| The expansion of animal husbandry makes accumulation of animal manure issues more and more serious because of China's rapid economic development. Livestock produced manure more than 4 billion tons in 2009. Manure reached 11.23 million tons every day was 4.1 times of industrial organic pollutants. The manure caused serious pollution of the soil, water and air. Pollution prevention and use of manure have become an urgent task.The one hand, livestock manure is a good source of organic fertilizer, It contains a lot of organic matter, NPK and other trace elements which is essential plant nutrients, and also contains a variety of enzymes and microorganisms. It can play an irreplaceable role by making of fertilizers, it helps to improve soil organic matter and soil fertility, soil structure, improves soil physical and chemical environment and microbial environment. On the other hand, improve fertilizer use efficiency has been a hot research in related fields because of most of the phosphorus retention in soil. Phosphate utilization of quarter was only 10-25%. Data indicate that organic fertilizer has a significant effect on the activation of soil phosphorus, migration, and increased P use efficiency. The combination of phosphate fertilizer and organic manure can take advantage of synergies between fertilizer and organic manure. Superphosphate containing organic matter was prepared based on the diluted acid technology. It was animal dung as a source of solid waste and superphosphate as phosphate source in this paper. The purpose of this article provided a theoretical basis and experimental support to enhance the use of animal solid waste and improve fertilizer use efficiency.(1) Single factor experiment and Orthogonal experiments were conducted to find out optimum conditions of preparation of SSP. Results showed the optimum conditions were the addition of sulfuric acid at theoretical dosage,stirring intensity at 500 r/min, reaction duration for 15 min, and sulfuric acid concentration at 65%. The conversion in the fresh single superphosphate was 84.2%in the optimal treatment.(2) Fertilizer and nutrient changes were measured by experiment when cow dung was acid hydrolysis by sulfuric acid, phosphoric acid. Results showed the concentration of sulfuric acid and phosphoric acid was no significant effect on organic matter of cow dung. Organic matter content of cow dung by Sulfuric acid solution was lower than by phosphoric acid solution because of strong oxidizing of sulfuric acid.Determine the nutrient content of changes, acid solution crude protein, crude ash and calcium content, with little impact sulphuric acid concentration increases, samples of crude fibre could have certain degree reducing, phosphorus had grown to stable trend, crude fat content numerical severe eccentric explain its had been carbonized acids.(3) Cow dung and slag added step by step was better than cow dung added mixed with slag. This was because it would had a higher conversion rate of phosphorus and a lower free acid content.(4) Orthogonal experiments were conducted to find out the optimum conditions of preparation of organic manure SSP. Results showed the optimum conditions were cow dung fineness below 0.355 mm, the amount of cow dung at 10 grams, the addition of sulfuric acid at 110%of theoretical dosage, and adding slag first. The conversion in the fresh single superphosphate was 83.9%in the optimal treatment. Fresh manure conversion factors could be seen by direct analysis of the range of each factor. Decreasing order was added cow dung, cow dung fineness, the amount of sulfuric acid, the amount of cow dung. |
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