上海郊区稻田氮素流失研究

通过测坑和大田小区试验，研究了上海郊区稻田氮素排水流失和渗漏流失的特征、相关因素和流失负荷。结果表明，稻田综合排水TN为6.55mg／L，流失负荷为16．68kg／hm^2，以铵态氮为主，稻田氮素的排水流失负荷为16．68kg／hm^2。稻田渗漏水氮浓度与前茬作物有关，草莓和蔬菜高，麦茬低，TN为5．73mg／L，渗漏负荷为22．92kg／hm^2，其中硝态氮占50％左右。稻田氮素总流失负荷占稻季化肥用量的13．23％。测坑和大田试验都证明，施用有机肥可较多地减少稻田氮素流失量。     

一体式膜生物反应器回用处理生活污水

将循环活性污泥系统(Cyclic Activated Sludge System,CASS)与膜过滤技术组合为一体式膜生物反应器(Submerged Membrane Bioreactor,SMBR),研究其用于生活污水回用处理的可行性,对该工艺的适宜运行条件进行了研究.结果表明,水力停留时间(HRT)为4 h、DO在2.0～3.5 mg/L、温度控制在常温、pH在6.5～8.0的运行条件是比较经济高效的.并考察了装置对实际生活污水的处理效果,结果表明出水水质优异,优于中水回用标准(CJ 25.1-89).     

臭氧化对垃圾填埋场后期渗滤液的预处理研究

应用自制微孔扩散式接触反应器,考察了不同pH条件下垃圾填埋场后期渗滤液的臭氧化预处理效果.结果表明,渗滤液初始pH值升高,臭氧利用率增大,垃圾渗滤液中COD、腐殖酸的去除速率加快;当初始pH为10时,经臭氧化处理120 min后,模拟废水的BOD5/COD可从初始的0.17提高到0.36,改善了废水的可生化性,同时渗滤液的色度、浊度、腐殖酸和SS也有较高的去除率.     

热带海水养殖清洁生产技术模式探讨

采用太阳光化学修复原理对典型热带地区--海南省某养殖场废水进行清洁闭环生态养殖技术初步探讨.采用现场定位观测实验研究方法,探讨高位池光化学循环净化装置对养殖废水中COD、SS等污染物的去除效应、脱氮解毒效应以及增氧效应等.结果表明,本实验装置能有效地实现热带地区高位池循环水养殖及养殖污水的"零排放",是满足环保要求的一种多功能、低成本、效果好的水体净化方法.     

危险废物的处理处置措施研究

危险废物因具有毒性、易燃性、腐蚀性、反应性和感染性等多种危害特性,如果暴露于环境中将会对生态环境和人类健康造成很大威胁;所以及时而有效地处理处置危险废物意义极为重大.文章简要地介绍了危险废物的定义及其来源,并指出其对环境和人类造成的危害,总结了我国目前的危险废物处理处置技术的现状,根据我国危险废物污染防治的技术路线和技术政策,分析了危险废物的处置措施,系统地论述了常规危险废物的常用处置方法,从而揭示了我国在危险废物处理处置方面及管理方面的问题,并提出针对危险废物处理处置的对策与建议.     

广州市白云人工湖生态修复工程设计

广州市白云湖是广州市最大的人工生态服务湖泊,通过对白云湖生态修复工程进行设计,采用了炭素纤维生态草、微纳米气泡发生装置及纯氧发生器和人工干预与生物处理相结合生态浮床等环保新技术对白云湖水体进行综合生态修复,并对白云湖水质进行跟踪监测。结果显示,白云湖水质提升工程实施之后,白云湖各项水质指标都有一定的改善。白云湖生态修复工程的设计经验对于类似人工水体的水质改善和生态修复工程建设具有参考意义。     

Biosorption and degradation of decabromodiphenyl ether by <Emphasis Type="Italic">Brevibacillus brevis</Emphasis> and the influence of decabromodiphenyl ether on cellular metabolic responses

There is global concern about the effects of decabromodiphenyl ether (BDE209) on environmental and public health. The molecular properties, biosorption, degradation, accumulation, and cellular metabolic effects of BDE209 were investigated in this study to identify the mechanisms involved in the aerobic biodegradation of BDE209. BDE209 is initially absorbed by wall teichoic acid and N-acetylglucosamine side chains in peptidoglycan, and then, BDE209 is transported and debrominated through three pathways, giving tri-, hepta-, octa-, and nona-bromodiphenyl ethers. The C–C bond energies decrease as the number of bromine atoms on the diphenyl decreases. Polybrominated diphenyl ethers (PBDEs) inhibit protein expression or accelerate protein degradation and increase membrane permeability and the release of Cl^?, Na⁺, NH₄ ⁺, arabinose, proteins, acetic acid, and oxalic acid. However, PBDEs increase the amounts of K⁺, Mg²⁺, PO₄ ^3?, SO₄ ^2?, and NO₃ ^? assimilated. The biosorption, degradation, accumulation, and removal efficiencies when Brevibacillus brevis (1 g L^?1) was exposed to BDE209 (0.5 mg L^?1) for 7 days were 7.4, 69.5, 16.3, and 94.6 %, respectively.     

Sources and the distribution of heavy metals in the particle size of soil polluted by gold mining upstream of Miyun Reservoir,Beijing: implications for assessing the potential risks

Mining has been carried out upstream of Miyun Reservoir, Beijing, for several decades, and has caused metal emissions to the environment, threatening human health. We conducted a soil survey to assess metal contamination in this area and to determine distribution of heavy metals in the particle size. We attempted to determine the possible sources of the metals and the significance of metals in the fine particle fractions to soil risk assessments. Thirty-four soil samples were collected, and eight samples were partitioned into seven size fractions. Most of the metal concentrations in the soils were higher than the background levels in Beijing, and the metal concentrations and total organic matter (TOC) contents generally increased as the particle size decreased. Each metal except Hg significantly positively correlated with the TOC. The metals in the coarse-grained soils were mainly derived from parent materials, but the metals in the fine fractions were mostly anthropogenic. Statistical analyses showed that there were three metal sources: Cd, Cu, Hg, Pb, and Zn had anthropogenic sources; Co, Cr, Ni, and V had mixed anthropogenic and natural sources; and As and Be had natural sources. The trace metals were primarily in the clay and fine silt fractions, and they might pose health risks through the inhalation of resuspended soil particles (PM10 and PM2.5). The elevated accumulation factors, enrichment factors, and ecological risk indices for the metals in the fine fractions suggest that risk assessments should be based on the fine particle size.     

Functional soil organic matter fraction in response to short-term tillage management under the double-cropping rice paddy field in southern of China

Environmental Science and Pollution Research - Soil organic matter (SOM) and its fraction play an important role in maintaining and improving soil fertility of paddy field. However, there is still...     

Interaction of pig manure-derived dissolved organic matter with soil affects sorption of sulfadiazine,caffeine and atenolol pharmaceuticals

Environmental Geochemistry and Health - Pharmaceutically active compounds (PhACs) released into the environment have an adverse impact on the soil and water ecosystem as well as human health....