Technology Of Sludge Fast Solid Fermentation And Preliminary Development Of Bio-Organic Fertilizer

Along with the accelerating pace of urbanization and daily broadening scale growth of environmental quality standards, proportion and efficiency of wastewater treatment are increasingly improved and deepened, resulting in the greatly increasing sludge production. How to eliminate pollution from sludge, take full advantage of them, and exert their potential big value is an important subject of the recycling economy at present.Utilizing sludge as main materials, using dairy manure, straw and fermentation agent as auxiliary raw materials, the basic requirements of improving fermentation conditions, enhancing fermentation rate, shortening manurity time, increasing sludge nutrients,and achieving the aim of fertilization of sludge were investigated. Changes of physic-chemical and maturity indexes were recorded in the process of fast solid fermentation. Conclusions are as follows:(1) Through the single factor experiment of water content,ventilation quantity and addition of wheat straw,the conditions of fermentation were water content 65%, ventilation quantity 0.5L(/min·kg dry material),addition of wheat straw 2kg, sludge 10kg, dairy manure 4kg.(2) Study of fermentation agent for the materials getting maturity time showed that, addition of sludge and fermentation agent can promote heating and shorten the maturity time. The treatment without sludge and fermentation agent couldn't become thoroughly decomposted in 30d, and 30d's GI was 73.4%; in the 30th day, GI was 80.3% in the treatment with fermentation agent and 81.0% in the treatment with sludge, both treatments reached maturity in 30 days. While the treatment added sludge and fermentation agent reached maturity in 20d, and GI was 81.2%; also GI was 85.6% and ammonia nitrogen content was 0.26g/kg in the 30th day; the time for the treatment getting maturity cost 10 days shorter than other 2 treatments adding fermentation agent or sludge.(3)Different ratios of materials for nutrient in the product were recorded by changing the amount of sludge and dairy manure. Afer 30 days,the main nutrient content including humus, total nitrogen, available nitrogen, total phosphorus, available phosphorus in the treatment with sludge 5kg, dairy manure 4kg, wheat straw 2kg were 218.7/kg, 13.2g/kg, 5.08g/kg, 14.2g/kg, 3.72g/kg; in the treatment with sludge 10kg, dairy manure 4kg, wheat straw 2kg ,the content were 185.6/kg, 17.7g/kg, 4.40g/kg, 20.7g/kg, 6.52g/kg; in the treatment with sludge 15kg, dairy manure 4kg, wheat straw 2kg ,the content were 143.8/kg, 19.7g/kg, 2.93g/kg, 19.9g/kg, 5.40g/kg;in the treatment with sludge 15kg, dairy manure 2kg, wheat straw 2kg ,the content were 268.3/kg, 20.4g/kg, 8.12g/kg, 19.8g/kg, 5.4g/kg. A conclusion that with the ratio of addition of sludge, dairy manure and wheat straw differed, the content of main nutrients such as humus, available nitrogen and available phosphorus also changed can be got.(4) The effect of adding fermentation agent for the quantity of useful microorganisms in the treatments was studied. After adding fermentation agent, through comparing the 4 treatments, the results were as follows:The quantity of useful microorganisms in the treatment with fermentation agent was far more than the CK, and the number was 3.35×10~7CFU/g dry material,which was 148 times of the CK content. The content in the treatment with sludge was 1.30×10~8CFU/g dry material, 157 times of CK. The content in the treatment with sludge was 2.78×10~8CFU/g dry material, largest of all, 336 times of CK. In all 4 treatments, the quantity of useful microorganisms after fermentation was more than the beginning.(5) According the ratio of sludge, dairy manure, straw additional dose, another fast solid fermentation was conducted again. At the end of the fermentation, the content of various nutrients indicators were as follows:Organic matter: 420.2g/kg;Total nitrogen:18.7g/kg;Total phosphorus(P):22.0g/kg;Total potassium:6.71g/kg;Number of effective microorganisms live:1.28×10~8cfu/g;Death rate of egg of ascaris lumbricoides:100%; Number of fecal coliform:3.53/g;Cd:3.02mg/kg,Cr:96.3mg/kg,Pb:46.4mg/kg,As and Hg:0, GI 86.5%.Compare various indicators with the bio-organic standards, almost every indicators can be considered in accordance with the requirements. Following the best parameter for the fast solid fermentation to produce bio-organic fertilizer could be considered.