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The use of blends of small molecule organic semiconductors (OSCs) with insulating binding polymers has been shown to be a promising route to facilitate the processing of OSCs over large areas using printing techniques. Here we fabricated organic field-effect transistors (OFETs) and phototransistors using the benchmark OSC 7-decyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) and blends of this material with polystyrene (PS), poly(pentafluorostyrene) (PFS) and poly(methyl methacrylate) (PMMA). We show that the nature of the binding polymer has a significant impact on the device performance. The OFETs showing the best performance are the ones based on blends of PS since they reveal less interfacial traps, leading to devices with higher mobility, threshold voltage close to zero and high bias stress stability. The lowest OFET performance is found in the devices based on PMMA blends due to the higher density of majority charge carrier (i.e., holes) traps. On the other hand, regarding the response of the devices to UV light, the PFS and pristine films exhibited the highest photoresponse, which was attributed to the higher density of minority charge carrier (i.e., electrons) traps. Therefore, this work demonstrates that the binding polymer is a useful tool to optimise the OFET electrical characteristics as well as its photoresponsivity., This work was funded by the projects GENESIS PID2019-111682RB-I0 and Severo Ochoa FUNFUTURE CEX2019-000917-S from MCINN/AEI/10.13039/501100011033/and by the Generalitat de Catalunya (2017-SGR-918). J. L. acknowledges funding from the Chinese Scholarship Council (CSC). J. L. is enrolled in the UAB Materials Science PhD program. S.R-G. acknowledges support from the Marie Skłodowska Curie Cofund, Beatriu de Pinós Fellowship (AGAUR-2019 BP 00200). R. P. acknowledges support from the Ramón y Cajal Fellowship (Ref. RyC2019-028474-I)., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

In complex interactive scenarios, action understanding lies at the heart of social interactions. Nevertheless, the ability to understand action intention may differ among people. The current study distinguished two groups of participants with different social intention-understanding abilities (high and low) based on a perspective-taking task to investigate the influence of social intention on object affordance under conditions of individual and cooperative action intention. In the affordance perception experiment, participants were shown a video with the presenter reaching to grasp an object in different grips and asked to classify objects into kitchen or non-kitchen items by pressing the left- or right-hand button under the two intention conditions. The results showed that the object affordance effects were modulated by the participants' understanding of social intention in the interactive scenarios. Specifically, the object affordance effects were observed only in the high perspective-taking ability group under the condition of cooperative action intention. However, under the condition of individual action intention, object affordance effects were shown in both the high and low perspective-taking ability groups, and the difference between the two groups was not significant. This study suggests that processing of object affordance depends greatly on the contextual correspondence of perception and action and that the understanding of cooperative action intention can affect the activation of object affordance.

Herein, cobalt embedded in nitrogen-doped porous carbon (Co@NC) was developed as a robust heterogeneous catalyst for the dehydrogenative coupling of primary alcohols and hydroxides. With Co@NC as the first earth-abundant metal/carbon composite material for this transformation, numerous aromatic and aliphatic carboxylic acids were efficiently afforded. Notably, the newly prepared Co@NC was fabricated in a facile and straightforward manner and reused up to 15 recycle rounds without activity decay. It is also worth emphasizing that the catalyst recycling was realized via magnetic separation with no special treatment or activation. Additionally, further experiments elucidated the pivotal role of the cobalt and nitrogen elements dispersed in the carbon matrix as well as the hierarchical porosity (micro-/meso-pores) in the catalytic activity and recyclability. Considering the active sites of Co@NC, we envisioned that the Co–N species was the most active site, while other active sites such as Co–O, Co0 species and free N-doped carbon were also present, but demonstrating lower activity or stability in comparison with the Co–N species. Additional mechanistic investigations were carried out to gain more insights into the possible reaction pathways. We found that the aldehyde was identified as a crucial intermediate, and two possible pathways were proposed for this catalytic process.

Despite numerous studies on the distributions of organophosphate triesters (tri-OPEs) in various environmental compartments, few have investigated organophosphate diesters (di-OPEs) in natural envi...

Oxazolidinones and α-hydroxyl ketones are two series of fine chemicals that have been generally utilized in biological, pharmaceutical, and synthetic chemistry. Herein, a AgNO3/ionic liquid (IL) catalytic system was developed for the simultaneous synthesis of these compounds through the atom-economical three-component reactions of propargyl alcohols, 2-aminoethanols, and CO2. Notably, this system behaved excellent catalytic activity with the lowermost metal loading of 0.25 mol%. Meanwhile, it is the first reported metal-catalyzed system that could efficiently work under atmospheric CO2 pressure and be recycled at least five times. Evaluation of the green metrics proved the AgNO3/IL-catalyzed processes to be relatively more sustainable and greener than the other Ag-catalyzed examples. Further mechanistic investigations revealed the derivative active species of N-heterocyclic carbene (NHC) silver complexes and CO2 adducts generated during the process. Subsequently, their reactivity in this reaction was assessed for the first time, which was finally identified as beneficial for the catalytic activity.

Facile strategies for noble metal dispersion in the shell-layer of core–shell structured metal–organic frameworks based on Zr-MOFs (UiO-66@Pd-UiO-67-BPY) was developed. The robust structure of the core-structure UiO-66 was firstly synthesized before covering up with a shell-structure of UiO-67-BPY obtaining the core–shell structure (UiO-66@UiO-67-BPY). The metallation with active palladium species (PdII) was designed on the shell-layer of core–shell MOFs via a post-synthetic method. The Pd species were coordinated explicitly in a bidentate manner to the bipyridyl linkers of the shell-structure (UiO-67-BPY). Excellent dispersion of Pd in the shell structure was obtained, resulting in UiO-66@Pd-UiO-67-BPY, as confirmed from characterizations. Taking advantage of the designed catalyst, the synthesized UiO-66@Pd-UiO-67-BPY was examined for the catalytic hydrogenation reaction. The results revealed an excellent catalytic performance of UiO-66@Pd-UiO-67-BPY compared with the traditional catalyst Pd-UiO-67-BPY. Moreover, the designed catalyst structure exhibited outstanding performance and paved the way towards a cost-effective catalyst synthesis based on MOFs combined with a noble metal.

The current study investigated the role of both involuntary motor activations and voluntary stimulus-response (S-R) mappings (i.e., the subjects voluntarily learned altered S-R mappings) in perception-action processing. Involuntary motor activations were triggered by graspable objects, and voluntary S-R mappings were manipulated by adjusting the proportion of compatible trials (PC; 80%, 50%, and 20%) for which the potential motor properties of objects were compatible with the responses. The results showed large positive compatible effects when regular S-R associations were strong (80% PC) but negative compatible effects when reversed S-R associations were established (20% PC). Moreover, the size and developing speed of the compatible effects were larger with 80% PC than with 20% PC. The findings suggest that the direction, magnitude, and developing speed of object affordances are codriven by both involuntary motor activations and voluntary S-R mappings. Specifically, when these two factors are consistent with each other, motor activations will be amplified, and the magnitude and developing speed of affordance effects will thus be increased. However, when they are inconsistent, they will compete with each other, and affordance effects will be decreased or reversed with an increasing proportion of trials within the S-R mappings. The codriven model of perception-action processes reflects the optimization of our cognitive control system for processing a complicated environment.

