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101.
建立潜流湿地有机污染物迁移转化模型,采用多孔介质模型描述潜流湿地的水力特性,并引入Monod方程相耦合,实现对湿地系统内部流场及水质浓度的同时模拟。通过实验,校核模型参数,并验证模型。结果表明,该模型能较好模拟潜流湿地中有机污染物的去除效果;计算条件下,在不同基质填料的潜流湿地中都会出现滞水区和快速通道,影响水力效率与污染物去除效果;预测了不同填料系统中7种典型选控性有机污染物的去除效果,其处理效率:苯胺苯酚二甲苯甲苯苯硝基苯氯苯,可通过优选填料提高吸附量和延长停留时间来提高选控性有机物的处理效果。 相似文献
102.
重铬酸钾─三氯化钛法测定水中溶解氧 总被引:1,自引:0,他引:1
杨积晴 《环境监测管理与技术》1996,(5)
介绍了三氯化钛(TiCl3)与氧反应,以钨酸钠(Na2WO4)作指示剂,用重铬酸钾溶液滴定过剩三氯化钛来测定水中溶解氧的方法。本法与碘量法比较,结果表明方法准确、快速,适合于水样中溶解氧的测定 相似文献
103.
104.
Mercury (Hg) has received considerable attention because of its association with various human health problems. Adsorption-desorption behavior of Hg at contaminated levels in two paddy soils was investigated. The two representative soils for rice production in China, locally referred to as a yellowish red soil (YRS) and silty loam soil (SLS) and classified as Gleyi-Stagnic Anthrosols in FAO/UNESCO nomenclature, were respectively collected from Jiaxin County and Xiasha District of Hangzhou City, Zhejiang Province. The YRS adsorbed more Hg(2+) than the SLS. The characteristics of Hg adsorption could be described by the simple Langmuir adsorption equation (r2 = 0.999 and 0.999, P < 0.01, respectively, for the SLS and YRS). The maximum adsorption values (Xm) that were obtained from the simple Langmuir model were 111 and 213 mg Hg(2+) kg(-1) soil, respectively, for the SLS and YRS. Adsorption of Hg(2+) decreased soil pH by 0.75 unit for the SLS soil and 0.91 unit for the YRS soil at the highest loading. The distribution coefficient (kd) of Hg in the soil decreased exponentially with increasing Hg(2+) loading. After five successive desorptions with 0.01 mol L(-1) KCl solution (pH 5.4), 0 to 24.4% of the total adsorbed Hg(2+) in the SLS soil was desorbed and the corresponding value of the YRS soil was 0 to 14.4%, indicating that the SLS soil had a lower affinity for Hg(2+) than the YRS soil at the same Hg(2+) loading. Different mechanisms are likely involved in Hg(2+) adsorption-desorption at different levels of Hg(2+) loading and between the two soils. 相似文献
105.
Dryland area occupies 37% of the national territory in China. Desertification and other disasters have limited dryland sustainable development. Here we overview the dryland characteristics and desertification status and introduce four regionally optimized eco‐productive paradigms for dryland sustainable development, i.e., the mountain‐oasis paradigm in arid desert; the small watershed‐based paradigm on the Loess Plateau; the integrated animal husbandry paradigm on the Inner Mongolia Steppe and the agro‐pastoral transitional region; and three circle paradigm on the Ordos Plateau. These paradigms are established on the basis of regional landscape patterns and their underlying material and energy flow rules, and different functional belts are determined and capitalized upon with the integrated consideration of regional biogeophysical processes, biogeochemical cycles and biogeosocial relations. These paradigms cannot cover all complex landscape types, but provide theoretical frameworks and practicable models for dryland sustainable development in China. 相似文献
106.
固相微萃取(SPME)技术在水质监测中的应用 总被引:3,自引:0,他引:3
固相微萃取技术(SPME)作为一种样品前处理技术,具有方便、快捷、不使用有机溶剂、灵敏度高、价格低廉等优点,已被广泛地应用于环境样品的分析.本文综合评述了采用SPME法预处理环境水体中的有机物、无机离子等污染物的监测情况,并对SPME法在环境水质监测中的应用以及对国外的研究进展进行了展望. 相似文献
107.
Environmental contaminants with estrogenic activity have recently attracted attention due to their potential detrimental effects on the reproduction of human and wildlife. The aim of this study was to evaluate the use of endogenous glutathione and glutathione-related enzymes as biomarkers of exposure to landfill leachate effluent and bisphenol A (BPA) in the freshwater snail, Bellamya purificata. Following exposure to 1%, 5% and 10% landfill leachate effluent and 1, 10, 50 and 100mugl(-1) BPA for 0, 2, 7 and 15d, activities of glutathione S-transferase (GST), selenium-dependent glutathione peroxidase (SeGPx) and glutathione reductase (GR) and levels of total glutathione were measured in the gills and digestive glands of the snails. GST and total glutathione were the most sensitive parameters in both exposure scenarios. GST activities increased by about 80%, while total glutathione decreased to 70% and 80% in the gills and digestive glands, respectively. In contrast, SeGPx and GR activities remained at the same levels in all the treatment groups compared with those of controls. The results indicated that among glutathione and glutathione-related enzymes, GST activity and total glutathione level, which showed dose-dependent dynamics, could be used as biomarkers of aquatic ecosystems contaminated with landfill leachate. 相似文献
108.
