芦苇化感组分对羊角月牙藻和雷氏衣藻生长特性的影响

研究了从芦苇(Phragmitis communis Trin)中分离得到的化感组分对羊角月牙藻(Selenastrum caprtcornutum)和雷氏衣藻(Chlamydomonas reinhardtii)生长特性的影响.在藻类生长的对数期向培养液中投加不同浓度的化感组分,分别测定并观察了培养期间受试藻种藻密度和藻细胞形态的变化情况.结果表明,该化感组分对羊角月牙藻藻密度的增长具有明显的抑制作用,半效应浓度(EC50.7d)值为0.60mg/L,同时使羊角月牙藻细胞内部结构改变,形态变大.投加6mg/L化感组分后,藻细胞平均宽度是对照组的1.5倍.该化感组分对雷氏衣藻藻密度的增长没有明显的抑制作用,但使其运动性能降低.     

苦草(Vallisneria spiralis)释放的酚酸类物质对铜绿微囊藻(Microcystis aeruginosa)的化感作用

采用广谱性固相萃取小柱富集以10 g( FW)/L的密度培养三天后的苦草(Vallisneria spiralis)种植水,不同溶剂洗脱得到的各组分对铜绿微囊藻(Microcystis aeruginosa)的生长表现出不同程度的抑制,其中甲醇洗脱组分抑藻活性最强.去除该组分中的酚酸后,其抑藻活性下降了22.8％,表明...     

香蒲、灯心草人工湿地的研究——Ⅰ.净化污水的效果

本文研究了种植香蒲Ｔｙｐｈａ ａｎｇｕｓｔｉｆｏｌｉａ或灯心草Ｊｕｎｃｕｓ ｅｆｆｕｓｕｓ的人工湿地对城镇污水和人工不污染物的净化效果,调查了香蒲,灯心草不同季节的生长差异及高浓度污水冲击负荷对其生长的影响。香蒲,灯心草人工湿地净化城镇污水,出水水质总体上达到国家Ⅱ,Ⅲ类地面水标准,灯心草湿地对人工污水中凯氏氮,总磷,化学耗氧量地去除率维持在９４％以上,氨氮的去除率为８２．７％－９９．７％;在正常     

再生水补给河流北运河CODCr降解系数变化及影响因素

化学需氧量（COD）是影响地表水体水质的主要污染指标.明确地表水中COD的降解系数,可为把握有机物污染过程变化以及有效控制污染提供科学依据.北运河是城市再生水河流,COD污染严重.以北运河从上游至下游的5个典型断面（马坊桥、火沙路、东关大桥、榆林庄桥、杨洼闸）为例,通过室内模拟实验,估算了不同断面COD_Cr降解系数,并对COD_Cr降解系数进行校正;测定了颗粒物沉降速率、复氧系数,评估了水体自净能力;分析了不同环境条件（温度、溶解氧、流速）对COD_Cr的降解影响.结论如下：北运河水体自净能力较差,颗粒物沉降速率范围为1.09~3.22 m/d,杨洼闸断面颗粒物沉降速率最低为1.09 m/d,其复氧系数偏低,为0.016 d^-1.北运河水体COD_Cr降解系数符合一级动力学方程;经水力、温度经验公式校正后,COD_Cr降解系数范围为0.0184~0.0883 d^-1,低于我国其他平原地区河流.北运河COD_Cr降解系数存在明显的空间差异性,上游断面的降解系数高于下游断面,不过下游北京界最后出水断面杨洼闸表现出闸坝特殊性,降解系数最高（0.0416~0.0883 d^-1）.水质参数中温度、溶解氧、氧化还原电位、营养盐以及总有机碳是COD_Cr降解系数的主要影响因子.COD_Cr降解系数随着温度、溶解氧、外源动力增加而增大;COD_Cr降解系数与营养盐、TOC呈显著正相关,与氧化还原电位呈显著负相关.研究结果可为我国相关城市再生水体水质改善和城市黑臭水体治理提供科学依据.     

人工湿地废水处理系统的生物学基础研究进展

主要阐述了人工湿地废水处理系统中生物学基础的研究进展,至今,对作为湿地生产者的水生植物研究较多,水生植物除直接吸收利用废水中的营养物质,吸附和富集重金属外,还起输送氧气至根区,形成根区多种微环境和维护湿地水力传输的作用;而对作为湿地分解者的微生物的研究较少,湿地微生物的代谢活动是废水中有机物质降解的基础机制。     

Effects of long-term wastewater irrigation on soil physical properties and performance of selected infiltration models in a semi-arid region

