음식물류 폐기물 악취제거를 위한 바실러스균의 특성 및 분리동정

Abstract

About 67 % of odor complaints generated from environmental foundational facilities was found to occur in wastewater treatment plants and food waste treatment plants. Food waste occurred offensive odor in almost all processes, such as collecting, transporting, etc., until it is treated. It is impossible to fundamental solutions if we do not decompose and remove the odor components itself. Thus, it is necessary to take the biological methods that is economical and easy to operate and maintain. The application of deodorant microorganisms, one of the biological methods, could solve the odor problems effectively by introducing the odor induction region. At the present study, the experiment performed by using Bacillus separated from sludge of excreta treatment plant in Busan to solve the offensive odor effectively generated from food waste. To separate only Bacillus, sludge was heated at 80 ℃ for 15 minutes to form spore. LB medium was used culture medium, and three species colony observed dominant bacteria on LB medium. Pure cultured microorganisms were identified as Bacillus methylotrophicus (B1), Bacillus subtilis (B2) and Bacillus atrophaeus (B3). Central composite design (CCD), one of the response surface methodologies, and analysis of variance (ANOVA) were adopted to further investigate the mutual interaction between Bacillus (mL/L) and time (day) on TON removal. Bacillus (mL/L) and time (day) were independent variables for odor removal and response variable was TON. Changes of variables between Bacillus (mL/L) and time (day) on TON reduction were observed the more variables increased, the more improved efficiency of odor removal. Final TON value of mixed Bacillus was reduced to 40, Bacillus methylotrophicus (B1), Bacillus subtilis (B2) and Bacillus atrophaeus (B1) showed 40, 34 and 50 respectively. Bacillus subtilis (B2) was the most effective deodorizing bacteria. Based on the result, Bacillus subtilis (B2) was carried out experiments for the mass culture. Plackett-Burman design and response surface methodology were used to optimize cultural conditions for Bacillus subtilis growth. Plackett-Burman design was an appropriate method to screen significant variables. Statistical analysis of variance (ANOVA) of the results showed soy peptone, sucrose, yeast extract, K2HPO4 and CuSO4 were important components and that their interactions were strong. And the optimum medium concentration considered with cost was composed of soy peptone 2.6 g/L, sucrose 10 g/L, yeast extract 3.57 g/L, K2HPO4 and CuSO4 were presented that was not significant. Economic evaluation of the product has determined in comparison with the selling price. Manufacturing price was determined 500 won/L that was cheaper than the selling price (3,000 won/L) about 83 %.