Enantioselective monitoring of chiral fungicide mandipropamid enantiomers were carried out in grapes and wine-making process. The enantiomers of mandipropamid were separated on a Lux Cellulose-2 column and determined by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS). The processing procedure included washing, fermentation, and clarification. Significant enantioselectivity was observed in grape under field conditions and during wine-making processing. The half-lives of R-mandipropamid and S-mandipropamid were 5.63 days and 7.79 days under field conditions 43.3 h and 69.3 h during wine-making processing, respectively. The EF values ranged from 0.498 to 0.283 in grape under field conditions, and the EF values were from 0.458 (0 h) to 0.362 (312 h) during the whole fermentation process. The results indicated that R-mandipropamid degraded faster than S-mandipropamid in grape under field conditions and during the fermentation process. The processing factors (PFs) were less than 1 for each procedure, and the PF ranged from 0.005 to 0.025 in the overall process, which indicated that the wine-making process can reduce mandipropamid residue in grape wine. The results of this study could help facilitate more accurate risk assessments of mandipropamid in table grapes and during wine-making process.

As a tool for mitigating water scarcity, membrane technologies have attracted much attention in the field of industrial effluent treatment. Notably, standard membranes suffer rejection issues that lead to short membrane life and high operational costs. Thus, better rejection-resistant materials (e.g., polyethersulfone (PES) membrane blended with carboxylated multi-walled carbon nanotubes (carboxylated-MWCNT)) have been developed via a phase-inversion process. Fabricated nanocomposite membranes are characterized in terms of physico-chemical characteristics and permeation properties. The removal performance of nanocomposite membranes is evaluated via the filtration of 1000 mg/L electroneutral bromothymol blue and anionic methyl orange dyes. According to the results, the optimum blending of 0.2 wt% carboxylated-MWCNTs exhibits an increase in surface properties and thermo-mechanical properties. Moreover, carboxylated-MWCNT/PES nanocomposites exhibit the highest pure-water permeability at 20.0 L/m².h.bar and superior removal of dyes (greater than 95%) with different charges at an operating pressure of 3 bar. The carboxylated-MWCNTs/PES are promising nanocomposite membranes that exhibit favorable removal performance when dealing with industrial effluent.

The concentrations and fractions of heavy metal in sediments at different altitudes in the water-level fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR) were determined. The Pearson correlation analysis was used to determine the differences between heavy metal fractions and physicochemical properties. The results showed that Cr and Cu were mainly horizontally and vertically distributed in the residual (RE) fractions with the highest stability and relatively low ecological risk. Pb and Zn were mainly in the Fe-Mn oxide-bound (Fe-Mn) fractions, which can be reduced to a bioavailable state when the redox potential decreased or the oxygen was severely depleted in the aquatic environment. There were significant differences in the heavy metal fractions and risks in sediment in the three different altitudes of the TGR. The physicochemical characteristics of the sediment indicated that the sediments in the low altitude area had rough forms and large pores. In addition, heavy metals at low altitudes were likely to be released into the water during antiseasonal water storage, causing secondary pollution, which greatly increased the mobility of heavy metals and ecological risks to the environment.

Copper (Cu) and zinc (Zn) are two heavy metal pollutants that pose a serious risk in the Jialing River. Cu and Zn are transported into the sediment primarily due to the activities of the mining and smelting industries. In this study, we employed the diffusive gradient in thin films (DGT) technique, sequential extraction, and two assessment methods to evaluate the remobilization, fractions, and environmental risk in the downstream section of the Jialing River. The total concentrations of Cu and Zn in the four study areas followed the order S3 > S2 > S4 > S1, and the assessment results indicated that Cu and Zn presented a low environmental risk in the study area. Cu and Zn were primarily bound to the Fe/Mn oxide fraction (F2) and the residual fraction (F4). The results of the DGT probe showed a clear vertical distribution of Cu and Zn in the sediment (from 3 to − 12 cm), and both elements showed obvious increasing trends at the bottom of the probe. The correlation analysis indicated that CDGT-Cu correlated well with CDGT-Zn (r = 0.834, p < 0.01). The flux results showed that the sediment in the downstream section of the Jialing River is a major source of Cu and Zn and that there is a potential risk of release to the overlying water. Further analysis found that CDGT-Fe was negatively correlated with CDGT-Cu and CDGT-Zn, indicating that Fe may influence the remobilization of these metals. In addition, a hotspot of CDGT-Cu and CDGT-Zn at the bottom of the probe corresponded with a dark area in the AgI gel measuring CDGT-S. These results indicate that Fe and S are factors that mitigate the release of Cu and Zn from sediments.

