Benefits and limits of biological nitrification inhibitors for plant nitrogen uptake and the environment.

Plant growth and high yields are secured by intensive use of nitrogen (N) fertilizer, which, however, pollutes the environment, especially when N is in the form of nitrate. Ammonium is oxidized to nitrate by nitrifiers, but roots can release biological nitrification inhibitors (BNIs). Under what conditions does root-exudation of BNIs facilitate nitrogen N uptake and reduce pollution by N loss to the environment? We modeled the spatial-temporal dynamics of nitrifiers, ammonium, nitrate, and BNIs around a root and simulated root N uptake and net rhizosphere N loss over the plant's life cycle. We determined the sensitivity of N uptake and loss to variations in the parameter values, testing a broad range of soil-plant-microbial conditions, including concentrations, diffusion, sorption, nitrification, population growth, and uptake kinetics. An increase in BNI exudation reduces net N loss and, under most conditions, increases plant N uptake. BNIs decrease uptake in the case of (1) low ammonium concentrations, (2) high ammonium adsorption to the soil, (3) rapid nitrate- or slow ammonium uptake by the plant, and (4) a slowly growing or (5) fast-declining nitrifier population. Bactericidal inhibitors facilitate uptake more than bacteriostatic ones. Some nitrification, however, is necessary to maximize uptake by both ammonium and nitrate transporter systems. An increase in BNI exudation should be co-selected with improved ammonium uptake. BNIs can reduce N uptake, which may explain why not all species exude BNIs but have a generally positive effect on the environment by increasing rhizosphere N retention.

The effects of plastisphere on the physicochemical properties of microplastics.

The plastisphere is the microbial communities that grow on the surface of plastic debris, often used interchangeably with plastic biofilm or biofouled plastics. It can affect the properties of the plastic debris in multiple ways. This review aims to present the effects of the plastisphere on the physicochemical properties of microplastics systematically. It highlights that the plastisphere modifies the buoyancy and movement of microplastics by increasing their density, causing them to sink and settle out. Smaller and film microplastics are likely to settle sooner because of larger surface areas and higher rates of biofouling. Biofouled microplastics may show an oscillating movement in waterbodies when settling due to diurnal and seasonal changes in the growth of the plastisphere until they come close to the bottom of the waterbodies and are entrapped by sediments. The plastisphere enhances the adsorption of microplastics for metals and organic pollutants and shifts the adsorption mechanism from intraparticle diffusion to film diffusion. The plastisphere also increases surface roughness, reduces the pore size, and alters the overall charge of microplastics. Charge alteration is primarily attributed to changes in the functional groups on microplastic surfaces. The plastisphere introduces carbonyl, amine, amide, hydroxyl, and phosphoryl groups to microplastics, causing an increase in their surface hydrophilicity, which could alter their adsorption behaviors for heavy metals. The plastisphere may act as a reactive barrier that enhances the leaching of polar additives. It may anchor bacteria that can break down plastic additives, resulting in decreased crystallinity of microplastics. This review contributes to a better understanding of how the plastisphere alters the fate, transport, and environmental impacts of microplastics. It points to the possibility of engineering the plastisphere to improve microplastic biodegradation.

The formation of gold in woody biomass combustion ashes.

This paper investigates the enrichment of gold through combustion and ash-leaching techniques utilizing woody biomass as a fuel source. It delves into the formation of gold in ashes derived from the fixed grate combustion of pelletized woody biomass containing noble metals, conducted at a pilot-scale boiler. The biomass sample was gathered from a brownfield land at an abandoned mining area, avoiding induced phytoextraction. The fuel contained <0.05 mg/kg gold, while the bottom ash, after heat exchanger ash, deposited ash, and fly ash contained 1.52 mg/kg, 1.99 mg/kg, 2.64 mg/kg, and 3.52 mg/kg of gold, respectively. Although the amount of fly ash is lower compared to bottom ash, the concentration of gold is the highest in fly ash, which follows the after heat exchanger ash and bottom ash. The concentration of gold was enriched by a three-stage procedure of water leaching, acid leaching (10 % HCl), and alkaline leaching (5 % NaOH), after which 12.1 mg/kg and 12.6 mg/kg gold was found in the residues obtained from leached bottom ash and deposited ash, respectively. SEM was utilized to depict the morphology of gold, which appears in bottom ash as individual neat particles with a purity higher than 98 %. Pure gold particles in the size of 1-2 µm are presented in the after heat exchanger ash; meanwhile, gold in fly ash is primarily associated with potassium, sodium, sulfur, and oxygen. The findings in this study pave the way for reclaiming gold from bio-ores as well as assist in better understanding the formation of this precious metal in these secondary resources.

