Ternary Ti₃C2/TiO2/BiOBr heterojunction was constructed via a facile one-pot hydrothermal strategy. During hydrothermal treatment, partial in-situ oxidation of Ti3C2 occurred, resulting in well-anchored TiO₂ nanoparticles at the MXene interface. The influence of hydrothermal parameters on structure, optical and photoelectrochemical properties, and photocatalytic performance was systematically investigated. The optimized catalyst exhibited degradation efficiency of 74.4% for tetracycline (TC) and 87.4% for rhodamine B (RhB) within 30min. The formation of heterojunction extended the visible-light response of BiOBr and accelerated the efficient separation and migration of photogenerated charge carriers. Moreover, enlarged specific surface area of the composite offered a large number of active sites for photocatalytic reaction. Radical trapping experiments further revealed •O2− and h+ served as the primary reactive species in degradation process. On the basis of these findings, the charge transfer pathway was proposed to explain the enhanced photocatalytic activity.

Tetracycline (TC) has been emerged as a recalcitrant pollutant in water environment, and how to efficiently remove it has become a recent research focus. In this study, a low-cost SnO2-Sb/FTO electrode has been successfully constructed using fluorine-doped tin oxide (FTO) conductive glass as the substrate by simple sol-gel and calcination method, and was utilized in the electrocatalytic oxidation of TC in aqueous solution. The surface morphology and crystal structure of the SnO2-Sb/FTO electrode were characterized by various techniques. Electrochemical characterization indicated that SnO2-Sb/FTO electrode has good conductivity, excellent electrocatalytic activity and high oxygen evolution potential. In a 50 mM Na2SO4 solution, 5 mg.L-1 TC was completely removed within 25 min at 1.25 mA.cm(-2) with no pH adjustment (pH 6), and the first-order reaction rate constant was obtained as 0.144 min(-1) with the energy consumption of 13.63 kW.h.kg(-1). Electron paramagnetic resonance measurement (EPR) and free radical quenching experiments indicated the crucial role of .OH in the electrocatalytic oxidation process. By identifying the degradation products and DFT calculations, the possible degradation pathways of TC were proposed, and the reaction regions of TC were analyzed. Moreover, the electrode exhibited outstanding stability and reusability. It is promising to efficiently remove TC in wastewater by using the SnO2-Sb/FTO electrode.

In this study, a cerium doped-acidified red mud and powder biochar particle electrode (ARM-PBC/Ce electrode) was fabricated with impregnation-coprecipitation-calcination method, and was employed in a three-dimensional electro-Fenton (3D/EF) system for levofloxacin (LEV) degradation. The preparation conditions of ARM-PBC/Ce electrode were optimized, and the electrode was characterized by various techniques. In contrast with RM, the ARM-PBC/Ce electrode had higher specific surface area, lower charge transfer resistance and excellent electrochemical performance, and the valence state conversions of Fe and Ce facilitated the generation of center dot OH. Under the optimum degradation conditions (0.03 M Na2SO4 solution, initial pH 5, ARM-PBC/Ce dosage 0.4 g, applied voltage 6 V, and aeration rate 300 mL center dot min- 1), the removal efficiency of 10 mg center dot L- 1 LEV reached 95.82 % in 60 min electro-Fenton oxidation, and the bacterial toxicity decreased significantly. The 3D/EF system demonstrated superior oxidation capability and energy efficiency compared to the 2D/EF system, and center dot OH and center dot O2- were the dominant active species in the electro-Fenton oxidation of LEV. The potential degradation pathways, mainly including decarboxylation, demethylation, piperazine ring opening and hydroxylation, were proposed based on the identification of intermediate products and active species. Moreover, the particle electrode remained remarkable stability and reusability after five cycles, suggesting its promising potential for the efficient treatment of LEV in wastewater.

