发光细菌法评价疫情暴发对长江流域地表水生态毒性的影响

在疫情暴发期间,大量使用的消毒剂和抗疫药物对水生态环境带来未知的潜在风险。本研究以长江流域为研究对象,选取4个江段(攀枝花、三峡、九江和南京江段),在3个季节(疫情暴发前、中、后期)采集表层水样,利用生物毒性测试对长江流域多个地区进行发光菌急性毒性研究。空间分布上,从长江流域上游到下游,水中有机污染物急性毒性呈现逐渐升高的趋势,其中南京江段水中有机物急性毒性相对较高。时间分布上,丰水期(疫情暴发期间)有机污染物急性毒性高于枯水期和平水期,可能源于疫情期间大量使用的消毒剂等带来的生态毒性效应。发光细菌急性毒性检测体系简单快速,能够全面客观地评价水质,可以弥补化学分析只能检测有限目标化合物的不足。

The progress of catalytic technologies in water purification:A review

Catalytic technologies have been paid increasing attention in refractory pollutants abatement due to its practical and potential values in water purification. As effective and efficient approaches for water purification, Fenton＇s reagent, ozonation, electrochemical and photocatalytic methods have been widely studied and applied in different aspects and have been reviewed by several articles. In recent years, some novel catalytic processes based on above processes have been developed for enhancing the efficiency of removing the organics from water. This review emphasized on the recent development of heterogeneous catalytic ozonation, electrocatalysis in respect of novel electrodes and electro-Fenton method, photoelectrocatalysis process and photoelectron-Fenton in water purification. It was also an attempt to propose general ideas about mechanism and principle enhancing the catalytic efficiency for the degradation and the mineralization of organics in water.

Research progress of novel adsorption processes in water purification: A review

As an effective, efficient, and economic approach for water purification, adsorbents and adsorption processes have been widely studied and applied in different aspects for a long time. In the recent years, a lot of novel adsorption processes have been developed for enhancing the efficiency of removing the organic and inorganic contaminants from water. This article reviews some new adsorbents and advanced adsorption methods that specialize in their compositions, structures, functions, and characteristics used in water treatment. The review emphasizes adsorption/catalytic oxidation process, adsorption/catalytic reduction process, adsorption coupled with redox process, biomimetic sorbent and its sorption behaviors of POPs, and modified adsorbents and their water purification efficiency.

Characterization of dissolved organic matter fractions and its relationship with the disinfection by-product formation

Dissolved organic matter （DOM） has been identified as precursor for disinfection by-products （DBPs） formation during chlorination. Recently, it has been demonstrated that the characteristics of DOM influence the DBPs formation mechanism. A study was, therefore, initiated to investigate the effects of DOM fractions on DBPs formation mechanism. In the chlorination process, organic acids are dominant precursors of total thihalomethanes （TTHM） because of the vc-o and unsaturated structures. Furthermore, the TTHM formation of organic acids was affected by pH more greatly. Based on the fluorescence spectroscopy analysis, DOM fractions contained several fluorescence substances. During chlorination, humic acid-like substances were found to exhibit high chlorine reactivity and hydrophobic organics decomposed to smaller molecules faster than hydrophilic organics even at lower chlorine dosages. Unlike hydrophobic fractions, hydrophilic organics showed no toxicity following chlorination, suggesting that the toxic structures in hydrophihc organics showed high chlorine reactivity during chlorination.

Preparation of organically functionalized silica gel as adsorbent for copper ion adsorption

A novel adsorbent （AMPS-silica） was synthesized by bounding AMPS （2-acrylamido-2-methylpropanesulfonic acid） onto silica surface, which functioned with γ-methacryloxypropyltrimethoxysilane reagent. The adsorbent was characterized by nitrogen adsorption/desorption measurement, thermogravimetric analysis （TGA） and potentiometric titration analysis. The TGA result indicated that the surface modification reactions introduced some organic functional groups onto the surface of silica. The surface area of AMPSsilica was 389.7 m2/g. The adsorbent was examined for copper ion removal in series of batch adsorption experiments. Results showed that the adsorption of Cu2＋ onto AMPS-silica was pH dependent, and the adsorption capacity increased with increasing pH from 2 to 6. The adsorption kinetics showed that Cu^2＋ adsorption was fast and the data fitted well with a pseudo secondorder kinetic model. The adsorption of Cu^2＋ onto AMPS-silica obeyed both Freundlich and Langmuir isotherms, with r^2 = 0.993 and r^2 = 0.984, respectively. The maximum Cu^2＋ adsorption capacity was 19.9 mg/g. The involved mechanism might be the adsorption through metal binding with organic functional groups such as carboxyl, amino and sulfonic groups. Cu^2＋ loaded on AMPS-silica could be desorbed in HNO3 solution, and the adsorption properties remain stable after three adsorption-desorption cycles.