Leaching behavior and kinetics of beryllium in beryllium-containing sludge (BCS).

Beryllium-containing sludge (BCS) is a byproduct of the physicochemical treatment of beryllium smelting wastewater. The pollutant element beryllium within BCS is highly unstable and extremely toxic, characterized by its small ionic radius and low charge density, resulting in a high risk of leaching and migration. This study is the first to investigate the leaching behavior, influencing mechanisms, and kinetic processes of beryllium in BCS under various environmental conditions. The results indicate that, under national standard conditions, beryllium exhibits a rapid leaching phase within the first 5 h, which then stabilizes after 10 h, with the total leached content significantly exceeding the leaching toxicity identification standards. Under mildly acidic (pH ≤ 5) or highly alkaline (pH = 14) conditions, beryllium demonstrates pronounced leaching and migration behaviors. Notably, in acidic conditions, the leaching rate exceeds 80% within 5 h. Combining the treatment process of beryllium-containing wastewater with analytical methods such as SEM, XPS, ToF-SIMS, and FTIR, it is revealed that due to the heterogeneous nature of BCS, the particle aggregates dissociate over time under acidic conditions. The particle surfaces become increasingly rough, leading to dissolution and the emergence of more reactive sites, resulting in a high proportion of beryllium leaching. Under these conditions, the gradual reaction of Be(OH)2 in BCS to form soluble Be2+ and its hydrolytic complexes is identified as the primary mechanism for extensive beryllium migration. The process encounters minimal diffusion resistance and is classified as reaction-controlled. In acidic conditions with pH = 4, the leaching rate of beryllium significantly increases with rising temperature. The leaching kinetics equation is [(1-x)-0.44]=e(18.26-53050RT)·t, with an apparent activation energy of 53.05 kJ mol-1.

Enhanced consolidation and removal of accumulated flocculants in dredged soil via leaching with vacuum preloading.

The vacuum preloading coupling flocculation treatment is a widely employed method for reinforcing soils with high water content in practical construction. However, uneven distribution and accumulation of flocculants pose significant damage to the soil environment and result in uneven soil consolidation, leading to severe issues in subsequent soil development and exploitation. To address these concerns, an evolved leaching with vacuum method is developed for facilitating soil consolidation while preventing the accumulation of flocculant in the soil. In this study, five model tests are conducted in which FeCl3 is chosen as the typical flocculant to promote soil consolidation, and deionized water is used for leaching. The final discharged water, settlement, water content and penetration resistance of soil are obtained to evaluate the soil reinforcement effect, while the flocculant removal effect is evaluated by the Fe3+ content in the filtrate and soil. The comprehensive reinforcement and flocculant removal effect show that this method is extremely effective compared to traditional vacuum preloading. The two leaching is clarified as the best choice, resulting in a 22% decrease in the soil water content and a 25% in soil penetration resistance, meanwhile a 12.8% removal rate of the flocculant. The test results demonstrate that leaching with vacuum preloading can contribute to promoting soil consolidation and reducing the accumulation of flocculant in the soil, ensuring the safe and eco-friendly use of the soil for future applications. The conclusions obtained are of significant theoretical value and technical support for practical construction and sustainable development.

Ultrasound-assisted efficient and convenient method of extracting valuable metals (Ni, Co, and Cd) from waste Ni-Cd batteries using DL-malic acid.

