各种影响因子对电解法预处理医药废水的影响研究

探讨了电解法预处理医药废水时停留时间、电解电压、废水初始浓度、温度和废水pH值等影响因子对去除色度、COD和提高废水可生化性等处理效果的影响,并考察了其应用于工业实际废水处理的可行性.实验结果表明:电解法更适合高浓度医药废水的处理,色度的去除率可达到90%以上;电解时间宜控制在40～60 min;电解电压越高,废水COD和色度去除效果越好;在实验温度范围内,温度对色度和COD去除率的影响不大;废水pH值为7.5时电解效果最佳,工程运用宜控制在6～9之间.     

Environmental contamination from electronic waste recycling at Guiyu, southeast China

The disposal, recycling, and part salvaging of discarded electronic devices such as computers, printers, televisions, and toys are now creating a new set of waste problems. This study is aimed at identifying the sources and quantifying the pollution levels generated from electronic waste (e-waste) activities at Guiyu, Guangdong Province, China, and their potential impacts on the environment and human health. The preliminary results indicate that total polycyclic aromatic hydrocarbons (PAHs) in soil obtained from a printer roller dump site was 593 μg/kg dry weight (dry wt.) and in sediment from a duck pond, the PAH concentration was 514 μg/kg (dry wt.). Sediment from the Lianjiang River was found to be contaminated by polychlorinated biphenyls (743 μg/kg) at a level approaching three times the Canadian Environmental Quality Guidelines probable effect level of 277 μg/kg. Total mono- to hepta-brominated diphenyl ether homologue concentrations (1140 and 1169 μg/kg dry wt.) in soils near dumping sites were approximately 10–60 times those reported for other polybrominated diphenyl ether-contaminated locations in the world. In-house study on the open burning of cable wires showed extremely high levels of polychlorinated dibenzo-p-dioxins and dibenzofurans resulting in 12419 ng toxic equivalents (TEQ)/kg of waste input and 15 610 ng TEQ/kg for two separate tests, respectively, which were about three orders of magnitude higher than those for the open burning of household waste. High levels of Cu (712, 528, and 496 mg/kg), exceeding the new Dutch list action value, were determined for soil near the printer roller dumping area, sediment from Lianjiang River, and soil from a plastic burn site, respectively. A more thorough study is underway to elucidate the extent of contamination of toxic pollutants in different ecological compartments to establish whether these pollutants are bioaccumulated and biomagnified through food chains. Assessments of human health impacts from oral intake, inhalation, and dermal contact will be subsequently investigated. An erratum to this article is available at.     

Effect of Changing VOC Influent Composition on the Microbial Community Structure of TBABs

Microbial communities in trickle bed air biofilters (TBABs) were evaluated under conditions of interchanging the feed volatile organic compounds (VOCs) and VOC mixtures. Three independent TBABs (Biofilter “A,” “B,” and “C”) were run under interchanging VOCs conditions with different initial VOCs. Two aromatic compounds (toluene and styrene) and two oxygenated compounds (methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK)) were interchanged as single solutes. Two other TBABs “D” and “E” were run for two VOC mixtures. Biofilter “D” had a VOC mixture with equal molar ratio of the four components and Biofilter “E” received a VOC mixture with its composition based on EPA 2003 emission report. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes was used to assess the microbial richness in TBABs for treating the VOC mixtures and the impact of interchanging VOCs on the bacterial community structure in the biofilters. The results from DGGE indicated that the microbial community structure in the biofilter was different after each interchange of VOCs. Some bands of microbial species faded and some bands were strengthened. For the two TBABs treating VOC mixtures, the microbial species did not show significant difference, but the richness among these species was different from each other.     