α-Hydroxy ketones are a series of biologically active fragments in nature as well as important synthons for organic chemistry. Herein, an AgOAc/1-ethyl-3-methylimidazolium acetate ionic liquid syst...

Mercury speciation in groundwater affects its removal effectiveness and methylation potential. Yet, most studies focus on the removal of inorganic dissolved Hg(II) and few studies explored the mercury methylation before and after the treatment. This study comprehensively explored the removal performance of three model mercury species, namely, dissolved inorganic divalent Hg (Hg(II), including free Hg2+ and Hg2+ complexes with Cl− and OH−), Hg2+ bound to dissolved organic matter (Hg-DOM), and HgS nanoparticles by FeS nanoparticles and further investigated the resultant impacts on the microbial methylation of Hg. Among three different stabilizers (starch, carboxymethyl cellulose (CMC), carboxymethyl starch (CMS)), CMC stabilized FeS nanoparticles (CMC-FeS) demonstrated best physical stability and highest mercury uptake. The CMC-FeS nanoparticles efficiently immobilized the three mercury species within 20 h. The sorption isotherm data of Hg(II) and Hg-DOM were well fitted by the dual-mode isotherm model and the maximum sorption capacities were 3358.28 and 2396.38 mg/g, respectively. Hg(II) and Hg-DOM were predominantly removed via ion exchange, chemical precipitation, and surface complexation whereas HgS was mainly immobilized through heteroaggregation. The simple treatment greatly reduced the bioavailable Hg species, thereby diminishing the net MeHg production by 70.2 %, 32.7 %, and 11.3 %, respectively. This study provides compelling evidence that FeS nanoparticles efficiently removed various mercury species in groundwater and remarkably inhibited the microbial methylation of mercury.

Antimony(III) or Sb(III) contamination in surface waters poses a serious threat to the ecological system and human health, and green and cost-effective technologies are urgently needed to mitigate its toxic effects. We green synthesized a novel oxidative sorbent, referred to as Al2O3-supported Fe–Mn binary oxide nanoparticles (Fe–Mn@Al2O3), and investigated its removal effectiveness and dynamic quantitative removal mechanisms of Sb(III) at environmentally relevant levels from simulated surface water. Fe–Mn binary oxides (Fe–Mn) were successfully attached on the surface of Al2O3via intermolecular hydrogen bonding, resulting in the formation of Fe–Mn@Al2O3 with a larger specific surface area, greater oxidizing reactivity, and more sorption sites compared to Fe–Mn. The resulting composite is mainly composed of FeOOH, Fe2O3, MnO2, and Al2O3. Life cycle assessment (LCA) indicated that the Fe–Mn@Al2O3 synthesis met green chemistry principles. Fe–Mn@Al2O3 at a Fe : Al2O3 molar ratio of 1 : 2 displayed an enhanced Sb(III) sorption capacity of 272.2 mg g−1 at pH 6.4 within 48 h. Sorption kinetic data were adequately simulated with the pseudo second-order kinetic model and the intraparticle diffusion model, suggesting that the sorption kinetics were a combination of chemisorption and intraparticle diffusion. The Freundlich isotherm model outperformed the Langmuir model in simulating the sorption isotherm data, which aligns with the heterogeneous surface sorption sites of Fe–Mn@Al2O3. MnO2 in Fe–Mn@Al2O3 oxidized Sb(III) to Sb(V), whereas FeOOH and Al2O3 acted as adsorption sites towards Sb(III) and Sb(V). Most importantly, Fe–Mn@Al2O3 still maintained high sorption efficiencies towards Sb(III) after five consecutive regeneration cycles. The dynamic quantitative removal mechanisms were proposed thereafter. Upon equilibrium, 92.8% of Sb(III) was sorbed by Fe–Mn@Al2O3, and 94.9% of sorbed Sb(III) was oxidized to produce Sb(V) and Mn(II). 59.1% of the formed Sb(V) was adsorbed onto Fe-Mn@Al2O3 and 40.9% of Sb(V) was released into the solution. The new quantitative and mechanistic insights contribute to an improved understanding of the uptake of Sb(III) by Fe–Mn@Al2O3 in natural and engineered systems, and the results may guide further preparation and application of reactive adsorbents for removal of redox-active contaminants from water.

A core-shell structure metal-organic framework based on the Zr clusters bridging with BDC linkers (UiO-66) as a core-structure and BPYDC linkers (UiO-67-BPY) as a shell-structure was developed (UiO-67-BPY@UiO-66). The combination of several techniques such as XRD, FTIR, SEM, TEM, and surface area analysis etc. were applied for the characterization and confirmed a core-shell structure of UiO-67-BPY@UiO-66. Taking advantage of the high porous stability of the core-structure (UiO-66) and the presence of active Lewis basic sites from the bipyridinic linker in the shell layer (UiO-67-BPY) could be advantageous for basic-catalyzed reactions. The synthesized core-shell material was applied as a heterogeneous catalyst for the Knoevenagel condensation as a model reaction. An excellent catalytic performance was obtained by the core-shell material over traditional MOFs and other previous reports based on MOFs. The excellent dispersion of the active sites (Lewis basic) in the outer layer of the designed core-shell structure was a breakthrough to prevent mass diffusion limitation during catalysis. Additionally, the catalyst can be recycled and maintained its high catalytic performance at least for four cycles.

Soil contamination by heavy metals and metalloids has been a major environmental challenge. While various remediation technologies have been reported, field data on the remediation effectiveness have been limited. We tested a new remediation technology for on-site immobilization of As(III) and Pb(II) in a contaminated soil at an abandoned chemical plant site. A novel ternary amending agent consisting of Fe2O3, MnO2, and Mg(OH)2 (molar ratio = 1.0:5.5:5.5) was used to amend the soil on-site. Field monitoring data indicated that the amendment severed as a pH buffer and a long-term sequester for both As and Pb in the soil. At a dosage of 3 wt.%, the acid-leachable As and Pb were lowered from 0.042-0.077 mg/L and 0.013-0.022 mg/L to 0.0062-0.0093 mg/L and 0.0030-0.0080 mg/L, respectively, after one day of the amendment, and to 0.0020-0.0050 mg/L and 0.0020-0.0054 mg/L after 240 days of aging. As(III) was oxidized to As(V) and subsequently immobilized via complexation and precipitation, whereas Pb(II) was sequestered via electrostatic attraction and chemical precipitation. The treatment cost was estimated at $31.5/m3. The results indicate that complex contaminants in soil can be effectively immobilized using combined amending agents that can interact with the target chemicals and induce synergistic immobilization reactions.

