基于弹性系数的大兴区环境-经济预警研究

在环境-经济系统中,选择弹性系数对区域节能减排做预警研究,构建基于弹性系数的区域环境-经济预警系统。将该预警系统应用于实际案例中,计算了符合北京市大兴区节能减排目标要求的弹性系数区间,对区域未来的环境-经济状况进行预测和预警。在惯性发展情景下,大兴区2010年和2020年环境-经济系统处于临界状态,节能减排达标尚存在一定困难,其中SO2、COD排放是区域环境-经济安全的最大影响因素。     

抑制城市内涝的有效措施:雨水资源化

频繁发生的城市内涝灾害,成为城市建设管理工作中讫待解决的的重大问题。地面明流超量、城市大量蓄水场地被侵占、城市路面下渗能力降低是引发内涝的主要原因。城市雨水资源化是从雨水源头做起,增加雨水收集利用量,优化排蓄组合,增大渗透量。既有效地实现雨水资源化,又达到减排与缓排洪水流量,抑制城市内涝的目的。     

Zero-valent iron and iron oxide-coated sand as a combination for removal of co-present chromate and arsenate from groundwater with humic acid

The combination of zero-valent iron (Fe⁰) and iron oxide-coated sand (IOCS) was used to remove Cr(VI) and As(V) from groundwater in this study. The efficiency and the removal mechanism of Cr(VI) and As(V) by using this combination, with the influence of humic acid (HA), were investigated using batch experiments. Results showed that, compared to using Fe⁰ or IOCS alone, the Fe⁰-IOCS can perform better on the removal of both Cr(VI) and As(V). Metal extraction studies showed that As(V) was mainly removed by IOCS and iron corrosion products while Cr(VI) was mainly removed by Fe⁰ and its corrosion products. Competition was found between Cr(VI) and As(V) for the adsorption sites on the iron corrosion products. HA had shown insignificant effects on Cr(VI) removal but some effects on As(V) removal kinetics. As(V) was adsorbed on IOCS at the earlier stage, but adsorbed/coprecipitated with the iron corrosion products at the later stage.     

红斑顠体虫在活性污泥中的生长特性研究

以活性污泥为研究对象,研究了污泥中红斑顠体虫的生长情况以及红斑顠体虫对污泥减量的影响.结果表明:(1)红斑顠体虫的培养温度应该保持在20℃以上.在低污泥负荷(F/M) (＜0.4 mg/(mg·d))下,红斑顠体虫均能大量出现.(2)当温度大于20℃、红斑顠体虫处于生长期的活性污泥浓度(MLSS)＞3.0 g/L时,红...     

纳米光催化还原去除水中铜离子

基于纳米光催化还原技术,以纳米二氧化钛作为光催化剂,研究一种水体中重金属Cu2＋去除方法。采用原子吸收评价水体中Cu2＋去除效果,考察了水体pH值、不同光源及光照时间、催化剂添加量、Cu2＋初始浓度以及乙醇加入量的影响。结果表明,Cu2＋初始浓度在2～50 mg/L,pH为6.0～8.0,添加0.3 g/L纳米二氧化钛...     

阴极氧还原产电生物可渗透反应栅的研究Ⅱ.酸蚀处理对不锈钢丝电极性能的影响

不锈钢毛虽然用作阴极氧还原产电生物反应栅（CORE—PRB）的电极材料虽然有很多优点,但是反应电流较小。尝试对不锈钢毛进行酸蚀处理后用作电极材料,并分别研究比较了4种不同电极组合的产电反应性能。酸蚀处理显著提高不锈钢毛阳极的反应性能,并对提高不锈钢毛阴极的反应性能有一定作用。酸蚀的作用主要是使不锈钢毛表面变得粗糙,有利于提高电极表面积和材料的生物亲和性。虽然生物产电反应对COD降解的直接贡献不到10％,但是不同电极组合下COD的去除率与它们生物产电反应的贡献率呈现高度正相关性。     

关于编制“十二五”环保规划的思考

围绕新形势下创建环保工作新道路这一主线,抓住十二五时期重大环境问题做了深刻思考,提出编制十二五环保规划应建立六个机制,即环境现状的评估机制、总量控制的扩项机制、污染减排的拓展机制、专项规划的环评机制、规划项目的筛选机制、规划执行力的保障机制,对基层工作具有借鉴作用。     

燃煤烟气中SO3成因、影响及其减排对策

煤燃烧过程中产生的SO3不仅造成了酸性烟雾,而且排放时会形成蓝色或黄色烟羽,增加了烟囱排放的烟羽浊度,破环了景观。近年来,火电厂烟囱常见的蓝烟/黄烟现象给周边大气环境带来一定的影响。针对部分燃煤电厂在脱硫、脱硝装置投运后,出现蓝烟/黄烟现象进行了研究,并提出了可供选择的控制对策和建议。     

柴油机SCR催化器载体结构参数优化

提出一种柴油机选择催化还原（SCR）催化器载体结构参数优化的设计方法,根据车用柴油机排量,将SCR催化器载体分为4类,选取载体体积、长度、目数、壁厚和涂层厚5个结构参数为设计变量,以高NO。转化率及低压力损失为优化目标,利用拉丁超立方实验设计选择样本点进行数值模拟,在构建的Kriging近似模型基础上,对载体结构参数采用改进的非支配排序遗传算法NSGA—II（non—dominatedsortinggeneticalgorithm—II）进行优化设计。结果表明：Kriging近似模型的拟合精度较高,结合NSGA—II算法对SCR催化器载体结构参数进行优化是可行的、有效的,不同排量下的优化结果均能够较好地满足设计要求。     

Effects of probiotic bacteria on the bioaccessibility of aflatoxin B1 and ochratoxin A using an in vitro digestion model under fed conditions

In the present study, we aimed at determining the release of aflatoxin B₁ (AFB₁) and ochratoxin A (OTA) from different food products in the gastro-intestinal tract in the absence and presence of probiotics, a possible adsorbent. The average bioaccessibility of AFB₁ and OTA without probiotics was about 90%, and 30%, respectively, depending on several factors, such as food product, contamination level, compound and type of contamination (spiked versus naturally contaminated). The six probiotic bacteria showed varying binding capacity to AFB₁ and OTA depending on the bacterial strain, toxin studied, type of food and contamination level. A reduction to a maximum of 37% and 73% as observed for the bioaccessibility of AFB₁ and OTA in the presence of probiotic bacteria, respectively. This is the first report on the effect of probiotic bacteria on reducing the fraction of mycotoxins available for absorption in the gastrointestinal tract from different food products.