Electrochemical incineration of dimethyl phthalate by anodic oxidation with boron-doped diamond electrode

The anodic oxidation of aqueous solutions containing dimethyl phthalate （DMP） up to 125 mg/L with sodium sulfate （Na2SO4） as supporting electrolyte within the pH range 2.0-10.0 was studied using a one-compartment batch reactor employing a boron-doped diamond （BDD） as anode. Electrolyses were carded out at constant current density （1.5-4.5 mA/cm^2）. Complete mineralization was always achieved owing to the great concentration of hydroxyl radical （-OH） generated at the BDD surface. The effects of pH, apparent current density and initial DMP concentration on the degradation rate of DMP, the specific charge required for its total mineralization and mineralization current efficiency were investigated systematically. The mineralization rate of DMP was found to be pH-independent and to increase with increasing applied current density. Results indicated that this electrochemical process was subjected, at least partially, to the mass transfer of organics onto the BDD surface. Kinetic analysis of the temporal change of DMP concentration during electrolysis determined by High Performance Liquid Chromatography （HPLC） revealed that DMP decay under all tested conditions followed a pseudo first-order reaction. Aromatic intermediates and generated carboxylic acids were identified by Gas Chromatography- Mass Spectrometry （GC-MS） and a general pathway for the electrochemical incineration of DMP on BDD was proposed.

Development and application of innovative technologies for drinking water quality assurance in China

The continuously deteriorating quality of source water is threatening the safety of drinking water in China.Various efforts have been made to update water treatment processes to decrease the pollution problems of drinking water,such as protection of drinking water sources,enhance-ment of conventional treatment processes,and development of new or advanced treatment technologies.This paper reviews a variety of protection and remediation methods for drinking water sources,development and application of drinking water treatment technologies,new technologies for special pollutants removal from groundwater,and the latest research progress on water distribution systems in China.

山水林田湖草沙一体化保护和系统治理面临的机遇与挑战——第二届环境与生态系统工程发展论坛主题沙龙

在2023年7月17—18日召开的全国生态环境保护大会上,习近平总书记提出要全面推进美丽中国建设,加快推进人与自然和谐共生的现代化步伐,近5年要着重处理好五大关系——高质量发展和高水平保护的关系、重点攻坚和协同治理的关系、自然恢复和人工修复的关系、外部约束和内生动力的关系、以及“双碳”承诺和自主行动的关系,其中的两大关系指出要坚持系统观念,坚持山水林田湖草沙一体化保护和系统治理,构建从山顶到海洋的保护治理大格局(综合运用自然恢复和人工修复两种手段,努力找到生态保护修复的最佳解决方案)。

Hydrotalcite-supported Pd-Cu catalyst for nitrate adsorption and reduction from water

Hydrotalcite-supported Pd-Cu catalyst for nitrate adsorption and catalytic reduction from water is prepared by co-impregnation method and characterized by surface area (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), trans- mission electron microscope (TEM) and X-ray pho- toelectron spectrum (XPS). The performance of ad- sorption and hydrogenation of nitrate was evaluated and compared with Al2O3, TiO2, and HZSM-supported Pd-Cu catalysts. The experimental results demon- strated that hydrotalcite-supported Pd-Cu catalyst exhibited a high surface area (185.3 m2/g) and mesopore structure (average pore diameter of 52.2 ?). The active metal clusters were homogeneously dispersed on the support, and the size of the most was less than 10 nm. Excellent adsorption for nitrate resulted from that nitrate ions were forced to enter the interlayer space when the calcined hydrotalcite re- generated layer structure in nitrate solution. The ad- sorption isotherm could be well described by the Langmuir model. The comparison between the ad- sorption and catalytic hydrogenation for nitrate using hydrogen indicated that nitrate reduction on hydro- talcite-supported Pd-Cu catalysts was a consecutive and dynamic adsorption and catalytic hydrogenation process. Compared with the Al2O3, TiO2, and HZSM- supported catalysts, hydrotalcite-supported Pd-Cu catalyst possessed higher catalytic activity and se- lectivity. The analysis on the dissolving of metals in the solution demonstrated that there was hydrolyza-tion on the surface of the hydrotalcite-supported Pd-Cu catalyst. However, the concentrations of dis- solved metals in the solution were lower than the standard executed in China. The activity of the hy- drotalcite-supported Pd-Cu catalyst for nitrate reduc- tion kept steady after repeated use.