Background: Given changes in the care and outcomes of acute myocardial infarction (AMI) patients over the past several decades, we sought to develop prediction models that could be used to generate accurate risk-adjusted mortality and readmission outcomes for hospitals in current practice across Canada. Methods: A Canadian national expert panel was convened to define appropriate AMI patients for reporting and develop prediction models. Preliminary candidate variable evaluation was conducted using Ontario patients hospitalized with a most responsible diagnosis of AMI from April 1, 2015 to March 31, 2018. National data from the Canadian Institute for Health Information was used to develop AMI prediction models. The main outcomes were 30-day all-cause in-hospital mortality and 30-day urgent all-cause readmission. Discrimination of these models (measured by c-statistics) was compared with that of existing Canadian Institute for Health Information models in the same study cohort. Results: The AMI mortality model was assessed in 54,240 Ontario AMI patients and 153,523 AMI patients across Canada. We observed a 30-day in-hospital mortality rate of 6.3%, and a 30-day all-cause urgent readmission rate of 10.7% in Canada. The final Canadian AMI mortality model included 12 variables and had a c-statistic of 0.834. For readmission, the model had 13 variables and a c-statistic of 0.679. Discrimination of the new AMI models had higher c-statistics compared with existing models (c-statistic 0.814 for mortality; 0.673 for readmission). Conclusions: In this national collaboration, we developed mortality and readmission models that are suitable for profiling performance of hospitals treating AMI patients in Canada. RÉSUMÉ: Contexte: Compte tenu des changements apportés au cours des dernières décennies aux soins des patients ayant subi un infarctus aigu du myocarde (IAM) et aux issues d'un tel événement, nous avons voulu élaborer des modèles prédictifs pouvant servir à calculer de façon précise les résultats relatifs à la mortalité et aux réadmissions, ajustés selon les risques, pour les hôpitaux dans la pratique actuelle au Canada. Méthodologie: Un groupe national d'experts canadiens a été mis sur pied et a reçu le mandat de définir les critères appropriés applicables aux patients ayant subi un IAM aux fins de déclaration des cas et d’élaborer des modèles prédictifs. L’évaluation préliminaire des variables proposées a été effectuée à partir de patients hospitalisés en Ontario entre le 1er avril 2015 et le 31 mars 2018 chez lesquels l'IAM était le diagnostic principal à l'origine de l'hospitalisation. Les données à l’échelle nationale de l'Institut canadien d'information sur la santé (ICIS) ont été utilisées pour élaborer des modèles prédictifs d'IAM. Les deux principales issues évaluées étaient la mortalité hospitalière toutes causes confondues à 30 jours et la réadmission urgente toutes causes confondues à 30 jours. Le pouvoir discriminant de ces modèles (mesuré par la statistique C) a été comparé à celui des modèles existants de l'ICIS dans la même cohorte de l’étude. Résultats: Le modèle de mortalité par IAM a été évalué auprès de patients ayant subi un IAM, dont 54 240 en Ontario et 153 523 dans l'ensemble du Canada. Nous avons observé un taux de mortalité hospitalière à 30 jours de 6,3 % et un taux de réadmission urgente à 30 jours toutes causes confondues de 10,7 % au Canada. Le modèle canadien final de prédiction de la mortalité par IAM était constitué de 12 variables et avait une statistique C de 0,834. Pour la réadmission, le modèle comportait 13 variables et présentait une statistique C de 0,679. Le pouvoir discriminant des nouveaux modèles d'IAM présentait une statistique C supérieure à celle des modèles existants (statistique C de 0,814 pour la mortalité et de 0,673 pour la réadmission). Conclusions: Dans le cadre de cette collaboration nationale, nous avons élaboré des modèles prédictifs de la mortalité et de la réadmission hospitalière qui permettent d’établir un profil des résultats obtenus par les hôpitaux traitant des patients ayant subi un IAM au Canada.

Many glycine-rich RNA-binding proteins (GR-RBPs) have critical functions in RNA processing and metabolism. Here, we describe a role for the tomato (Solanum lycopersicum) GR-RBP SlRBP1 in regulating mRNA translation. We found that SlRBP1 knockdown mutants (slrbp1) displayed reduced accumulation of total chlorophyll and impaired chloroplast ultrastructure. These phenotypes were accompanied by deregulation of the levels of numerous key transcripts associated with chloroplast functions in slrbp1. Furthermore, native RNA immunoprecipitation-sequencing (nRIP-seq) recovered 61 SlRBP1-associated RNAs, most of which are involved in photosynthesis. SlRBP1 binding to selected target RNAs was validated by nRIP-qPCR. Intriguingly, the accumulation of proteins encoded by SlRBP1-bound transcripts, but not the mRNAs themselves, was reduced in slrbp1 mutants. Polysome profiling followed by RT-qPCR assays indicated that the polysome occupancy of target RNAs was lower in slrbp1 plants than in wild-type. Furthermore, SlRBP1 interacted with the eukaryotic translation initiation factor SleIF4A2. Silencing of SlRBP1 significantly reduced SleIF4A2 binding to SlRBP1-target RNAs. Taking these observations together, we propose that SlRBP1 binds to and channels RNAs onto the SleIF4A2 translation initiation complex and promotes the translation of its target RNAs to regulate chloroplast functions.

Sludge from wastewater treatment plants (WWTPs) is considered to be reservoirs of antibiotic resistance genes (ARGs), which can be efficiently removed by sludge treatment processes, e.g., aerobic sludge digestion. However, recent studies report microplastics, which also accumulate in sludge, may serve as carriers for ARGs. In the presence of microplastics, whether ARGs can still be efficiently destroyed by aerobic sludge digestion remains to be urgently investigated. In this study, the fate of ARGs during aerobic digestion was investigated with and without the addition of three prevalent categories of (i.e., polyvinyl chloride (PVC), polyethylene (PE), and polyethylene terephthalate (PET)). Nine ARGs and class 1 integron-integrase gene (intI1) that represents the horizontal transfer potential of ARGs were tested in this study. Compared with the control, the ARGs removal efficiency decreased by 129.6%, 137.0%, and 227.6% with the presence of PVC, PE, and PET, respectively, although a negligible difference was observed with their solids reduction efficiencies. The abundance of potential bacterial hosts of ARGs and intI1 increased in the reactors with the addition of microplastics, suggesting that microplastics potentially selectively enriched bacterial hosts and promoted the horizontal transfer of ARGs during aerobic sludge digestion. These may have contributed to the deteriorated ARGs removal efficiency. This study demonstrated that microplastics in sludge would decrease the ARGs removal efficiency in aerobic digestion process, potentially leading to more ARGs entering the local environment during sludge disposal or utilization.

