不同水源补给河流浮游植物群落结构特征及其与环境因子的关系

为探究不同水源补给河流浮游植物群落结构的差异,于2019年5~11月对北京市北运河水系和永定河水系7条河流进行逐月采样调查,分析不同水源补给河流浮游植物群落结构特征,并采用相关性分析和冗余分析（RDA）探究浮游植物群落与环境因子之间的关系.结果表明,7条河流共监测到9门127种浮游植物,硅藻、绿藻和蓝藻为优势种群,分别占种类总数的40.94%、34.65%和10.24%.浮游植物密度介于（0.24~169.14）×10⁶ cell·L^-1之间,均值为38.20×10⁶ cell·L^-1,生物量介于0.21~78.50 mg·L^-1之间,均值为16.49 mg·L^-1.浮游植物种类、密度和生物量均表现为：混合水源补给组>完全再生水补给组>无再生水补给组.浮游植物生物多样性指数H''均值介于1.56~2.18之间,均匀度指数J均值介于0.47~0.67之间,H''和J均表现为：无再生水补给组>混合水源补给组>完全再生水补给组.RDA排序结果表明,影响混合水源补给组浮游植物优势种的主要环境因子为DOC、pH、Chla、DO和TP,影响无再生水补给组和完全再生水补给组优势种的主要环境因子为TN、NH₄⁺-N、N/P和ORP.     

Effect of applying persulfate on the accumulation of arsenic in rice plants grown in arsenic-contaminated paddy soil

Environmental Science and Pollution Research - Arsenic is known to be a notorious human carcinogen and rice consumption is becoming the primary human exposure route for As, especially in many Asian...     

Associations of long-term ambient air pollution and traffic-related pollution with blood pressure and hypertension defined by the different guidelines worldwide: the CHCN-BTH study

Environmental Science and Pollution Research - The assessment of the generalization of the strict hypertension definition in the 2017 ACC/AHA Hypertension Guideline from environmental condition...     

城市污水处理厂在工业污水管理中的地位

本文探讨了污水处理厂与源处理之间的相互影响和制约关系，目的是为有关部门进行水环境管理及做出科学决策提供依据．     

WO3/H2O2光催化氧化法处理草浆纸厂废水的研究

讨论了光催化氧化处理造纸废水的影响因素,如催化剂的用量、pH值、过氧化氢的用量、光照时间等,并通过正交试验,得出了WO3作为光催化剂处理草浆废水时的影响因素次序是:H2O2的用量＞WO3的用量＞光照时间＞pH值.确定了反应最佳工艺条件为:pH=6.00,H2O2加入量为0.24 mL,WO3用量为3g/L,光照时间为4 h,出水COD值达到排放标准.同时通过对造纸废水光催化氧化动力学级数的研究发现,光催化技术处理造纸废水的反应符合一级反应动力学.     

水中三嗪类除草剂的检测与分析质量控制

三嗪类除草剂作为预防农田杂草生长的除草剂在世界范围内广泛使用.由于水中农药残留浓度属痕量级,建立高效富集与分析方法非常重要.选取了6种三嗪类物质,建立了对水中痕量三嗪类物质的SPE-HPLC分析方法,并对其分析方法进行了质量保证与质量控制QA/QC研究.研究结果表明: 6种三嗪类物质的回收率在94%～116%之间,方法检测限在0.08～0.18 μg·L-1之间,方法重复性和检测限均能满足痕量分析及其质量控制的要求.3种水样的实际测试结果表明,在某河水中测得莠去津和扑草净的质量浓度分别为(5.28±0.43) μg·L-1和(7.12±0.54) μg·L-1.这说明该水体三嗪类农药的污染需受到重视.     

二氧化锰氧化降解五氯酚

以二氧化锰为氧化剂,研究了pH 4.12的水溶液中五氯酚氧化降解的反应动力学,并讨论了反应溶液的pH对反应动力学的影响.结果表明,五氯酚对二氧化锰的氧化作用具有较强的反应感受性.在pH一定和二氧化锰充分过量的条件下,随着反应的进行,五氯酚的降解速度变慢,遵循的不是简单的准一级反应动力学而是复合的反应动力学.此外,随溶液pH由3.5升高6.6,五氯酚的降解速度发生显著地下降.运用溶剂萃取和气质联用仪的分析方法,检测到2个主产物和1个次产物.其中,次产物是由四氯-1,4-氢醌与四氯儿茶酚组成的混合物;2个主产物是由五氯酚氧自由基偶合而成的二聚体,且是同分异构体.在观测到的表面反应动力学和降解产物的基础上,提出了五氯酚被二氧化锰氧化降解的反应流程图.     

Biosorption of cadmium(Ⅱ) and lead(Ⅱ) ions from aqueous solutions onto dried activated sludge

The removal of heavy-metal ions from aqueous solutions by using dried activated sludge has been investigated in batch systems. Effect of solution pH, initial metal ion concentration, and temperature were determined. The results of the kinetic studies showed that the uptake processes of the two metal ions（Cd（Ⅱ） and Pb（Ⅱ）） followed the pseudo-second-order rate expression. The equilibrium data fitted very well to both the Langmuir and Freundlich adsorption models. The FT-IR analysis showed that the main mechanism of Cd（Ⅱ） and Pb（Ⅱ） biosorption onto dried activated sludge was their binding with amide I group.     

Biotransfer of persistent organic pollutants from a large site in China used for the disassembly of electronic and electrical waste

Samples of groundwater, river water, river sediment, paddy soil, rice seeds, hen eggs, fish, umbilical cord blood, and newborn meconium were collected from October 2002 to October 2003 near a large site in China used for the disassembly of obsolete transformers and other electronic or electrical waste. Six indicator PCB congeners, three non-ortho dioxin-like PCB congeners, and six organochlorine pesticides were determined in the samples by GC with electron capture detector. The results demonstrated that the local environment and edible foods had been seriously polluted by toxic PCBs and organochlorine pesticides. The actual daily intakes (ADIs) of these pollutants were estimated for local residents living in the area. The intake data showed that the contents of PCBs in these local residents were substantial, as the ADI estimates greatly exceed the reference doses set by the World Health Organization and the United States Agency for Toxic Substances and Disease Registry. The presence of the indicator PCB congeners in the cord blood and the meconium samples, as well as significant correlations (r ² > 0.80, p < 0.05) between these levels, suggests a potential biotransfer of these indicators from mothers to their newborns. This preliminary study showed that obsolete transformers and other electronic or electrical waste can be an important source for the emission of persistent organic pollutants into the local environment, such as through leakage, evaporation, runoff, and leaching. Contamination from this source appears to have reached the level considered to be a serious threat to environmental and human health around the disassembly site.     

多源数据融合的城市区域型消防风险分布特征研究 ——以太原都市圈所在区域为例

分析区域消防风险的空间演化特征,针对性建立并调整消防站点,可预见性地降低消防风险.以太原都市圈所在区域作为研究对象,将遥感数据、POI兴趣点数据经标准化处理后融入GIS-GANP模型中,识别城市区域间特异性消防风险因子,探讨区域消防风险系数及空间分布特征,并多角度分析消防站点规划趋势.结果表明:POI数据符合区域融合发...