The continuous accumulation of antibiotics in the environment has become an increasingly concerned global environmental problem. Electrochemical advanced oxidation processes (EAOPs) have been attracted much attention in antibiotic degradation due to their unique advantages, but their effectiveness is influenced by various factors, and how to pinpoint the crucial factors remains unclear. In this study, six machine learning algorithms (i.e., GBDT, XGBoost, SVM, KNN, RF and BPNN) were employed to simulate and predict antibiotic degradation based on a dataset incorporating key features: (i) electrode properties (anode material, cathode type and oxygen evolution potential); (ii) degradation conditions (initial pH, electrode distance, temperature, current density, electrolysis time, electrolyte type and concentration, and antibiotic concentration); (iii) antibiotic properties (pKa and logKow). The optimized GBDT model achieved excellent prediction performance (R2 = 0.91, RMSE = 2.21). Feature importance analysis revealed that the degradation conditions, antibiotic properties and electrode properties contributed 69.96 %, 15.4 %, and 14.6 % to the removal efficiency, respectively. SHapley Additive exPlanations (SHAP) further highlighted current density, antibiotic concentration and pKa as critical factors. Additionally, an open-source web application based on stacked models was developed. This work can offer guidance for optimizing experimental design and provide insights into effective strategies for antibiotic pollution control.

To promote the formation of granular sludge with high polyhydroxyalkanoates (PHAs) synthesis ability, an anaerobic dynamic feeding process (AnDF) was proposed. This process combines the feast-famine mode with an anaerobic plug flow feeding process and involving variations in cycle length and settling time. The effects of lactic acid (LA) content (0%, 20%, and 40% COD) on sludge granulation and PHAs production were investigated using three AnDF reactors (R1, R2, and R3). The results showed that the AnDF process feeding with LA not only effectively promoted sludge granulation but also improved its PHAs synthesis ability. The granules were quickly observed in R3 after 50 days of cultivation, with an average diameter of 0.69mm. The maximum PHAs content reached 47.0wt.% in R3, representing a 30.09% increase compared to R1. Additionally, extracellular polymeric substances (EPS)-producing bacteria observed in granular sludge may be the prime drivers of the formation of PHAs-producing granular sludge (PHAGS), which was defined as granular sludge with an average particle size larger than 0.30mm and PHAs content above 40% cell dry weight (CDW) of sludge samples.

In order to understand the spatial-temporal distribution and ecological risk of antibiotics in the soil of an agricultural watershed in the Three Gorges Reservoir area, the topsoil samples were collected at 26 sites in the Wangjiagou small watershed, Fuling District, Chongqing in spring, summer, autumn, and winter of 2022, and 21 antibiotics with five classes were determined using solid phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry. The content levels and spatial-temporal distribution of antibiotics were analyzed, the correlations between antibiotic contents and soil physicochemical factors were discussed, and the potential ecological risk of antibiotics in the soil was evaluated using the risk quotient method. The results showed that the detection rates of 21 antibiotics were 0-100% with the range of ND-219.5 μg·kg-1, and those of tetracyclines （TCs）, quinolones （FQs）, and chloramphenicols （CAPs） reached 100% in all four seasons. The total antibiotic content ranged from 14.35 to 504.1 μg·kg-1 with the average value of 149.7 μg·kg-1, and the average contents of the five classes of antibiotics showed a decreasing trend of TCs （77.95 μg·kg-1）, FQs （34.96 μg·kg-1）, CAPs （28.14 μg·kg-1）, sulfonamides （SAs, 7.15 μg·kg-1）, and macrolides （MLs, 1.48 μg·kg-1）. The antibiotic contents of soils during autumn and winter were significantly higher than those in summer （P < 0.05） and showed an overall variation trend of first decreasing and then increasing with the season and a distribution situation of "low in the west and high in the east." The sites with high antibiotic contents were mainly concentrated in vegetable fields, residential areas, and dry lands. In spring soils, the contents of tylosin （TYL） （P < 0.01）, tetracycline （TC） （P < 0.01）, doxycycline （DXC）, and sulfamethodiazine （SMR） （P < 0.05） were significantly negatively correlated with soil pH. In summer soils, total phosphorus （TP） had significantly positive effects on the contents of sulfamethoxazole （SFZ） and TC （P < 0.05） and had extremely significant positive effects on sulfamethoxazole （SMX）, SMR, and ofloxacin （OFL） （P < 0.01）. Total nitrogen （TN） had significantly positive effects on the contents of SMX （P < 0.01） and SMR （P < 0.05）, and soil organic matter （SOM） had significantly positive effects on the contents of TC and enrofloxacin （ENR） （P < 0.05）. However, ciprofloxacin （CIP） （P < 0.001）, sulfampyridine （SPD）, norfloxacin （NOR）, and TYL contents （P < 0.05） were significantly negatively correlated with soil pH. In autumn soils, TN significantly negatively affected CIP content （P < 0.05）； the contents of sulfadiazine （SDZ）, TC, and DXC were negatively affected by soil pH （P < 0.05）； and cation exchange capacity （CEC） significantly positively affected the contents of TC and SFZ （P < 0.05）. In winter soils, TP had a significantly positive effect on TYL content, and TN had a significantly positive effect on SFZ content （P < 0.05） and an extremely positive effect on sulfamethoxine （SMM） （P < 0.001）. Chlorotetracycline （CTC） （P < 0.01）, CIP （P < 0.01）, thiamphenicol （TAP） （P < 0.001）, chloramphenicol （CAP） （P < 0.001）, oxytetracycline （OTC） （P < 0.001）, and sulfadimidine （SM2） （P < 0.05） were significantly negatively correlated with soil pH, and CEC had a significantly negative effect on SDZ content （P < 0.05）. The soils in the Wangjiagou agricultural small watershed were mainly threatened by SMX, SDZ, TC, DXC, erythromycin, NOR, OFL, CIP, and ENR, and their ecological risks should not be ignored.

