Analyses of deodorization performance of mixotrophic biotrickling filter reactor using different industrial and agricultural wastes as packing material

In this study, to efficiently remove malodorous gas and reduce secondary pollution under mixotrophic condi-tions, pine bark, coal cinder, straw and mobile bed biofilm reactor (MBBR) fillers were used as packing materials in a biological trickling filter (BTF) to simultaneously treat high-concentration H2S and NH3. The results showed that the removal rate of BTF-A filled with pine bark was the highest, which was 86.31% and 94.06% under the H2S and NH3 loading rates of 53.59 g/m(3).h while the empty bed residence time (EBRT) was 40.5 s. The theo-retical maximum load was obtained by fitting the kinetic curve, and the value were 90.09 g H2S m(-3).h(-1) and 172.41 g NH3 m(-3).h(-1). Meanwhile, after treating with 720 ppm of NH3, the average concentration of NO3- in the BTF circulating fluid was only 127.58 mg/L, indicating the better performance of secondary pollutants control. Microbiological analysis showed that Dokdonella, Micropruina, Candidatus_Alysiosphaera, Nakamurella and Thio-bacillus possessed high abundance at the genus level, and their entire percentage in four BTF reactors were 62.87%, 46.32%, 47.98%, and 57.35% respectively. It is worthwhile that the genera Comamonas and Tricho-coccus with heterotrophic nitrification and aerobic denitrification capabilities and proportion of 3.66%, 1.45%, 5.43%, and 3.23% were observed in four reactors.

Automated summary

In this study, different fillers were used in a biological trickling filter to treat H2S and NH3 gas, with pine bark showing the highest removal efficiency. Microbial analysis revealed the important roles of certain microbial populations with nitrification and denitrification capabilities in the treatment process.