基于层次分析法的人工湿地减排绩效评估指标体系研究

绩效减排有助于发挥减排工程潜力,为水污染减排提供更大空间.结合人工湿地特点,以水污染物减排为主要目标,从减排治污、资源利用、经济和管理指标选择了12个评估指标,并基于层次分析法对各个评价因子的权重进行了确定和判断,构建了人工湿地减排绩效评估指标体系,评估人工湿地减排绩效.通过科学分析人工湿地的减排绩效,优化人工湿地规划、设计和管理水平.     

人工湿地中抗生素抗性大肠杆菌和抗性基因的去除与分布

抗生素的滥用导致抗生素抗性菌和抗性基因随生活污水和养殖废水的排放在环境中肆意散播,其去除及环境行为越来越受到关注。采用K-B纸片法测定了9套不同工艺构型模拟人工湿地中大肠杆菌对7种抗生素的抗性率,并应用多重PCR检测磺胺类sul1、2、3与四环素tetA、B、C、D抗性基因,探究人工湿地对抗性菌的去除效率及抗性菌、抗性基因的分布规律。结果显示,人工湿地能有效去除污水中70%左右的抗性大肠杆菌,有效降低了细菌抗性的传播风险;共计分离出535株大肠肝菌中有378株对一种以上抗生素有抗性性,以四环素、磺胺类和氨苄西林抗性率最高,达到25%以上,其他4种抗性率较低,不足20%;2种抗性基因的检出率都在70%以上;对不同采样点大肠杆菌的抗性性及抗性基因的比较发现,各部分大肠杆菌的抗性水平、多重抗性指数(MRI)以及抗性基因(sul、tet)检出率和组合数表现出:基质≥出水>进水,推测抗性菌被湿地基质截留,在基质生物膜上发生抗性基因的重组,并释放抗性菌,提高了出水中抗性水平和抗性基因检出率。     

油田污水处理水质影响因素与改善措施

随着油田开发阶段的延长,污水处理系统能力出现不足,排污系统和日常排污以及收油是影响油田污水处理水质的重要因素。针对这些因素提出利用人工湿地对洗井、修井污水进行处理,减轻水处理站压力,通过合理加药提高除油罐除油效率,从含油污水进口进行杀菌,防止对管线设备的腐蚀,防止细菌菌体堵塞过滤器,过滤后根据细菌监测结果再次进行杀菌,保证出水合格等改善措施。     

农村小型生活污水处理技术研究进展

针对农村的实际情况,寻找高效低耗的农村生活污水处理技术是很有实际意义的。本文主要从活性污泥法、生物膜法、人工湿地和组合工艺这几方面介绍了农村小型生活污水的处理现状,介绍了近几年来国内外的一些农村小型生活污水处理的研究发展情况。采用生物生态组合工艺,操作管理简单,投资和运行费用较低,适宜在农村小型生活污水处理中应用。     

Riparian Ground‐Water Flow Patterns Using Flownet Analysis: Evapotranspiration‐Induced Upwelling and Implications for N Removal1

Abstract: Ground‐water flow paths constrain the extent of nitrogen (N) sinks in deep, stratified soils of riparian wetlands. We examined ground‐water flow paths at four forested riparian wetlands in deep, low gradient, stratified deposits subjected to Southern New England’s temperate, humid climate. Mid‐day piezometric heads were recorded during the high water table period in April/May and again in late November at one site. Coupling field data with a two‐dimensional steady‐state ground‐water flow model, flow paths and fluxes were derived to 3 m depths. April/May evapotranspiration (ET) dominated total outflux (44‐100%) while flux to the stream was <10% of total outflux. ET exerted upward ground‐water flux through shallow carbon‐rich soils, increasing opportunities for N transformations and diverting flow from the stream. Dormant season results showed a marked increase in flux to the stream (27% of the total flux). Riparian sites with deep water tables (naturally or because of increased urbanization or other hydrologic modifications) or shallow root zones may not generate ground‐water upwelling to meet evaporative demand, thereby increasing the risk of N movement to streams. As water managers balance issues of water quality with water quantity, they will be faced with decisions regarding riparian management. Further work towards refining our understanding of ET mediation of N and water flux at the catchment scale will serve to inform these decisions.     

基于改进熵权的灰色关联模型在湿地水质综合评价中的应用

湿地是自然界生物多样性较为丰富的生态系统,具有很大的生态功能及生态学价值,湿地水质评价需要综合考虑各指标的属性.介绍了基于改进熵权的灰色关联模型在湿地水质综合评价中的应用.以黑龙江省扎龙国家级自然保护区湿地调查采样数据为例,通过构建灰色关联决策矩阵,同时采用改进熵值法确定权重,再由计算各样本的灰色关联度来确定其所属级别,进而对保护区水质采样点的水质进行综合评价.基于改进熵权的灰色关联度模型,为湿地生态系统水质综合评价提供了新的思路.     

人工湿地处理污水的机理与其应用前景

人工湿地法处理废水的技术是目前国际污水处理研究领域的热点,该方法利用生态系统中物质循环的原理,使用生物方法去除污染物质.本文对人工湿地处理污水的机理研究现状进行了总结,并讨论了人工湿地处理污水应用的适应性.     

两种典型PPCPs在潜流人工湿地中的季节性去除效果及降解产物

药物及个人护理品(PPCPs)在地表水中的污染问题已引起了广泛关注,人工湿地(constructed wetlands,CWs)在PPCPs去除中具有突出优势,然而关于不同类型PPCPs 在CWs 去除中的相互作用研究得还较少.本研究选取两种常用且相对分子质量接近的典型PPCPs——广谱抗菌剂三氯生(TCS)和非甾体抗...     

Estimating Evapotranspiration and Seepage for a Sinkhole Wetland From Diurnal Surface‐Water Cycles1

Abstract: This study used measured diurnal surface‐water cycles to estimate daily evapotranspiration (ET) and seepage for a seasonally flooded sinkhole wetland. Diurnal surface‐water cycles were classified into five categories based on the relationship between the surface‐water body and the surrounding ground‐water system (i.e., recharge/discharge). Only one class of diurnal cycles was found to be suitable for application of this method. This subset of diurnal cycles was used to estimate ET and seepage and the relative importance of each transfer process to the overall water budget. The method has limited utility for wetlands with erratic hydrologic regimes (e.g., wetlands in urban environments). This is due to violation of the critical assumption that the inflow/outflow rate remains constant throughout the day. For application to surface‐water systems, the method is typically applied with an assumed specific yield of 1.0. This assumption was found to be invalid for application to surface‐water systems with a noncylindrical pond geometry. An overestimation of ET by as much as 60% was found to occur under conditions of low pond stage and high water loss. The results demonstrate the high ET rates that can occur in isolated wetlands due to contrasting roughness and moisture conditions (oasis and clothesline effects). Estimated ET rates ranged from 4.1 to 18.7 mm/day during the growing season. Despite these large ET rates, seepage (recharge) was found to be the dominant water loss mechanism for the wetland.