Lakes, crucial antibiotic reservoirs, lack thorough exploration of quantitative relationships between antibiotics and influencing factors. Here, we conducted a comprehensive year-long investigation in Changshou Lake within the Three Gorges Reservoir area, China. The concentrations of 21 antibiotics spanned 35.6-200 ng/L, 50.3-348 ng/L and 0.57-57.9 ng/g in surface water, overlying water and sediment, respectively. Compared with abundant water period, surface water and overlying water displayed significantly high antibiotic concentrations in flat and low water periods, while sediment remained unchanged. Moreover, tetracyclines, fluoroquinolones and erythromycin posed notable risks to algae. Six primary sources were identified using positive matrix factorization model, with aquaculture contributing 21.2%, 22.7% and 25.4% in surface water, overlying water and sediment, respectively. The crucial predictors were screened through machine learning, redundancy analysis and Mantel test. Our findings emphasized the pivotal roles of water quality parameters, including water temperature (WT), pH, dissolved oxygen, electrical conductivity, inorganic anions (NO3-, Cl- and F-) and metal cations (Ca, Mg, Fe, K and Cr), with WT influencing greatest. Total nitrogen (TN), cation exchange capacity, K, Al and Cd significantly impacted sediment antibiotics, with TN having the most pronounced effect. This study can promise valuable insights for environmental planning and policies addressing antibiotic pollution.

Our previous study indicated excellent dechlorination efficiency and phenol conversion rate in the electrocatalytic reduction of 2,4-dichlorophenol (2,4-DCP) with a Pd-MWCNTs/Ni-foam electrode; it is deserved to investigate whether this electrode can efficiently degrade phenol in electro-Fenton oxidation (EFO) process and realize the effective mineralization of 2,4-DCP in aqueous solution. In this work, the sequential electrocatalytic reduction and oxidation of 2,4-DCP were studied after examining phenol degradation in the EFO process. The results showed that the removal efficiency of 0.31 mM phenol could reach 96.76

