基于污水处理厂运营成本的污水处理费制度分析

通过选取全国东、中、西部227个污水处理厂为样本,估算这些样本的运营成本及其结构,分析其地区差异与执行标准的关系.结果显示样本平均运营成本为1.38元/t,并且通过与污水处理厂所在地的污水处理费征收标准比较,判断当前我国大部分地区征收的污水处理费只覆盖污水处理厂的运行成本,并未覆盖我国城镇污水处理厂的全部运营成本.运用成本收益分析研究污水处理厂运行状况,结果显示227个样本的平均单位污水处理费收入为0.80元/t,平均治理污水的单位收益为3.24元/t,平均单位盈利水平为2.09元/t,政策补贴成为污水处理厂主要收入.进一步探索污水处理费制度的不足,并以此提出我国污水处理费征收标准应基于科学的排放标准下的污水处理厂的运营成本而制定,坚持污染者付费原则和因地制宜原则.     

DGT和传统化学法比较研究复合污染土壤中Cd的生物有效性

以小麦和玉米2种陆生植物为金属吸收材料,利用盆栽试验比较研究了新型DGT(diffusive gradients in thin films,薄膜扩散梯度技术)法与5种传统化学法评价土壤中Zn复合存在下Cd的生物有效性. 结果显示:①土壤中w(Cd)为4 mg/kg时明显抑制了2种植物的生长,与对照组相比,小麦的地上部和根系生物量分别降低了26.2%和23.4%,玉米的分别降低了23.5%和30.9%. ②Zn的添加能够减轻Cd对植物的毒害,并促进植物生长;Cd污染土壤中Zn的复合存在会抑制2种植物对Cd的吸收,并随w(Zn)的增加其抑制作用更加明显;DGT法、土壤溶液法测定的土壤溶液中ρ(Cd)和4种化学提取法(HAc、EDTA、CaCl₂和NaAc)测定的土壤中w(有效态Cd)均随w(Zn)的增加而明显降低. ③Pearson相关分析显示,2种植物体内w(Cd)与6种方法表征的土壤中w(有效态Cd)均呈显著正相关(R>0.900,P<0.01),但植物体内w(Cd)与DGT和土壤溶液法测定的土壤溶液中ρ(Cd)的R(>0.940)大于其他4种化学提取法. 可见,对于评价Cd-Zn复合污染土壤中Cd的生物有效性而言,DGT与土壤溶液法均优于传统的化学提取法.      

五元联系数在垃圾填埋场地下水评价中的应用

环境系统是各项指标相互作用的复杂系统,因此,综合环境质量评估应考虑到各指标间的内在联系,以获取更加符合实际情况的评估结果。集对分析(SPA)考虑了环境作为一个系统的确定性和不确定性,研究系统的内在联系。本文应用集对分析法的引申方法——五元联系数法对垃圾填埋场地下水环境质量进行分级、排序,结果证明该法在地下水环境评价中具有一定的应用潜力。     

水生植物提取液对蓝藻的抑制作用

采用对照试验,模拟研究不同氮磷营养、水温等条件下,添加水生植物（睡莲）提取液对蓝藻生长的抑制作用。实验证实了植物提取液对蓝藻有抑制作用,在不同生长条件下,细胞密度为6×10^7～2×10^10个／L时,可达到降低蓝藻50％的生长率。     

海水抽水蓄能电站防污方案研究

为了给未来建设海水抽水蓄能电站提供防污解决方案,分析了海洋污损生物的附着过程及特点,以及海水抽水蓄能电站需要防污的部位,比较国内外现有的海洋污损生物的治理技术。得到了海水抽水蓄能电站水工建筑物、管道、水泵水轮机组及其辅助系统的防污方案。通过分析国内海水抽水蓄能电站防污的现状、存在的不足,展望了未来重点研究的方向,为国内海水抽水蓄能电站的建设提供参考。     

Characteristics of microbial community involved in early biofilms formation under the influence of wastewater treatment plant effluent

Effluents from wastewater treatment plants (WWTPs) containing microorganisms and residual nutrients can influence the biofilm formation. Although the process and mechanism of bacterial biofilm formation have been well characterized, little is known about the characteristics and interaction of bacteria, archaea and eukaryotes in the early colonization, especially under the influence of WWTP effluent. The aim of this study was to characterize the important bacterial, archaeal and eukaryotic species in the early stage of biofilm formation downstream of the WWTP outlet. Water and biofilm samples were collected 24 and 48 hr after the deposition of bio-cords in the stream. Illumina Miseq sequencing of the 16S and 18S rDNA showed that, among the three domains, the bacterial biofilm community had the largest alpha and beta diversity. The early bacterial colonizers appeared to be “biofilm-specific”, with only a few dominant operational taxonomic units (OTUs) shared between the biofilm and the ambient water environment. Alpha-proteobacteria and Ciliophora tended to dominate the bacterial and eukaryotic communities, respectively, of the early biofilm already at 24 hr, whereas archaea played only a minor role during the early stage of colonization. The network analysis showed that the three domains of microbial community connected highly during the early colonization and it might be a characteristic of the microbial communities in the biofilm formation process where co-occurrence relationships could drive coexistence and diversity maintenance within the microbial communities.     

