Anaerobic Treatment and Resource Recovery from Methanol Rich Waste Gases and Wastewaters

Methanol is an important volatile organic compound (VOC) present in the gaseous and liquid effluents of process industries such as pulp and paper, paint manufacturing and petroleum refineries. An estimated 65% of the total methanol emission was from the Kraft mills of the pulp and paper industries. The effect of selenate, sulfate and thiosulfate on methanol utilization for volatile fatty acids (VFA) production was individually examined in batch systems. Gas-phase methanol removal along with thiosulfate reduction was carried out for 123 d in an anoxic BTF. To examine the gas-phase methanol removal along with selenate reduction, another anoxic biotrickling filter (BTF) was operated for 89 d under step and continuous selenate feeding conditions. For the study on liquid-phase methanol, acetogenesis of foul condensate (FC) obtained from a chemical pulping industry was tested in three upflow anaerobic sludge blanket (UASB) reactors operated at 22, 37 and 55 C for 51 d. The recovery of VFA was explored through adsorption studies using anion exchange resins in batch systems. The adsorption capacity of individual VFA on Amberlite IRA-67 and Dowex optipore L-493 was examined by fitting the experimental data to adsorption isotherms and kinetic models. A sequential batch process was tested to achieve selective separation of acetic acid from the VFA mixture.