Organochlorine pesticides in the dust fall around Lake Chaohu, the fifth largest lake in China

The residual levels of organochlorine pesticides (OCPs) in the dust fall around Lake Chaohu were measured using gas chromatography mass spectrometry from April 2010 to March 2011. The fluxes, components, temporal–spatial variations, and sources of OCPs were also analyzed. Twenty-one types of OCPs were detected in the dust fall samples around Lake Chaohu, with a total concentration of 51.54?±?36.31 ng/g and a total flux of 10.01?±?13.69 ng/(m² day). Aldrin (35.3 %), endosulfan (39.1 %), dichlorodiphenyltrichloroethanes (DDTs) (49.8 %), and isodrin (37.1 %) were the major OCPs in the spring, summer, autumn, and winter, respectively. Both the residual level and the flux were higher in the spring than in other seasons and higher at the outer lake sampling sites than inner lake sampling site. The potential source of the hexachlorcyclohexanes in the dust fall may be recent lindane usage. The DDTs mainly came from historical dicofol usage, and a significant input of DDT was found during April and June. The presence of endosulfan may be due to the present use of technical endosulfan. The aldrin in the dust might be due to its occasional usage, and isodrin may be a result of long-distance transport from other countries.     

TiO2光催化-微滤膜分离深度净化亚甲基蓝印染废水

采用悬浮式TiO2光催化膜反应器深度净化纺织工业园区含亚甲基蓝印染废水经生物处理二级出水,利用中空纤维微滤膜进行催化剂截留分离,研究催化剂投加量、运行时间、溶解氧、搅拌方式对出水水质及膜通量的影响。结果表明:光催化会消耗体系溶解氧,鼓风曝气搅拌可同时为系统供氧,优于机械搅拌;该耦合体系的催化剂最佳投加量为1 g/L,经光催化氧化-膜组合工艺处理后水质优于GB 4287-1992《纺织染整工业污染物排放标准》的I级标准,符合建设部颁布的《生活杂用水水质标准》(CJ/T 48-1999)。     

基于主体分级的社会救援资源分类及结构框架

社会救援资源是应急救援工作的重要资源支撑。从资源供给角度出发,给出社会救援资源的概念,并综合"社会"和"应急救援资源"范围的研究,界定社会救援资源的范围,继而阐述了社会救援资源的普遍特点和特殊特点;提出一种新的资源分类方法———基于主体分级的资源分类方法,并基于此方法,将社会救援资源提供的社会主体分为3类共10个主体,即第一类主体(大型国有企业、国家级慈善社团)、第二类主体(其他公有制企业、其他慈善社团、相关民办非企业单位、公民自组织形式)、第三类主体(其他所有制企业、一般社团、其他民办非企业单位、公民个人);在主体分级的基础上,从救援资源的角度将不同社会主体的供给力度分为强、中、弱三级,初步构造一个矩阵网状的社会救援资源结构框架。     

温度对亚硝化及氧化亚氮释放的影响

采用批次实验的方法探讨了3种不同温度(15℃,25℃,35℃)对亚硝化及其过程中温室气体氧化亚氮释放情况。结果表明,温度对亚硝化过程及氧化亚氮的释放有显著影响。在15～35℃范围内,随着温度的升高,氨氧化率和亚硝化积累率逐渐升高,N2O释放量也逐渐增大,35℃可以作为适宜的亚硝化温度,平均氨氧化率为50.9%,亚硝化积累率为55.6%,NO2--N与NH4+-N出水浓度比为1.1,氨氧化率,亚硝化积累率和出水中亚硝氮与氨氮浓度比较合适,从而可以为厌氧氨氧化工艺提供合适的进水,但在此温度下平均N2O释放量相对较高,为1.494μg/g MLSS。     

紫外催化湿式双氧水氧化处理化学镀铜废液

利用化学镀铜废液自身含有的铜作为催化剂,应用紫外催化湿式双氧水氧化工艺处理化学镀铜废液取得了良好效果。通过单因素实验确定的推荐工艺条件为：pH=2.0（保持原始值不变）;不额外投加铜催化剂;H₂O₂用量为2倍理论量。在此条件下处理化学镀铜废液180 min,COD去除率可达到96.6%;之后采用沉淀法回收铜,调节处理后废水pH到9.5,铜的回收率可达到99.8%。     

