三甲基氯化锡对斑马鱼(Danio rerio)生理生化特性的影响

为初步探讨三甲基氯化锡(trimethyltin chloride,TMT)对鱼类的毒性效应以及评价环境中TMT的安全性,采用静态鱼类急性毒性试验法测定了TMT对斑马鱼(Danio rerio)生理生化指标的影响;参考TMT的96 h-LC50值,设定3个浓度(0.39、0.78和1.17 mg·L-1)处理斑马鱼,测...     

共存阳离子对砷、硒和钒毒性效应的影响及预测模型研究

为探明并量化共存阳离子存在下含氧阴离子型金属在生物体中的毒性效应,以模式植物小麦(Triticum aestivumL.)为研究对象,通过单一变量控制实验,探究了4种阳离子(Ca⁽²⁺⁾、Mg(2+)、Mg⁽²⁺⁾、Na(2+)、Na⁺和K+和K⁺)对3种典型含氧阴离子型金属(AsO_4+)对3种典型含氧阴离子型金属(AsO_4^(3-)、SeO_3(3-)、SeO_3^(2-)和VO_4(2-)和VO_4^(3-))毒性的影响,并构建了静电作用模型来预测和评估As、Se和V的生态毒性效应与风险。结果表明,Ca(3-))毒性的影响,并构建了静电作用模型来预测和评估As、Se和V的生态毒性效应与风险。结果表明,Ca⁽²⁺⁾对As、Se和V毒性的影响呈现出3种不同的趋势：在相同设计浓度范围内Ca(2+)对As、Se和V毒性的影响呈现出3种不同的趋势：在相同设计浓度范围内Ca⁽²⁺⁾的增加显著引起了As毒性的减弱(Adj.R(2+)的增加显著引起了As毒性的减弱(Adj.R²=0.76,P<0.05)、V毒性的加剧(Adj.R2=0.76,P<0.05)、V毒性的加剧(Adj.R²=0.81,P<0.05),而对Se毒性却没有显著影响。当Mg2=0.81,P<0.05),而对Se毒性却没有显著影响。当Mg⁽²⁺⁾从0.20 mmol·L(2+)从0.20 mmol·L^(-1)增加到2.73 mmol·L(-1)增加到2.73 mmol·L^(-1)时,Se主导形态的半数有效活度值(EC_(50){HSeO+3(-1)时,Se主导形态的半数有效活度值(EC_(50){HSeO+3^-})从40.40 μmol·L-})从40.40 μmol·L^(-1)显著下降为27.98 μmol·L(-1)显著下降为27.98 μmol·L^(-1),即Se毒性增强到原来的1.44倍(Adj.R(-1),即Se毒性增强到原来的1.44倍(Adj.R²=0.79,P<0.05)。静电作用理论能够很好地解释Ca2=0.79,P<0.05)。静电作用理论能够很好地解释Ca⁽²⁺⁾(或Mg(2+)(或Mg⁽²⁺⁾)在显著增强V(或Se)毒性中发挥的作用,将这种静电作用影响纳入考虑成功构建了可以定量预测V(Adj.R(2+))在显著增强V(或Se)毒性中发挥的作用,将这种静电作用影响纳入考虑成功构建了可以定量预测V(Adj.R²=0.88)和Se(Adj.R2=0.88)和Se(Adj.R²=0.95)毒性的静电作用模型。研究结果弥补了目前含氧阴离子型金属生态毒性研究的不足,为含氧阴离子型金属的土壤污染生态风险评估提供了指导与参考。     

连续式生物吸收工艺脱除二氧化硫

运用连续式生物吸收处理工艺,以废糖蜜发酵液作为碳源进行了微生物法去除SO2气体的研究,在简单粗放的实验条件下,研究了脱硫脱硫弧菌对较大气量SO2气体的去除效果,并对产物H2S在第二级生物反应器中的去除率进行了测定。实验结果表明,随着进气量由0.18 m3/h增大至5 m3/h,脱硫率会降低,但是随之提高搅拌速度和补料速度后,脱硫率又恢复到较高水平,当搅拌速度为590 r/min时,5 L生物反应液可以处理5 m3/h的SO2气体,1#反应器SO2去除率和2#反应器H2S去除率分别达到92%和98%以上。在气量增至5 m3/h时,1#和2#反应器补料流速分别为175 mL/h和200 mL/h时,没有亚硫酸盐和硫化物的积累,pH值和菌体浓度稳定,系统运行良好。     

Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and heavy metals (HMs) as well as their genotoxicity in soil after long-term wastewater irrigation

A study was carried out on the residue level of major concern pollutants (PAHs, PCBs and HMs) and the assessment of their genotoxicity in soils obtained from Shenyang, northeast of China which had been subjected to wastewater irrigation for more than 40 years. Topsoils (0-20cm) in paddy fields were sampled along the upper, middle and lower reaches of the wastewater disposal channel. Sixteen USEPA PAHs were determined by High Performance Liquid Chromatography (HPLC) with fluorescence detector, eight PCBs were detected by Gas Chromatography (GC) with electron capture detector, and six heavy metals (Cd, Cu, Pb, Zn, Ni, and Cr) were measured by Atomic Absorption Spectrophotometer (AAS). The genotoxicity effect of soils was examined by Vicia faba micronucleus (MN) test. Archived soils that had undergone a similar history of wastewater irrigation provided by Technical University of Berlin, Germany were subjected to analysis of the above pollutants and Vicia faba/MN test for comparison. Results indicated elevated residues of the studied pollutants (PAHs, especially benzo (a) pyrene, the eight PCB congeners and heavy metals) in both tested and archived soils. The MN frequencies were 2.2-48.4 times higher compared with the control. However, there was no correlation between the MN frequencies and the concentration of pollutants detected. This investigation suggested a potential ecological risk even with a lower level of residual pollutants in soil matrix after long-term wastewater irrigation.     

纳米Pd／Fe双金属颗粒对单氯酚及二氯酚的还原脱氯

采用改进液相化学还原法制备纳米Pd／Fe双金属颗粒,研究其钯化率为0．045％和0．135％的条件下分别对3种单氯酚（2-CP、3-CP和4-CP）和3种二氯酚（2,3-DCP、2,4-DCP和2,6-DCP）的脱氯反应。结果表明,合成的纳米Pd／Fe颗粒分散性良好,粒径分布介于25～40nm。纳米Pd／Fe双金属颗粒对单氯酚及二氯酚具有良好的去除效果,3种单氯酚和3种二氯酚的脱氯难易程度分别为2-CP〉4-CP〉3-CP和2,6-DCP〉2,4-DCP〉2,3-DCP,脱氯反应均符合拟一级反应动力学方程。通过还原脱氯实验揭示了分子中氯原子的化学环境对还原脱氯过程具有明显影响。     

钙型天然斜发沸石去除猪场废水中营养物的实验研究

以钙型天然斜发沸石为实验材料,研究反应时间、沸石投加量、pH值、有机物浓度等因素对去除实际猪场废水中氨氮、磷和COD效果的影响。研究表明,钙型天然斜发沸石对实际猪场废水的处理效果良好,在沸石投加量为250 g/L、pH值为8.0～9.0、反应时间为24 h的条件下,钙型天然斜发沸石对氨氮、磷和COD的去除率分别达到96%、97%和84%。pH值对钙型天然斜发沸石氨氮去除效果影响不大,但对磷和COD的去除效果影响较显著;当pH值由6.0升高至7.0时,磷的去除率由63%迅速升高至93%,pH值为8.0以上时,去除率接近95%;随pH值的升高,COD的去除率先升高后降低,在pH值为8.0时,去除率达到最大,为84%。废水COD浓度对氨氮去除率的影响基本可忽略,但对磷的去除有轻微的抑制作用。采用固定滤柱过滤时,水力负荷控制在375 mL/h以下,氨氮、磷和COD的去除效果较好。     

Feasibility of a membrane-aerated biofilm reactor to achieve single-stage autotrophic nitrogen removal based on Anammox

