低温低C/N比复合A~2/O启动实验研究

研究了低温低碳氮比条件下好氧段添加AquaMat(s阿科蔓)的A2/O工艺的挂膜启动实验。结果表明:在环境温度为10¹2℃,C/N为3.5左右的条件下,当系统HRT为10 h,SRT为15 d,污泥回流比为100%,硝化液回流比为200%,好氧段DO在212℃,C/N为3.5左右的条件下,当系统HRT为10 h,SRT为15 d,污泥回流比为100%,硝化液回流比为200%,好氧段DO在2³ mg/L,初始MLSS为4 000 mg/L时,好氧段阿科蔓经30 d左右挂膜成功。系统对COD,氨氮,总氮的去除率分别达到90%、97%、60%。对总磷的去除率低且不稳定。实验研究了挂膜过程中COD、氨氮、硝酸盐氮、总氮、总磷、ORP、MLSS及微生物相的变化规律并分析了变化原因。     

皇甫川流域百里香光合和蒸腾作用日进程及影响因子分析

采用Li-6400光合系统测定仪,测定了皇甫川流域百里香(Thymus serpyllum)的光合速率和蒸腾速率日变化特征及生理生态因子对其的影响.结果表明:百里香的光合和蒸腾速率日进程曲线为双峰型,其光合“午休”现象是受到气孔因素限制.百里香光合和蒸腾速率主要受到气孔导度、胞间CO2浓度的影响.     

城市大气污染分析及综合防治

城市大气污染已成为世界各国面临日益严重的环境问题,制约各国政治经济的快速发展,同时危害了人民群众的正常健康生活.如何防止城市大气污染,减轻其危害和影响,是当今重大而紧迫的课题.本课题系统分析了当前我国城市大气污染的状况、特点及成因,为有效防治大气污染提供了理论基础.     

毒死蜱工艺废水预处理研究

毒死蜱工艺废水中含有吡啶类衍生物,属高浓度、难降解有毒有机废水.采用电催化氧化-微电解-混凝沉淀组合工艺对毒死蜱工艺废水进行预处理研究,结果表明,当电催化氧化单元进水pH值为3～4、电流密度为14mA/cm2、主反应器HRT为150 min,微电解单元铁炭比1∶1、进水pH值为3～4、HRT为100 min时,COD,TP,TOC的去除率分别为32.49％,37.39％,51.4％;在电催化氧化单元COD去除率出现负值,表明废水中吡啶类物质被有效分解.高效液相色谱分析结果表明,该预处理工艺对废水中3,6,5-三氯吡啶醇有着很好的去除效果,去除率达到99.9％以上.GC--MS分析结果表明,该预处理工艺对废水中的3,6,5-三氯吡啶醇分解彻底.     

一、二次风配比对75t/h循环流化床的影响

本文利用FLUENT模拟软件对75t/h循环流化床进行数值模拟,研究了一、二次风配比(5∶5、5.5∶4.5和6∶4)对炉内温度场、速度场和CO2分布的影响,发现一、二次风配比为5.5∶4.5时,循环流化床运行较优,炉内温度场较均匀,且基本能达到规定运行温度,速度分布均匀,炉内烟气流速较高,出口烟气速度分别比1、3#工况要高33.42％和13.70％,炉内CO2分布较优,旋风分离器具有很高的工作效率.     

涂料项目环境影响评价中的清洁生产分析

从产品先进性、生产工艺与设备水平、物耗能耗水平、污染物产生水平四个方面对某生产规模为9000t／a的防腐涂料制造项目的清洁生产水平进行分析评价,并提出进一步提高项目清洁生产水平的建议。     

Effects of fenvalerate concentrations and its chiral isomers on bacterial community structure in the sediment environment of aquaculture ponds

To investigate the effect of chiral pesticide fenvalerate (FV) on the micro-ecological environment of aquaculture pond sediment, we used an indoor static experiment to observe the effects of FV added at different concentrations with different chiral isomers on the changes in the sediment bacterial community. The 16S rDNA high-throughput sequencing technique was used to conduct sequencing and analysis of the bacterial community structure as well as changes in aquaculture pond sediments after 4 weeks of cultivation. The results showed that the microbial alpha diversity indices (Sobs and Shannon indices) of the treated groups were significantly lower than those of the control group after 4 weeks (P < 0.05), and the values in the high-concentration group were significantly lower than those of the low-concentration group (P < 0.05). In terms of bacterial group composition, the proportion of abundance of Proteobacteria and Acidobacteria in the treated groups were greater than in the control group after 4 weeks, while the proportion of abundance of Bacteroidetes and Verrucomicrobia were lower. In the high-concentration FV treatment group, the proportion of abundance of Bacteroidetes, Acidobacteria, Chloroflexi, Nitrospinae, unclassified_k_norank, Ignavibacteriae, and Nitrospirae were significantly different from those of the other groups (P < 0.05). Principal coordinate analysis (PCoA) and ANONISIM/Adonis analysis showed that the cis-enantiomer had a stronger effect on the bacterial community as the concentration of FV increased. In addition, the linear discriminant analysis effect size (LEfSe) and linear discriminant analysis (LDA) results revealed differences in the level of enrichment of bacterial groups caused by FV at different concentrations and isomer levels. Collectively, this study showed that FV residue has a pronounced effect on bacterial communities in sediment, which becomes more significant with increasing exposure concentration. The effects of the cis- and trans-enantiomers of FV on the sediment environment are different; the cis-enantiomer has a stronger effect on the bacterial community.

     

Comparison analysis on simultaneous decolorization of Congo red and electricity generation in microbial fuel cell (MFC) with l-threonine-/conductive polymer-modified anodes

Environmental Science and Pollution Research - l-Threonine and three kinds of conductive polymers were applied for anode modification in microbial fuel cells (MFCs) for decolorization of Congo red...     

Antibiotic accumulation,growth performance,intestinal diversification,and function of Nile tilapia (Oreochromis niloticus) feed by diets supplemented with different doses of sulfamethoxazole

Environmental Science and Pollution Research - To comprehensively investigate the effects of exposure to legal doses of sulfamethoxazole (SMZ) in Nile tilapia (Oreochromis niloticus), fishes were...     

宜昌市大气微塑料的分布、呼吸暴露及溯源

微塑料作为一种新兴环境污染物备受关注,但大气微塑料的来源和健康危害尚不明晰.为探究宜昌市不同功能区微塑料的分布特征和人体呼吸暴露风险,分析不同地区大气微塑料的可能来源,于2019年10～12月,采集和分析宜昌市16个观测点的大气微塑料样品,并利用HYSPLIT模型模拟大气后向轨迹.结果表明,宜昌市大气微塑料有纤维状、碎片状和薄膜状这3种形状;透明、红色、黑色、绿色、黄色和紫色这6种颜色;尺寸最小的为10.42μm,最大的为4 761.42μm;平均沉降通量为(4 400±474)n·(m²·d)^-1;种类有：聚酯纤维(PET)、丙烯腈-丁二烯-苯乙烯共聚合物(ABS)、聚酰胺(PA)、橡胶(Rubber)、聚乙烯(PE)、醋酸纤维素(CA)和聚丙烯腈(PAN)这7种.各功能区沉降通量依次为：城市居民区>农业生产区>垃圾填埋场>化工园区>城镇居民区.人体呼吸暴露风险评估模型表明,城市居民区成人和儿童每天大气微塑料摄入量(EDI)高于城镇居民区.大气后向轨迹模拟表明,宜昌市各区县大气主要受周边地区影响,部分大气微塑料可能来...