Lignocellulosic biomass can be effectively digested in animal rumen,which makes rumen-derived anaerobic digestion an attractive strategy.In order to improve the utilization efficiency of straw and other materials,this study designed an integrated two-phase anaerobic reactor based on the principles of bionics,and investigated its hydrolysis acidification and methane-producing capability by feeding straw,pig manure and river sediment as substrates.The results indicated that the biogas production rate in 1-6 d was fast,and the increasing rate of cumulative gas production was 366.87 mL/（L·d）.The fastest biogas production rate in this period was 22.3 mL/（g·d）（measured by the volume of biogas produced per gram of volatile solids per day）,and the cumulative gas production per gram volatile solid was 0.13 L.The pH value ranged from 7.3 to 8.2,and showed an overall opposite variation trend with the concentration of volatile fatty acids（VFAs）,indicating that ammonia inhibition did not occur in the reactor.The soluble chemical oxygen demand（SCOD）produced by main reaction chamber was substantially utilized in secondary reaction chamber in 1-21 d,realizing the separation of hydrolysis process and the utilization process of hydrolysis products.In the reactor,Firmicutes and Bacteroidetes were the two most abundant bacterial phyla with hydrolysis and acid-production abilities.The reactor not only had the functions of substrate stratification and continuous absorption of VFAs,but also had the upper layer hydrolysis and acid production and lower layer methane production.Therefore,the reactor can effectively extend the solid residence time,improve the hydrolysis and acidification efficiencies,and eliminate partial acid inhibition in the reactor.

In this study, a blue TiO2 nanotube arrays anode on porous titanium substrate (Ti-porous/blue TiO2 NTA) was successfully fabricated by facile anodization and in situ reduction, and was used to investigate the electro-chemical oxidation of carbamazepine (CBZ) in aqueous solution. The surface morphology and crystalline phase of the fabricated anode were characterized by SEM, XRD, Raman spectroscopy and XPS, and the electrochemical analysis confirmed that blue TiO2 NTA on Ti-porous substrate had larger electroactive surface area, better electrochemical performance and higher center dot OH generation ability than that on Ti-plate substrate. The removal efficiency of 20 mg L-1 CBZ in 0.05 M Na2SO4 solution reached 99.75% at 8 mA cm-2 after 60 min electro-chemical oxidation, and the rate constant was 0.101 min-1 with low energy consumption. EPR analysis and free radical sacrificing experiments showed that center dot OH played a key role in the electrochemical oxidation. The possible oxidation pathways of CBZ were proposed through the identification of degradation products, and the main reactions may involve deamidization, oxidization, hydroxylation and ring-opening. Compared with Ti-plate/blue TiO2 NTA anode, Ti-porous/blue TiO2 NTA anode displayed excellent stability and reusability, and is promising to be used in the electrochemical oxidation of CBZ in wastewater.

The accumulation of Cd in soil-rice systems at a large region is often extremely complicated due to environmental heterogeneity and the interactions of multiple influencing factors. However, the interactive effects and quantification of the contributions of influencing factors on Cd accumulation in large regions remain unclear. In this study, conditional inference trees and random forest analysis were used to identify the interactions of various factors (soil properties, topography and demographic-economic), and quantify their contributions to Cd accumulation in soil-rice systems of Sichuan-Chongqing region, China. The results showed that Cd content in the soil was the most significant influencing factor on Cd accumulation in soil-rice systems, especially bioavailable Cd in soil contributed to 35.73 % and 54.78 % for soil total Cd (Cdsoil) and brown rice Cd (Cdrice), respectively. Population density (PD) and elevation contributed 31.16 % and 27.40 % to Cdsoil content, respectively, and their interaction promoted the increase in Cdsoil content. Moreover, PD played a leading role in Cdsoil content when the elevation exceeded 324 m. The relative importances of slope and elevation for Cdrice content were 16.81 % and 8.49 %, respectively, and their interaction facilitated the increment of Cdrice content. As soil pH, gross domestic product (GDP) and slope decreased, the interaction of soil pH with GDP led to the increase of bioavailability factor (BAF), and that with slope enhanced the bioaccumulation factor (BCF). In addition, soil pH, PD and elevation were of considerable importance for the migration and transformation of Cd, with contributions of 22.11 %, 12.90 % and 12.52 % to BAF, and 5.05 %, 5.62 % and 5.50 % to BCF, respectively. This study is hopeful to provide a scientific insight into the prevention and control of Cd contamination in soil-rice systems at a large region.

