Effects of temperature and discharge parameters on ozone concentration of negative corona discharge

The relationship of the ozone generation and the heating power, corona wire surface temperature, discharge electrode and netting electrode was studied during the negative corona discharge. The experimental results showed that the ozone concentration reduced with applied voltage decrease. With heating power increase, the ozone concentration of unit current decreased at exponential rate and it almost change no longer over 0.40 W. Under given temperature, the lower the applied voltage was, the smaller the ozone concentration was; while under given applied voltages, only over 11 kV could decrease with the surface temperature increase. The ozone concentration decreased with the lengthening of corona wire, and could reduced to 10 ppb under experimental condition of 14.2 kV; it also decreased with the shortening of wire diarmeter,and could decrease 67% at best in the given condition. Moreover, it decreased with the increasing size of netting electrode mesh. At the anion current of 1.65 μA, the ozone concentration of 5.0 x 5.0 cm^2 is only 41% of that of 3.3 x 3.3 cm^2 .     

Enhanced metronidazole removal by binary-species photoelectrogenic biofilm of microaglae and anoxygenic phototrophic bacteria

High efficient removal of antibiotics during nutriments recovery for biomass production poses a major technical challenge for photosynthetic microbial biofilm-based wastewater treatment since antibiotics are always co-exist with nutriments in wastewater and resist biodegradation due to their strong biotoxicity and recalcitrance. In this study, we make a first attempt to enhance metronidazole (MNZ) removal from wastewater using electrochemistry-activated binary-species photosynthetic biofilm of Rhodopseudomonas Palustris (R. Palustris) and Chlorella vulgaris (C. vulgaris) by cultivating them under different applied potentials. The results showed that application of external potentials of -0.3, 0 and 0.2 V led to 11, 33 and 26-fold acceleration in MNZ removal, respectively, as compared to that of potential free. The extent of enhancement in MNZ removal was positively correlated to the intensities of photosynthetic current produced under different externally applied potentials. The binary-species photoelectrogenic biofilm exhibited 18 and 6-fold higher MNZ removal rate than that of single-species of C. vulgaris and R. Palustris, respectively, due to the enhanced metabolic interaction between them. Application of an external potential of 0V significantly promoted the accumulation of tryptophan and tyrosine-like compounds as well as humic acid in extracellular polymeric substance, whose concentrations were 7.4, 7.1 and 2.0-fold higher than those produced at potential free, contributing to accelerated adsorption and reductive and photosensitive degradation of MNZ.     

广州市油气回收治理现状浅析及存在问题对策研究

加油站等每天都有大量油气散发到大气中,严重污染环境,浪费能源,油气回收已成为环保领域的一个重要研究课题。本文重点对2010年全市油气回收验收监测及2011年抽测情况进行了全面梳理和综合分析,概述了广州市油气回收治理现状,并着重对关键性指标的不达标成因及应对措施进行了阐述。     

江苏省电镀污泥产生现状及预测分析

分析了江苏省及各省辖市电镀污泥产生现状,并对电镀污泥产量进行了预测。通过调研分析发现江苏省电镀污泥产生情况呈现地区分布不均、产生规模小和行业集中的特点。利用灰色模型对全省及重点地区产生量进行预测发现,全省未来6年电镀污泥产生量增长率为8.32%,到2020年将达到23.94万t,低于2014年江苏省电镀污泥核准处置量39.92万t。     

光化学污染科学及发展现状研究

对光化学污染研究及其发展进行了综述,概括了光化学污染研究的主要方法,即实验室研究、模式计算和现场监测分析等方法.介绍了欧美国家和中国在烟雾箱研究方面的发展情况,提出了控制自由基源以及痕量气体的检测方式有待提高等问题.阐述了光化学污染模式计算的发展现状和未来发展趋势以及在模式运用中影响模式计算准确性的主要因素.还介绍了国内外光化学污染监测发展历程和现状,并根据目前自动监测发展水平探讨了光化学烟雾监测因子及作用,最后提出加强光化烟雾研究具体建议和研究方向.     

乌兰察布市饮用水水源地现状及管理对策研究

《国务院关于落实科学发展观加强环境保护的决定》要求"环保工作要以饮水安全为重点,切实加强水污染防治工作",经济的高速发展对饮用水水源地环境影响的日益严重也使我们对饮用水水源地的管理提出了更高的要求。本文在对乌兰察布市饮用水水源地环境现状进行调查、总结的基础上,分析了乌兰察布市饮用水水源地环境保护管理方面存在的问题,并提出了相应的对策。     

采用节水措施促进秦皇岛市水资源可持续发展

水资源是人类生存与发展最宝贵的自然资源,是任何其他资源都无法取代的、有限的资源.中国人均水资源量只有世界人均占有量的四分之一,是一个水资源贫乏的国家.秦皇岛市人均水资源量为597 吨/年,是全国平均值的1/4左右,属于缺水城市.在可供水不断减少的情况下,水资源需求量又在不断增加,因此,未来水资源的短缺形势将更为严峻,以水资源紧张为特征的水危机将会不断加剧.面对水资源短缺危机,节水成为秦皇岛市水资源可持续利用的根本出路.     

电絮凝-过滤法去除源水中微量有机物

利用电絮凝-过滤法进行了源水中有机物去除的实验研究,探讨了电流密度、电解时间和pH值等因素对源水中TOC去除效果的影响。结果表明,在电极间距1.0cm,电流密度47.2 A/m2,初始TOC浓度为12.4mg/L时,反应12min后,出水浓度为3.60mg/L,TOC去除率可达71%。表明电絮凝法可有效去除源水中微量有机物。其去除机理包括电絮凝、电化学氧化和还原以及电气浮等。     

电流探头分析设计

分析了电流探头的两大技术指标,传输阻抗及传输阻抗宽频平坦度,并从电流探头物理结构模型出发,构建了电流探头的电路模型,推导出传输阻抗的计算公式,并从电路模型出发,分析了绕线电阻、端接电阻、分布电容对传输阻抗的影响。     

小城镇环境保护规划现状及对策——以铁岭市八棵树镇为例

小城镇环境保护规划的编制是实现科学发展,积极探索中国农村环境保护新道路的必要举措。文章以铁岭市八棵树镇为典型,通过对环境现状及存在问题的分析,提出了八棵树镇环境保护规划,并为搞好小城镇环保规划和生态建设给出一些合理的对策和建议。