Latha K
Anna University, Chennai
Title: Bio-process optimisation for biohydrogen and methane generation in an anaerobic co-digestion of kitchen waste with sewage treatment plant sludge
Biography
Biography: Latha K
Abstract
The biomethanisation process alone for solid waste management becomes less energy efficient with high residual waste generation and less calorific value for methane (42kJ/gm) than the Hydrogen (122kJ/gm). Therefore, the anaerobic sequential production of hydrogen followed by methane maximise the energy recovery with an intensive bioprocess optimisation. One such approach of potential importance is the production of hydrogen and methane from sewage sludge co-digested with kitchen waste. This paper focuses on generation of hydrogen and methane through bio-process optimisation using different pH , and oxidation reduction potential (ORP). The sewage sludge sample mixed with minced kitchen waste was optimised using different pH between 4.5 and 7.5. The optimised pH was further regulated with ORP between -100mV to – 400mV. The maxima hydrogen production was occurred at a pH of 5.5 and the ORP of -380 mV, whereas the methane maxima was noticed in the pH of 6.8 and the ORP of -210mV. This was consistent with predominant rods shaped microorganisms in hydrogen maxima while the cocci shaped organisms at methane maxima correlated with the results reported elsewhere. The study demonstrated the specific hydrogen yield potential of 0.3 Nm.L/g of VS removed (VSr) and the specific methane yield potential of 0.6 Nm L/gm of VSr against the control specific hydrogen and methane yield potential of 0.05 Nm.L/gm VSr and 0.3 Nm.L/gm VSr . Hence, the study demonstrated that the minced kitchen waste co-digested with STP sludge becomes an energy efficient solid waste management option as a sequential production of hydrogen and methane using two stage hydrogeniser followed by methaniser ameliorating the existing two stage anaerobic hydrolyser followed by methaniser.