We investigated three common alkaline agents (NaOH, CaO, and Mg(OH)2) for immobilization of four heavy metals (Pb, Zn, Cu, and Cd) in a field-contaminated soil and elucidated the underpinning principles. NaOH caused the highest pH spike in the soil, while CaO and Mg(OH)2 served as a longer-lasting source of OH-. Amending the soil with CaO or Mg(OH)2 at ≥0.1 mol as OH- (kg·soil)−1 for 24 h was able to immobilize all four metals, while NaOH failed. NaOH leached up to 3 times more organic carbon than CaO and Mg(OH)2, resulting in elevated leachability of the metals. Column elution tests showed that amendments by CaO and Mg(OH)2 lowered the leachable Pb2+, Zn2+, Cu2+, and Cd2+ by 52–54%, 71–75%, 69–73%, and 68%, respectively, after 1440 pore volumes of elution. Sequential extraction revealed that the soil amendments converted the exchangeable fraction of the metals to the much less available forms. XRD and FTIR analyses indicated that formation of metal oxide precipitates and complexation with soil organic matter were responsible for the metals immobilization. Taken together the chemical cost, technical effectiveness, and environmental impact, CaO is the most suitable alkaline agent for remediation of soil contaminated with heavy metals.

Supplementary material

We prepared and tested carboxymethyl-cellulose-bridged nano-chlorapatite (CMC-CAP) for simultaneous immobilization of Pb, Zn, Cu, and Cd in a field-contaminated acidic soil. Amending the field-contaminated soil using 0.5 wt.% CMC-CAP and 0.1 wt.% CaO was most effective in immobilizing the four metals, which decreased the leachabilities by 98.2%, 98.3%, 96.3%, and 96.2% for Pb, Zn, Cu, and Cd, respectively, after 1 day of treatment. The acid-leached metals fluctuated in the first 60 days, and then approached to steady state after 180 days, where the acid-leachable concentrations all met the regulation levels, and the immobilization was further consolidated when further aged for 365 days. Column elution tests showed that the soil amendment lowered the peak metal concentrations by > 92.5%, and the total eluted masses by >71.9%. Sequential extraction revealed that the soil amendment converted the exchangeable fractions to the much less available Fe-Mn oxides bound and residual forms, and thus, lowered the risk levels to “low risk” for all the metals. The immobilization of the metals was facilitated through formation of stable metal (chloro)phosphates, surface complexation, and/or ion exchange reactions. Combined CMC-CAP and CaO may serve as an effective formulation for simultaneous and long-term immobilization of multiple heavy metals in acidic soil.

A core-shell metal-organic frameworks (MOF@MOF) based on the Zr-MOFs assembly from core-structure UiO-66 combined with shell-structure UiO-67-BPY were explored. The synthesized materials were characterized via XRD, FTIR, SEM, TEM, and surface area analysis, etc. indicating the presence of a core-shell structure of UiO-66@UiO-67-BPY. Furthermore, incorporation of the bipyridinic (BPY) group in the linker used to construct the shell layer (UiO-67-BPY) could coordinate with active metal species and thus create an advantage for site-selective metal incorporation in the core-shell structure. Silver (Ag) was selected for the selective metal incorporation and an excellent Ag-dispersion via coordination with the bipyridinic groups in the UiO-67-BPY layer of the core-shell material was obtained. The synthesized material (UiO-66@UiO-67-BPY-Ag) was successfully applied as a heterogeneous catalyst for the CO2 fixation via carboxylation of terminal alkynes. The catalytic material showed excellent yields using at a low Ag-loading under mild reaction condition (50 °C, 1 bar). Moreover, the catalyst can be recycled for at least 5 times maintaining a stable catalytic performance. Interestingly, the high catalytic activity of the synthesized material demonstrated clearly the beneficial advantage of the metalated core-shell structure over the reported routes to synthesize silver catalysts such as encapsulated Ag nanoparticles (AgNP@MOF) or Ag-bidentately coordinated on traditional MOFs applying the same reaction model.

Mercury contamination in soil and water has become a major concern to environmental quality and human health. Among the existing remediation technologies for mercury pollution control, sorption via iron-based materials has received wide attention as they are environmental friendly and economic, and their reactivity is high and controllable through modulating the morphology and surface properties of particulate materials. This paper aimed to provide a comprehensive overview on environmental application of a variety of iron-based sorbents, namely, zero valent iron, iron oxides, and iron sulfides, for mercury remediation. Techniques to improve the stability of these materials while enhancing mercury sequestration, such as nano-scale size control, surface functionalization, and mechanical support, were summarized. Mechanisms and factors affecting the interaction between mercury and iron-based materials were also discussed. Current knowledge gaps and future research needs are identified to facilitate a better understanding of molecular-level reaction mechanisms between iron-based materials and mercury and the long-term stability of the immobilized mercury.

Microalgae are third generation feedstocks for bio-hydrogen production to achieve a low carbon economy. Nevertheless, the bio-hydrogen production from microalgae is generally low. In this study, an...

Nanoplastics (NPs) pollution of aquatic systems is becoming an emerging environmental issue due to their stable structure, high mobility, and easy interactions with ambient contaminants. Effective removal technologies are urgently needed to mitigate their toxic effects. In this study, we systematically investigated the removal effectiveness and mechanisms of a commonly detected nanoplastics, carboxyl-modified polystyrene (PS-COOH) via coagulation and sedimentation processes using aluminum chloride (AlCl3) as a coagulant. PS-COOH appeared as clearly defined and discrete spherical nanoparticles in water with a hydrodynamic diameter of 50 nm. The addition of 10 mg/L AlCl3 compressed and even destroyed the negatively charged PS-COOH surface layer, decreased the energy barrier, and efficiently removed 96.6% of 50 mg/L PS-COOH. The dominant removal mechanisms included electrostatic adsorption and intermolecular interactions. Increasing the pH from 3.5 to 8.5 sharply enhanced the PS-COOH removal, whereas significant loss was observed at pH 10.0. High temperature (23 °C) favored the removal of PS-COOH compared to lower temperature (4 °C). High PS-COOH removal efficiency was observed over the salinity range of 0 − 35‰. The presence of positively charged Al2O3 did not affect the PS-COOH removal, while negatively charged SiO2 reduced the PS-COOH removal from 96.6% to 93.2%. Moreover, the coagulation and sedimentation process efficiently removed 90.2% of 50 mg/L PS-COOH in real surface water even though it was rich in inorganic ions and total organic carbon. The fast and efficient capture of PS-COOH by AlCl3 via a simple coagulation and sedimentation process provides a new insight for the treatment of NPs from aqueous environment.

