环境浓度抗生素选择性压力改变活性污泥微生物群落结构

为探究环境浓度抗生素(5μg·L~(-1)和50μg·L~(-1))选择性压力下活性污泥微生物的性能变化,选择四环素及磺胺甲噁唑2种高频检出的抗生素作为研究对象,分别考察2种抗生素单一和复合作用下对序批式活性污泥反应器(SBR)中废水处理效能、微生物活性及群落结构的影响。结果表明,与不添加抗生素的空白对照组相比,2种抗生素在50μg·L~(-1)和5μg·L~(-1)暴露浓度下,经过60 d运行,COD和NH+4-N去除效果未受明显影响(P0.05),微生物的活菌比变化不显著(P0.05),ATP含量显著降低(P0.05)。在微生物群落结构方面,革兰氏阳性菌增加,革兰氏阴性菌减少,原生动物含量减少,香农-威尔生物多样性指数下降。添加抗生素的样品中微生物优势菌群由变形菌门变为放线菌门,放线菌含量(均高于45%),高于空白对照组(30.72%);放线菌门的Micropruina属所占比例最高(24%),且高于空白对照组(18.77%)。抗生素选择性压力可改变活性污泥微生物的活性及群落结构,但长期作用下对污水处理效能及抗生素抗性基因传播的影响还需要进一步研究。     

海藻提取物对富营养化水体氮素循环影响研究

利用国外引进的海藻提取物EClean制剂对富营养化水体进行处理试验,经过定量测定处理和对照水体中氮循环细菌数量的变化,得出EClean制剂能够促进水体的氨化细菌、亚硝化细菌、硝化细菌的生长,并维持了曝气条件下一定数量的反硝化细菌,通过此处理使得在同一反应器中、同一条件下完成硝化作用和反硝化作用成为可能,加速了水体的氮素循环,使水体总氮下降明显。     

Toward Integrated Environmental Management for Challenges in Water Environmental Protection of Lake Taihu Basin in China

Lake Taihu is the third largest freshwater lake in China. It serves many social, economic, and ecological purposes in the drainage basin. Unfortunately, the water has been heavily polluted due to rapid industrialization and urbanization during the last two decades. Notwithstanding great efforts made so far to improve the water quality, the environmental situation is still far from being optimistic. The basin and the lake are facing a range of severe environmental challenges: rapid socio-economic development continues to place great pressures on the environment, current pollution control projects have many problems from the viewpoint of effectiveness and efficiency of their implementations, and the non-point sources of pollution such as agricultural fields, for which control is more difficult than for industrial point sources, have become the main contributors to serious eutrophication of the lake. Considering the characteristics of the environmental challenges and problems confronting the basin and the lake, we focus on integrated environmental management (IEM) as a promising and effective approach to overcome these predicaments. Current practices and problems of environmental management in the basin are examined, and potential future developments are discussed. Three aspects of the IEM are emphasized: institutional cooperation, public participation, and internalization of environmental externalities. We think these are the most critical for not only the basin but also for the whole of China to achieve a sustainable society.     

构筑地震安全城市

遭遇过地震和突发性公共卫生事件后,人们更加关注自身的生存安全和生存环境,安全城市的概念逐步得到了强化。在全面建设小康社会和以人力本的执政理念逐渐深入人心的过程中,构筑安全城市,努力营造安全人居环境成为人们理智的选择和目标。有效抵御地震的袭击,缔造地震安全城市也是其重要内容。     

简捷硝化-反硝化过程处理焦化废水的研究

简捷硝化-反硝化过程处理焦化废水具有去除负荷高、出水浓度低、可节省反硝化碳源等优点.试验表明,当系统进水COD、NH₃-N和TN浓度分别为1204.8、274.3和443mg/L,系统总水力停留时间为26.2h时,系统出水COD、NH₃-N、NO₂^--N、NO₃^--N和TN浓度分别为36.3、12.1、9.25、2.46和44.4mg/L.试验结果还证明本文所采用的系统确实处于简捷硝化-反硝化状态.     

内循环式生物反应器氧传质及流态特性研究

通过气-液两相普通流化床和内循环式生物反应器(DTBR)的对比研究,发现DTBR具有更好的氧传质能力和氧转移效率。本试验条件下,当表面气速为0.29cm/s时,DTBR的(KLα)20和E4值分别为普通流化床反应器的1.2倍和1.3倍。通过研究影响DTBR混合特性的主要因素,发现表面气速的影响最大,表面液速的影响最小。其它条件相同,表面气速分别为0.29和0.074cm/s时,DTBR的循环时间分别为12s和16s,混合时间分别为76.2s和91.8s。      

O_3-H_2O_2催化氧化技术深度处理石化含盐废水

采用O_3-H_2O_2-催化剂氧化体系对某石化企业含盐废水的二级生化出水进行处理,考察了不同反应体系下的反应时间、O_3流量、H_2O_2投加量对COD去除效果的影响。实验结果表明:O_3-H_2O_2-催化剂氧化体系对石化含盐废水的处理效果最好;在臭氧流量为40 m L/min、H_2O_2投加量为50 mg/L、催化剂投加量为300 g/L、反应时间为60 min的条件下,COD去除率为51.4%,出水COD为52.0 mg/L,达到GB31570—2015《石油炼制工业污染物排放标准》的要求。     

Coupling coordination measurement of environmental governance: case of China

Environmental and Ecological Statistics - The results show that a comprehensive evaluation system consisting of natural resources, pollution response, government management, and legal involvement...     

燃煤电厂烟气中铅的测定方法初探

采用过滤法与吸收法联用的采样方法,测定燃煤电厂烟气中Pb,并通过试验考察4种不同的吸收液和4种不同采样流量对测定的影响。结果表明:0.1 mol/L HNO_3、体积分数为5%的HNO_3+10%的H_2O_2和体积分数为1.6%的HNO_3+2.5%的HCl 3种吸收液均对Pb起到良好的捕集作用,且测定结果相近。采样流量控制在20 L/min吸收效果最好。     

基于人工神经网络的街道峡谷NO_x浓度的数值模型研究

通过对反向传播人工神经网络的算法和网络结构的研究,发现拟牛顿算法训练速度较快,能够较好地接近误差目标值,同时建立了包括输入层、隐含层、输出层的人工神经网络三层拓扑结构。通过对街道峡谷人工神经网络的训练,模拟计算了街道峡谷NOx浓度分布值。结果显示,训练误差和测试误差比为1.11,训练样本的模拟值与实测值的相关系数为0.93,测试样本的模拟值与实测值的相关系数为0.87,模拟值与实测值的相关系数均高于显著水平为α=0.05与α=0.01所对应检验性表的相关系数临界值。该模型能够用于街道峡谷污染物浓度的模拟计算,具有较好的泛化能力。