Effects of different dewatering methods on phosphorus form distribution and availability in sewage sludge
At present,phosphorus resources are in short supply all over the world.Municipal sewage is rich in phosphorus.Recycling phosphorus from municipal sludge can not only alleviate the shortage of phosphorus resources,but also remove phosphorus.In order to study the effect of dewatering method,the phosphorus form in sludge treated by several treatment methods was analyzed.On this basis,the difference of biological availability of phosphorus in sludge from different treatment methods after entering soil was compared.The results showed that after incineration,the total content of inorganic phosphorus in sludge increased significantly (1137％),and the content of exchangeable phosphorus,the most active inorganic phosphorus component,increased significantly.However,the contents of total inorganic phosphorus and exchange phosphorus decreased significantly after the addition of excessive dehydrating agent and plate and frame filtration,and a certain amount of inactive Fe-Al binding and closed storage phosphorus appeared,which was not conducive to phosphorus recovery.After soil culture experiment,the improvement effect of available phosphorus of the obtained product reached or exceeded that of calcium magnesium phosphate fertilizer,and the group with the most obvious improvement effect reached 2.5 times that of calcium magnesium phosphate fertilizer,while the improvement of phosphatase activity exceeded that of calcium magnesium phosphate fertilizer.The above results indicated that the recovered phosphorus product from municipal sludge had a significant effect on the improvement of soil phosphorus availability and the supply capacity of soil phosphorus,and its fertilizer effect reached or exceeded the traditional phosphate fertilizer.
万方数据
维普
