主养草鱼(Ctenopharyngodon idellus)池塘3种混养模式下氮含量的比较

对主养草鱼(Ctenopharyngodon idellus)池塘3种混养模式(模式Ⅰ,草鱼、鲢、鳙、鲫分别为250、35、40、15尾;模式Ⅱ,草鱼、鲢、鳙、匙吻鲟、鲫分别为250、35、20、20、15尾;模式Ⅲ,草鱼、鲢、鲫分别为250、35、15尾)水体和底泥中氮含量进行比较分析。结果表明,模式Ⅰ、Ⅱ、Ⅲ水体TN含量均值分别为1.251、1.001和1.228 mg.L-1,NH4+-N含量均值分别为0.391、0.345和0.319 mg.L-1,NO3--N含量由高到低为模式Ⅰ、Ⅱ和Ⅲ,NO2--N含量由高到低为模式Ⅱ、Ⅰ和Ⅲ。模式Ⅰ、Ⅱ、Ⅲ底泥TN含量均值分别为0.793、0.910和0.963 mg.g-1,NH4+-N含量均值分别为0.005、0.006和0.004 mg.g-1。模式Ⅱ水体TN含量显著低于模式Ⅰ和Ⅲ(P<0.05),底泥中氮营养盐的转化也优于其他2种模式,可见模式Ⅱ最有利于水体中氮营养盐的转化和利用。     

水产养殖对水生生态系统中汞甲基化影响研究进展

水产养殖造成的水体富营养化不仅导致有机质增加,而且致使很多水体理化参数发生变化,包括水中溶解氧下降、沉积物中有机质和硫酸盐、硫化氢的增加、pH值的下降、生物和微生物群落的破坏等.然而,目前国内外在这方面的研究极少,水产养殖对水体汞甲基化的影响尚不清楚,对其进行深入的研究,并提出合理利用和开发水资源的科学建议具有重要的现实意义.     

我区城市排水生物稳定塘（污水库）功能,利用现状及对策简析

生物稳定塘在我区城市污水处理、利用中具有相当重要的作用,在今后相当长的时间内它将继续存在,生物稳定塘使用中存在的问题也反映了我区城市污水处理及排水利用系统的运行水平及要害问题,须通过综合决策、集中治理、强化管理等手段加以解决。     

Heavy metal and nutrient contamination of marine sediments in Hong Kong

A monitoring programme was performed to use marine sediments as an indicator of marine contamination in Hong Kong. A total of 51 samples were collected from eight marine sites and analysed for pH, redox potential, salinity, total‐N, total‐P, total organic carbon, and total Cu, Zn Pb, Cr and Cd. Sites with high industrial or aquacultural activities contained high total organic carbon contents, total‐N and total‐P contents. Sediments from sites with high industrial activities also enriched with heavy metals. Metal speciation results indicate that Cu and Cr existed mainly in the organic fraction, Pb and Zn were distributed approximately equally in both the organic and residual fractions while Cd mainly occurred in the residual fraction. The Cu, Cr and Zn contents were highly correlated with total organic carbon contents. All samples were classified as non‐acid forming according to the net acid generation test and only samples from the industrial site released a high concentration of heavy metals under a complete oxidising condition. The present study reveals that organic and heavy metal pollution is serious in the marine sediments of Hong Kong, and industrial and aquacultural activities are probably the major sources of contamination.     

户用沼气池建设对改善农村生态环境效果分析

通过对河南省9个县(市)中9个乡(镇)的非沼气户和沼气户土壤、地表径流和室内空气进行监测,定量对比分析了户用沼气池建设对农村生态环境改善效果。结果显示,沼气户土壤中的速效磷、速效钾、有机质和全氮含量要高于非沼气户,且"四位一体"生态模式沼气户土壤中4种养分含量明显高于"三位一体"生态模式;沼气户地表径流中的COD、NH₃-N、 TP浓度均低于非沼气户;沼气户室内空气中的CO、SO₂、NH₃、PM₁₀浓度均低于非沼气户,且室内空气中的4项污染物浓度随季节变化而不同。这说明户用沼气池建设对于增加土壤养分、减轻农村面源污染、改善农户居住环境、实现节能减排效果显著。     

秦岭山区尾矿库环境防护距离研究

尾矿库对其周边居民的环境影响目前已受到较大关注,如何对尾矿库环境防护距离进行确定是目前尾矿库建设项目环境影响评价的重点.基于大气环境防护距离、溃坝环境防护距离的基本原理,选取扬尘影响、溃坝事故影响这两种主要影响,计算对比出了秦岭山区尾矿库的环境防护距离.通过与以前使用的《一般工业固体废物贮存、处置场污染控制标准》(GB18599—2001)规定的防护距离进行比较,结果表明:1以前使用的《一般工业固体废物贮存、处置场污染控制标准》(GB18599—2001)中规定的环境防护距离明显过小,不能满足保证尾矿库周边居民的生命及财产安全的要求;2尾矿库溃坝事故影响为尾矿库环境防护距离确定的决定性因子.     

Prospects for a self-sustainable sewage treatment system: a case study on full-scale UASB system in India's Yamuna River Basin

The government of India decided to launch a project to implement 16 full-scale Upflow Anaerobic Sludge Blanket (UASB) reactors (with a total capacity of 598,000 m(3)/d) in the Yamuna River basin under its Yamuna Action Plan (YAP). A polishing pond called the Final Polishing Unit (FPU) was utilized for post-treatment. This paper evaluates the sewage treatment efficiency of the combined system of full-scale UASB reactors and polishing ponds under Indian climatic conditions. Results have shown that the effluent from the sewage treatment plants (STPs) investigated failed to comply with applicable discharge standards in terms of BOD, SS, and fecal coliform removal. Therefore, it is proposed that such proper operation and maintenance as removing excess sludge and scum be conducted in order to increase treatment efficiency. Moreover, trained and experienced workers are also required to operate and maintain the systems, along with a scientific approach.     

水产养殖自身污染及其生物修复技术

介绍了生物修复的概念、水产养殖存在的自身污染问题及其主要生物修复技术.营养物污染、药物污染和底泥富集污染是水产养殖存在的主要自身污染问题;微生物修复、水生植物修复和水生动物修复是污染养殖水域生物修复的3种主要形式;微生物的有效性、生物入侵、二次污染、修复生物的季节性和非水生植物的利用等方面是实施生物修复应注意的主要方面.最后指出,推行清洁生产、实行生态养殖是水产养殖业可持续发展的出路.     

人工粘土层在枯水期对小清河氧化塘底质水盐运动的抑制模拟研究

利用实验室土柱模拟装置对枯水条件下盐渍地区氧化塘不同底质土壤结构的水盐运移状况进行了定性模拟研究,结果表明,原底质均质白汤土输水能力较大,蒸发较易发生,因而带动盐分在塘底表面大量累积,维持该水盐运移的最大吸力值为１２０ｃｍ,而经人工改造后,表层有３０ｃｍ粘土覆盖的土壤层结构对水盐运移有强烈的抑制作用,在模拟３个月的蒸发时间内表面没有盐分累积。     

华北稳定塘氧平衡的研究

溶解氧(DO)是氧化塘内有机物降解的主要动力,本文介绍了华北稳定塘中的妤氧塘和强化塘进行污水妤氧处理所需氧的来源主要是浮游藻类光合放氧。在春季和秋季藻类产的氧可占水体溶解氧总来源的80％左右,氧的消耗是以“水呼吸”耗氧为主,“泥呼吸”耗氧为次。从氧平衡的角度阐述了各塘有机物降解与藻类产氧、生物耗氧的关系。