Recycling waste Ni-Cd batteries has received much attention recently because of the serious environmental pollution they cause and to avoid the dissipation of valuable metals. Despite significant research, it is still difficult to efficiently recycle valuable and hazardous metals from waste Ni-Cd batteries in an economical and environmentally friendly manner. This study employed a novel process utilizing ultrasound-assisted leaching to recover Ni, Cd, and Co from waste nickel-cadmium (Ni-Cd) batteries. Organic DL-malic acid served as the leaching agent and H2O2 was employed as an oxidizing agent. The effects of various factors on the recovery efficiency of Ni, Cd, and Co, such as leaching temperature, time, DL-malic acid concentration, pulp density, H2O2 concentration, and ultrasound frequency, were also examined. To predict the chemical compounds present before and after the recycling experiments, the solid residues from the metal extraction were analyzed using XRD, XPS, FE-SEM, and EDS element mapping. Concurrently, ICP-OES was utilized to determine the metal content in the leachate. Under optimized conditions of 90 °C, 90 min, 2M DL-malic acid, 160 mL/g pulp density, and 20% ultrasound frequency, over 83% of Ni, 94% of Cd, and 98% of Co were effectively leached from the waste Ni-Cd battery powder. The leaching kinetics of Ni, Cd, and Co followed the surface chemical reaction control model. The activation energies (Ea) for Ni, Cd, and Co leaching were 21.34, 20.47, and 18.38 kJ/mol, respectively. The findings suggest that ultrasound-assisted leaching is an efficient, cost-effective, environmentally friendly, and sustainable alternative for extracting precious and hazardous metals from waste Ni-Cd batteries. Additionally, it reduces industrial chemical usage and enhances waste management sustainability.

An unconventional approach for the efficient recovery of iron, cobalt, copper and silicon from copper slag.

High-grade heavy metal elements in copper slag (CS) are worth recovering. Unfortunately, the high viscosity of leaching solution, low leaching efficiency, difficult filtration and low separation efficiency of valuable components exist in the traditional sulfuric acid leaching process. In this study, the above problems are solved by sulfuric acid pretreatment + curing + water leaching. Moreover, iron, cobalt and copper ions in solution are separated by stepwise precipitation. The final iron, cobalt, copper and silicon recoveries are 99.01 %, 98.45 %, 93.13 % and 99.52 %, respectively. Thermodynamic calculations show that H4SiO4 can be converted to insoluble SiO2 to improve filtration properties under curing conditions of sulfur dioxide partial pressures of 10-20∼0 atm, oxygen partial pressures of 10-20∼0 atm and 400-600k. Simulation studies of the phase equilibria of the components of the leach solution by Visual MINTEQ showed that the oxidation of Fe2+ to Fe3+ is necessary for the removal of Fe2+ from the solution by precipitation. This study provides a new idea for the efficient utilization of CS.

Negative effects of cigarette butt leachate on freshwater phytoplankton communities.

We experimentally tested the effects of different concentrations of cigarette butt leachate on freshwater phytoplankton chlorophyll-a, species richness, cell density, and community composition. For this, we sampled the phytoplankton from a eutrophic lake and acclimated it for 24 h in microcosms. We then conducted the experiment in microcosms maintained for 96 h. The experiment consisted of four treatments: control and leachate from 1 butt L-1 (T1), 5 butts L-1 (T5), and 10 butts L-1 (T10), which were prepared by diluting a stock solution of leachate from 50 butts L-1. We found that algal chlorophyll-a content was not affected by different leachate concentrations. In contrast, phytoplankton cell density decreased in a dose-dependent manner as concentrations of the leachate increased. Similarly, the number of species was highest in the control group relative to all other treatments, with T1 and T5 showing higher species richness than T10. Additionally, the exposition to different concentrations of the leachate impacted community composition across all treatments in comparison to the control group. Our results suggest that cigarette butt leachate alters the number of cells and species, as well as the distribution of abundance, without necessarily reducing chlorophyll-a concentrations. Our findings indicate that to gain a comprehensive understanding of the effects of cigarette butt leachate on freshwater ecosystems, it is essential to evaluate more realistic scenarios that incorporate aquatic communities, rather than isolated species.

Dataset from an investigation of the effect of natural zeolite particle size reduction as a material for the manufacture of slow-release potassium fertilizer in oil palm seedlings growth with peat soil planting media.

