Decomposition of simulated odors in municipal wastewater treatment plants by a wire-plate pulse corona reactor

Abstract

Decomposition of simulated odors in municipal wastewater treatment plants was investigated experimentally by a wire-plate pulse corona reactor. A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse forming network (BPFN) was adopted in our experiments, and the testing malodorants were ammonia, ethanethiol and tri-methyl amine, respectively. The maximum output power of the pulse voltage source and the maximum peak voltage were 1 kW and 100 kV. The experiments were conducted at the gas-flow rate of 4.0–23.0 m 3 h −1. Important parameters, including peak voltage, pulse frequency, capacitance (inductance) of the BPFN, gas-flow rate, initial concentration, which influenced on the removal efficiency, were investigated. The results show that the odors can be treated effectively. Almost 100% removal efficiency was obtained for 32 mg m −3 ammonia at the gas-flow rate of 4.0 m 3 h −1. The maximum removal efficiencies of 85 mg m −3 ethanethiol and 750 mg m −3 tri-methyl amine at 10.0 m 3 h −1 were 98% and 91%, respectively. The energy yield of 110 mg m −3 ammonia was 2.99 g kW h −1 when specific energy density was 106 J l −1. In the cases of ammonia, ethanethiol and tri-methyl amine removal, ozone and nitrogen oxides were observed in the exit gas. The carbon and sulfur elements of ethanethiol and tri-methyl amine were mainly converted to carbon dioxide, carbon monoxide and sulfur dioxide. Moreover, the ammonium nitrates and sulfur were discovered in the reactor.