绿洲农区土地可持续利用初步研究——以河西走廊临泽样区为例

土地可持续利用就是实现土地生产力的持续增长和稳定性 ,保证土地资源潜力和防止土地退化 ,并具有良好的社会效益和经济效益。本文以河西走廊临泽样区为例 ,以根据土系划分出的三种土地利用方式为研究对象 ,对其在土地可持续利用方面进行了定量化评价研究 ,在此基础上 ,提出了绿洲农区土地可持续利用途径     

聚合硫酸铁絮凝剂的物化性质研究

本文通过对直接氧化法聚合硫酸铁(PFS)的热力学研究,首次报道了PFS的一些物化数据:热容、积分溶解热和反应热效应,并根据稀溶液的依数性原理测定了PFS的平均分子量。     

A new polystyrene-latex-based and EPS-containing synthetic sludge

Since the living microorganisms in activated sludge continuously change, it is difficult to conduct controlled experiments and achieve reproducible results for evaluating sludge characteristics. Synthetic sludge, as a chemical surrogate to activated sludge, could be used to investigate the sludge physicochemical properties, and it is desirable to prepare synthetic sludge with similar structure and properties to real activated sludge to explore the flocculation and settlement processes in activated sludge systems. In this work, a high-strength synthetic sludge was prepared with functional polystyrene latex particles as the framework and extracellular polymeric substances (EPS) to modify its surface. The flocculation and settling characteristics of the microspheres and the prepared synthetic sludge were tested. Compared with other three functional polystyrene latex microspheres, the synthetic sludge prepared with EPS-modified polystyrene latex microspheres showed good settling characteristics and a significantly higher strength. They could be used for studying the physicochemical properties of activated sludge.     

Effect of periphyton community structure on heavy metal accumulation in mystery snail (Cipangopaludina chinensis):A case study of the Bai River, China

The ratio of metal:P stoichiometry was used to identify the accumulation pathways of heavy metals (V, Cr, Co, Ni, Cu, Cd, and Pb) from periphyton to snails Cipangopaludina chinensis Gray (C. chinensis) in the Bai River watershed. The results showed that periphyton communities were mainly composed of two types of algae, filamentous green algae and unicellular diatoms. The proportion of unicellular diatoms in the periphyton community is a key factor that influences metal accumulation in C. chinensis. The V, Cr, Co, Ni, and Cd content of C. chinensis increased steadily as the corresponding metal content of periphyton increased, but Cu and Pb in the snail did not increase in the periphyton. Mechanisms of V, Cr, and Ni accumulation were found to be related to the proportion of diatoms, while Cd and Pb accumulation were dependent on the physiological characteristics of C. chinensis. The accumulation of Cu in C. chinensis was closely related to their grazing behavior. The metal:P stoichiometry revealed that Cr, Ni, and Cd can reduce the potential ecological risks associated with increased P inputs to the ecosystem. V and Co were considered to be relatively safe, regardless of the periphyton P content. Finally, Pb may not be prone to transfer to higher trophic levels, and may pose the lowest ecological risks of the studied heavy metals, but Cu can cause potential ecological risks when eutrophication has occurred.     

市政污水处理厂事故水池设计及配套应急响应措施

与普通工矿企业的污水处理系统相比,市政污水处理系统规模大、源头广,其配套的事故水池不仅容积大,投资高,而且控制难。本文从动态管理角度,提出了一种市政污水处理厂事故水池的设计方法以及配套应急响应措施,既能有效发挥事故水池的作用,遏制环境事故,又能减少事故水池容积,节省占地与投资。     

海洋大气环境金属防护涂层技术与工艺研究

通过对某沿海工程防腐蚀技术较长时间的研究、试验及腐蚀控制设计,分析了海洋大气环境的主要特点和影响涂层体系防护性能的主要因素。在此基础上,研究了海洋大气环境金属结构涂装防护技术、工艺与主要技术保障措施。     