Particle size is one-factor influencing zeolite's ion exchange properties. This study used natural zeolite with a particle size of ±0.147 mm and ±500 nm as a carrier for K-zeolite-based fertilizer. K in the zeolite-based fertilizer was expected to be released slowly and more effectively in supplying K for oil palm seedlings on peat soil media compared to conventional K fertilizer (Muriate of Potash, or MoP). The study was arranged using a completely randomized design (CRD) with eight treatments and three replications. The treatments tested were: (1) control/no fertilization; (2) MoP fertilizer; (3) fine-polite-fertilizer formula-1 (FPF-1); (4) fine-polite-fertilizer formula-2 (FPF-2); (5) fine-polite-fertilizer formula-3 (NPF-3); (6) micro-polite-fertilizer formula-1 (MPF-1); (7) micro-polite-fertilizer formula-2 (MPF-2); and (8) micro-polite-fertilizer formula-3 (MPF-3). K zeolite-based fertilizers generally had better effectiveness than MoP, where formula 2 (50 % zeolite: 50 % MoP fertilizer) was the best among the three K zeolite-based fertilizer formulas. There were no significantly different effects of zeolite with a particle size of ±500 nm and ±0.147 mm on the growth and K uptake of oil palm seedlings and the amount of leached K from the peat soil. This data set could be helpful for researchers who want to develop an environmentally friendly fertilizer to implement sustainable agriculture.

Manipulating geological phosphorus resources for improved production and environmental outcomes during plant establishment.

Phosphorus (P) fertilisers are under scrutiny due to resource constraints and environmental impacts. Simple rock phosphate (RP) modifications with acids and co-applied with microbial inoculum could offer sustainable alternative P fertiliser products. We evaluated the effects of acid-treated rock phosphate (RP) in combination with fungal inoculum on plant establishment, environmental impacts (nutrient leaching) and soil quality in a 5-month pot trial. The treatments were evaluated in a clayey Vertisol and a silty Acrisol using cotton (Gossypium hirsutum) as a model plant. The RP treatments - apart from the unmodified and HCl products - were effective in promoting plant establishment with two of the microbial formulations superior to conventional P fertilisers by an average factor of 2 in both soil types (p < 0.05). All RP products restricted P leaching compared with conventional P fertilisers (p < 0.05), by an average factor of 5 for diammonium phosphate (DAP) in both soil types and 3 for the triple superphosphate TSP (only in Acrisol). Nitrate leaching from all treatments was high although much lower from the RP treatments compared with the conventional fertilisers towards the end of the establishment trial, by an average factor of 1.5 (p < 0.05). Ranking analysis revealed that some RP treatments showed evidence for improved ongoing soil quality, including decreased P leaching and soil acidification risks. Microbial analysis showed complex interactions between treatment and soil type. Nonetheless, inoculum persistence at the end of the plant establishment phase was observed for all pots analysed. Our results demonstrate that relatively simple modifications to RP could pave the way for developing sustainable P fertilisers.

Synergistic solidification and mechanism research of electrolytic manganese residue and coal fly ash based on C-A-S-H gel material.

Electrolytic manganese residue (EMR) is known for high concentrations of Mn2+, NH4+, and heavy metals. Failure to undergo benign treatment and landfill disposal would undeniably lead to negative impacts on the quality of the surrounding ecological environment. This study sought to mitigate the latent environmental risks associated with EMR using a cooperative solidification/stabilization (S/S) method involving coal fly ash (CFA). Leveraging leaching toxicity tests, the leaching behavior of pollutants in electrolytic manganese residue-based geopolymer materials (EMRGM) was determined. At the same time, mechanistic insights into S/S processes were explored utilizing characterization techniques such as XRF, XRD, FT-IR, SEM-EDS, and XPS. Those results confirmed significant reductions in the leaching toxicities of Mn2+ and NH4+ to 4.64 µg/L and 0.99 mg/L, respectively, with all other heavy metal ions falling within the permissible limits set by relevant standards. Further analysis shows that most of NH4+ volatilizes into the air as NH3, and a small part is fixed in the EMRGM in the form of struvite; in addition to being oxidized to MnOOH and MnO2, Mn2+ will also be adsorbed and wrapped by silicon-aluminum gel together with other heavy metal elements in the form of ions or precipitation. This research undeniably provides a solid theoretical foundation for the benign treatment and resourceful utilization of EMR and CFA, two prominent industrial solid wastes.

