麦饭石促进异养反硝化去除水中硝酸盐的研究

微生物异养反硝化技术是市政污水处理中广泛应用的技术,但在实际应用中,微生物活性易受冲击负荷、重金属胁迫等环境条件影响,使出水效果不稳定。麦饭石作为一种天然硅酸盐矿物,能有效提高微生物活性及对环境胁迫的抗性,可以将其应用于微生物污染治理领域。通过批实验研究麦饭石的剂量、处理方式对异养反硝化的促进作用并探究麦饭石作用于微生物的机理。结果表明,麦饭石的投加剂量和处理方式均显著影响了微生物对硝酸盐的去除效果。硝酸盐去除率与麦饭石投加量呈正相关,麦饭石投加量为350 g/L时硝酸盐去除率可达96%,未添加麦饭石的空白组硝酸盐去除率仅为25%;处理方式会影响麦饭石对反硝化过程的强化作用,研磨后过200目筛的麦饭石在投加量<150 g/L时具有优势,投加量继续增大后,未经处理的麦饭石表现出更强的反硝化促进作用。进一步采用未经处理的麦饭石、研磨后过200目筛麦饭石及球磨麦饭石浸出液进行反硝化的促进实验及微生物毒性实验探究麦饭石作用于微生物的机理。实验结果表明,麦饭石浸出液能够提高微生物的活性及对环境胁迫的抗性,影响麦饭石生物促进作用的主要因素为其溶出微量元素的成分及浓度。本研究为天然矿物麦饭石应用于微生物污染治理提供理论依据和实际应用价值。     

Distinguishing between natural and aquaculture-derived sediment concentrations of heavy metals in the Broughton Archipelago, British Columbia

Marine sediment samples were collected in the Broughton Archipelago, British Columbia, to assess the use of a geochemical normalization technique in the identification of a chemical tracer of aquaculture waste material. Zinc and copper were suggested as tracers of feed pellets, while copper was considered an indicator of anti-foulant agents used on netpen systems. The sediment samples were analyzed for carbon, nitrogen, organic matter, water, trace-element, and free sulfide concentrations, and sediment grain-size distribution. Sediment texture analysis revealed a wide range of substrate types from sand to silty loam categories. Strong relationships between sediment texture, sediment porosity, and organic content were observed across both near-field and far-field stations. Excess zinc and copper sediment concentrations, identified using a lithium-normalization technique, were restricted to near-field sampling stations (0 and 30m from netpen systems). The relationships between these metal tracers and organic content and sulfur concentrations were explored to account for variations in sediment concentrations of zinc and copper.     

北京市杨镇一中人工湿地设计及污水处理效果

针对北京市农村地区居民居住相对分散、生活污水集中处理难度大的状况,在北京市杨镇一中,建立了经济且简便易行的用于处理污水的人工湿地。该人工湿地由地埋式一体化预处理、多级复合式人工湿地系统、景观湿地系统三部分组成。通过单元实验,对人工湿地的填料结构、植物选择、布水设计、水位调节、湿地防堵系统设计、预处理系统设计进行了创新,研究了1d、2d和3d水力停留时间对污水中有机物处理效应的影响,并开展了人工湿地基质堵塞实验、冬季保温措施研究以及人工湿地脱氮除磷效果研究。结果表明,比较而言,1d和3d的水力停留时间不利于有机物的去除,2d的水力停留时间有利于有机物的去除;人工湿地0～10m的水平距离内,0～5cm、30～35cm、60～65cm深度的基质的堵塞差异显著(n=10,p<0.05),从水平上看,在0m、2m、4m处基质的堵塞最为明显,因此,在更换人工湿地基质时,只需更换0～4m内的基质;棚膜+蒲席覆盖系统去除污水中总氮的效果要优于结冰盖系统,更适宜于北方使用;预处理系统、人工湿地系统、景观湿地系统三部分共同处理污水,优势互补,能使处理后的出水符合北京市水污染排放标准一级B限值。     

聚甲醛污水处理技术总结

作者阐述了聚甲醛污水的水质特点,提出了聚甲醛污水工程的设计要点,介绍了两个聚甲醛污水工程实例,并对已实施的工程进行了总结。     

Exploitation of gold in an historic sewage sludge stockpile, Werribee, Australia: resource evaluation, chemical extraction and subsequent utilisation sludge

Sewage sludges are potential targets for economic extraction of Au because of the documented Au content of sewage sludges worldwide, which are of the order of some ore deposits currently mined for Au. The sewage of Melbourne, Australia, was stockpiled in large, closed, lagoonal tanks from 1898 until 1980. Reeves, Plimer and Foster, 1999, have conducted, and published, an extensive and exhaustive study of the Werribee sewage reserves utilising RNAA, INAA, GFAAS, ICPMS, and FLAAS to determine 31 elements, including Au, Ag, Sb, As, Cd, Hg, Zn, Cu, and Pb. The study was initiated to determine Au, Ag and other metal variations in both space and time and to investigate the economics of chemical extraction of the precious metals. A total of 149 samples from over 50 hand-auger drillholes to a depth up to 4m were analysed from the stockpiles, with Au assays yielding remarkably consistent results. Average grades of 0.77 g/t Au and 18.8 g/t Ag have been documented for a measured resource of 770,000 m³. Laboratory-based extractive metallurgy of the Werribee sludges has demonstrated that Au, Ag, and Zn can be removed with relative ease by heap-leaching using modified conventional technology, albeit with prohibitive reagent consumption. The extraction of the precious metals also results in the variable removal of contaminant metals such as Cd, As, Sb, Hg and Cr which may render the sludges fit for sale as agricultural fertiliser, provided organic pollutants and pathogenic organisms are below governmental environmental protection limits.     

