Abstract: VOCs and odour waste gas from refinery sewage treatment plant can be divided into two types: high-concentration waste gas, among which the non-methane hydrocarbon concentration (NMHC) is 500 - 40 000 mg/m3, total gas flow rate 1 000 - 10 000 m3/h ), is from waste-water lifting tank, water homogenizer, oil separator, flotation tank, waste oil tank; low-concentration waste gas (NMHC 10～300 mg/m3, gas flow 20 000 - 50 000 m3/h) is from aeration tank, oxidation ditch and sludge dewatering process. Technologies SWAT-1 and SWAT-2 were developed by Fushun Research Institute of Petroleum and Petrochemicals (FRIPP) to treat high-concentration and low-concentration exhaust gas from refinery wastewater treatment plants. In SWAT-1, high-concentration waste gas from oil separator, flotation tank is treated by “desulfurization and total hydrocarbon concentration homogenization-catalytic oxidation ”process; the low concentration exhaust gases from aeration tank are treated with "scrubbing - adsorption" process, and the saturated low concentration exhaust gas adsorbent is regenerated by the hot gas from catalytic oxidation and then returned to catalytic oxidation treatment process. In SWAT-2, high-concentration waste gas is treated by “low temperature diesel absorption-desulfurization and total hydrocarbon concentration homogenization-catalytic oxidation” process. By SWAT-1 and SWAT-2 technologies, NMHC of purified gas is less 50 mg/m3 and the minimum is less than 10 mg/m3, and the concentration of benzene, toluene and xylene is less than the detection limit, and the odor concentration is less than 20 (non dimensional)

Key words: refining, sewage treatment plant, VOCs, odor, wash, adsorption, homogenization, catalytic oxidation