Adsorption-desorption and leaching behavior of benzovindiflupyr in different soil types.

Benzovindiflupyr is a succinate dehydrogenase inhibitor fungicide that targets mitochondrial function for disease control. In this study, we investigated the adsorption-desorption and leaching behavior of benzovindiflupyr in eight soil types using the batch equilibrium method and the soil column leaching method. A Freundlich model (r2 > 0.9959) was used to better characterize the adsorption-desorption process in eight soil types, with adsorption coefficients (KF-ads) ranging from 2.303 to 17.886. KF-ads was significantly and positively correlated (p < 0.05) with the organic carbon content. High temperatures and increased initial pH of aqueous solutions led to a decrease in benzovindiflupyr adsorption in the soil. The adsorption was also influenced by factors such as ionic strength, humic acid, surfactant type, microplastic type, and particle size and concentration. Moreover, benzovindiflupyr exhibited low leachability in all four soils selected, but different leaching solutions affected the risk of benzovindiflupyr migration to groundwater. Overall, this study provides insights into the adsorption characteristics of benzovindiflupyr in different soils and provides key information for environmental risk assessment.

Improved recovery of lithium from spent lithium-ion batteries by reduction roasting and NaHCO3 leaching.

Lithium supply risk is increasing and driving rapid progress in lithium recovery schemes from spent lithium-ion batteries (LIBs). In this study, a facile recycling process consisting mainly of reduction roasting and NaHCO3 leaching was adopted to improve lithium recovery. The Li of spent LiNixCoyMn1-x-yO2 powder were converted to Li2CO3 and LiAlO2 with the reduction effect of C and residual Al in the roasting process. NaHCO3 leaching was utilized to selectively dissolve lithium from Li2CO3 and water-insoluble LiAlO2. The activation energy of NaHCO3 leaching was 9.31 kJ∙mol-1 and the leaching of lithium was a diffusion control reaction. More than 95.19 % lithium was leached and recovered as a Li2CO3 product with a purity of 99.80 %. Thus, this approach provides a green path to selective recovery of lithium with good economics.

Evaluation and modelling of polycyclic aromatic hydrocarbon (PAH) bioavailability in soils affected by coal tar asphalt.

There are large masses of coal tar asphalt present in old roads, containing high concentrations of polycyclic aromatic hydrocarbons (PAHs). Uncertainty surrounding the risk they pose causes problems during road reconstruction and for the reuse of the asphalt present. To help elucidate potential risks, a parsimonious linear equilibrium partitioning model for the bioavailability of PAHs in soils contaminated by tar asphalt particles was developed. Furthermore, a set of partitioning coefficients for PAHs between sampled coal tar binders and water were determined experimentally, as well as measurements of freely dissolved concentrations using polyoxymethylene samplers in batch tests and column recirculation experiments with various mixtures of different soils (peat and sandy loam) and tar asphalts. The model predictions of freely dissolved concentrations were conservative and within an order of magnitude of measurements in both batch and column tests. The model presented here only relies on soil organic carbon content and the fraction coal tar binder in the soil to model PAH partitioning. This model could be used for more realistic. Low tier risk assessments towards rational prioritization of sensitive areas for risk reduction efforts.

Experimental Study on the Preparation of High-Purity Iron Oxide Red by Acid Leaching Iron from Coal Gangue.

