title: Effect of molybdate on methanogenic and sulfidogenic activity of biomass.
abstract: The effect of molybdate, a sulfate analog, on the total methanogenic activity (TMA) and total sulfidogenic activity (TSA) of biomass metabolizing synthetic sucrose based substrate containing sulfate was investigated in batch assays. In Phase I of the study, TMA and TSA were assessed twice for four feed changes at a chemical oxygen demand to sulfate (COD/SO(4)(2-)) ratio of 3.5. In Phase II, long-term experiments were conducted for 10-13 feed changes with varying chemical oxygen demand (COD) concentration, sulfate concentration, COD/SO(4)(2-) ratio, molybdate dose and biomass with different growth histories. Assays with 3mM molybdate showed TSA inhibition over 85%. Dose dependency was observed for sulfate concentration, COD/SO(4)(2-) ratio, and biomass history. The minimum concentration that gave over 93% TSA inhibition was 0.25 mM. However, intermediate concentrations of molybdate inhibited methane producing bacteria (MPB) activity. TMA stimulation was observed at 0.75-2.0 mM molybdate.
authors.affiliation: Department of Civil Engineering, National Institute of Technology, Kurukshetra 136 119, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Patidar
authors.forename: Vinod
authors.initials: V
authors.lastname: Tare
mesh_terms: D001421:Bacteria, Anaerobic / Q000187:drug effects* / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors; D002244:Carbon / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D008697:Methane / Q000378:metabolism*; D008982:Molybdenum / Q000633:toxicity*; D010100:Oxygen / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism*
chemical_list: D013431:Sulfates; D013440:Sulfides; C044659:molybdate; D002244:Carbon; D008982:Molybdenum; D008697:Methane; D010100:Oxygen