排序方式： 共有31条查询结果，搜索用时 27 毫秒
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以自制的两性聚丙烯酰胺分散体系作为污水絮凝剂,考查对城市污水的处理能力。以絮体体积和上清液的透光率为考查参数,研究了聚合物用量、聚合物的离子度、体系pH值和样品溶解时的盐浓度对絮凝效果的影响,并与离子型絮凝剂进行了比较。研究发现,两性聚丙烯酰胺的絮凝能力比阴离子型聚合物的絮凝能力强,比阳离子型聚合物的絮凝能力略强,最佳使用量为3.0 mg.L-1。两性聚丙烯酰胺的絮凝能力受离子度的影响,离子基团越多,絮凝能力越强,但过多的离子基团可带来负面影响。两性聚丙烯酰胺对体系的pH值的适应范围较宽。两性聚丙烯酰胺在应用时需先用1%的氯化钠溶液溶解,盐浓度过低时聚合物不能充分溶解,高于此值对絮凝过程无明显影响。 相似文献
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R. A. Crichton 《Geotechnical and Geological Engineering》1994,12(3):183-212
Summary The legislative framework within which the disposal of sewage sludge is managed in England and Wales and the methods employed are outlined. Those factors which affect management decisions are analysed and consideration is given to the environmental implications of those decisions. Sewage processes and sludge disposal are considered, and the problems, especially those of heavy metal contamination, are addressed. An indication is given as to how the Water Services Companies are likely to implement the more stringent controls on disposal. Finally, the future of sludge management in England and Wales is discussed.Abbreviations BAT
Best available technology
- BATNEEC
Best available technology not entailing excessive cost
- BOD5
Biochemical oxygen demand
- BPEO
Best practicable environmental option
- CBI
Confederation of British Industry
- CEST
Centre for Exploitation of Science and Technology
- COD
Chemical oxygen demand
- CSC
Customer Services Committee
- DAF
Dissolved air flotation
- DG
Director General
- DoE
Department of the Environment
- DS
Dried solids 相似文献
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The main removal mechanisms for the degradations of seven pollutants in wastewater treatment wetlands were analysed, and a mathematical model was established to quantify the removal of each pollutant, based on its main removal mechanisms. Subsurface horizontal flow wetlands were treated as a series of continuous stirred - tank reactors (CSTRs). Kinetic models for the removal of biochemical oxygen demand, chemical oxygen demand, ammonia, total nitrogen and faecal coliforms were established by combining Monod or first - order kinetics with CSTR assumptions. These tentative models account for a wide range of factors that affect wetland performance, but the models have not been proven by ex periment data. Depending on the derivation of various coefficients in the models and verification by actual performance data, this study may provide a starting point for an integrated pollutant removal model to be developed, and experimen tally verified, thereby making a step forward from the current greenbox' approach of wetland design. 相似文献
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从厌氧反应器的发展谈UASB反应器的改良 总被引：10，自引：0，他引：10
对厌氧反应器的发展沿革、技术现状和研究进展进行了较为全面的总结。介绍了第 1代、第 2代和第 3代厌氧反应器的特点及应用状况。分析了厌氧反应器的发展趋势 ,对比了 EGSB、IC反应器与 UASB反应器的结构特征 ,提出并验证了改良 UASB反应器。结果显示 ,改良 UASB反应器有利于提高负荷和设备开发。 相似文献
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SUN Guangzhi 《湿地科学》2010,8(2)
The removal of ammonia and phosphorus from an artificial wastewater was studied in two lab-scale reed beds.During batch and continuous operations,it was found that ammonia was removed from the wastewater via a two-step process,sorption inside bed matrices followed by nitrification into nitrite and nitrate.Rapid decrease in the concentration of ammonia in the artificial wastewater was observed during the batch operation,whereas during the continuous operation,which lasted for 39 days,the percentage removal of ammonia decreased gradually with time before stabilizing at around 20%.The efficiency of phosphorus removal exhausted rapidly during the continuous operation,from 39% on the first day of operation to virtually zero after only 5 days.The results suggest that sorption (which may include ion exchange,adsorption,and biomass assimilation) serves as an initial step to remove ammonia and phosphorus from the wastewater,prior to any microbial transformations. 相似文献
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人工湿地中植物的作用 总被引：19，自引：0，他引：19
近20 a来,人工湿地系统由于具有独特的净化机理和功能而越来越多地被用于处理生活污水、工业废水和农业污水。人工湿地系统之所以受到国际上广泛的关注,这是由于它具有低能耗,低成本,运行费用少和操作简便等优势。湿地植物在人工湿地中起着非常重要的作用,不但可以直接摄取和利用污水中的营养物质、吸收富集污水中的重金属等有毒有害物质;而且还能输送氧气到根区,提供根区微生物生长、繁殖和降解过程中对氧的需求。通过详细阐述植物对水中营养元素的吸收作用,说明了植物在人工湿地处理污水中的重要性,并提出了一些改进人工湿地处理污水能力的设想以及人工湿地系统水生植物有待进一步研究的问题,研究结果可以为进一步优化人工湿地系统的设计提供参考。 相似文献
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在环境温度下,水中Cu^2+与铁硫化物矿物交换反应形成的铜蓝的结晶度可以影响Cu^2+的回收效率及交换反应的完全程度。本文利用Cu Cl2和Na2S直接反应生成铜蓝,讨论了不同p H值、反应时间、反应温度、反应物浓度、反应物滴加速度、外加电解质浓度等条件对铜蓝晶体生长的影响,并采用XRD、TEM和EDX方法对铜蓝结晶度和形貌进行了表征,用Scherrer公式计算了晶体的平均粒径。结果表明,反应p H值越低,时间越长,温度越高,反应物滴加速度越慢,越有利于铜蓝晶体生长;铜蓝晶体结晶度随着反应物浓度的增加呈先增后减的趋势,而在不同外加电解质浓度条件下表现出不同的结晶度。 相似文献
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利用一株絮凝效果好的胶质芽胞杆菌所产的微生物絮凝剂进行了深圳市较具代表性电镀废水絮凝性实验。结果表明,微生物絮凝剂有较强的吸附作用,能降低电镀废水中重金属离子的浓度,对废水pH值有一定的调节作用。实验确定了处理综合电镀废水中重金属的条件,初步提出电镀废水的处理和回用工艺。 相似文献
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