2-chlorophenol induced ROS generation in fish Carassius auratus based on the EPR method

In the present study, a secondary spin trapping technique was used followed by electron paramagnetic resonance (EPR) analysis, to study the potential of reactive oxygen species (ROS) production after fish (Carassius auratus) were injected i.p. with different doses (50, 100, 200, 250, 500mgkg(-1)) of 2-chlorophenol (2-CP). The ROS signal intensity of the EPR spectrum showed a significant increase (p<0.05, compared with the control) when the 2-CP dose was as low as 50mgkg(-1). There is a good relationship between the 2-CP administered doses and ROS generation. Based on the hyperfine splitting constants and shape of the EPR spectrum, the ROS which was generated in fish liver after intraperitoneal (i.p.) injection of 2-CP was identified as ()OH. SOD and CAT activities were found to be induced at lower doses of 2-CP. GSH levels fell below the control level following all treatments with 2-CP, and GSSG levels changed along with those of GSH. These observations indicated that the fish experienced oxidative stress. The strong positive correlation (r=0.966, p<0.005) between ()OH radical and lipid peroxidation suggested that lipid peroxidation was possibly induced by ()OH. The phase II detoxification enzyme glutathione-S-transferase (GST) may play an important role in 2-CP metabolism or excretion and, consequently, reduce ROS production. This study provides strong evidence that level of ROS is significantly increased in 2-CP stressed fish, and ROS may serve as a potential biomarker to indicate 2-CP contamination.     

混凝过程中流场结构的PIV测量与表征

采用粒子成像速度场仪(PIV)在不投加专用示踪粒子的条件下,以混凝絮体为示踪粒子,对Taylor-Couette反应器内的絮凝反应流场进行测量与表征.结果表明,内筒旋转雷诺数Re在900~2900时,流场中产生的涡具有相似的特殊波状涡结构,相邻涡旋形态大小发生周期性变化,涡间存在主流液体的移动,这种涡结构有利于絮体结合生长成较大的絮体颗粒,便于沉降而导致较高的絮凝沉淀去除率.这也证实PIV技术能够在进行混凝反应的同时,用混凝过程中的微絮体为示踪粒子对混凝过程进行流场测量,不必再额外添加示踪粒子,就能较好地反映混凝过程中涡旋的形态变化特征,从而实现对絮凝过程的同步测量与表征.     

基于延拓盲数的湖库水体富营养化评价模型

基于湖库水环境系统随机性、模糊性、灰性、未确知性等多种不确定性共存或交叉存在的特点,将延拓盲数引入水体富营养化评价,通过与综合营养状态指数方法的综合集成,构建了湖库水体富营养化评价延拓盲数模型和等级识别模式,并将其应用于巢湖塘西河河口水体富营养化评价.结果表明:塘西河河口水体处于重富营养化状态,可信度超过0.86(即86%),且在模糊截集水平α=0.8情形下,综合营养状态指数期望值达79.34,属于重富营养等级.实例研究证明了新构建模型对于不确定性条件下湖库水体富营养化评价的适用性和有效性.     

机动车尾气排放对城市空气质量的影响研究——以乌鲁木齐市春节前后对比分析

随着我国经济的高速发展,机动车尾气逐渐成为城市大气污染物的主要来源之一.在2013年2月5—18日春节前后,乌鲁木齐市节日前3 d大量机动车外流,节日期间2月10—12日滞留市内的机动车停运,通过对比春节前后乌鲁木齐市汽车流出量和油耗减少量,分析该时段5项大气污染物逐小时浓度变化,研究机动车尾气对乌鲁木齐市大气污染的潜在贡献和影响程度.结果表明:春节机动车停运期间,市区机动车流量下降明显,成品油消耗量减少约60%,尽管天气条件以不利于大气污染物扩散为主,但PM2.5、PM10、SO2、NO2和CO等5项大气污染物浓度均降至当月最低值(且均在达标范围内),分别比节日前下降44.2%、49.3%、54.5%、28.2%和3.7%.因此,"煤改气"工程实施后,乌鲁木齐市的煤烟污染得到极大改善,乌市大气污染类型已由煤烟型向机动车尾气混合型转化.提高成品油品质将促进减少城市机动车尾气污染,在当前的油品标准下,重大节假日期间机动车停驶有助于显著改善城市空气质量.     

Effects of cathode potentials and nitrate concentrations on dissimilatory nitrate reductions by Pseudomonas alcaliphila in bioelectrochemical systems

The effects of cathode potentials and initial nitrate concentrations on nitrate reduction in bio- electrochemical systems （BESs） were reported. These factors could partition nitrate reduction between denitrification and dissimilatory nitrate reduction to ammonium （DNRA）. Pseudomonas alcaliphilastrain MBR utilized an electrode as the sole electron donor and nitrate as the sole electron acceptor. When the cathode potential was set from -0.3 to -I.1 V （vs. Ag/AgC1） at an initial nitrate concentration of 100 mg NO~-N/L, the DNRA electron recovery increased from （10.76 ± 1.6）% to （35.06 ± 0.99）%; the denitrification electron recovery decreased from （63.42 ± 1,32）% to （44.33 ± 1.92）%. When the initial nitrate concentration increased from （29.09 ± 0.24） to （490.97 ± 3.49） mg NO3-N/L at the same potential （-0.9 V）, denitrification electron recovery increased from （5.88 ± 1.08）% to （50.19 ±2.59）%; the DNRA electron recovery declined from （48.79 ±1.32）% to （16.02 ± 1.41）%. The prevalence of DNRA occurred at high ratios of electron donors to acceptors in the BESs and denitrification prevailed against DNRA under a lower ratio of electron donors to acceptors. These results had a potential application value of regulating the transformation of nitrate to N2 or ammonium in BESs for nitrate removal.     

化学镀镍废水中磷处理的研究

化学镀镍技术,以其独特的优越性正被广泛应用。但是化学镀镍溶液因其自身的还原反应性质导致镀液不稳定、使用寿命短。产生的废液中含有大量的镍离子、亚磷酸盐、硫酸钠及一些有机物等。镍是一种致癌的重金属物质,也是一种短缺昂贵的金属资源,磷则是引起水体富营养化现象的主要污染因素之一。因此,如何有效地处理化学镀镍废液中的磷,减少对环境的污染及生态平衡的破坏,有着非常重要的现实意义。本文通过大量的试验对影响磷处理效果的氯化钙投加量、反应温度、反应时间、反应pH值等因素进行了优化。在试验的基础上,可根据实际操作所得出的温度与pH值对镀镍废水磷处理的影响的结论,设计出一套化学镀镍废液综合治理的工艺流程。因此,具有非常重要的现实意义。     

沈阳市农村环境基础设施运营与管理对策探讨

分析了沈阳市农村环境基础设施运营管理存在的问题,提出了解决对策。     

内蒙古“十二五”规划中重点产业及区域发展水污染负荷环境压力评估

“十二五”内蒙城镇化率的提高,使得城镇生活点源COD和氨氮负荷产生量有较高增长.“十一五”期间内蒙城镇生活污水COD和氨氮的去除率较低,为实现十二五减排目标的完成,需大幅提高城镇污水处理厂处理能力,实现盟市污水处理厂收集处理率达到90％.此外城镇污水处理厂COD和氨氮的去除率,分别至少达到80％和45％以上.这样才能够满足重点产业发展增排的COD和氨氮的同时,实现十二五总量目标的实现.     

“十二五”辽河流域沈阳段污染治理对策初探

在研究分析“十二五”期间辽河流域沈阳段污染治理工作面临形势的基础上,总结了目前存在的主要问题,并有针对性地提出了解决对策。