Investigation On Disposal And Resource Utilization For Sewage Sludge In Zhejiang Province

Sewage sludge is the main solid waste form sewage treatment. With the raising of rate for waste water treatment, the wastewater treatment plants will be doubled and redoubled and produce more and more sewage sludge. Properly treatment, disposal or usage for sewage sludge is needed because it is huge, vertiginous, putrid, niff and toxic. Abandon or direct usage will not only reduce the ability of water treatment for wastewater treatment plants, but also have an urgent threaten to the environment and human activity.The methods of disposal for sewage sludge and their technique level, economic, environment and society development are compared and evaluate in the paper. It also indicated that resource utilization is the direction of development for sewage sludge disposal in the future.Since now there are about 40 wastewater treatment plants in Zhejiang Province which produce about one million tons of wet sludge each year. At present the main treatment method is burying which may cause social or environmental problems and can not achieve a comprehensive utilization. So they are not the best methods for sewage sludge treatment. Based on the detailed research of the wastewater treatment plants in Zhejiang Province, the present situation of production, performance and disposal of sludge are introduced in this paper, as well as some advices and countermeasures for disposing are put forward. Furthermore, the feasibility for using cement producing process to dispose sewage sludge is studied in the paper.A new drying technique is put forward for the treatment of sewage sludge in cement production. The flow and equipments of drying technique are designed. Investment and running cost are also estimated. All this indicated that this method is feasible.At last, some experiments about sewage sludge treatment in cement production are done in the lab. The results indicated that sludge can improve the burnability of cement raw meal and don't influence the ability of cement. Meanwhile, heavy metal can be solidified in the cement and the lixivium is below the standard.At last, the mechanism of production and prevention and cure measures for dioxins are discussed in the paper.