Metal oxide charge transport layers have been widely employed to prepare inverted polymer solar cells with high efficiency and long lifetime. However, the intrinsic defects in the metal oxide layers, especially those prepared from low-temperature routes, overshadow the high efficiency that can be achieved and also introduce “light-soaking” issues to these devices. In this work, we have employed polyethyleneimine (PEI) and poly[9,9-bis(6′-(N,N-diethylamino)propyl)-fluorene-alt-9,9-bis-(3-ethyl(oxetane-3-ethyloxy)-hexyl)-fluorene] (PFN-OX) to modify our low-temperature-processed TiO2 electron-transport-layer(ETL), and demonstrated that the light-soaking issue can be effectively eliminated by PEI modifications due to the formation of abundant dipole moments, whilst PFN-OX was ineffective due to deficient dipole moments at the interface. Excitingly, PEI modifications enable versatile device architectures to obtain light-soaking-free, inverted PTB7-Th:PC71BM solar cells with efficiencies over 10%, by adding PE...

A novel biochar supported nanoscale iron sulfide (FeS) composite (CMC-FeS@biochar) combining the advantages of biochar, carboxymethyl cellulose (CMC), and FeS was synthesized and tested for Cr(VI) removal efficiency and mechanisms. FeS particles were effectively soldered onto the surface of biochar through OH, C C, O C O, C O, and Si O functional groups. The composite at a mass ratio of FeS:CMC: biochar = 1:1:1 displayed an enhanced Cr(VI) adsorption capacity of 130.5 mg/g at pH 5.5 compared to 38.6 mg/g for FeS and 25.4 mg/g for biochar. Surface sorption and reduction were the dominant removal mechanisms. At the equilibrium Cr(VI) concentration of 13.4 mg/L, 57% of Cr(VI) removal was attributed to reduction and 43% was ascribed to surface sorption. The adsorption kinetic data were adequately simulated with pseudo second-order kinetic model and mass transfer model, suggesting that sorption kinetics were the combination of chemisorption and external mass transfer. The Redlich-Peterson model fitted better than the Langmuir and Freundlich models in simulating the adsorption isotherm data, again suggesting a hybrid chemical reaction-sorption process. The Dubinin–Radushkevich isotherm model resulted in an adsorption energy of 10.0 kJ/mol, implying a chemisorption between Cr(VI) and CMC-FeS@biochar. The present study demonstrated the promise of CMC-FeS@biochar composite as a low-cost, “green”, and effective sorbent for removal of Cr(VI) in the environment.

A novel thiol-functionalized graphene oxide/Fe-Mn composite (SGO/Fe-Mn) was synthesized via three different methods, i.e., acetic acid method (SGO/Fe-Mn-ac), neutral method (SGO/Fe-Mn-ne), and ammonium hydroxide method (SGO/Fe-Mn-am). The composites were characterized and tested for aqueous methylmercury removal. SGO/Fe-Mn was prepared using 3-mercaptopropyltrimethoxysilane (3-MPTS) as a silanizing reagent, and hydrolyzed 3-MPTS mainly interacted with GO/Fe-Mn through surface oxygen-containing groups (i.e., OH, C O, epoxy C O C, carboxyl O C O, and C O) and π-π interactions, partially through self-polymerization. SGO/Fe-Mn-am showed the largest hydrodynamic diameter, strongest π-π bond, fewest S oxidation products, most thiol groups, negative charge, sp 3 defects, and FeOOH. Pseudo-second-order kinetic model and Langmuir and Freundlich isotherm models fitted well with methylmercury sorption kinetic and isotherm data, respectively, resulting in a CH 3 Hg + maximum sorption capacity of 43.88 mg/g for SGO/Fe-Mn-am, 36.33 mg/g for SGO/Fe-Mn-ac, and 28.00 mg/g for SGO/Fe-Mn-ne. The removal mechanism was described by electrostatic attraction, ligand exchange, and surface complexation. This study demonstrates potential and viability of SGO/Fe-Mn for enhanced immobilization of CH 3 Hg + in surface water, groundwater, and soil/sediments.

ELONGATED HYPOCOTYL 5 (HY5), a basic domain/leucine zipper (bZIP) transcription factor, acts as a master regulator of transcription to promote photomorphogenesis. At present, it’s unclear whether HY5 uses additional mechanisms to inhibit hypocotyl elongation. Here, we demonstrate that HY5 enhances the activity of GSK3-like kinase BRASSINOSTEROID-INSENSITIVE 2 (BIN2), a key repressor of brassinosteroid signaling, to repress hypocotyl elongation. We show that HY5 physically interacts with and genetically acts through BIN2 to inhibit hypocotyl elongation. The interaction of HY5 with BIN2 enhances its kinase activity possibly by the promotion of BIN2 Tyr200 autophosphorylation, and subsequently represses the accumulation of the transcription factor BRASSINAZOLE-RESISTANT 1 (BZR1). Leu137 of HY5 is found to be important for the HY5-BIN2 interaction and HY5-mediated regulation of BIN2 activity, without affecting the transcriptional activity of HY5. HY5 levels increase with light intensity, which gradually enhances BIN2 activity. Thus, our work reveals an additional way in which HY5 promotes photomorphogenesis, and provides an insight into the regulation of GSK3 activity., HY5 is a bZIP transcription factor and master regulator of photomorphogenesis in plants. Here, the authors show that in addition to regulating transcription, HY5 promotes the activity of the GSK3-like kinase BIN2 thus negatively regulating hypocotyl elongation by suppressing brassinosteroid signaling.

Phosphorus recovery from water is not only necessary for the protection of aquatic environments but also to meet the needs of sustainable development. We find that the adsorption capacity of nano-MgO is far from being fully utilized because of its simultaneous hydration into brucite. Annealing is a useful method of recovering its adsorption capacity without the need for desorption. Phosphate can be accumulated to a much higher level, even surpassing its theoretical equilibrium adsorption limit, so that high-quality fertilizer can be obtained (115.9 mg-P/g-MgO). Phosphate ions exist as HPO42− and PO43− in the sorbent during its phase transition from periclase to brucite, which is the main reason for its extremely high and reactivatable phosphorus recovery properties. This finding not only provides a new efficient phosphorous recovery strategy but will also lead to new understandings of traditional reactive nano-sorbents.

Microplastic (MP) pollution has become an area of increasing concern because MPs accumulate various types of pollutants. Many previous studies have explored the interactions between MPs and hydrophobic pollutants. However, little research has been conducted on hydrophilic pollutants, which are of much higher concentration and ubiquitous in environment. Surfactants cause hydrophobic MPs to become hydrophilic, which may significantly enhance their capacities to adsorb hydrophilic pollutants. This study explored the influence of co-existing surfactants on the adsorption of ionic organic pollutants by MPs, and found that the presence of an ionic surfactant could significantly enhance the capacity of polyvinyl chloride (PVC, 0.2 mm) MPs to adsorb pollutants with opposite charges. The Langmuir methylene blue adsorption capacity of PVC could be increased from 172 to 4417 ppm in the presence of a sodium dodecyl benzene sulfonate surfactant. Nonionic surfactants impeded the adsorption of both cationic and anionic pollutants due to the steric resistance of the hydrophilic polyethelene glycol chains. The electrostatic interaction mechanism dominated the interfacial behaviors of ionic pollutants on surfactant-adsorbed MP interfaces. The effects of the surfactants were further verified using four different model pollutants and six surfactants. The adsorption capacities of real environmental MPs, including PVC, polyethylene (PE), polypropylene (PP), and polystyrene (PS), increased by three to twenty-six times. The adsorption properties of MPs may be determined by the presence of co-existing surfactants, rather than their polymer species or additives.