锡林郭勒盟不同草原类型植物群落多样性初步研究

应用双指示种分析法TWINSPAN（Two-Way Indicators Species Analysis,TWINSPAN）和无偏对应分析DCA（Detrended Correspondence Analysis,DCA）对2005年7月中旬在锡林郭勒盟不同草原类型下采集的32个样方进行分类和排序处理。研究结果表明：1）研究区依据水分的差异包括3个不同草原类型（荒漠草原、典型草原、草甸草原）,再依据热量和人为干扰的差异包括8个植物群落类型;2）草原植物群落多样性随荒漠草原-典型草原-草甸草原的变化而增加;在中度干扰下,草原植物群落比原生群落具有更高的多样性;不同草原类型过渡带的草原植物群落结构多样性比物种多样性明显。     

低碳氮比进水AAO污水处理厂低碳运行

为探明低碳氮比进水条件下AAO污水处理厂的碳排放特征,提出可行的低碳运行策略,基于排放因子法对7座低碳氮比进水AAO污水处理厂(分为AAO组和AAO-MBR组)运行1a产生的碳排放进行核算与评价,对具有显著低碳表现的污水处理厂开展全流程分析剖析其碳减排途径.结果表明,电耗和N₂O排放是主要碳排放来源,分别贡献49.43%和25.75%的碳排放.AAO-MBR组以间接碳排放为主,电耗碳排放占至约60%,而AAO组生物作用导致的直接碳排放占主导. AAO组平均吨水比碳排放显著低于AAO-MBR组(0.47和0.79kgCO₂eq/m³),更具低碳运行潜力. 7座污水处理厂中,WWTP7各项比碳排放评价指标均为最低,意味着其最具低碳运行能力.充分利用进水碳源,多路径协同脱氮除磷同时精准控制溶解氧浓度避免过曝气是其大幅削减能耗和物耗,实现碳减排的关键路径.     

低温环境下人工湿地植物组配对养殖废水的处理效果研究

强化低温环境下人工湿地的污水处理能力,对于促进人工湿地的应用推广具有重要的意义。本研究利用绿狐尾藻(Myriophyllum aquaticum)和菖蒲(Acorus calamus L.)两种湿地植物,在室外低温环境下(＜15℃),研究人工湿地植物组配对不同负荷养殖废水的处理效应及关键影响因素。结果表明,在不种、单种和不同顺序混种绿狐尾藻(M.aquaticum)和菖蒲(A.calamus L.)处理下,菖蒲+绿狐尾藻组合湿地(AM)对TN、TP和COD去除率均为最高,在低负荷和高负荷环境下平均去除率分别为74.2%、71.3%、83.0%和67.3%、81.9%、75.3%。相较于空白对照和植物单种的湿地系统,植物混种系统的DO较高,且AM处理在低负荷和高负荷环境下均能保持较高的C∶N。根据Pearson相关性以及PCA分析,DO与TN、NH⁺₄-N去除率显著相关(P<0.05),C∶N与COD去除关联性最好。可见,菖蒲+绿狐尾藻植物组合可能通过改善DO和C∶N等湿地微环境条件来增强湿地对污染物的去除,能够作为低温环境下强化湿地对污染物去除的一种有效措施。     

Drivers of microbial beta-diversity in wastewater treatment plants in China

As one of the most well-documented biogeographic patterns, the distance-decay relationship provides insights into the underlying mechanisms driving biodiversity distribution. Although wastewater treatment plants (WWTPs) are well-controlled engineered ecosystems, this pattern has been seen among microbial communities in activated sludge (AS). However, little is known about the relative importance of environmental heterogeneity and dispersal limitation in shaping AS microbial community across China; especially they are related to spatial scale and organism types. Here, we assessed the distance-decay relationship based on different spatial scales and microbial phylogenetic groups by analyzing 132 activated sludge (AS) samples across China comprising 3,379,200 16S rRNA sequences. Our results indicated that the drivers of distance-decay pattern in China were scale-dependent. Microbial biogeographic patterns in WWTPs were mainly driven by dispersal limitation at both local and national scales. In contrast, conductivity, SRT, and pH played dominant roles in shaping AS microbial community compositions at the regional scale. Turnover rates and the drivers of beta-diversity also varied with microorganism populations. Moreover, a quantitative relationship between dispersal limitation ratio and AS microbial turnover rate was generated. Collectively, these results highlighted the importance of considering multiple spatial scales and micro-organism types for understanding microbial biogeography in WWTPs and provided new insights into predicting variations in AS community structure in response to environmental disturbance.