Characterization and adsorption behavior of a novel triolein-embedded activated carbon composite adsorbent

A novel triolein-embedded activated carbon composite adsorbent was developed. Experiments were car-ried out in areas such as the preparation method, the char-acterization of physicochemical properties, and the adsorp-tion behavior of the composite adsorbent in removing diel-drin from aqueous solution. Results suggested that the novel composite adsorbent was composed of the supporting acti-vated carbon and the surrounding triolein-embedded cellu-lose acetate membrane. The adsorbent was stable in water, for no triolein leakage was detected after soaking the ad-sorbent for five weeks. The adsorbent had good adsorption capability to dieldrin, which was indicated by a residual di-eldrin concentration of 0.204 μg·L?1. The removal efficiency of the composite adsorbent was higher than the traditional activated carbon adsorbent.

Species transformation and structure variation of fulvic acid during ozonation

The species transformation and structure variation of fulvic acid (FA) during ozonation were investi- gated in this study. The molecular weight (MW) distribution, the species of intermediate products and the variation of polar functional groups were studied by ultrafiltration, gas chromatography/mass spectrometry (GC/MS) and titration analyses respectively. The average MW of FA decreased signifi- cantly during ozonation. The amount of polar functional groups (carboxylic and phenolic (ph-OH) groups) per unit DOC (mol/kg C) increased with increasing ozonation time. Furthermore, GC/MS ex- periments demonstrated the formation of polar species (e.g., hexadecanoic acid, benzoic acid and oc- tadecanoic alcohol) and less-polar species (e.g., aliphatic hydrocarbons and butanedioic acid, bis(2-methylpropyl) ester). Electron spin resonance (ESR) measurements proved the presence of ·OH radicals in the ozonation system. Based on our experimental results, it appears that the oxidations by ozone molecule and ·OH radicals were responsible for the transformation of organics (FA and its oxi- dation products) during ozonation. These two oxidants showed significant influence on organics transformation and exhibited different mechanisms contributing to these processes.

Effect of chlorination and ozone pre-oxidation on the photobacteria acute toxicity for dissolved organic matter from sewage treatment plants

The effect of chlorination and ozone pre-oxidation on the photobacteria acute toxicity for dissolved organic matter(DOM) from sewage treatment plants was investigated in this study.The results show that ozone pre-oxidation enhanced the photobacteria acute toxicity of the water samples.DOM before and after ozone pre-oxidation was fractionated by resins into six kinds of hydrophobic and hydrophilic organics.The six fractions were chlorinated individually and the photobacteria acute toxicity before and after chlorination was tested.It was found that the percentage of hydrophilic organics in DOM significantly increased after ozone pre-oxidation and hydrophilic organics exhibited remarkably higher acute toxicity than hydrophobic organics.In view of potentiometric titration and fourier transform infrared(FTIR) analysis,the hydrophilic organics showed a rather higher content of ph-OH structures than hydrophobic organics.

Coagulation properties of an electrochemically prepared polyaluminum chloride containing active chlorine

With high content of the Al13 species and the active chloride, an electrochemically prepared polyaluminum chloride (E-PACl) presents integrated efficiency of coagulation and oxidation. The coagula- tion properties of E-PACl were systemically investi- gated through jar tests in the various water quality conditions. The active chlorine in E-PACl can signifi- cantly influence the coagulation behavior due to the active chlorine preoxidation, which can change the surface charge characteristic of organic matter (OM) in water. The active chlorine preoxidation could im- prove the E-PACl coagulation efficiency if the water possessed the characteristics of relatively low OM content (2 mg/L) and high hardness (278 mg CaCO3/L). In the water with medium content of OM (5 mg/L), dosage would be a crucial factor to decide whether the active chlorine in E-PACl aided coagula- tion process or not. Comparing with alkaline condition, active chlorine would show a more significant influ- ence on the coagulation process in acidic region.