Characteristics of trace elements in contaminated rivers and their environmental significance

Several rivers researched around Taihu Lake in Chinese eastern plain are distributed to the west of the lake. Pollutants of different types from tributaries and inlets flow directly into the main rivers and finally into the lake. They change trace elements of rivers fi＇om which we can analyze. Researches about trace elements are helpful for understanding the pollutant characteristics, industrial structure and agricultural cultivation in the area of network rivers in the plain of China. Samples of water column, suspended matter and sediment were collected fi＇om the west rivers of Taihu Lake, which represent three typical rivers. Observation in the field and the primary composition analysis showed the Caoqiao River was mainly contaminated by industrial wastewater, the Liangxi River was discharged by domestic sewage and the Dapu River was principally input by farmland runoff. REE concentrations and their normalized curves showed obvious characters for rivers discharged by different sewages. The contents of total REE in water column followed the order of the Caoqiao River, the Dapu River and the Liangxi River fi＇om high to low. TREEs in suspended matter and sediments follow the order of the Dapu River 〉 the Caoqiao River 〉 the Liangxi River. REE normalized curves （for Australia shale） suggested that significant diversities were presented in water column, suspended matter and sediments, i.e., heavy REE enrichment in water, middle REE enrichment in suspended matter, and smooth curves for sediments. But the heavy pollution resulted in several anomalous curves in the same rivers. Some element ratios were selected as indices for polluted rivers based on their geochemical properties and diversities between rivers. The results displayed the discriminative indices for water column, suspended matter and sediment. The effective indices were Pb/Fe, Cr/Fe, Ni/Fe, Pb/Ni, Zn/Ni for water column, Cu/Al, Cu/Fe, Zn/Fe, K/Ca, K/Na, Pb/Co, Zn/Co for suspend matter and Pb/Fe, K/Ca, Ca/Mg, Zn/Ni for sediment, respectively. In general, rivers mainly discharged by industrial sewage have high ratios of Pb/Ni, K/Ca, are enriched in the middle REE and have positive Gd anomaly. The domestic sewage flowing into rivers reveals high ratios of Zn/Ni, Pb/Fe, and is enriched in the heavy REE, and has the positive Eu anomaly. If runoff of farmland enters into the rivers, it will have high ratios of Ca/Mg, K/Na, high lanthanum, and show the smooth normalized curves of REE.     

Failure of swim bladder inflation of perch,Perca fluviatilis L. found in natural populations

Perch suffering from swim bladder inflation failure (sinkers) are reported from wild populations of Lakes Constance, Geneva, Lucerne, Sempach, and Zurich in central Europe. Sinkers were found at all 7 locations considered in a survey. Relative abundance of sinkers varied from 0.1% to 7.9% of local perch populations. Sinkers from wild populations and sinkers reared in the laboratory showed similar behaviour and malformations. Information on sinker syndrome in 26 physoclistous species is compiled. It is found to be a widespread problem in aquaculture, but is reported here for the first time from natural populations.     

GIS环境下污水管网设计流量的快速计算

针对ＧＩＳ环境下污水管网设计问题，提出了一种快速计算管段设计流量的方法——递归方法。分析了递归的原理、链式表的建立以及递归算法的具体实现等，并以实例阐述了递归计算的各个步骤     

污水泵浓盐水示踪测流研究

针对污水泵流量监测中常规测流方法的缺点,结合工程实践,研究浓盐水示踪法在污水泵流量监测中的可行性,提出该方法适于在低背景盐浓度下污水的测流;观察激励信号、温度等对测流结果的影响,给出修正方法;利用计算机采集技术,提高方法的准确性、实时性。     

δ15N在污水生物脱氮机理研究中的应用

近年来,硝酸盐氮的污染愈来愈严重.无论是地表水还是地下水都受到不同程度的氮污染.控制氮污染及处理氮污染问题已经提到我国水污染控制的议事日程.本文探索微生物处理含氮污水的过程中反硝化作用的脱氮机理,使用δ15N标识技术研究水体中三氮运移转化过程中的质量不守恒,证明δ15N标识技术研究确定不同形态氮的数量各系是可行的.研究水体中三氮质量不守恒现象,将解决含氮污水生物净化中污泥上浮问题、氮污染含水层生物修复中气阻问题.