Excess natural organic matter (NOM) in water not only lead to unpleasant black color and dissolved oxygen depletion in wastewater and natural water body but also causes carcinogenic chlorinated organic byproduct during drinking water chlorine disinfection. We try to develop a novel cost-effective and green technology for water NOM removal. In our simulated NOM removal process using humic acid (HA) as typical organic matter, we find that mesoporous nano-MgO performs an abnormally high NOM removal capacity (1260 mg-HA/g-MgO, or 446 mgC/g-MgO) when coupled with microfiltration membrane separation, which can’t be illustrated by traditional adsorption mechanism. Actually, Mg2+ from dissolved Mg(OH)2 contributes ∼ 92% NOM removal via coagulation while Mg(OH)2 is responsible for the residue ∼ 8% via adsorption. MgO serves as a two-in-one coagulant and adsorbent. The MgO treatment process is highly pH sensitive and weak acidic condition is favored for high NOM removal efficiency. MgO can be regenerated for more than 10 circulations by annealing Mg(OH)2/Mg-NOM composite at 500 °C, so that our MgO recycling process will be sustainable without the need of continuous chemical purchase. More importantly, no solid waste is generated in this novel process. This MgO-recycling NOM-removal process is simple, efficient, and sustainable for water NOM removal and will be significant in promoting novel sustainable technologies for NOM- or HA-related water remediation and treatment while minimizing the generation of solid waste.

Fully stabilized FeS nanoparticles were prepared with water-soluble carboxymethyl cellulose (CMC) as a stabilizer, and investigated for adsorption of lead (Pb2+) ions from simulated drinking water. The optimum particle stabilization was achieved using 0.0025 wt.% of CMC for 50 mg/L FeS (i.e., CMC-to-FeS molar ratio of 0.0005). The particle stabilization technique increased lead removal from 78.1% to 90.3%. However, further increasing the CMC-to-FeS molar ratio to 0.0025 diminished the removal. Rapid adsorption kinetics of Pb by CMC-FeS was observed with an equilibrium time of 240 min. The kinetic data was adequately fitted by a pseudo-second-order kinetic model. The adsorption isotherm showed a sigmoidal S-shape due to complexation of Pb with soluble CMC molecules, and the Sigmoidal isotherm model well fitted the adsorption isotherm data with a maximum monolayer adsorption capacity of 77.0 mg/g. FTIR and XRD analyses indicated that both surface complexation and chemical precipitation (in the form of PbS) were the dominant adsorption mechanisms. Pb uptake was enhanced with increasing CMC-FeS dosage from 10 to 125 mg/L and increasing pH from 4.5 to 8.5. The material can perform well under typical concentrations of a model humic acid (HA) and salts. Yet, unusually high concentrations of HA or hardness ions may exerted elevated inhibitive effect. The findings indicated that CMC-stabilized FeS nanoparticles are promising for effective immobilization of lead in contaminated water and soil.

Lead (Pb) contamination in soil has been a major concern. Yet, cost-effective remediation technologies have been lacking. This study pilot-tested a new type of carboxymethyl cellulose (CMC) bridged chlorapatite microparticles (CMC-CAP) for immobilization of Pb at an abandoned chemical plant site, and monitored long-term (1 year) stability of Pb under the field conditions. Concentrated CMC-CAP (18 g L−1) was prepared at the pilot scale and then used for amending the soil on the site. CMC-CAP appeared as interwoven flocks of CAP microparticles with a hydrodynamic diameter of 2442 nm, which is 2.2 times smaller than that for bare CAP. CMC-CAP at a dosage of 0.5 wt% resulted in the highest immobilization of Pb, and decreased the acid-leachable Pb in the soil from 1.46 mg L−1 to 0.008 mg L−1 after 1 day of reaction, and further to 0.005–0.006 mg L−1 when aged for 180 and 365 days under the field conditions. The long-term aging consolidated the Pb immobilization, securing the compliance with the Chinese regulatory limit (0.010 mg L−1 for Pb). CMC-CAP served as a long-term sink for leachable Pb in soil and a pH buffer to maintain an alkaline soil pH. Sequential extraction data confirmed that the CMC-CAP amendment converted the more leachable Pb fractions into the less available Pb species. The soil amendment reduced the risk assessment code from “High risk” for the untreated soil to “Low risk” after 120 days of aging. XRD and FTIR results revealed the immobilization of Pb by CMC-CAP was achieved through the formation of the highly stable pyromorphite, surface complexation, and/or ion exchange reactions. Based on the field data, the remediation cost of the CMC-CAP based technology was estimated to be $36.2/m3. This study provides important field data on the effectiveness of CMC-CAP for cost-effective immobilization of Pb in soil.

The current study investigated the role of the automatization of stimulus and response (S-R) associations and response readiness in triggering the motor activation for masked primes in two experiments. The automatization of associations was manipulated by employing different types of stimuli, and response readiness was manipulated by varying the relative frequency of Go trials in a modified Go/No-Go task. Compatibility (compatible and incompatible), stimulus type (arrows and parallel lines), and test session (Sessions 1, 2, and 3) were manipulated in a high response-readiness condition (Experiment 1) and in a low response-readiness condition (Experiment 2). Negative compatibility effects (NCEs) occurred regardless of session and experiment in the arrow stimuli condition. However, in the parallel-line stimuli condition, no significant compatibility effect (CE) appeared regardless of the experiment in Sessions 1 and 2, whereas a significant NCE appeared in Experiment 1 but not in Experiment 2 in Session 3. These results are consistent with the claim that motor activation can only occur if the association between specific stimuli and specific responses has been automatized by previous practice, and response readiness can modulate the development of automaticity, but this modulation will have a minimal effect once the association is automatized. The findings also provide experimental evidence for the assumption that the formation of association-based automaticity could be modulated by top-down control (e.g., response readiness).