The effect of plantain peel biochar on the uptake of six heavy metals (Cd, Cr, Cu, Fe, Pb and Zn) in spinach (Spinacia oleracea L.) irrigated with untreated wastewater was investigated in nine outdoor lysimeters (0.45 m diameter × 1.0 m height) arranged in a completely randomised design with three replicates. The lysimeters were packed with sandy soil (bulk density 1.35 Mg m⁻³) and brought to field capacity 1 day before starting the experiment. Biochar (1% w/w) was mixed in the top 0.10 m of soil under biochar amendment. Spinach were planted in each lysimeter, irrigated (every 10 days for 4 times in total), harvested (harvest 1 and harvest 2) and analysed for the heavy metals. Spinach leaves accumulated more heavy metals than the roots and stems. Biochar amendment did not affect the translocation of heavy metals (Cd, Cu, Cr, Fe and Pb) to spinach leaves, possibly due to competition with other compounds in the soil solution. However, the biochar amendment improved CEC and increased the pH of soils which resulted in a 42% reduction of translocation of Zn in spinach leaves. Assuming daily spinach consumption of 200 g per person, Zn in spinach grown in soil amended with biochar would be below the provisional maximum tolerable daily intake limit for adults (20 mg) as prescribed by WHO/FAO/IAEA. Consumption of spinach grown with wastewater in soil without biochar amendment may not be safe because of Zn toxicity. Likewise, the concentration of Cd, above CODEX permissible levels in the spinach leaves and eleven times higher in wastewater than freshwater irrigation, raises a concern for consumers in developing countries where untreated wastewater is often used for irrigation.

The objective of this research is to analyse the feasibility of reusing the fly ash waste, which is produced in biomass plants, during the production of renewable energy, for controlling phosphorus contamination in the wastewater being processed in sewage treatment plants. The research examines the efficiency of using different types of ash, obtained from representative biomass materials after combustion in an energy plant (paulownia wood, wheat straw and barley straw), in removing phosphorus from water. The ashes were respectively mixed with synthetic water, rich in phosphorus; then, using batch experiments, the effects that the pre-treatment of ash, adsorbent dosage, contact time and temperature had on the adsorption process were studied. The main results show that phosphorus adsorption by the tested ashes augments as temperature increases. Similarly, the adsorbed amount of phosphorus increases by increasing the dose of the adsorbent. In addition, the adsorption of phosphorus by these three materials has been described well by the Langmuir isotherm equation. It has been found that the removal process of phosphorus was endothermic. Finally, this study concludes that waste ash from biomass plants can be used to remove phosphorus from wastewater in sewage treatment plants.

Consuming drinking water contaminated with As(V) represents a hazard to human health. Adsorption of As(V) onto bone char (BC) has been studied previously, but a detailed study is required for applying BC to remove arsenate present in drinking water. The effect of the operating conditions, water matrix, and presence of fluoride onto the adsorption capacity of BC toward As(V) were thoroughly investigated. The XRD examination confirmed the presence of hydroxyapatite in BC, and the TEM examination of BC showed the random piling of the layers of hydroxyapatite. The BC adsorption capacity was contrasted with that of reagent-grade hydroxyapatite, and it was found that the BC capacity was mainly attributed to its hydroxyapatite content. The BC capacity is augmented by diminishing the solution pH because of the rise of the electrostatic attraction between the arsenate in water and the positive charge of the BC surface. The adsorption capacity was improved by incrementing the temperature so that the adsorption of As(V) was endothermic. The adsorption mechanism of As(V) on BC comprised electrostatic attraction and ion exchange. The simultaneous elimination of fluoride and arsenate in drinking water samples in San Luis Potosí, SLP, México, revealed that both pollutants could be effectively removed by adsorption on BC, and the presence of As(V) did not affect the adsorption capacity of BC toward fluoride. In contrast, the capacity of BC for adsorbing As(V) was enhanced in the drinking water compared with that of deionized water, and this synergistic behavior was due to a screening effect.