岩溶区与非岩溶区土壤微生物活性的对比研究

通过野外采样和室内实验,研究了不同地质背景、不同土地利用方式对土壤微生物活性的影响。研究表明,土壤微生物数量、微生物量碳在林地、灌木丛、草丛三种不同的土地利用方式下均表现为岩溶区>非岩溶区;岩溶区土壤微生物数量、微生物量碳表现为林地>灌木丛>草丛;非岩溶区土壤微生物数量表现为草丛>林地>灌木丛,微生物碳表现为林地>草丛>灌木丛。对于同一种土地利用方式,脲酶和蔗糖酶活性均表现为非岩溶区>岩溶区,过氧化氢酶活性表现为岩溶区>非岩溶区;除非岩溶区土壤脲酶活性表现为林地>草丛>灌木丛外,非岩溶区土壤过氧化氢酶、蔗糖酶活性及岩溶区土壤脲酶、过氧化氢酶、蔗糖酶活性均表现为林地>灌木丛>草丛。岩溶区土壤脲酶、过氧化氢酶、蔗糖酶活性和非岩溶区土壤蔗糖酶活性能作为土壤较理想的肥力指标。     

有机负荷对除磷颗粒污泥的培养及特性的影响

采用SBR反应器,以厌氧/好氧方式运行,控制SBR反应器内好氧反应时段饱食期溶解氧水平在1.0～2.0 mg/L之间,研究有机负荷对除磷颗粒污泥的培养及其除磷特性的影响.结果表明,当有机负荷（以COD计）为0.482～0.986 kg/（m^3·d）时,SBR内的污泥为大量絮体状污泥和少量形状规则的颗粒污泥的混合物;当...     

搅拌棒吸附萃取-气相色谱-质谱联用测定海水中邻苯二甲酸酯

为了测定海水中痕量邻苯二甲酸酯,构建并优化了搅拌棒吸附萃取-气相色谱-质谱联用方法.选取邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯、邻苯二甲酸丁基苄基酯、邻苯二甲酸二(2-乙基己基)酯和邻苯二甲酸二辛酯这6种邻苯二甲酸酯作为研究对象,优化了萃取时间和解析时间等5种因素,通过回收率和相对标准偏差等对SBSE-GC-MS方法进行验证.结果表明,最佳萃取时间为2 h,最佳甲醇添加量为10%,最佳氯化钠添加量为5%,最佳解析时间为50 min,最佳解析溶剂为甲醇∶乙腈=4∶1(体积比).6种邻苯二甲酸酯的峰面积和质量浓度线性对应关系良好,相关性系数均大于0.997,检出限在0.25~174.42 ng·L-1之间,不同质量浓度的回收率均在56.97%~124.22%之间,相对标准偏差在0.41%~14.39%之间.在建立方法的基础上,测定了胶州湾主要河流入海口的样品,结果表明所有采样点均检出邻苯二甲酸酯,邻苯二甲酸二乙酯检出率为100%,质量浓度较大的污染物为邻苯二甲酸二丁酯、邻苯二甲酸丁基苄基酯、邻苯二甲酸二(2-乙基己基)酯和邻苯二甲酸二辛酯.     

珠江三角洲典型区域农产品中邻苯二甲酸酯(PAEs)污染分布特征

在珠江三角洲典型区域(中山市、珠海市、东莞市和惠州市)内共采集了131个农产品样品,进行了6种优先控制污染物邻苯二甲酸酯(PAEs)含量水平分析及风险评价.结果表明,珠三角地区农产品样品中6种邻苯二甲酸酯累计含量(∑PAEs)范围为nd~79.86 mg·kg~(-1),平均含量为2.84 mg·kg~(-1),检出率为98.5%.各类农产品中∑PAEs平均含量的顺序依次为蔬菜(3.03 mg·kg~(-1))水稻(2.52 mg·kg~(-1))水果(1.26 mg·kg~(-1)).各城市产区内农产品中∑PAEs平均含量顺序为:珠海(6.53 mg·kg~(-1))东莞(2.59 mg·kg~(-1))惠州(1.53 mg·kg~(-1))中山(1.12 mg·kg~(-1)).农产品中PAEs的主要成分为邻苯二甲酸二正丁酯(DBP)、邻苯二甲酸二(2-乙基)己酯(DEHP)和邻苯二甲酸二正辛酯(DnOP),三者的累计含量占∑PAEs总量的90.8%.其中生菜(珠海)和芥兰(东莞)二者中∑PAEs的总量以及生菜、油麦菜(珠海)样品中DEHP的含量均超过美国和欧洲的建议标准,存在潜在的健康风险.芥兰、生菜等叶菜类蔬菜在14种不同蔬菜样品中的∑PAEs总量较高,而菜心和苋菜的∑PAEs含量最低.蔬菜品种间结构特征和生长环境(大气和土壤)的差异是影响其对PAEs的吸收及在体内累积的主要因素.