为发展废水中双酚A(BPA)的处理技术和保护水环境安全,采用"电沉积-热分解"法制备负载多壁碳纳米管(MWCNTs)的多孔Ti/SnO2-Sb-Ni电极,研究了电极对BPA的去除能力、动力学特征和矿化效率,初步分析了 BPA的降解途径.结果表明,当浸渍液中n(Sn)∶n(Sb)∶n(Ni)为100∶10∶1、ρ(MWCNTs)为0.8 g·L-1时,制备的电极对BPA的去除效果最好;负载MWCNTs使得电极表面的晶体尺寸更小,可增大电极的比表面积,为电催化反应提供更多的活性位点,进而提高电极的电催化效率.当c(Na2SO4)为10 mmol·L-1、反应液初始pH为5和电流密度为50 mA·cm-2时,对50 mg·L-1的BPA降解60 min时去除效率达到99.76％;去除过程符合一级反应动力学方程,速率常数为0.096 min-1;电解120 min时,TOC去除率达到67.01％.采用液相色谱-串联质谱分析法(LC-MS/MS)鉴定BPA的降解产物,电催化降解BPA可能包括羟基化、异亚丙基C—C键断裂、脱水、脱氢和·OH氧化等途径.

SiC/g-C3N4 composite (SCN) showed the potential for photocatalytic degradation of synthetic dyes, it is deserved to study whether it is effective for the photocatalytic degradation of ciprofloxacin (CIP). In this work, persulfate-enhanced CIP degradation was investigated with SCN under visible light irradiation. The results showed that the degradation efficiency of 10 mg L-1 CIP could reach 95% for 30 min under the conditions of 0.4 g L-1 SCN, 2 mM persulfate (PS) and solution initial pH 6. The degradation process abided by pseudo first-order kinetic equation, and the observed rate constant (k(obs)) with SCN/PS (0.132 min(-1)) was 13 times of that with SCN (0.0102 min(-1)), and twice of that with g-C3N4/PS (0.0649 min(-1)). The quenching experiments and electron paramagnetic resonance analysis indicated that O-2(-)center dot and O-1(2) played the main role and other active species (e.g., h(+), SO4-center dot and center dot OH) also participated in CIP degradation. The possible degradation pathways were proposed through identifying the intermediate products, and the main reactions may include the ring opening of piperazine, decarbonylation, decarboxylation and defluorination. Bacterial toxicity test showed that the toxicity of the reaction solution decreased dramatically after 30 min degradation. Overall, this work could provide an efficient and environmentally friendly technology for eliminating CIP. (C) 2021 Elsevier Ltd. All rights reserved.

Rice has a strong ability to accumulate Cd in soil, and it is of great significance to study Cd pollution and safe planting zoning in paddy soils. In this work, 300 sets of paddy soil-rice samples were simultaneously collected in 22 towns in a District of Chongqing, and soil pH, soil total and available Cd contents, and brown rice Cd contents were determined. Soil Cd pollution was assessed using the geoaccumulation index, bioconcentration factor, and the single-factor pollution index. Based on the Cd pollution indices of soil and brown rice, safe planting zoning for rice was determined. The results showed that the paddy soils were generally acidic, and total Cd contents ranged from 0.09 mg·kg-1 to 1.60 mg·kg-1, with 35.0% of sites exceeding the risk screening value. The Cd contents of the brown rice ranged from 0.002 mg·kg-1 to 0.808 mg·kg-1 and exceeded the food safety limit in 13.7% of cases. Pearson correlation analysis showed that the Cd content of brown rice was significantly positively correlated with soil total and available Cd (P<0.01). The pollution evaluation indicated that significant Cd accumulation occurred in the paddy soils, with some areas showing light-to-moderate pollution levels. The enrichment coefficients of rice to soil Cd ranged from 0.004 to 1.72. Overall, the paddy soils in the studied area were considered generally safe with respect to Cd pollution, with low-risk areas distributed in the south, west, and east, whereas some medium-high risk areas were detected in eight towns.

