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861.
正Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter(NOM)and thousands that derive from anthropogenic contaminants.As complex as these samples are,drinking water can be even more complex.Due to disinfectants that are used to treat drinking water(e.g.,chlorine,chloramines, 相似文献
862.
The individual and simultaneous effects of acid and ultrasonic pretreatment on the disintegration of municipal waste activated sludge (WAS) were investigated based on chemical properties of WAS. In the combination of acid and ultrasonic pretreatment methods (ultrasonic-acid pretreatment), lowering pH accelerated and enhanced the disintegration of waste biological sludge. Therefore, the same disintegration efficiency (obtained by ultrasonic pretreatment alone) was achieved by the combined pretreatment in shorter sonication times. Optimum pretreatment conditions were ultrasonic power density of 1.0 W/mL and pretreatment time of 10 min for ultrasonic pretreatment alone, and ultrasonic power density of 1.0 W/mL, pretreatment time of 10 min and initial sludge pH of 2.0 for the combined pretreatment. Sludge disintegration degrees were about 30% and 40% under these optimized conditions, respectively. Optimum sludge concentration was found to be 1.0% total solid (TS) content for the combined pretreatment. As a result, ultrasonic-acid pretreatment has been determined as a new and effective combined sludge pretreatment method to improve the sludge disintegration. 相似文献
863.
Patrick A.W. van Hees Kristin Elgh-Dalgren Magnus Engwall Thomas von Kronhelm 《Resources, Conservation and Recycling》2008,52(12):1349-1361
The disposal of soil material after ex situ treatment of contaminated soil is an issue of growing concern. The handling and use of this material are surrounded by numerous regulatory, economic, technical and societal aspects that complicate or hinder re-cycling. As a consequence, the lack of means of recovery can in the long-term bias the whole remedial process. In addition, it can affect the competition between various treatment options such as ex situ, and in situ techniques and landfilling. At the same time the materials must not have any negative environmental impacts, and their usage must be compatible with existing risk assessment and management frameworks regarding contaminated land. Other concerns such as a possible distinction against “lightly” contaminated materials, waste status and public acceptance add to the complexity. This paper focuses on Swedish conditions, but does also provide an outlook concerning EU regulation. A summary of leaching and batch tests employed for re-use of soil and waste is presented as well as an overview of the eco-toxicological aspects of treated materials. The main conclusion is that re-cycling of treated soil is desirable from numerous aspects, but has to go along an adequate risk assessment. 相似文献
864.
Characteristics, treatment and utilization of residues from municipal waste incineration 总被引:12,自引:0,他引:12
Beneficial utilization of residues from municipal solid waste incineration is an important objective for integrated waste management in many jurisdictions. When residues are to be used as an aggregate substitute in construction applications, the release of constituents of concern to soils and water through leaching is an important environmental consideration. In this paper, residue characteristics that control constituent leaching and testing approaches for evaluating leaching are discussed. Quality control and potential improvement in case of beneficial application are addressed. 相似文献
865.
微波消解ICP-AES法测定城市污水中11种元素 总被引:4,自引:1,他引:3
介绍了微波消解电感耦合等离子体发射光谱法测定城市污水中Cu、Zn、Pb、Cd、Cr、Na、Mn、Fe、Ni、Se、Sb等11种元素的方法。在最佳试验条件下,被测元素的检出限为0.004μg/mL~0.12μg/mL,相对标准偏差为1.9%~11%,回收率为93.1%~104%。 相似文献
866.
概括总结了目前涂装(前处理)废水处理工艺,并对这些工艺进行了比较分析,并针对某厂家的涂装废水提出了可行可靠的处理工艺流程。最后提出几点建议来改善和优化涂装废水工艺。 相似文献
867.
Ni-Si交联改性膨润土的制备与应用研究 总被引:1,自引:0,他引:1
以钠基膨润土为原料,制备了镍硅交联改性膨润土,并应用于模拟废水、实验室废水,探讨了镍硅交联改性膨润土对废水中COD、Cr6+、色度、浊度的去除率的影响因素,分别对镍硅交联改性膨润土的镍硅比、废水处理的pH、改性膨润土的投加量、搅拌时间等条件进行了选择。结果令人满意。 相似文献
868.
869.
870.
The twentieth century saw a dramatic increase in the production of urban solid waste, reflecting unprecedented global levels of economic activity. Despite some efforts to reduce and recover the waste, disposal in landfills is still the most usual destination. However, landfill has become more difficult to implement because of its increasing cost, community opposition to landfill siting, and more restrictive environmental regulations regarding the siting and operation of landfills. Moreover, disposal in landfill is the waste destination method with the largest demand for land, while land is a resource whose availability has been decreasing in urban systems. Shortage of land for landfills is a problem frequently cited in the literature as a physical constraint. Nonetheless, the shortage of land for waste disposal has not been fully studied and, in particular, quantified. This paper presents a method to quantify the relationship between the demand and supply of suitable land for waste disposal over time using a geographic information system and modelling techniques. Based on projections of population growth, urban sprawl and waste generation the method can allow policy and decision-makers to measure the dimension of the problem of shortage of land into the future. The procedure can provide information to guide the design and schedule of programs to reduce and recover waste, and can potentially lead to a better use of the land resource. Porto Alegre City, Brazil was used as the case study to illustrate and analyse the approach. By testing different waste management scenarios, the results indicated that the demand for land for waste disposal overcomes the supply of suitable land for this use in the study area before the year 2050. 相似文献