ABSTRACT

In many arid and semi-arid countries, wastewater irrigation is becoming a common practice in agriculture. In this study, the effect of long-term (40 years) wastewater irrigation on selected physical and hydraulic properties of soil in different parts of a landscape was investigated. The performance of some infiltration models, including Philip (Ph), Kostiakov (Kos), Kostiakov-Lewis (Kos-L), Horton (Ho), Huggins and Monke (Hug-M), and linear and nonlinear Smith-Parlange (S-P(L) and S-P(NL)), was compared. This study was performed in the Urmia region, Iran, where flooding wastewater irrigation has been practised for at least 40 years. Five paired sites, each of which contained a measurement location at the wastewater-irrigated (WWI) and adjacent control area were studied. Accuracy of the infiltration models was evaluated using several statistical criteria, including root mean square error (RMSE) and Akaike information criterion (AIC). The models were classified into groups using cluster analysis based on level of similarity in their performance. The cumulative water infiltration into soils after 1 h (I_1h) was calculated using the selected most accurate models and introduced so as to use only one term to compare the infiltration behaviour of soils. Based on RMSE and AIC, the performance of the Ph, Ho, Kos and Kos-L models was considerably better than that of Hug-M, S-P(L) and S-P(NL). The ranking of the models in terms of their AIC values was: Kos-L > Ho > Kos > Ph > S-P(L) > Hug-M > S-P(NL). The models were classified into two distinct groups. The similarity among Ph, Ho, Kos and Kos-L models was more than 80% and for Hug-M, S-P(L), and S-P(NL) models, it was more than 79%. However, the similarity between these two groups of models was less than 58%.

Editor M.C. Acreman; Associate editor not assigned     

Estimating the influence of increased nitrate loads from wastewater on phosphorus mobility in river sediments

Research on the sediment‐surface water transition zone in three study site regions, different in hydrological conditions, was conducted to estimate to which extent nitrate in surface water can contribute to riverbed sediment oxidation and thus prevent release of sediment phosphorus to surface water. Consequently, the Du tch Flow Model (DUFLOW) based water quality model “Spreewald” and results from the emission model “ Mo delling N utrient E missions in Ri ver S ystems” (MONERIS) were used to estimate to which extent wastewater treatment plants (WWTPs) could contribute to the NO₃^– concentration in surface waters if they were operated without denitrification. It is demonstrated that an effective phosphorus retention in sediments by means of surface water NO₃^– is possible only under specific conditions, i. e. (i) a sufficient supply of surface water to the sediment by advective fluxes, (ii) a sufficient amount of sediment iron to provide phosphorus binding sites in the case of sediment oxidation, (iii) a redox system not leading to a rapid NO₃^– and FeOOH depletion and to phosphorus release from organic pools by high microbial activities. Model results show that in‐stream denitrification processes counteract a significant increase of NO₃^– surface water concentrations from WWTPs operated without denitrification during summer, when eutrophication risk through phosphorus is highest. The increase of NO₃^– surface water concentrations in winter due to decreased denitrification in the surface water is of minor relevance for phosphorus release from sediments.     

添加固体碳源对垂直流人工湿地污水处理效果的影响

以垂直流人工湿地小试系统为研究对象,探讨了不同位置(表层、上层、中层和下层)添加固体碳源对系统氮、磷及COD_Cr去除效果的影响.结果表明:湿地下层硝态氮去除率低于中层,最适宜碳源添加位置为垂直流人工湿地中、下层.添加碳源系统中,碳源添加位置为表层的系统COD_Cr去除率最高,各系统出水COD_Cr浓度均低于进水,不引起系统出水中COD_Cr浓度的增加.添加碳源显著提高脱氮除磷效果,碳源添加位置为下层的系统TN去除率最高,碳源添加位置为表层的系统氨氧化作用明显,出水铵态氮浓度最高,各系统对亚硝态氮和硝态氮去除率差异不明显,但对硝态氮都表现出良好的去除效果.碳源添加位置为下层的系统硝化作用最完全,TP去除能力也显著优于其他各系统.添加碳源至垂直流人工湿地下层可以达到同步脱氮除磷的效果.     

野外模拟扰动对太湖微囊藻群体大小的影响

风浪扰动是影响湖泊生态系统重要的环境因素之一.为了解风浪扰动对湖泊微囊藻群体大小的影响,在野外模拟了风浪扰动对太湖微囊藻群体大小的影响.结果表明,实验组模拟风浪连续扰动24 h,扰动结束时实验组和对照组微囊藻群体大小分别为68.38和12.56μm,实验组和对照组微囊藻群体大小呈极显著差异;扰动结束时实验组和对照组微囊藻胞外多糖含量分别为1.49×10~~(-6)和1.26×10~(-6)mg/cell,二者差异显著.表明适当强度的风浪扰动短时间内能促使微囊藻群体显著增大,有助于人们对太湖微囊藻水华暴发机理的认识.     

低溶氧生物膜反应器对城郊低浓度混合污水进入湿地前的预处理

采用低溶氧生物膜反应器对滇池北岸村镇混合污水进行预处理,旨在去除难以自然沉淀的固体污染物,便于后续湿地深度净化.以小试规模在现场自然条件下进行了12个月的连续动态模拟实验,结果表明,水力负荷3-12m31/(m2d)、气水比为1:1-2:1、DO浓度基本维持在O.1-2.Omg/L时,生物膜反应器对污水中有机物能够有效去除,进水COD负荷低于0.58kg/(m3d的情况下.去除率可稳定在60%以上.低溶氧条件下生物膜脱落缓慢,膜厚度达到 800pm,增强了对进水SS的拦截、吸附作用.SS平均去除率达到了90.7%.实验发现低溶氧条件下系统对氮、磷仍具有一定的去除效果.降低曝气量后运行能耗明显减小,以4000t/d的处理规模计算,运行费用在0.05-0.1元/t尽管混合污水中COD、SS浓度波动范围大,但反应器出水及生物膜的生长都能保持相对稳定,为后续湿地系统的稳定运行提供了保障,试验为滇池流域城郊水污染控制提供了新的技术途径与应用参考.