用味精生产废水培养好氧颗粒污泥

以厌氧颗粒污泥为接种污泥,采用味精生产废水进行培养,在SBR中以逐渐降低污泥沉淀时间的方法成功培养出好氧颗粒污泥。实验结果表明：污泥接种65 d后,出现细小的好氧颗粒污泥,呈黄褐色,95 d后颗粒污泥趋于成熟,粒径达0.6 mm左右,且周围存在大量原生动物;运行95 d后MLSS提高至8.00 g/L,SVI降至30.00 mL/g左右;成熟后的好氧颗粒污泥对味精生产废水中的COD和NH₃-N具有良好的去除效果,出水COD和ρ（NH₃-N）分别为80 mg/L和2 mg/L左右。     

蜂窝陶瓷载体生物膜技术处理农药废水

以蜂窝陶瓷为载体进行生物挂膜,处理经化学预处理后的某农药厂有机磷和除虫菊酯类混合废水。对处理结果、蜂窝陶瓷载体及其生物挂膜法的特点进行了深入讨论。当废水的COD为1 600～1 700 mg/L,TP(总磷)为70～80mg/L,DMAC(二甲基乙酰胺)为0.8～1.2 mg/L,甲醇为8～12 mg/L,pH为6.8～7.2,水温为27～30℃,流量为0.1 m3/h,水力停留时间为15 h,进水容积负荷约为2.5 kg COD/(m3.d)时,发现15 d就完成生物挂膜,连续运行20 d COD去除率为73%～75%,TP去除率为53%～55%,DMAC去除率为54%～57%,甲醇去除率为91%～93%。与同样条件下的普通活性污泥处理相比,COD去除率提高85%,TP去除率提高83%,DMAC去除率提高119%,甲醇去除率提高27%,排出的剩余活性污泥量减少89%。测得的活性生物膜量为1.8 kg/m2,生物膜的厚度为1.5～2 mm,用偏光显微镜摄取了载体表面生物膜的图像。     

分层式潜流人工湿地水力学特性数值模拟与分析

人工湿地水力学特征对其污染物去除过程有重要影响.采用计算流体力学软件FLUENT中的多孔介质模型对分层式潜流人工湿地内部的流场进行模拟,并分析了不同进出口位置对湿地水力学行为的影响.模拟结果表明,分层式潜流人工湿地基质层内部速度分布的差异较大,水流多从进口端的左半部汇人下部砾石层以大于3.69×10-4m/s的速度出流...     

K-Ca-Mg-Cl-H2O体系中硫酸钙结晶介稳区的研究

对K-Ca-Mg-Cl-H2O体系中硫酸钙结晶介稳区进行了研究.以一定浓度氯化钙溶液与硫酸镁溶液反应结晶的方式,采用激光散射法测定了不同浓度复合盐溶液和温度下硫酸钙过饱和度与结晶之间的关系,并测定了与之平衡的溶解度,从而确定该体系中硫酸钙结晶介稳区宽度,探讨了影响结晶介稳区的因素,以及硫酸钙结晶和结晶相与复合盐溶液浓度...     

Accumulation levels and characteristics of some pesticides in human adipose tissue samples from Southeast China

This paper presents a comprehensive study of pesticide levels and bio-accumulation characteristics in human adipose tissues among residents of Southeast China. A large number of adipose samples (n = 633) were selected for 58 pesticides and were analyzed by high sensitive Gas Chromatography-Tandem Mass Spectrometry (GC-MS/MS). The results showed that POPs pesticides were frequently detected, including 2,4′-DDD, 2,4′-DDE, 2,4′-DDT, 4,4′-DDD, 4,4′-DDE, 4,4′-DDT, α-HCH, β-HCH, γ-HCH, δ-HCH, hexachlorobenzene (HCB), and mirex. Other detected pesticide species were dicofol, methamidophos and chlordimeform, which have rarely been reported. Comparing to different countries, the concentrations of total DDT and HCH in these three Chinese southeastern sites were in the middle range, whereas the HCB and mirex were in the lower end. A significant correlation was observed between region as well as age and POPs pesticide levels. Some pesticide residue levels were also found significantly correlated to occupation. However, there was no significant correlation between gender and pesticides. Meanwhile, it is interesting to find that mortality of malignant tumors tends to associate with the pesticides levels in human adipose tissue. More importantly, the measured data presented in this study provide realistic information which is useful for assessing human exposure to pesticides in the general population of Southeast China.