在贵州草海国家级自然保护区,通过对湖区沉积物的采样分析,结合资料搜集,研究了草海沉积物中养分的空间分布特征及不同时间的养分含量变化,并利用模糊综合评价法对其养分进行了评价.结果表明:沉积物中有机质、总氮、碱解氮、总磷、有效磷和速效钾含量分别为251.19 g/kg,11.77 g/kg,910.63 mg/kg,0.46 g/kg,19.95 mg/kg和456.67 mg/kg,其中有机质、总氮和总磷含量呈现出由东至西递增的趋势;草海沉积物模糊综合指数平均为4.62,养分含量较高,其中有机质、总氮和碱解氮含量达到Ⅰ级水平,90.91％ 的样点速效钾含量达到Ⅰ级水平,81.82％ 的样点总磷含量处于Ⅳ级及以下水平,81.82％ 的样点有效磷含量达到Ⅲ级及以上水平;2010-2016年沉积物有机质、总氮和碱解氮含量分别增加3.26％,1.29％ 和37.11％,总磷和有效磷含量分别降低31.34％ 和18.87％,草海有机质含量分别是红枫湖、乌梁素海、青海湖和滇池的6.54,12.00,7.83和2.81倍,总氮含量分别是上述湖泊的2.05,13.69,6.76和3.34倍,但总磷含量均低于这些湖泊.

Soil salinization has severely affected the quality of tillage land in China, and most greenhouse soils in Shanghai suburb suffer from secondary salinization with high salinity levels dominated by Ca2+, Mg2+ and NO3-. In this work, a sandy loam soil (Calcaric Fluvisols) contaminated by the above ions was selected as research object, and the binding conditions and abilities of gamma-polyglutamic acid (gamma-PGA) to water-soluble Ca2+ and Mg2+ in the soil were examined, and then pot experiments were conducted to remove Ca2+, Mg2+ and NO3- by two halophytes (Sedum aizoon L., Sesbania cannabina Pers.) integrated with gamma-PGA application. The results showed that under the conditions of adding 1000 mg L-1 gamma-PGA (pH 7) and 25 degrees C, the binding efficiencies of Ca2+ and Mg2+ were 51.59% and 68.03%, respectively. Compared with Sesbania cannabina Pers., Sedum aizoon L. displayed better remediation performance for the soil with gamma-PGA application in pot experiments, and the removal efficiencies of Ca2+, Mg2+ and NO3- reached 93.25%, 94.78% and 84.26% after applying 1000 mg L-1 gamma-PGA for 56 d, respectively. Moreover, gamma-PGA application could mitigate salt stress and promote plant growth, and activate antioxidant defense systems. Compared with the control, 1000 mg L-1 gamma-PGA application significantly increased plant height and fresh weight of Sedum aizoon L., and the removal efficiencies of Ca2+, Mg2+ and NO3- increased by 45.48%, 82.62% and 69.91%, respectively. In the future, more in-depth mechanism of joint effect and field-scale investigation need to be further studied.