This study investigated the effects of 3 model oil dispersants (Corexit EC9500A, Corexit EC9527A and SPC 1000) on photodegradation of pyrene under simulated sunlight. Both Corexit dispersants enhanced photodegradation of pyrene, while SPC1000 slightly inhibited the reaction. Span 80 and Tween 85 were the key ingredients causing the effects, though the underlying mechanisms differed. Span 80 enriches pyrene in the upper layer of water column, whereas Tween 85 induces a photosensitization process. Two reactive oxygen species, 1O2 and O2-, were found responsible for pyrene photodegradation, though the presence of EC9500A suppressed the 1O2 pathway. In terms of photodegradation products, EC9500A enhanced generation of polyaromatic intermediates, i.e., phenaleno[1,9-cd][1,2]dioxine, 1-hydroxypyrene, and 1,8-pyrenequinone, but did not alter the classical photodegradation pathway. The Corexit dispersants were more prone to photochemical decomposition, with multiple by-products detected. The information aids in our understanding of the effects of dispersants on photochemical weathering of oil compositions.

This work developed a new method to determine concentration of Corexit EC9500A, and likely other oil dispersants, in seawater. Based on the principle that oil dispersants decrease surface tension, a linear correlation was established between the dispersant concentration and surface tension. Thus, the dispersant concentration can be determined by measuring surface tension. The method can accurately analyze Corexit EC9500A in the concentration range of 0.5-23.5mg/L. Minor changes in solution salinity (

Electroplating sludge (ES) containing large quantities of heavy metals is regarded as a hazardous waste in China. This paper introduced a simple method of treating ES using environmentally friendly fixatives biochar (BC) and iron sulfide (FeS), respectively. After 3 days of treatment with FeS at a FeS-to-ES mass ratio of 1:5, the toxicity characteristic leaching procedure (TCLP)-based leachability of total Cr (TCr), Cu(II), Ni(II), Pb(II), and Zn(II) was decreased by 59.6, 100, 63.8, 73.5, and 90.5 %, respectively. After 5 days of treatment with BC at a BC-to-ES mass ratio of 1:2, the TCLP-based leachability was declined by 35.1, 30.6, 22.3, 23.1, and 22.4 %, respectively. Pseudo first-order kinetic model adequately simulated the sorption kinetic data. Structure and morphology analysis showed that adsorption, electrostatic attraction, surface complexation, and chemical precipitation were dominant mechanisms for heavy metals immobilization by BC, and that chemical precipitation (formation of metal sulfide and hydroxide precipitates), iron exchange (formation of CuFeS2), and surface complexation were mainly responsible for heavy metals removal by FeS. Economic costs of BC and FeS were 500 and 768 CNY/t, lower than that of Na2S (940 CNY/t). The results suggest that BC and FeS are effective, economic, and environmentally friendly fixatives for immobilization of heavy metals in ES before landfill disposal.

In this investigation, we propose a strip segmentation phase (SSP) method for a spatial light modulator (SLM) to generate independent multifocal spots when the beam passes through a high numerical aperture (NA) lens. With the SSP method, multifocal spots can be generated with each spot independently, flexibly and uniformly distributed. The performance of the SSP method is first validated with numerical simulation. Then, by applying the modulation method with SLM and importing the beams into an inverted fluorescence microscopy system with a high-NA lens, the spot distribution and their shapes can be observed by fluorescent image. The fluorescent image exhibits high uniformity and high consistency with the aforementioned numerical simulations. Finally, we dynamically load a series of phase maps on SLM to realize continuous and independent spot movement in a multifocal array. By laser direct writing on photoresist, a complex NWU-shape structure can be realized flexibly with multi-task fabrication capability. The SSP method can significantly improve the efficiency and flexibility of laser direct writing. It is also compatible with most recent techniques, e.g., multiphoton absorption, stimulated emission depletion and photo-induced depolymerization etc., to realize parallel super-resolution imaging and fabrications.

As the traditional anode material of lithium-ion batteries, tin dioxide (SnO2) has the characteristics of a high theoretical capacity and stable crystal structure. However, the alloying/de-alloying reaction between tin and lithium ions causes volume expansion and continuously generates an SEI film, which causes the electrode to fall off the current collector and the capacity fade rapidly. Generally, a composite of carbon materials and SnO2 can alleviate the expansion and pulverization phenomena. However, the microstructure of carbon materials is complex and changeable, which makes it difficult to definitively state the influence mechanism of the microstructure on the lithium storage performance of composite materials. Here, three kinds of lignin-based porous carbons (LPCs) with different microstructural characteristics, along with a high graphitization, high specific surface area and hierarchical porosity, are obtained by regulating the process of gas exfoliation and in situ activation. Furthermore, a series of LPC/SnO2 composites are obtained by an ultrasonic dispersion and ball milling method. Electrochemical property results show that the hierarchical porous LPCs are more conducive to the dispersion/coating of SnO2 nanoparticles and that the reversible specific capacity of the electrode material increases from 64 to 620 mA h g−1, effectively mitigating the expansion and pulverization of SnO2 during the lithium storage process.

Rapid industrialization, urbanization, and population growth have led to the common occurrence of black-stinking urban rivers. Assessing regional anthropogenic influences is beneficial to develop effective remediation strategies. This study comprehensively investigated the occurrence and fate of linear alkylbenzenes (LABs) as molecular markers of anthropogenic influences in three media (filtered water, suspended particulate matter (SPM), and sediment) in a highly urbanized river (Baihaimian River) in Guangzhou, South China. The concentrations of LABs ranged from 41 to 215 ng/L in the dissolved phase, from 7122 to 46,640 ng/g dry weight in the SPM phase, and from 73 to 3650 ng/g dry weight in surface sediments (0–10 cm depth). The spatial distribution of LABs was probably affected by the surrounding environment, river flux, and sediment properties. No biotransformation of LABs in water samples and a slight biotransformation in sediments were observed. Significant correlations were found between total nitrogen, ammonia nitrogen, and LABs in river water, indicating the same domestic wastewater sources. The positive correlation between total organic carbon (TOC) and LABs in sediments suggested that TOC worked as the controlling factor for the redistribution of LABs and that local sewage discharge was the dominant TOC input. The total mass inventory of LABs in sediment in Baihaimian River was 21 kg. The total mass of LABs released into Baihaimian River was 183 kg per year, among them, 63% was discharged into the adjacent Liuxi River.

Zinc (Zn2+) and cadmium (Cd2+) in water pose serious threats to human health and the environment. In search for a more effective treatment technology, we prepared a type of carboxymethyl cellulose (CMC) bridged chlorapatite (CMC-CAP) nanoparticles and tested the material for removal of Zn2+ and Cd2+ from water. CMC macromolecules were attached to CAP by bidentate bridging and hydrogen bonding, preserving the high adsorption capacity of CAP nanoparticles while allowing for easy gravity-separation of the nanoparticles. CMC-CAP showed rapid adsorption kinetics and 22.8% and 11.2% higher equilibrium uptake for Zn2+ and Cd2+, respectively, than pristine CAP. An extended dual-mode isotherm model, which takes into account both sorption and chemical precipitation, provided the best fits to the sorption isotherms, giving a maximum Langmuir sorption capacity of 141.1 mg g−1 for Zn2+ and 150.2 mg g−1 for Cd2+ by CMC-CAP. Na+ at up to 5 mM showed modest effects on the uptake of the heavy metals, while 2–5 mM of Ca2+ exerted notable inhibitive effects. Dissolved organic matter (up to 5 mg L−1 as TOC) inhibited the Zn2+ uptake by 16.5% but enhanced the Cd2+ removal by 8.6%. Material characterizations and surface binding analyses revealed that ion exchange, surface precipitation, and surface complexation were the removal mechanisms for the heavy metals. This study demonstrates stabilizer bridging may serve as a convenient strategy to facilitate water treatment uses of nanoparticles.

