Study On The Application Of The Biological Membrane Treatment System In Shrimp Culture Water Treatment

In this study, we use bagasse particle as carbon-based biological membrane carrier, using bacillus strains as inoculate bacteria, predominant bacteria as membrane-forming method. By studying the variation of water quality factor and density of bacteria to explore the membrane-hanging result; construct biological membrane treatment system based on the biological membrane, apply it to the water treatment in shrimp culture and observe the efficiency; screen bagasse-cellulose degrading-bacteria from the system. The main results are as follows:1. Construction of the biological membrane treatment systemSelect the diameter of 250μmm-600μmm, treated bagasse particle as carrier, Bacillus BZ5 as inoculate bacteria to culture the biological membrane, consider rapid decline of ammonia nitrogen, nitrite nitrogen concentration as the token of successful at hanging membrane. Under certain conditions, in about 25 days the biological membrane can be formed, at this time the densities of total bacteria and bacillus bacteria in bagasse were 2.40×108 cfu/g、8.14×107 cfu/g, densities of total bacteria and bacillus bacteria in water were 5.04×105cfu/mL、4.17×104cfu/mL, and then construct biological membrane water treatment system based on the biofilm. The results of the study show that, bagasse particle can qualify the requirements of biological membrane treatment technology, and the predominant bacteria method can effectively shorten the time needed for membrane-forming.2. Efficiency study on the biological membrane water treatment systemThe variation of water quality factor (ammonia nitrogen, nitrite nitrogen et al.) and density of bacteria in water as indicators to evaluate the degradation efficiency of aquaculture water, the affection of addition of carbon source. The study found that, ammonia nitrogen and nitrite nitrogen can be translated into bacterial protein、nitrate nitrogen and nitrogen by the system, and controlled the concentration in 0.2 mg/L、 0.05 mg/L. At the same time, through the competitive antagonism of micro-organisms can significantly reduce the density of Vibrio while largely increase the density of bacillus, maintaining at 102 cfu/mL,104 cfu/mL level. We also discovered that, when the nitrogen removal ability of biological membrane drop down, adding additional carbon source can effectively improve the efficiency of biological membrane.3. Isolation and screening of bagasse-cellulose degrading-bacteria from the treatment systemCellulose congo-red culture medium was used to screening, and extracellular enzyme activity as re-screening methods from seawater the treatment system, and to research the influence on bagasse cellulose enzymatic activity by mixed-fermentation of strains and their ability of utilizing bagasse carbon source. Two strains (Z4 and S5) were isolated and identified as Bacillus licheniformis by 16S rRNA sequence similarity analysis, mixed-fermentation between bagasse-cellulose degrading-bacteria S5 and Z4 could obviously increase in cellulose enzyme activity, bagasse cellulose activity increased by 14.21% compared to S5. Mixed-fermentation of S5 and non-bagasse-cellulose degrading-bacteria Bacillus BZ5 increased bagasse cellulose activity 25.92%.