In order to develop an electrochemical chlorophenol removal process in wastewaterꎬ a Pd ̄MWCNTs ̄nickel foam electrode was prepared by dippingꎬ drying and electrodeposition. The electrocatalytic dechlorination capability and kinetics of 2ꎬ4 ̄dichlorophenol (2ꎬ4 ̄DCP) were studiedꎬ and the dechlorination mechanisms were discussed. The results showed that good removal performance could be obtained by the electrode prepared with the loading amounts of 0.7 mg􀅰cm-2 MWCTs and 0.01 mmol􀅰cm-2 Pdꎬ respectively. MWCNTs could increase the surface area of the electrode and improve the dispersion of Pdꎬ and thus enhance the catalytic performance of the electrode. Under the conditions of 0.05 mol􀅰L-1 Na2 SO4 solutionꎬ -1 V applied voltage and reaction solution initial pH 7ꎬ the removal efficiencyreached 99.74% at 90 min for 50 mg􀅰L-1 2ꎬ4 ̄DCP. The degradation process could be described with the first order reaction kinetic modelꎬ and the rate constant was 0. 0667 min-1 . The degradation products were monitored by high performance liquid chromatographyꎬ and phenol was found as the final reduction product. The degradation pathways included direct removal of two chlorine to phenolꎬ and stepwise removal of two chlorine and then transformation into phenolꎬ but the main approach was to remove two chlorine atoms directly. The active group quenching experiments proved that the hydrodechlorination reaction of 2ꎬ4 ̄DCP was performed through the adsorbed hydrogen atoms (Hads) generated on the electrode.

Biochar, an effective and low-cost amendment for immobilizing heavy metals, has been extensively studied. However, the simultaneous inhibition effects of biochar on the plant uptake for arsenic (As) and cadmium (Cd) in co-contaminated soils are still ambiguous due to their distinct environmental behaviors. A meta-analysis was conducted to quantitatively assess the effects using 1030 individual observations from 52 articles. On average, biochar application significantly decreased the bioavailability of Cd in soils by 50.12%, while slightly increased the bioavailability of As in soils by 2.39%. The more instructive result is that biochar application could also simultaneously reduce the concentration of As and Cd in plants by 25.48% and 38.66%, respectively. The orders of the decreased percentage of As and Cd in various tissues were root < stem< leaf < grain, and root < leaf < stem < grain, respectively. According to the analysis of critical factors, manure biochar, low pyrolysis temperature (at <400 °C), low application rate (<2%), and high SOC (>30 g/kg) were more conducive to reduce the bioaccumulation of As and Cd simultaneously in co-contaminated soils. Pristine and modified biochar could inhibit As and Cd accumulation in crops, but their efficiencies need to be further improved to ensure the safety of crop productions. Overall, the meta-analysis suggests that biochar has the potential to remedy the As and Cd co-contaminated soils.

自2004年发现二维石墨烯以来,二维非金属材料因其丰富多样的性质受到广泛关注.该类材料具有极高的比表面积,可以作为光催化剂和电催化剂,为开发高效的可见光驱动的光催化材料提供了可能.该文综述了4种新型二维非金属材料:二维石墨烯、二维石墨相氮化碳、二维黑磷和二维氮化硼在光催化降解印染废水中的研究进展,并展望了未来的研究方向.

The excessive use and abuse of antibiotics has brought about serious threats to water environmental safety and human health. It is necessary to develop efficient, cheap, and environmentally friendly treatment technologies for antibiotics. In this work, a Ni-doped Sb-SnO2 microporous ceramic ring particle electrode was prepared by the dipping method and characterized by scanning electron microscopy, energy dispersion spectroscopy, and X-ray diffraction. The electrocatalytic oxidation ability and kinetic characteristics of sulfadiazine (SDZ) were studied using the prepared electrode, and the degradation pathways of SDZ were analyzed preliminarily. The results showed that Ni and Sb-SnO2 crystals were loaded on the particle electrode surface, which is beneficial for electron transfer and SDZ adsorption and improvement of electrocatalytic oxidation efficiency. Under the conditions of 0.02 mol·L-1 NaCl solution (pH 8), 15 mA·cm-2 of current density, and 15 g particle electrode, 50 mg·L-1 SDZ could be completely removed on the three-dimensional electrode within 15 min. The removal efficiency of TOC in the reaction solution reached 80.8% for 3 h degradation and was 17.6% higher than that with two-dimensional electrode. The kinetic process of the electrocatalytic oxidation could be well described by the first-order reaction kinetic model, and the rate constant was 0.329 min-1. The degradation products of SDZ were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the possible pathways of electrocatalytic degradation mainly include the fractures of S-N bond on sulfamido and C-N bond on pyrimidine ring, desulfonation, deamination, and·OH oxidation.