Biological control experiment of excess propagation of Cyclops for drinking water security

Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this study, an ecological project was put forward for the excess propagation control of Cyclops by stocking the filter-feeding fishes such as silver carp and bighead carp under the condition of no extraneous nutrient feeding. The results of experiments with different stocking biomass showed that the propagation of Cyclops could be controlled effectively, and the water quality was improved simultaneously by impacting on nutriment level and plankton community structure at proper stocking density of 30 g/m^3 of water. The growth of Cyclops may not be effectually controlled with lower biomass of fish （10 g）, and the natural food chain relation may be destroyed for Cyclops dying out in water while the intense stocking of 120 g per cubic meter of water. In addition, the high predator pressure may accelerate supplemental rate of nutrients from bottom sediments to water body to add the content of total nitrogen and phosphorus in water.     

Sludge concentration dynamic distribution and its impact on the performance of UNITANK

UNITANK is a biological wastewater treatment process that combines the advantages of traditional activated sludge process and sequencing batch reactor, which is divided into Tank A, B and C. In this study, the sludge distribution and its impact on performance of UNITANK were carried out in Liede Wastewater Plant （WWTP） of Guangzhou, China. Results showed that there was a strong affiliation between Tank A and B of the system in sludge concentration distribution. The initial sludge concentration in Tank A could present the sludge distribution of the whole system. The sludge distribution was mainly influenced by hydraulic condition. Unsteady sludge distribution had an impact on variations of substrates in reactors, especially in decisive reactor, and this could lead to failure of system. Settler could partially remove substrates such as COD and NO3-N, but there was adventure of sludge deterioration. The rational initial sludge concentration in Tank A should be 4000-6000 mg/L MLSS.     

Immunotoxicity of bisphenol a to Carassius auratus Lymphocytes and macrophages following in vitro exposure

Bisphenol A （BPA） is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical （EDC）. The reproductive toxicity of BPA has been extensively studied in mammals; however, relatively little information is available on the immunotoxic responses of fish to BPA. In this study, we investigated the effects of BPA on the immune functions of lymphocytes and macrophages in Carassius auratus. The effects of BPA were compared with those of two natural steroid hormones, estradiol and hydrocortisone. Proliferation of the two types of cells in response to PHA was measured using colorimetric MTT assay. Macrophage respiratory burst stimulated by Con A was measured using chemiluminescence assay. Results showed that BPA （0.054-5.4 mg/L）, estradiol （0.0002-2.0 mg/L） and hydrocortisone （5-50 mg/L） significantly induced Carassius auratus lymphocyte proliferation while higher doses of hydrocortisone （500-5000 mg/L） appeared to be inhibitory. BPA （0.005-50 mg/L）, estradiol （0.005-800 mg/L） and hydrocortisone （0.005-500 mg/L） markedly enhanced macrophage proliferation, whereas higher doses of BPA （500-1000 mg/L） appeared to inhibit cell proliferation. Furthermore, higher dosage of BPA （50 mg/L） and hydrocortisone （50 and 500 mg/L） suppressed the macrophages respiratory burst while estradiol is stimulative all the doses tested （0.05-500 mg/L）. In conclusion, BPA could have immunotoxicity to Carassius auratus and functional changes of lymphocyte and macrophage in Carassius auratus may be different between low and high dosages.     

基于不确定性分析的健康环境风险评价

基于对水源地石油污染等现场调查数据为基础,选取典型污染物苯,利用可传递参数差异的蒙特卡罗技术方法,分析了乙烯厂不同分区苯污染经过呼吸和饮水暴露途径造成人体健康风险的不确定性,量化不确定性因素影响的A地区人体健康风险水平.结果表明,裂解装置区是苯污染影响人体健康风险水平的主要来源,产生的健康风险水平均值为1.17×10^-4,而其他3个分区的影响较小;所有分区苯污染对A地区产生的人体健康总风险均值为1.18×10^-4,大于美国环保局人体健康风险建议值10^-6,对人体健康已产生影响;受不确定性因素影响,根据不同的人体健康可以承受的风险水平限值,污染对人体健康产生影响的概率存在差异.因此量化不确定性对风险水平的影响,可为污染场地的风险管理和修复行动提供科学依据.     

GC/MS法测定生物样品中多溴联苯醚类化合物

本研究建立了多溴联苯醚（PBDEs）生物样品分析方法,获得了优化的前处理条件、气相色谱和质谱检测条件.对定性定量方法及实验条件必须满足的要求进行了评价.通过质量控制（quality control, QC）对整个方法进行了验证.结果证明,本研究所建立的分析方法满足生物样品PBDEs测定的要求,回收率在50.5%～112.3%之间,回收率相对标准偏差在5.3%～9.9%之间,方法检测限在7.1～161.8 pg/g之间.在建立的方法基础上,测定了部分养殖和野生鱼类样品,测得的野生鳜鱼和鲫鱼以及2个养殖鲈鱼样品的结果分别为1.53、1.11、5.31和6.15 ng/g(干重),其中主要的同族体为BDE47.     