Microplastics (MPs) have aroused rising social concerns. Although amounts of surfactants exist in wastewater and are expected to alter the surface properties of MPs significantly as they are designed to be adsorbed by hydrophobic particles. However, rare works have been done on the influence of surfactants on the coagulation removal process of MPs which was thought to be an effective way to remove MPs together with other natural particles, such as clay. We used 3-D fluorescence imaging to track the coagulation removal process of polystyrene MPs. Our results indicate that nonionic surfactant, tween 20 in ppm scale, could inhibit the coagulation removal of polystyrene MPs significantly. Residue MPs in the effluent is proportional with the surfactant concentration and increases up to tens of times, which will lead to a dramatic increase in their potential environmental risks. Apparent size effect exists in the coagulation in which smaller MPs can escape from the coagulation removal more easily. Mechanism study suggests that the steric resistance of the hydrophilic flexible polyethylene glycol (PEG) layer formed by tween 20 adsorbed on MP surface inhibits clay deposition and thus hinders subsequent agglomeration and precipitation. A surfactant stealth effect, which is used in the design of nanomedicine to avoid the human immune recognition and clearance of nano-drugs from blood circulation, also exists in the coagulation removal process of MPs. Our finding not only proves the strong influence of surfactants on MPs but also will stimulate related studies on other latent surfactant effects of MPs.

Mercury contamination poses a serious threat to the ecological system and human health. Yet, removal of mercury at parts per billion (ppb) level in surface water is difficult to achieve. This study developed a Mg2Al layered double hydroxide supported iron sulfide composite (FeS@Mg2Al-LDH) and investigated its removal effectiveness and mechanisms of mercury from surface water. FeS was successfully soldered onto Mg2Al-LDH via surface complexation and surface adsorption. The composite (FeS:Mg2Al-LDH mass ratio of 1:1) at 20 mg/L effectively removal 89.4% of 110 µg/L mercury at pH 7.0 within 72 h. A pseudo-second-order kinetic model well simulated the sorption kinetic data and a Sigmoidal Langmuir isotherm model perfectly fitted the sorption isotherm data with a maximum monolayer sorption capacity of 116.96 mg/g. X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses suggested that mercury was removed via chemical precipitation, ion exchange, and surface complexation. The supporting material Mg2Al-LDH greatly enhanced the antioxygenic and pH-resistant properties of FeS, and the composite offered high selectivity for mercury. FeS@Mg2Al-LDH and immobilized mercury remained stable over 6 months. This study demonstrated the potential and viability of FeS@Mg2Al-LDH for efficient removal of aqueous mercury.

Hydrous zirconium oxide (HZO) encapsulated alginate gel beads were synthesized for phosphate recovery from water. Importantly, we find that HZO/alginate gel beads (ZrA) crosslinked with Ca2+, Mg2+, Fe3+, Al3+, and Zr4+ are unstable under an intense alkali regeneration condition. Only Sr2+-crosslinked ZrA can endure a high alkali solution. ZrA possesses a high specific surface area (80.84 m2·g−1) and a mesoporous structure (15.3 nm and 0.196 cm3·g−1), which endow them with a high Langmuir adsorption capacity of 52.5 mg-P/g. ZrA can be easily recycled, and the mass loss of HZO is prevented. Furthermore, the strontium alginate gel framework protects the encapsulated HZO nanoparticles from adverse humic acid contamination. ZrA can be regenerated for at least 5 adsorption/desorption cycles. Cost analysis indicates the potential scale application feasibility for ZrA. This study provides a novel, simple, and environmentally benign solution to immobilize HZO for efficient phosphate recovery.

Mercury (Hg) contamination in soil is a paramount concern to the environment and public health. Yet, effective in situ remediation technologies have been lacking. In this study, a novel thiol-functionalized graphene oxide/Fe-Mn (SGO/Fe-Mn) composite was prepared and investigated for in situ immobilization of Hg in contaminated soil. Batch tests showed that application of SGO/Fe-Mn at doses of 0.4% and 0.8% effectively reduced H2O, H2SO4 and HNO3, CH3COOH, and CaCl2-extractable Hg by 90.3-98.9% and 96.5-98.9%, respectively, upon equilibrium after 72 d. An increasing of soil moisture content from 0 to 12.5% significantly enhanced the immobilization efficiency from 75.0% to 97.6%. XRD, FTIR, and XPS analyses suggested that the composite mainly immobilized Hg through surface complexation and chemical precipitation. Sequential extraction procedure demonstrated that the composite promoted the conversion of more accessible Hg (exchangeable and carbonate fractions) into the less accessible forms, i.e., oxides, organic matter, and residual fractions, resulting in substantially reduced environmental risk of Hg. The application of SGO/Fe-Mn enhanced soil cation exchange capacity, available N and K, and total organic carbon, and can be used to effectively improve soil properties. Moreover, immobilized Hg in soil by this composite remained stable over one year. The present study demonstrates the potential and viability of SGO/Fe-Mn for enhanced immobilization of Hg in soil and sediment.

Mercury contamination in groundwater has been considered as an environmental and public health issue all over the world. Yet, effective in situ remediation techniques have been lacking. A thiol-modified graphene oxide/Fe–Mn composite (SGO/Fe–Mn) was employed as a reactive sorbent of permeable reactive barrier (PRB) for in situ remediation of mercury contaminated groundwater using fixed-bed columns. Mercury existed as HgCl2, Hg(OH)2, and HgClOH, and was mainly removed through surface complexation. The Brunauer-Emmett-Teller sorption isotherm model provided adequate fitting of the sorption isotherm data with a maximum monolayer sorption capacity of 112.03 ± 16.59 mg g−1. Breakthrough time, the time when 5% of initial Hg concentration is measured in the effluent, increased with the decrease of influent mercury concentration, pore velocity, dissolved oxygen (DO), and dissolved organic matter (DOM). The resultant column sorption capacity was enhanced at higher influent mercury concentration, lower groundwater pore velocity, lower DOM and DO. Moreover, when the SGO/Fe–Mn was thoroughly mixed with quartz sand in the column, the breakthrough time was increased and the resultant sorption capacity was improved compared to the case that SGO/Fe–Mn was packed between two layers of quartz sand. Mathematically, the Adams-Bohart model satisfactorily reproduced the initial behavior of mercury breakthrough curves (