新安江流域土地利用结构对水质的影响

以新安江上游流域为研究区域,用该流域2010年5月TM遥感影像图作为底图,通过实地野外调查获取了新安江流域的土地利用图.运用ArcGIS的水文、空间分析功能,将流域划分为8个子流域,并分析各子流域的土地利用结构.根据2010年1～12月的水质监测数据,分析TN、TP、高锰酸盐指数、NH4+-N、粪大肠菌群的时空变化特征,以及与土地利用结构之间的定量关系.结果表明,TN和NH4+-N有明显的时间变化特征,为枯时期>丰水期>平水期,而其他几种指标没有明显的时间变化.在空间上,整体上呈现出渔梁、浦口污染最为严重.流域内土地利用结构与水质之间的相关关系表现为:耕地、水体、建筑用地起源作用,林地、草地起汇作用.在年度上看,耕地对TN、NH4+-N、高锰酸盐指数影响最大,草地对TP影响最大;不同水期上,枯水期和丰水期,对各指标影响最大的土地利用类型为耕地,在平水期,对TN、TP、粪大肠菌群影响最大的土地利用类型分别为耕地、草地、林地.     

三峡库区大宁河枯水期藻细胞的时空分布

本研究旨在为三峡库区大宁河藻华预警提供基础数据,于2011年4～9月期间在大宁河流域选择4个取样点开展藻细胞时空变化研究.藻细胞在时间序列表现为:4～9月,藻种主要以蓝藻、绿藻和硅藻为主,藻密度呈逐步递增趋势;在此期间4个取样点的蓝藻比重均逐步增大,硅藻比重逐步降低,绿藻比重变化不显著.藻细胞在空间分布上表现为:藻密度与水温和叶绿素呈极显著相关,相关系数分别为0.97和0.95,与光照、溶解氧、pH值和可溶性磷盐呈显著相关,相关系数分别为0.87、0.83、0.82、0.82;菜子坝在整个试验期间0 m处藻密度比其他水层的藻密度高,白水河在6月和7月的2.0 m处藻密度最高,双龙在7、8和9月的0 m和2.0 m处藻密度较高,大昌在整个试验期间,藻密度变化不大;不同藻细胞在垂向水层中的比重也随时间的变化而改变,可能是不同藻细胞适合不同生态环境所致.     

滇池水葫芦规模化控养生态环境效应分析

水葫芦规模化控养是"十二五"期间滇池治理的重要措施之一。首先介绍了滇池水葫芦规模化控养现状,比较了滇池草海和外海在水葫芦控养前后水质的变化情况,指出滇池水葫芦规模化控养对草海水体生态恢复效果显著,可以在滇池选择适宜水葫芦生长的水域继续扩大水葫芦控养面积,使水葫芦在滇池生态治理中发挥更大的作用。     

不同Fe(Ⅲ)对活性污泥异化铁还原及除磷影响研究

以SBBR反应器活性污泥作为铁还原菌菌种来源,采用兼性厌氧/严格厌氧恒温培养试验,投加不同Fe(Ⅲ)考察各条件下的异化铁还原能力同时比较对磷的去除效果.结果表明:2种条件下Fe(Ⅲ)还原能力具有较好的一致性,依次为:Fe(OH)3＞氧化铁皮＞青矿＞红矿,其中严格厌氧条件下较好.同时,除磷效果与其呈正相关,富集培养至7d,Fe(OH)3及氧化铁皮体系出水磷浓度均达到2mg/L以下,之后继续降低,最终达到0.5mg/L以下.结合异化铁还原除磷机理,可以证明,不同Fe(Ⅲ)表面吸附作用对TP的去除贡献较小,其主要作用为铁还原菌驱动下的化学沉淀去除.     

Interface-mediated synthesis of monodisperse ZnS nanoparticles with sulfate-reducing bacterium culture

We have created a new method of ZnS nanospheres synthesis. By interface-mediated precipitation method (IMPM), monodisperse ZnS nanoparticles was synthesized on the particle surface of sulfate-reducing bacterium nutritious agar culture. Sulfate-reducing bacterium (SRB) was used as a sulfide producer because of its dissimilatory sulfate reduction capability, meanwhile produced a variety of amino acids acting as templates for nanomaterials synthesis. Then zinc acetate was dispersed into nutritious agar plate. Subsequently agar plate was broken into particles bearing much external surface, which successfully mediated the synthesis of monodisperse ZnS nanoparticles. The morphology of monodisperse ZnS nanospheres and SRB were examined by scanning electron microscopy (SEM), and the microstructure was investigated by X-ray diffraction (XRD). The thermostability of ZnS nanoparticles was determined by thermo gravimetric-differential thermo gravimetric (TG-DTG). The maximum absorption wavelengh was analysed with an ultraviolet-visible spectrophotometer within a range of 199–700 nm. As a result, monodisperse ZnS nanoparticles were successfully synthesized, with an average diameter of 80 nm. Maximum absorption wavelengh was 228 nm, and heat decomposed temperature of monodisperse ZnS nanoparticles was 596°C.     