温带典型草地土壤净氮矿化作用研究

应用树脂芯方法,研究了内蒙古锡林河流域不同降水强度3种草地类型土壤净氮矿化作用.结果表明,7～10月份,羊草草原的平均净氮矿化率为0.333 kg·(hm²·d)^-1,贝加尔针茅草原为0.316 kg·(hm²·d)^-1,克氏针茅草原为0.211 kg·(hm²·d)^-1;在相同的培养周期内,分阶段培养和连续培养对土壤的净氮矿化量和净氮矿化速率有显著影响;降雨是影响该区域氮素矿化的主要因素之一,3种草地类型土壤水分变化量与土壤净氮矿化速率呈正相关关系,相关系数分别为0.80、0.61、0.56.     

西藏拉萨市土壤气中氡、汞环境地球化学特征

研究了拉萨市及其附近土壤气中的氡、汞地球化学特征,利用地质累计指数法评价了其环境质量.1?579个测点的测量结果表明,土壤气中氡、汞的背景值分别是7?634.9 Bq/m³、41.5 ng/m³,标准偏差分别为2.7 Bq/m³、2.2 ng/m³.土壤气氡环境质量在研究区东部和西部比较好,在中部从南向北有逐渐加重的趋势,最高达到中度污染;氡的主要污染源是山间盆地沉积物中局部富集的放射性铀元素.从拉萨郊区向市中心,土壤气汞污染程度逐渐增加,最高达到严重污染;污染源主要是废气中的汞、宗教活动中使用的汞以及含汞的垃圾和废水.     

强化供氧条件下潜流型人工湿地运行特性

针对潜流型人工湿地中溶解氧浓度和脱氮率偏低的问题,试验研究了强化供氧对植物和微生物的影响及人工湿地内溶解氧浓度、净化效率的变化规律.结果表明,强化供氧宜在湿地前端进行,最佳气水比为6左右,可采用连续供氧方式.供氧对湿地植物生理特性无明显不良影响,可显著增加湿地中硝化菌、反硝化菌数量,硝化菌可比供氧前高出1～2个数量级,反硝化菌高出1个数量级.强化供氧有效改善了湿地内氧环境,供氧前湿地内溶氧浓度普遍低于0.6 mg/L,供氧后氧浓度上升至1 mg/L以上.强化供氧有利于各类污染物质尤其是有机物和氮类物质的去除,有机物去除率比原湿地高出10％左右, TN去除率能够达到60％以上.因此,强化充氧措施具有较好的研究和应用价值.     

内分泌干扰物4-叔丁基苯酚在水中的氯化动力学研究

对典型内分泌干扰物4-叔丁基苯酚（4-TBP）在水中的氯化反应动力学进行了研究.结果发现,在不同HOCl初始浓度和pH条件下,4-TBP能够迅速被氯氧化,4-TBP的氯化反应符合二级反应动力学.表观速率常数k_app与pH值有关,在pH为5和9左右时,k_app分别达到最小值和最大值;对氯化反应中的每一个基元反应的反应速率常数进行了计算, HOCl与4-TBP的酸催化反应及ClO^-与4-TBP反应的速率常数分别为4.99×10⁶　L²·（mol²·min）^-1和1.96×10⁴　L·(mol·min)^-1,而HOCl与4-TBP的反应及HOCl与4-TBP^-的反应较慢,4-TBP^-与ClO^-不发生反应.水处理中氯消毒工艺对4-TBP的降解有一定的影响,在氯投加量为3 mg/L时,4-TBP的半衰期为12.1　min.     

好氧颗粒污泥膜生物反应器污泥性状研究

采用厌氧-好氧运行方式的颗粒污泥膜生物反应器（GMBR）,连续运行近120　d表现出良好的有机物去除及同步硝化反硝化能力.对GMBR中污泥粒径分布变化研究表明,GMBR中污泥浓度的增加主要是由于粒径0.18～0.45　mm的小颗粒污泥及小于0.18　mm的絮状污泥的增加造成的,粒径大于0.45　mm的颗粒污泥能够基本稳定维持其颗粒形态,反应器运行末期,GMBR中颗粒污泥（粒径大于0.18　mm的污泥）含量稳定在污泥总量的60％～65％以上.污泥表面电荷量随着污泥组成形态的变化电负性逐渐增加,80　d后稳定在-0.42～-0.80　meq·g^-1之间.污泥表面电荷的负电性增加主要是由小于0.45　mm的污泥造成的,其中小于0.18　mm的絮状污泥对其影响最大.并且,污泥粒径越大污泥表面负电荷量越少,两者具有较好的线性关系.另外,GMBR中SVI稳定在60～90 mL/g之间,并且随着污泥表面电荷负电性的增加污泥SVI值增加,两者之间具有一定的相关性.