A green-house study was conducted in late 2005 to investigate the aging behavior of p,p'-DDE in two types of soil, Hydragric Anthrosols (An) and Hydragric Acrisols (Ac), according to the World Reference Base (WRB) [FAO/ISRIC/ISSS. 1998. World reference base for soil resources. World soil resources reports, Rome. p. 87]. Paddy rice and dry rice were grown in submerged paddy soils and non-submerged upland soils, respectively. The concentration of extractable p,p'-DDE in fresh DDE-spiked soils was 746.2ngg(-1). During the first few weeks of the experiment, the extractability of p,p'-DDE became increasingly low as the aging period prolonged. However, certain amount of p,p'-DDE that had been captured by soil minerals and organic matter (OM) could be released and became extractable in the later period. The extractability of p,p'-DDE in submerged soils was significantly lower than that in non-submerged soil, because flooding could increase the binding of pollutants to soil particles. The plantation of both dry rice and paddy rice slowed down the aging process of p,p'-DDE. After one month's growth of rice, p,p'-DDE bound to soil particles was released and became extractable. The OM and silt content of An are higher than that of Ac, resulting in more bound residues and relative lower extractability of p,p'-DDE in An. In addition, the extractability of p,p'-DDE could be reduced by the addition of rice straw to soils. 相似文献
109.
In order to evaluate the municipal sewage treatment systems used at Harbin municipal sewage treatment plant for their pollutant removal efficiency, raw sewage and effluent samples at different treatment stages from the sewage treatment systems were taken, priority pollutants (PPs) were identified and quantified using gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma-atomic emission spectrograph (ICP-AES). The test results indicated that there were one hundred and fifty species of organic pollutants identified in the raw sewage sample, and only ten species of PPs in all the sewage samples. The levels of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di-n-octyl phthalate (DnOP) in the sewage samples were 0.779-0.111 microg l(-1), 1.977-0.022 microg l(-1), 6.411-2.194 microg l(-1) and 7.152-2.953microg l(-1), respectively, and most of these phthalate esters (PAEs) were removed through anaerobic/aerobic (A/O) process; The levels of alachlor, acetochlor, atrazine were 0.074-0.021 microg l(-1), 0.160-0.096 microg l(-1) and 0.238-0.184 microg l(-1), respectively, and the total removal efficiency of atrazine was poorest through the sewage treatment systems. The levels of Cu, Cr, Se, Hg, Ni and Zn were 0.0030-0.2327 mg l(-1). It is therefore concluded from these results that the sewage treatment systems were efficient in removing most of the organic and inorganic compounds in this study, and so, the discharged effluent could cause little of the secondary pollution of the aquatic environment. 相似文献
110.
计算机模拟研究UO2+2在人体细胞液的形态分布 总被引:1,自引:0,他引:1
建立了由多种金属离子和小分子配体组成的多相细胞液热力学平衡模型.模拟研究了UO2 2在组织液和细胞液的形态分布及CO2-3、氨三乙酸(NTA)和乙二胺四乙酸(EDTA)浓度对细胞液中UO2 2形态分布的影响.在组织液中,正常生理pH下,当各形态UO2 2总摩尔浓度 [U]= 1.0×10-6 mol/L 或[U]=1.0×10-3 mol/L时,UO2 2均主要以[UO2(CO3)3]4-和[UO2(CO3)2]2-形态存在.在细胞液中,当[U]=1.0×10-6 mol/L时,UO2 2主要以[UO2(CO3)3]4-和[UO2(CO3)2]2-存在;当[U]=1.0×10-3 mol/L,pH为6.0~6.8时,细胞液中存在大量的固相(UO2)3(PO4)2·4H2O,当pH为6.8~7.4时,UO2 2主要以[UO2(CO3)3]4-、[UO2(CO3)2]2-和[(UO2)2CO3(OH)3]-存在.细胞液中(UO2)3(PO4)2·4H2O含量随[U]升高而增加.通过调节细胞液pH和增加细胞液CO2-3浓度均能降低其固相UO2 2配合物含量.在细胞液中增加NTA会增加(UO2)3(PO4)2·4H2O含量,当添加EDTA时会显著降低(UO2)3(PO4)2·4H2O含量. 相似文献