A laboratory-scale membrane-aerated biofilm bioreactor (MABR) equipped with non-woven fabrics support around the gas-permeable carbon tube was developed for single-stage autotrophic nitrogen removal based on partial nitrification and anaerobic ammonium oxidization. This reactor allowed air to be supplied through the microporous carbon tube wall to the biofilm that was supported by non-woven fabrics. The partial nitrification and consumption of dissolved oxygen occurred in the inner layer and Anammox in the anoxic outer layer of the non-woven fabrics, thus realizing autotrophic nitrogen removal in a single reactor. After 116d of operation, the maximal nitrogen removal of 0.77kgNm(-3)d(-1) at a volumetric ammonium loading rate of 0.87kgNm(-3)d(-1) was achieved. The spatial profiles of the ammonia-oxidizing bacteria and Anammox bacteria were evaluated by fluorescence in situ hybridization. This study demonstrated that MABR was a very suitable experimental set-up for the operation of the single-stage autotrophic nitrogen removal process.     

生物催化氧化法脱除H2S的试验研究

针对H₂S污染的严峻形势，构建了包括催化再生装置和生物滴滤器的生物催化氧化装置。该装置以沸石为填料，以氧化亚铁硫杆菌为脱硫菌种，通过微生物和Fe³⁺的双重氧化作用高效脱除H₂S。试验确定了装置的适宜喷淋量和沸石的最佳粒径。在温度为30℃，进气量为0.25 m³/h，进气H₂S浓度为2500mg/m³，喷淋量为1000mL/h，喷淋液的pH值为1.97、Fe³⁺浓度为0.05 mol/L的条件下，出气H₂S浓度足以达到GB14554-93规定的一级厂界标准值。试验证明，生物催化氧化法是一种新型高效的脱硫技术，应进一步开展中试研究。     

Evaluating the effectiveness of routine water quality monitoring in Miyun reservoir based on geostatistical analysis

This study used geographic information system techniques and geostatistics methods to evaluate the effectiveness of routine water quality monitoring in the western segment of the Miyun reservoir in Beijing. Methodologies as well as the sampling design are evaluated. The single-layer evaluation and three integrated evaluation methods including principal component analysis (PCA), ordinary kriging (OK)_Mean, and Mean_Layers were used to validate the effectiveness of evaluation methods, and the effectiveness of each sampling design was validated by comparing their errors. Results indicated that, while a single-layer evaluation only shows the trophic state of water at a specific level, an integrated evaluation synthetically analyzes and evaluates the trophic state of the entire water body. Furthermore, results of the integrated analysis show that a PCA method is more accurate and can represent the trophic state of the entire water body. The OK_Mean and Mean_Layers methods are only able to represent the mean level for trophic state of the entire water body but cannot reflect local trophic state and distribution details. Although methods used in the routine monitoring of Miyun reservoir have some similarities to the OK_Mean and Mean_Layers methods, their range of errors and uncertainty are greater because of a lack of detailed spatial continuous information. The analysis on the number of sampling points shows that, within a certain range of error, minor changes of sampling points will have no obvious impact on the monitoring results. For the routine monitoring of western Miyun reservoir, using only three to five sampling points for monitoring is inadequate. According to our analysis, it is more appropriate to use at least ten sampling points for monitoring these areas.     

Membrane fouling controlled by coagulation/adsorption during direct sewage membrane filtration (DSMF) for organic matter concentration

Unlike the role of the membrane in a membrane bioreactor, which is designed to replace a sediment tank, direct sewage membrane filtration(DSMF), with the goal of concentrating organic matters, is proposed as a pretreatment process in a novel sewage treatment concept. The concept of membrane-based pretreatment is proposed to divide raw sewage into a concentrated part retaining most organics and a filtered part with less pollutant remaining, so that energy recovery and water reuse, respectively, could be realized by post-treatment. A pilot-scale experiment was carried out to verify the feasibility of coagulant/adsorbent addition for membrane fouling control, which has been the main issue during this DSMF process. The results showed that continuous coagulant addition successfully slowed down the increase in filtration resistance, with the resistance maintained below 1.0 × 1013m~(-1) in the first 70 hr before a jump occurred. Furthermore,the adsorbent addition contributed to retarding the occurrence of the filtration resistance jump, achieving simultaneous fouling control and chemical oxygen demand(COD)concentration improvement. The final concentrated COD amounted to 7500 mg/L after 6 days of operation.