Aiming at the problems of the large storage, complex composition, low comprehensive utilization rate, and high environmental impact of coal gangue, this paper carried out experimental research on the preparation of iron oxide red from high-iron gangue by calcination activation, acid leaching, extraction, and the hydrothermal synthesis of coal gangue. The experimental results show that when the calcination temperature of coal gangue is 500 °C, the calcination time is 1.5 h, the optimal concentration of iron removal is 6 mol/L, the acid leaching temperature is 80 °C, the acid leaching time is 1 h, and the liquid--solid mass ratio is 4:1; the iron dissolution rate can reach 87.64%. A solvent extraction method (TBP-SK-hydrochloric acid system) was used to extract the leachate, and a solution with iron content up to 99.21% was obtained. By controlling the optimum hydrothermal conditions (pH = 9, temperature 170 °C, reaction time 5 h), high-purity iron oxide red product can be prepared; the yield is 80.07%. The red iron oxide was characterized by XRD, SEM-EDS, particle-size analysis, and ICP-OES. The results show that the red iron oxide peak has a cubic microstructure, an average particle size of 167.16 µm, and a purity of 99.16%. The quality of the prepared iron oxide red product meets the requirement of 98.5% of the "YHT4 Iron oxide Standard for ferrite". It can be used as a raw material to produce high-performance soft magnetic ferrite. In summary, this experimental study on the preparation of iron oxide red from coal gangue is of great significance for the comprehensive utilization of coal gangue to realize the sustainable development of the environment and economy.

Investigation of mechanical, microscopic, and leaching properties of coal-based solid waste geopolymer mortar activated by soda residue and phosphogypsum.

In this study, coal-based solid waste geopolymer mortar (SWCB) was prepared by using granulated ground blast-furnace slag (GGBS) and coal gasification coarse slag (CGCS) as precursors, and soda residue (SR) and phosphogypsum (PG) as activators, with gangue sand (GS) utilized as an inert filler. The corresponding compressive strength, fluidity, ion leaching, and microstructure of the developed SWCB were systematically investigated under varying solid contents, binder-to-sand ratios, and activator ratios. The findings suggest that the incorporation of activators promoted the dissolution of the silicon-aluminum phase in GGBS and CGCS into Al(OH)4-, [SiO(OH)3]-, and [SiO2(OH)2]2-, which could subsequently react with the Ca2+ and SO42- released by PG, forming AFt and C-(A)-S-H, thereby playing a crucial role in enhancing matrix strength. AFt was the predominant hydration product in the early reaction stage. The morphology of the AFt phase evolved from needle-like or filamentous to fine and coarse rods as hydration progressed. Initially, the formation of C-(A)-S-H gel increased with rising activator content before decreasing. The optimal synergy between AFt and C-(A)-S-H was observed at an activator content of 30 %. However, the growth of gypsum crystals was hindered when the activator content surpassed 30 %, resulting in a plate-like or columnar morphology. C-(A)-S-H gel exhibited remarkable adsorption capability towards P atoms attributed to intermolecular Van der Waal's forces, enabling simultaneous physical encapsulation of P atoms, while Cl element immobilization was primarily attributed to the contribution of SiOH sites to Cl adsorption.

Speciation distribution and leaching behavior of heavy metals in coal gasification fine ash: Influence of particle size, carbon content and mineral composition.

In this study, the occurrence and distribution of heavy metals in coal gasification fine ash (CGFA) with different particle sizes were investigated to ensure safer disposal and utilization strategies for CGFA. These measures are critical to sustainable industrial practices. This study investigates the distribution and leachability of heavy metals in CGFA, analyzing how these factors vary with particle size, carbon content, and mineral composition. The results demonstrated that larger CGFA particles (>1 mm) encapsulated up to 70 % more heavy metals than smaller particles (<0.1 mm). Cr and Zn were present in higher concentrations in larger CGFA particles, whereas volatile elements such as Zn, Hg, Se, and Pb were found in relatively higher contents in finer CGFA particles. At least 70 % of Hg in CGFA was present in an acid-soluble form of speciation, whereas Cd, Zn, and Pb were mostly present in a reducible form of speciation, which could be attributed to the presence of franklinite. More than 40 % of Cd and Zn in fine CGFA particles exist in an acid-soluble form. With the exception of CGFA_1.18, Se in CGFA mainly existed in an oxidizable form at a ratio of 60 %-80 %. This could be attributed to the presence of bassanite particles as well as the higher affinity of Se for S. In contrast, Cr, Cu, and As were mostly present in residual speciation forms owing to their parasitism in quartz, sillimanite, and amorphous Fe solid solution in CGFA. Additionally, the study revealed that there was no significant relationship between heavy metal content, leaching behavior, and carbon content in CGFA. Based on combined analyses using toxicity characteristic leaching procedure (TCLP) leaching concentrations and risk assessment code (RAC) results, it is recommended to focus on the environmental risks posed by Cd, Cr, Pb, Zn, and Hg in CGFA during their modification and utilization processes.

