Abstract:

In order to solve problems in biogas slurry of biogas project, such as its large amount, difficulties in disposal, storage, transport and low nutrients, high resistant contaminated reverse osmosis used to concentrate biogas slurry were put forward accordingly so as to achieve the high-value use of the biogas slurry. The feasibility of concentrating biogas slurry technology by membrane was analyzed, then the water quality of biogas slurry concentrated by membrane was introduced in brief. At the same time, by planting cabbage test used concentrated slurry as fertilizer, yield and quality of cabbage was studied. The results showed that the reverse osmosis technology concentrating the biogas slurry was feasible according to the analysis of the membrane flux and its influencing factors, the best operating pressure range was 4-5.5 MPa，reverse osmosis technology requirements were met by input water conductivity and temperature of the biogas slurry. The permeate water of RO system could met the standard of slurry mixing. Besides, the concentrated water could be widely used for agriculture due to its richer nutriments. Concentrating sully could met the Chinese cabbage’s demand of N nutriment, and the best fertilized concentrating biogas slurry whose N’s content was 1100 kg/ hm2, at this case it not only could harmonized the high yield of cabbage of the season but also the environmental effect, moreover, using biogas slurry planting could improved the quality of cabbage, its content of nitrate of cabbage could be controlled below 600 mg/kg.