Effect of calcium on adsorption capacity of powdered activated carbon

We investigated the effect of calcium ion on the adsorption of humic acid (HA) (as a target pollutant) by powered activated carbon. The HA adsorption isotherms at different pH and kinetics of two different solutions including HA alone and HA doped Ca²⁺, were performed. It was showed that the adsorption capacity of powdered activated carbon (PAC) for HA was markedly enhanced when Ca²⁺ was doped into HA. Also, HA and Ca²⁺ taken as nitrate were tested on the uptake of each other respectively and it was showed that the adsorbed amounts of both of them were significantly promoted when HA and calcium co-existed. Furthermore, the adsorbed amount of HA slightly decreased with the increasing of Ca²⁺ concentration, whereas the amount of calcium increased with the increasing of HA concentration, but all above the amounts without addition. Finally, the change of pH before and after adsorption process is studied. In the two different solutions including HA alone and HA doped Ca²⁺, pH had a small rise, but the extent of pH of later solution was bigger.     

战略环境评价研究与实践进展

回顾了战略环境评价的起源，发展历程，尤其是９０年代以来的实践与研究成果；分析了当前研究趋势并提出了今后我国战略环境评价工作的重点，包括加强研究，建立保证体系和进行试点等。     

环境空气中苯乙酸监测方法研究

采用预浓缩系统与GC/MS的联用,建立了受污染空气中恶臭气体的分析方法,用苏玛罐采集空气样品在预浓缩系统中经液氮于-160℃冷冻浓缩后,进入GC/MS进行分析.12h内,苏玛罐中24℃的凝结水不影响苯乙酸的再回收,三级冷阱预浓缩技术能够有效的除去水(相对湿度RH>95%)和二氧化碳(3.8%).该方法检测可以达到ng级,经6次重复测定,其相对标准偏差小于6.1%.     

Simulated wetland conservation-restoration effects on water quantity and quality at watershed scale

Wetlands are one of the most important watershed microtopographic features that affect hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models such as the Soil and Water Assessment Tool (SWAT), enhanced by the hydrologic equivalent wetland (HEW) concept developed by Wang [Wang, X., Yang, W., Melesse, A.M., 2008. Using hydrologic equivalent wetland concept within SWAT to estimate streamflow in watersheds with numerous wetlands. Trans. ASABE 51 (1), 55–72.], can be a best resort. However, there is a serious lack of information about simulated effects using this kind of integrated modeling approach. The objective of this study was to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota. The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes and wetland characteristics (e.g., size and morphology) to be accurately represented in the models. The loss of the first 10–20% of the wetlands in the Minnesota study area would drastically increase the peak discharge and loadings of sediment, total phosphorus (TP), and total nitrogen (TN). On the other hand, the justifiable reductions of the peak discharge and loadings of sediment, TP, and TN in the Manitoba study area may require that 50–80% of the lost wetlands be restored. Further, the comparison between the predicted restoration and conservation effects revealed that wetland conservation seems to deserve a higher priority while both wetland conservation and restoration may be equally important.     

七星河湿地水环境重金属污染特征与风险评价

为识别农业区湿地水环境中重金属的污染水平、空间分布特征和风险传递效应,采集了三江平原七星河湿地水体、沉积物和鱼类样品,并测定了Cu、Cr、Cd、Zn和Ni 5种重金属的含量。结果表明:水体和沉积物中重金属的平均含量由高到低依次为Zn （28.0） > Cr （4.5） > Cu （3.2） > Ni （2.6） > Cd （0.1）（水体,μg/L）和Zn （139.4） > Cr （81.9） > Ni （45.7） > Cu （24.4） > Cd （0.2）（沉积物,mg/kg）。水体中所有重金属含量均优于GB 3838—2002《地表水环境质量标准》Ⅰ类标准,而所有采样点沉积物中的Zn和Cd均超过黑龙江省土壤背景值（Zn:70.7 mg/kg;Cd:0.086 mg/kg）。除葛氏鲈塘鳢（Perccottus glenii）未检出Ni外,东北湖鱥（Phoxinus percnurus）和北方花鳅（Cobitis granoei）中5种重金属均有检出,且北方花鳅对Zn的富集已达到"中等富集"水平,鱼类样品中其他重金属均处于"低富集"状态。以水生生物允许限值和沉积物质量指南作为参考限值的单因子风险指数（CF）的计算结果表明,水体和沉积物中的Cr对水生生物构成了"高风险",且Cr对综合风险指数（PLI）的贡献最高。鱼类样品中5种重金属的目标危害系数（THQ）和综合危害指数（HI）均<1（Cr对HI的贡献率超过70%）,表明长期食用七星河湿地野生鱼类不会引起非致癌风险,但食用野生鱼类暴露Cd的癌症风险指数（CR）超过10-5,存在引发癌症风险的可能。     

城市综合污水处理厂污泥对Daphnia magna 的急性毒性与毒物特征

以城市综合污水处理厂污泥的浸提液对Daphnia magna的24h急性毒性为指标，研究了污泥放置时间与其毒性的关系。结果表明，污泥对Daphnia magna的急性毒性随旋转时间的增加逐渐增大，但在旋转两个月后毒性趋于稳定。对放置3d和84d的污泥，利用TIE（毒性鉴别评价）方法对其浸提液进行了毒物特性鉴别，结果表明，放置3d的污泥，浸提液毒性主要由酸性条件下易挥发的物质引起，放置84d的污泥浸提液中的毒物主要为金属离子和易与酸碱反应的物质。     

用于四氯乙烯降解的厌氧污泥的培养与驯化研究

由于四氯乙烯 (PCE)的大量使用和不合理的处置使其成为常见的污染物之一。PCE在好氧条件下不发生生物降解 ,只在厌氧条件下通过还原脱氯发生生物降解。本研究主要是对从不同处理厂获得的厌氧污泥进行培养 ,选出合适的厌氧污泥 ,进行降解PCE的厌氧污泥的驯化 ,为以后进行降解PCE的动力学研究和优势菌种的筛选做准备。同时 ,在实验中检测到了三氯乙烯 (TCE) ,表明PCE是通过还原脱氯发生生物降解的。     

炼油污水的深度处理

论述了炼油污水深度处理的常用技术--过滤、膜分离及化学氧化技术,对炼油污水深度处理进行了中试试验,并结合试验结果对动态砂滤系统、PAN膜处理系统和高级氧化系统处理炼油厂二级排放水的适用性进行了论证。结果表明,二级排放水经动态砂滤系统和NF纳滤系统处理后,COD、氨氮、SS、硫化物、酚、浊度、总铁等指标均达到循环水补水水质要求,可以回用于循环水场;经PAN膜制成的UF超滤和RO反渗透系统处理后,各种污染物指标和盐类指标都降至微量,且脱盐效果明显。     

分段重铬酸钾法测定高氯离子废水COD方法研究

通过对高盐废水COD测定时氯离子干扰与氧化剂浓度的关系研究发现:氧化剂浓度对氯离子干扰程度有较大的影响。根据研究结果,提出了用分段重铬酸钾法测定高盐废水COD的设想,并对此设想进行了验证。验证结果表明:用分段重铬酸钾法测定高盐废水COD的设想是完全可行的;而且方法的准确度较好,相对误差<9%,实际废水加有机物的回收率>92%。