Functionality of wheat straw-derived biochar enhanced its efficiency for actively capping Cd and Pb in contaminated water and soil matrices: Insights through batch adsorption and flow-through experiments.

The impact of functionality of biochar on pressing environmental issue of cadmium (Cd) and lead (Pb) co-contamination in simultaneous soil and water systems has not sufficiently reported. This study investigated the impact of Fe- and Mg-functionalized wheat straw biochar (Fe-WSBC and Mg-WSBC) on Cd and Pb adsorption/immobilization through batch sorption and column leaching trials. Importantly, Fe-WSBC was more effective in adsorbing Cd and Pb (82.84 and 111.24 mg g-1), regeneration ability (removal efficiency 94.32 and 92.365), and competitive ability under competing cations (83.15 and 84.36%) compared to other materials (WSBC and Mg-WSBC). The practical feasibility of Fe-WSBC for spiked river water verified the 92.57% removal of Cd and 85.73% for Pb in 50 mg L-1 and 100 mg L-1 contamination, respectively. Besides, the leaching of Cd and Pb with Fe-WSBC under flow-through conditions was lowered to (0.326 and 17.62 mg L-1), respectively as compared to control (CK) (0.836 and 40.40 mg L-1). In short, this study presents the applicable approach for simultaneous remediation of contaminated water and soil matrices, offering insights into environmentally friendly green remediation strategies for heavy metals co-contaminated matrices.

Boosting urea-assisted water splitting over P-MoO2@CoNiP through Mo leaching/reabsorption coupling CoNiP reconstruction.

Combining the urea oxidation reaction (UOR) with the hydrogen evolution reaction (HER) is an effective technology for energy-saving hydrogen production. Herein, a bifunctional electrocatalyst with CoNiP nanosheet coating on P-doped MoO2 nanorods (P-MoO2@CoNiP) is obtained via a two-step hydrothermal followed a phosphorization process. The catalyst demonstrates exceptional alkaline HER performance due to the formation of MoO2 and the dissolution/absorption of Mo. Meanwhile, the inclusion of Co and P in the P-MoO2@CoNiP catalyst facilitated the formation of NiOOH, enhancing UOR performance. Density functional theory calculations reveal that the hydrogen adsorption Gibbs free energy (ΔGH*) of P-MoO2@CoNiP is closer to 0 eV than CoNiP, favoring the HER. The catalyst only needs -0.08 and 1.38 V to reach 100 mA cm-2 for catalyzing the HER and UOR, respectively. The full urea electrolysis system driven by P-MoO2@CoNiP requires 1.51 V to achieve 100 mA cm-2, 120 mV lower than the traditional water electrolysis.

Cement pastes containing air entraining agent release the biocide octylisothiazolinone posing ecotoxicological effects.

We investigated whether cement pastes are a possible source of ecotoxicologically potent substances. For this purpose, leaching according to DIN EN 16637-2 was performed on portland cement pastes as well as blast furnace slag cement with and without an air entraining agent (AEA). The AEA, consisting of wood rosin and resin, contained the stabiliser drometrizole and the biocide octylisothizolinone (OIT), which was confirmed by our non-target screening (NTS). Our ecotoxicological studies (Daphnia magna, Aliivibrio fischeri and Desmodesmus subspicatus) of the pure cement eluates showed no effects at all. In these samples, it was possible to attribute up to 85 % of the dissolved organic carbon (DOC) to acetate, formate and diethylene glycol (DiEG). Eluates from cements with AEA contained up 70 µg/L octylisothizolinone (OIT), and no drometrizole was found. 90 % of the total OIT release happened within the first 6 h. It was possible to attribute the observed ecotoxicological effects mainly to the OIT concentrations. Additional leaching with elevated sulphate concentrations (800 mg/l) did not influence the release of DOC and OIT or increase the ecotoxicological effects. As a consequence, we advise curing the cement paste for 24 h prior to use, as this largely avoids the release of OIT and the observed ecotoxicological effects.