Study On Treatment Of Sludge In Municipal Sewage Treatment Plant

As the remaining residue from the process of sewage treatment and discharge, the sewage sludge containing a large number of pollutants, including organic polymer which is difficult to degradation, heavy metals and pathogenic organisms etc. Each year, a large number of sewage sludge were produced from our domestic sewage treatment plants and which have been caused the groundwater pollution, the soil ecological environment damage and other environment problems due to without treatment or disorganized dumping and landfill. How to treat the sludge properly has become an important issue which is needed resolving in current water supply industry.In this paper, based on the characteristics and sources of the sludge, listed various malign influence on the environment caused by sewage sludge, and putted forward the necessity of sewage sludge treatment and disposal. This paper analyzed the current situation and trend of sludge treatment/ disposal in both here and abroad, meanwhile, the typical sewage sludge treatment technologies in China were deeply studied and discussed. Furthermore, taking a sewage treatment plant as an example, bioleaching technique, a biodegradation of sewage sludge, were chosen as the treatment process of the project after comprehensive analyzed the characteristics and advantages, process design, investment estimation, cost analysis and other factors of three methods for sewage sludge treatment, which are the conditioning-press sludge drying process(the addition of lime ahead), the sludge and calcium stable stem(plus lime behind) and the bioleaching sludge drying, and give full consideration to the actual situation of wastewater treatment process and sludge properties, layout, short and long term project implementation plan of the sewage treatment plant.The results show that the advantages of bioleaching technology against other physical or chemical approaches are as follow: ①The sludge volume reduced significantly about 1/2~1/3; ②The lowest cost of running process, and after treatment the sludge from bioleaching is more suitable for diversified resources which lead to the most widely market prospect; ③The least dosage add, low cost of transport and disposal, high organic content and high calorific value; ④The bioleaching is a technology of flexible management, good operating environment, convenient operation and small labor intensity. In one word, the bioleaching process is in line with the current development status of the sewage treatment plant, in line with national policy of environmental protection, energy saving and emission reduction.