Biochar-enhanced hydrogen production from organic fraction of municipal solid waste using co-culture of Enterobacter aerogenes and E. coli

In the present study, biochar has been used to enhance hydrogen production from organic fraction of municipal solid waste (OFMSW) using co-culture of Enterobacter aerogenes and E. coli. Biochar facilitates biofilm formation and efficient colonization of microbes on its large surface area. Biochar was also analyzed for its ammonia mitigation potential. Cumulative hydrogen production, maximum hydrogen production rate and lag phases were analyzed using modified Gompertz model. Maximum overall hydrogen yield of 96.63 ± 2.8 mlH2/gCarboinitial and a maximum of 53.3 ± 1.0% COD removal were achieved at biochar concentration of 12.5 g/L. Biochar addition shortened lag phase from 12.5 ± 0.6 hr at control with nil biochar to 8.1 ± 0.5 hr with 12.5 g/L biochar and improved hydrogen production rates. The validation experiment with ammonia addition without biochar supplementation resulted in decreased hydrogen production. When biochar was supplemented in addition to ammonia, hydrogen production was increased in all the experimental batches. Results revealed that biochar can mitigate ammonia inhibition along with hydrogen enhancement. Biochar addition also increased volatile fatty acid generation.