甲基硫菌灵生产废水处理的研究

采用沉淀-氧化-厌氧-好氧工艺处理甲基硫菌灵生产废水。研究结果表明,废水经沉淀一氧化预处理后,COD从10000～12000mg／L降至1000～1500mg／L,再经厌氧和好氧处理后COD最终降至70～80mg／L;从废水的第一、第三次沉淀中均可回收铜离子（可作为第二次沉淀用沉淀剂）,从废水的第二次沉淀中可回收硫氰化亚铜产品,该产品用途广泛、市场价值高,可显著降低废水处理的成本。     

二氧化钛光催化降解处理染料废水

研究了TiO2的添加量，粒径大小，作用时间对3种染料废水脱色率的影响及TiO2薄膜对染料废水的处理效果。对于汽巴克染绿和直接大红染料溶液，适宜的TiO2添加量均为5g/L，紫外灯照射60min，其脱色率大于85％。对于阳离子红染料溶液，适宜的TiO2添加量为3g/L，其脱色率为83．5％。粒径小的TiO2作用效果优于粒径大的效果。在室温和适宜的TiO2添加量的条件下，随照射时间的延长，太阳光的光催化降解效果渐渐接近于紫外光的光催化降解效果。将TiO2薄膜固定在陶瓷睛上，有利于TiO2的重复使用。     

基于WEBGIS的地震灾情快速评估系统研究

快速进行地震灾情评估对地震应急响应与救援工作具有重要意义。鉴于当前GIS在地震灾情快速评估中数据利用程度低、难于管理与共享、可互操作性差的不足,利用WEBGIS的基本框架及主要技术优势,构建了基于WEBGIS的地震灾情快速评估系统,提出了系统的设计思想、体系结构和功能结构。采用ArcGISServer作为系统的框架平台,结合ASP.NET技术,实现了信息查询、地震影响场、损失评估和应急准备的相应功能模块,极大提高了地震应急的信息化水平。     

强降雨在滑坡发育中的关键控制机理及典型实例分析

通过构建水动力作用模型,对降雨的激发控制作用进行分析,得出水动力控制机理的结论:强降雨控制滑坡发育,集中表现在改变土体的静水压力、动水压力与浮托力的作用三方面.选取重庆市黔江流水湾滑坡为典型实例,对强降雨的激发控制作用进行验证,强降雨的水动力作用过程分为坡体剪切、滑动开始、剧烈滑动三个不同阶段.最后,提出久旱过后强降雨...     

植物对酞酸酯的敏感性

采用发芽试验和温室盆试验等方法，研究了酞酸酯（ＤＢＰ、ＤＥＨＰ）对番茄等１２种蔬菜以及水稻、小麦和油菜的影响。结果表明：酞酸酯（１０ｍｇ／１）对种子发芽率无明显影响，但对幼苗形态特征有一定作用。电镜观察表明：受害叶片叶绿体数量减少、结构改变。初步讨论了酞酸酯的理化性质与作物受害的关系，划分了蔬菜对酞酸酯的敏感性顺序。     

Electricity-driven ammonia oxidation and acetate production in microbial electrosynthesis systems

• MES was constructed for simultaneous ammonia removal and acetate production. • Energy consumption was different for total nitrogen and ammonia nitrogen removal. • Energy consumption for acetate production was about 0.04 kWh/g. • Nitrate accumulation explained the difference of energy consumption. • Transport of ammonia and acetate across the membrane deteriorated the performance. Microbial electrosynthesis (MES) is an emerging technology for producing chemicals, and coupling MES to anodic waste oxidation can simultaneously increase the competitiveness and allow additional functions to be explored. In this study, MES was used for the simultaneous removal of ammonia from synthetic urine and production of acetate from CO₂. Using graphite anode, 83.2%±5.3% ammonia removal and 28.4%±9.9% total nitrogen removal was achieved, with an energy consumption of 1.32 kWh/g N for total nitrogen removal, 0.45 kWh/g N for ammonia nitrogen removal, and 0.044 kWh/g for acetate production. Using boron-doped diamond (BDD) anode, 70.9%±12.1% ammonia removal and 51.5%±11.8% total nitrogen removal was obtained, with an energy consumption of 0.84 kWh/g N for total nitrogen removal, 0.61 kWh/g N for ammonia nitrogen removal, and 0.043 kWh/g for acetate production. A difference in nitrate accumulation explained the difference of total nitrogen removal efficiencies. Transport of ammonia and acetate across the membrane deteriorated the performance of MES. These results are important for the development of novel electricity-driven technologies for chemical production and pollution removal.