Land application of steam exploded sludge and the sludge compound fertilizer
热喷处理污泥及其复混肥的养分效率与生物效应

Sewage sludge was pretreated by steam explosion and then developed into the organo inorganic compound fertilizer through incorporating with a given amount of chemical fertilizers. The field experiment was conducted to assess the effect of pretreated sludge and the compound fertilizer on the no heading Chinese cabbage yield,soil fertility and nutrient bioavailability. The process of steam explosion can eliminate pathogen and disgusted odor in sewage sludge within a relative short time. The loss of total organic C, N and P of sewage sludge is negligible by steam\|exploded treatment, but the dissolved organic C, available N and P in the pretreated sludge can be increased significantly by 87%, 19% and 35%, respectively. Compared to inorganic compound fertilizer on basis of equal nutrient input, the application of the sludge compound fertilizer elevated vegetable yield by 38%, the bioavailablity of N and P and reduced nitrate content in plant by about 50%. The higher concentration of Vc and total sugar in the plants grown in the plots amended with sludge, pretreated sludge, and sludge compound fertilizer were also observed in this study.