Application of Alginate Embedded Immobilized Microbes in Oil Wastewater Treatment

Alginate-activated carbon immobilized microspheres(AACIM)were prepared through immobilized biosorption of activated carbon and Brevibacillus parabrevis Bbai-1 by sodium alginate.The maximum adsorbing capacity of Bbai-1 on activated carbon was measured at 25 ℃ by comparing the biomass of Bbai-1 before and after adsorption.4 major factors such as alginate concentration,activated carbon content,seed bacteria biomass and cross-linking time on physical properties and microbial activity of AACIM were investigated by orthogonal test,and the optimal preparation conditions of AACIM were determined as 3.5% of alginate,0.7% of activated carbon,6×107 cell/mL of seed bacteria and 24 h of cross-linking time.At the temperature of 25 ℃ and oil content 0.2%,the optimal volume ratio of AACIM and oil medium 3:20,the optimal pH and salinity of crude oil degradation for immobilized bacteria were investigated to compare with the free ones.Results indicated that under the conditions of pH 6~9 and salinity 1.5%~3.5%,the biodegradation rate of immobilized bacteria reached above 50%,which was 20% more than that of free ones,and the immobilized bacteria were also able to endure higher salinity and adapt to wider range of pH.