STRIPPING OF VOLATILE ORGANIC-COMPOUNDS AT FULL-SCALE MUNICIPAL WASTE-WATER TREATMENT PLANTS

A field investigation was carried out at four Ontario municipal wastewater treatment plants to characterize stripping of volatile organic compounds (VOCs) from aerated process vessels. Concentrations of VOCs in the off-gas and wasterwater at aerated grit chambers and aeration basins were measured. Thirty-two of 36 target VOCs were observed in at least one off-ps sample from the plants studied. The total emissions for the measured compounds ranged from 2 700 to 3 900 g/d or 36 to 50 g/1000 m3 of wastewater treated. Chlorinated VOCs tended to be stripped to a greater extent than nonchlorinated compounds. The data suggest that VOC stripping can be reduced by reducing aeration rates, and that operating and design parameters have an impact on the loss of VOCs.