温度和pH值对活性污泥法脱氮除磷的影响

温度和pH值是影响污水脱氮除磷效果的2个重要因素.试验采用连续搅拌槽式反应器(continuous stirred tank reactor,CSTR),通过对不同温度和pH值条件下的硝化、反硝化、释磷和吸磷反应速率的测定,总结出温度和pH值对活性污泥生化反应速率的影响规律.试验表明,硝化和反硝化速率随温度的升高而加快.在5℃和33℃时,硝化速率分别为0.01 kg NH4 -N/(kg VSS·d)和0.28 kg NH4 -N/(kg VSS·d);在5℃和30℃时,反硝化速率分别为0.097 kg NO3--N/(kg VSS·d)和0.476 kg NO3--N/(kg VSS·d);但温度对吸磷和释磷速率的影响不大.pH值对硝化、反硝化、吸磷和释磷速率均有显著影响,在pH值为7.74时,硝化速率为0.095 kg NO3--N/(kg VSS·d);而在pH值为4.9和10.08时,硝化速率仅为0.005 kg NO3--N/(kg VSS·d)和0.006 kg NO3--N/(kg VSS·d).在pH值为7.85时,反硝化速率达到最大值0.36 kg NO3--N/(kg VSS·d);而在偏酸性和碱性条件下,反硝化速率显著下降.     

速灭菊酯在水稻-水-鱼系统中的动态

采用同位素示踪技术和模拟生态系统试验法,对水田施用速灭菊酯后对邻近水域的污染、水域中鱼类对速灭菊酯残留物的浓缩和排除等进行了研究,结果表明,在田表水中,残留物浓度随处理后时间而迅速降低。水系中淤泥对水中残留物有明显的吸附净化作用,鱼对水中速灭菊酯残留物的摄取和排除均很迅速。 用二室模型对速灭菊酯残留物在田表水中的消失、用一级输入和输出的单室模型对鱼体中残留物浓度随时间的变化动态研究表明,在田表水中,土壤对水中残留物起着强烈的吸附净化作用;在水系中,鱼体中残留物浓度的消长主要取决于残留物自身在水中的消失速率,只是在前期同时依赖于鱼体对残留物的排除效应,鱼体的摄入常数只对鱼体累积浓度最大值及到达最大值的时间T_m产生影响。     

酒精废醪厌氧消化过程中的污泥产量

对酒精废醪在厌氧消化过程中厌氧污泥来源进行了分析，提出了计算厌氧污泥产量的方法，并对影响酒精废醪套也立立抟的了探讨。     

德腊门:要做可持续发展的领跑者

提到挪威。人们首先想到的肯定是冰封雪飘的北极圈。还有盛产石油天然气的北海油田和极其丰富的水利资源。为减缓气候变化。他们不再建设燃煤和燃油电厂、燃气发电厂以及水电站。转而用生物燃料和风能发电。发展可再生能源。我们选择德腊门市（Drammen）。这个荣获“2004年挪威环境奖”的绿色城市。去追寻其可持续发展的实践。[编者按]     

重庆市区2000年前大气环境质量的灰色预测

本文运用灰色系统理论,预测了重庆市区1990年至2000年的大气质量变化趋势。     

掺杂负载型纳米TiO2降解橙黄G的光催化活性及其动力学研究

采用溶胶-凝胶法和浸渍-焙烧法制备了掺杂Sn(Ⅳ)的TiO2/AC光催化剂,以偶氮染料橙黄G为目标降解物,对光催化反应条件进行了优化.结果表明:利用Sn(Ⅳ)掺杂量为2.5 at.%的TiO2/AC光催化剂,在进水浓度50 mg/L,催化剂的用量12.5 g/L,pH值2.0,H2O21.5 mL/L,主波长为365 nm的300W高压汞灯光照条件下,反应60 min,橙黄G的光催化去除率可达99.1%.该反应符合Langmuir-Hinshelwood动力学方程,其速控步为吸附反应.共存阴离子SO42-和H2PO4-,对橙黄G的光催化降解反应均有一定的抑制作用.     

Characterizing the antibiotic resistance genes in a river catchment: Influence of anthropogenic activities

Previous studies on environmental antibiotics resistance genes(ARGs) have focused on the pollution sources such as wastewater treatment plants, aquaculture and livestock farms,etc. Few of them had addressed this issue in a regional scale such as river catchment. Hence,the occurrence and abundances of 23 ARGs were investigated in surface water samples collected from 38 sites which located from the river source to estuary of the Beijiang River.Among them, 11 ARGs were frequently detected in this region and 5 ARGs(sul I, sul II, tet B,tet C, and tet W) were selected for their distribution pattern analysis. The abundances of the selected ARGs were higher in the upstream(8.70 × 10~6 copies/ng DNA) and downstream areas(3.17 × 10~6 copies/ng DNA) than those in the midstream areas(1.23 × 10~6 copies/ng DNA), which was positively correlated to the population density and number of pollution sources. Pollution sources of ARGs along the Beijiang River not only had a great impact on the abundances and diversity, but also on the distribution of specific ARGs in the water samples. Both sul I and sul II were likely originated from aquaculture farms and animal farms,tet W gene was possibly associated with the mining/metal melting industry and the electric waste disposal and tet C gene was commonly found in the area with multiple pollution sources.However, the abundance of tet B was not particularly related to anthropogenic impacts. These findings highlight the influence of pollution sources and density of population on the distribution and dissemination of ARGs at a regional scale.     

Green finance and corporate environmental responsibility: evidence from heavily polluting listed enterprises in China

Green finance is not just a global trend, but it has become an important channel for industrialized countries to achieve sustainable growth. However, few studies have discussed the environmental governance effects of green finance from the micro-firm level. Based on the data of Chinese A-share listed firms in heavily polluting industries, we, combining with property rights and environmental regulation, empirically research the influence of green finance on corporate environmental responsibility (CER) performance. Results indicate that green finance has a significant negative effect on the environmental responsibility of heavily polluting firms. The result remains after a series of robustness tests. In addition, property rights and environmental regulation play a moderating role in the above relationship. The negative impact of green finance on CER is stronger in private firms and firms in areas with low environmental regulation intensity. Moreover, we observe that green finance decreases the CER performance of heavily polluting firms by increasing financing constraints, reducing environmental investment, and diminishing technological innovation. This study identifies the external factors that influence CER and also provides implications and theoretical support for the government to improve the setting and the implementation of green finance policy in the future.

     

间接原子吸收法测定水中硫化物

通过将水样酸化后转化成硫化氢,用氮气带出,被含有定量且过量的铜离子吸收液吸收。分离沉淀后,通过测定上清液中剩余的铜离子,对硫进行间接定量。方法检出限为0.2 mg·L^-1,对实际水样进行分析,加标回收率在90%～95%之间,结果令人满意。