems of metal cations and dyes. For binary samples containing organic and inorganic contaminants, kinetic modeling evidenced the distinct nature of both types of adsorbates. Pb(II) biosorption was best described as a first-order process, while second-order and Elovich models better fitted methyl blue (MB) uptake data. For equimolar binary samples, the Sips isothermal model fitted the experimental data more satisfactorily at room temperature. Isotherms for 20, 30, 40, and 60 °C exhibited favorable adsorption profiles with spontaneous ΔG values for both raw macro-algae and waste from alginate extraction. Maximum adsorption capacities were competitive with previous reports in the literature for a wide range of biomaterials, pointing to the slightly higher efficiency with algae waste in batch experiments. In elution tests, HNO3 (0.5 M) showed the best recovery rates of metal cations. Continuous biosorption operation revealed the performance of the brown algae waste was considerably more efficient than raw algae with breakthrough biosorption capacities up to 3.96 and 0.97 mmol.g−1 for the removal of Pb(II) and MB, respectively. A total of 3.0 g of algae and algae waste were able to deliver 1.20 and 1.62 L of contaminant-free water, respectively. XPS analyses corroborate previous assays that pointed to the prevalence of physisorption with evidence of complexation, ionic exchange, and hydrogen displacement mechanisms. [ABSTRACT FROM AUTHOR]

Unfolded protein accumulation in the endoplasmic reticulum (ER) triggers ER stress, leading to a unique transcriptomic response called unfolded protein response (UPR). While ER stress is linked to various environmental stresses, its role in plant responses to heavy metal toxicity remains unclear. This study aimed to elucidate if heavy metals Fe, Zn, Cu, and As induce ER stress in plants. For this purpose, Arabidopsis thaliana seedlings were treated with Fe (200, 400 µM), Zn (500, 700 µM), Cu (25, 50 µM), and As (250, 500 µM) for 7 days, which resulted in 50–70% decrease in plant growth. All treatments increased insoluble protein levels, indicating unfolded protein accumulation, with the highest induction observed for 50 µM Cu treatment (fivefold). Expressions of genes involved in the perception and signaling of ER stress (IRE1, bZIP28, bZIP60, bZIP17) indicate that Zn toxicity specifically induces bZIP28 but not the IRE1 branch of UPR. All metals except Fe also induced genes associated with protein folding in the ER (BIP1, BIP3, and CNX) and ER-associated protein degradation (ERAD) (HRD1). This finding indicates Zn, Cu, and As but not Fe cause ER stress in plants. Furthermore, increased expression of ER oxidoreductase 1 (ERO1) suggests that metal toxicity also disrupts oxidative protein folding in the ER lumen. This study enhances our understanding of the intricate interplay between essential nutrients, metal toxicity, protein folding machinery, and ER stress, demonstrating that heavy metal toxicity has an ER stress component in plants alongside its established effects on energy metabolism, membrane integrity, and oxidative stress. [ABSTRACT FROM AUTHOR]