Microbial desulphurization of coal containing pyritic sulphur in a continuously operated bench scale coal slurry reactor

Pre-combustion microbial desulphurization of coal containing total sulphur (3.90%) and pyritic sulphur (2.80%) has been evaluated in a coal slurry reactor. The coal slurry reactor operated at hydraulic retention time (HRT) of 96 h with a coal pulp density of 15 percent and remove 79 percent of pyritic sulphur and 76 percent of ash with an increase in the calorific value of coal from 4400 to 6800 kcal kgK1 at a pyritic load of 1.9 kg pyritic sulphur kgK1 MLSS dK1. The treated coal yield is 72 percent. The biochemical kinetic coefficients, viz. yield coefficient (Y) and decay coefficient (Kd) in the coal slurry reactor system are 0.178 and 0.007 dK1, respectively, while maximum growth rate (mmax) and half saturation rate constant (Ks) are 0.025 hK1 and 0.220 g lK1 as pyrite, respectively

A modified anaerobic baffled reactor for municipal wastewater treatment

A nine-chambered modified anaerobic baffled reactor (MABR) was developed to evaluate its suitability for the treatment of municipal wastewater and to establish the understanding of the relationship between reactor design and operational parameters. The paper presents the configuration of the MABR, its start-up, effect of variation of hydraulic retention time (HRT) on treatment efficiency, and performance evaluation of the MABR while treating the municipal wastewater. To assess the self-inoculation potential of the MABR, the start-up was carried out without seed sludge at a HRT of 6 d. An acclimatization curve was plotted and indicated that a start-up period of 90 d was required for the MABR. Reactor performance evaluation was carried out for 375 d at 11 different HRTs ranging from 6 d to 3 h. The HRT of 6 h was adjudged to be appropriate for this reactor configuration. At a HRT of 6 h, the efficiencies of reduction in suspended solids (SS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were found to be 86%, 87% and 84% respectively. Specific biogas yield and methane content were found to be 0.34 m3CH4/KgCODr and 67% respectively. The study has evaluated the performance pattern of the MABR and identified it as a suitable reactor technology for municipal wastewater management in India.

A modified anaerobic baffled reactor for municipal wastewater treatment

A nine-chambered modified anaerobic baffled reactor (MABR) was developed to evaluate its suitability for the treatment of municipal wastewater and to establish the understanding of the relationship between reactor design and operational parameters. The paper presents the configuration of the MABR, its start-up, effect of variation of hydraulic retention time (HRT) on treatment efficiency, and performance evaluation of the MABR while treating the municipal wastewater. To assess the self-inoculation potential of the MABR, the start-up was carried out without seed sludge at a HRT of 6 d. An acclimatization curve was plotted and indicated that a start-up period of 90 d was required for the MABR. Reactor performance evaluation was carried out for 375 d at 11 different HRTs ranging from 6 d to 3 h. The HRT of 6 h was adjudged to be appropriate for this reactor configuration. At a HRT of 6 h, the efficiencies of reduction in suspended solids (SS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were found to be 86%, 87% and 84% respectively. Specific biogas yield and methane content were found to be 0.34 m3CH4/KgCODr and 67% respectively. The study has evaluated the performance pattern of the MABR and identified it as a suitable reactor technology for municipal wastewater management in India.