Photo-Fenton oxidation is one of the most promising processes to remove recalcitrant contaminants from industrial wastewater. In this study, we developed a novel heterogeneous catalyst to enhance photo-Fenton oxidation. Multi-composition (Fe-Cu-Zn) on aluminosilicate zeolite (ZSM-5) was prepared using a chemical process. Subsequently, the synthesized catalyst was characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (spectroscopy) (EDX), and Brunauer–Emmett–Teller (BET). Activity of the synthesized catalyst is analysed to degrade an azo dye, methyl orange. Taguchi method is used to optimize color removal and total carbon content (TOC) removal. The dye completely degraded, and 76% of TOC removal was obtained at optimized process conditions. The amount of catalyst required for the desired degradation of dye significantly reduced up to 92% and 30% compared to conventional homogenous and heterogeneous Fenton oxidation processes, respectively.

Oxidation of surface sediments is an important means for altering phosphorus (P) exchanges across sediment–water interface (SWI) in shallow lakes. In this study, the potential and composition of regenerated oxidation capacity (OC) of surface sediments were evaluated in three large shallow lakes (Tai Lake, Chao Lake, and Dianchi Lake) in China; the transformation of sedimentary P was quantified through P fractionation scheme. The composition of the regenerated OC differed among these three lakes, with Fe(III) and SO₄²⁻ dominant in Dianchi Lake, Mn(IV) and Fe(III) in Chao Lake and Tai Lake. Oxidation of sediments enhanced the transformation of sedimentary P and altered P exchanges across the SWI. In Chao Lake, the HCl-P was transformed to BD-P; in Tai Lake, the NaOH-P was involved too, and transformed to BD-P; whereas in Dianchi Lake, an increase in NH₄Cl-P was also observed except for the transformation from HCl-P to BD-P. The sediment-to-water flux of P was enhanced with 0.17 mg/g DW in Dianchi Lake and 0.08 mg/g DW in Chao Lake, while a contrary water-to-sediment flux of P was observed in Tai Lake, reaching 0.01 mg/g DW. This study advances our knowledge on the impacts of sediment oxidation on P cycles in lakes, which will be beneficial to eutrophication control.

Globally, heavy metal (HM) pollution of soil is a serious problem that can lead to long-term toxic effects on soil. In this milieu, the present study investigated the eco-toxicological effects of three trace elements, e.g., cadmium (Cd), copper (Cu), and lead (Pb), on enzyme activities and microbial function and structural diversity in phaeozem and red soil samples. Hormesis effects of Cd, Cu, and Pb on catalase and invertase activities were observed in phaeozem soil, while for red soil, there was an inhibitory effect on the activities of catalase and invertase under Cu- and Pb-contaminated soils. The utilization of carbon sources was inhibited in Cd- and Pb-treated phaeozem soil, but higher utilization of polymers and amines exhibited in Cu-contaminated soil. Although the substrates under the contamination of Cd, Cu, and Pb had high average well color development values across incubation time, the utilization of various substrates did not exhibit a regular trend under different treatments with HMs. The denaturing gradient gel electrophoresis (DGGE) analysis showed that the HMs led to marginal changes in the number and species of soil microbes, while the similarity indices decreased in HM-treated samples, varying from 66.2 to 77.3% in phaeozem soil and from 62.8 to 66.7% in red soil. However, the sequence analysis showed that there existed metal-resistant microbial communities such as Bacillales, Bacillus, and Massilia and so on under the stress of HMs.