Numerical simulation of alga growth and control in Dalian Bay

WAHMO model was used to simulate the distribution of pollutants in Dalian Bay, China as to predict well as the growth and control of alga. The observed and predicted values of main pollutants showed a good trend at all study locations and the different between them can be ignored. Simulation results illustrated that phosphate was one of limited factors to control algal growth at the location near the sewage outfall, meanwhile, away from the sewage outfall, the synergy of ammonium nitrogen and phosphate was the limited factor.     

Interface-mediated synthesis of monodisperse ZnS nanoparticles with sulfate-reducing bacterium culture

We have created a new method of ZnS nanospheres synthesis. By interface-mediated precipitation method (IMPM), monodisperse ZnS nanoparticles was synthesized on the particle surface of sulfate-reducing bacterium nutritious agar culture. Sulfate-reducing bacterium (SRB) was used as a sulfide producer because of its dissimilatory sulfate reduction capability, meanwhile produced a variety of amino acids acting as templates for nanomaterials synthesis. Then zinc acetate was dispersed into nutritious agar plate. Subsequently agar plate was broken into particles bearing much external surface, which successfully mediated the synthesis of monodisperse ZnS nanoparticles. The morphology of monodisperse ZnS nanospheres and SRB were examined by scanning electron microscopy (SEM), and the microstructure was investigated by X-ray diffraction (XRD). The thermostability of ZnS nanoparticles was determined by thermo gravimetric-differential thermo gravimetric (TG-DTG). The maximum absorption wavelengh was analysed with an ultravioletvisible spectrophotometer within a range of 199-700 nm. As a result, monodisperse ZnS nanoparticles were successfully synthesized, with an average diameter of 80 nm. Maximum absorption wavelengh was 228 nm, and heat decomposed temperature of monodisperse ZnS nanoparticles was 596℃.     

Identification of key factors governing chemistry in groundwater near the water course recharged by reclaimed water at Miyun County, Northern China

Reclaimed water was successfully used to recover the dry Chaobai River in Northern China, but groundwater may be polluted. To ensure groundwater protection, it is therefore critical to identify the governing factors of groundwater chemistry. Samples of reclaimed water, river and groundwater were collected monthly at Chaobai River from January to September in 2010. Fifteen water parameters were analyzed. Two kinds of reclaimed water were different in type (Na-Ca-Mg-Cl-HCO3 or Na-Ca-Cl-HCO3 ) and concentration of nitrogen. The ionic concentration and type in river were similar to reclaimed water. Some shallow wells near the river bed had the same type (Na-Ca-Mg-Cl-HCO3 ) and high concentration as reclaimed water, but others were consistent with the deep wells (Ca-Mg-HCO3 ). Using cluster analysis, the 9 months were divided into two periods (dry and wet seasons), and all samples were grouped into several spatial clusters, indicating different controlling mechanisms. Principal component analysis and conventional ionic plots showed that calcium, magnesium and bicarbonate were controlled by water-rock interaction in all deep and some shallow wells. This included the dissolution of calcite and carbonate weathering. Sodium, potassium, chloride and sulfate in river and some shallow wells recharged by river were governed by evaporation crystallization and mixing of reclaimed water. But groundwater chemistry was not controlled by precipitation. During the infiltration of reclaimed water, cation exchange took place between (sodium, potassium) and (calcium, magnesium). Nitrification and denitrification both happened in most shallow groundwater, but only denitrification in deep groundwater.     

载镁活化天然沸石处理高氟地下水实验研究

为了研究地下水中阴离子对载镁活化天然沸石除氟效果的影响,考察了4种主要阴离子——Cl-,HCO3-,SO42-,PO43-的影响,并分析了吸附剂的除氟机理及表面结构和成分。结果表明:对于初始氟浓度不同的水样,随着阴离子浓度的增加,吸附剂对氟的去除效率逐渐降低。Cl-对吸附剂除氟效果影响较小,氟去除率降低较慢;随着HCO3-浓度的增大(由100 mg/L到1 000 mg/L),水样pH缓慢由7.48增大到9.44,而氟去除率则由63.78%缓慢下降到52.70%(2 mg/L);SO42-及PO43-对改性沸石除氟效果影响较大,氟去除率降低较快,且SO42-的影响大于PO43-。所以,镁改性天然沸石对该4种阴离子的吸附顺序是:SO42->PO43->HCO3->Cl-。     

环境影响评价公众意见调查的真实性评价探讨

公众参与在环境影响评价中扮演着重要的角色,认真做好公众意见调查工作,可以促进环境影响评价工作公正、公开、公平地发展。虽然在建设项目环境影响评价工作中,公众参与起到了一定的积极作用,但是在公众参与的实际过程中,还是遇到了许多具体问题,本文对环境影响评价工作中公众意见调查的结果应如何评估,提出意见和建议。