Application of natural mixed bacteria immobilized carriers to different kinds of organic wastewater treatment and microbial community comparison

Highlights: • Two kinds of natural mixed bacteria immobilized carriers was prepared. • The immobilized microorganisms had good effect on both toxic and non-toxic wastewater treatment. • This approach can provide ways for low-cost wastewater treatment. • Microbial community of different carriers in different wastewater was studied and compared. -- Abstract: Although many literatures have reported that biomass materials had been used for water treatment, most of the biomass materials were directly used for adsorbing toxic or organic substances. In this research, modified pine bark and corn straw were used to prepare the high-efficiency and low-cost activated sludge immobilized materials. By treating phenol wastewater and ordinary organic wastewater, various factors influencing the treatment effect were investigated. The results showed that the immobilized biological carriers had good effects on the treatment of two kinds of wastewater. The removal efficiency of the phenol wastewater reached 100% in 24 h, and the removal efficiency of ordinary organic wastewater reached 95.5% in 96 h. The results of microbial community analysis showed that the abundance of the immobilized carrier and that of the original sludge was similar. But when treating different wastewater, the number and proportion of microorganisms were significantly different.