Study On The Disposal Of Sludge Of City Sewage Plants And Its Utilization As Resource

With the rapid growing of cities of our country, the amount of sludge produced from sewage treatment is increasing significantly along with the expansion of the scale of sewage plants. The sludge may cause serious pollution of environment without proper treatment and disposal. Traditional sludge treatment and disposal methods can not meet the present requirements of our environment protection and sustainable development strategy because of the higher standards of environment due to the development of our economy and living standards. Proper disposal of sludge from sewage plants has become one of the most critical problems we are facing and selection of protocols of sludge disposal that are suitable for us is very important.The thesis proposed a new sludge disposal protocol including optimized treatment scale, procedure and location of the plants according to the present status and future layout of sewage treatment of Xi'an, which is an attempt of sludge disposal appropriate to the western area of China. The present status and developing trends of sludge disposal for sewage treatment of big cities, either Chinese or international, were reviewed. The protocol is designed based on the overall level, techniques, crititical problems and developing tendency in our country and the detailed analysis of the sewage programs of Beijing and Shanghai. The venture of the projects and its economical benefits were also evaluated. The proposed protocol has advantages such as high efficiency, low investment, high stability, high new technique content and low energy consumption. It is possible to explore utilization of the sludge as a resource and balance the benefits among environment, society and economy.