Removal of priority pollutants from water by means of dielectric barrier discharge atmospheric plasma

Highlights: • DBD plasma reactors were used to remove pollutants from aqueous solutions. • Atrazine, chlorfenvinfos, 2,4-dibromophenol and lindane were studied. • First-order degradation kinetics were observed for all the compounds. • Degradation by-products were identified by GC–MS. • Treatment efficiencies were lower in industrial wastewater than in pure water. -- Abstract: Two different nonthermal plasma reactors at atmospheric pressure were assessed for the removal of organic micropollutants (atrazine, chlorfenvinfos, 2,4-dibromophenol, and lindane) from aqueous solutions (1–5 mg L−1) at laboratory scale. Both devices were dielectric barrier discharge (DBD) reactors; one was a conventional batch reactor (R1) and the other a coaxial thin-falling-water-film reactor (R2). A first-order degradation kinetics was proposed for both experiments. The kinetic constants (k) were slightly faster in R1 (0.534 min−1 for atrazine; 0.567 min−1 for chlorfenvinfos; 0.802 min−1 for 2,4-dibromophenol; 0.389 min−1 for lindane) than in R2 (0.104 min−1 for atrazine; 0.523 min−1 for chlorfenvinfos; 0.273 min−1 for 2,4-dibromophenol; 0.294 min−1 for lindane). However, energy efficiencies were about one order of magnitude higher in R2 (89 mg kW−1 h−1 for atrazine; 447 mg kW−1 h−1 for chlorfenvinfos; 47 mg kW−1 h−1 for 2,4-dibromophenol; 50 mg kW−1 h−1 for lindane) than in R1. Degradation by-products of all four compounds were identified in R1. As expected, when the plasma treatment (R1) was applied to industrial wastewater spiked with atrazine or lindane, micropollutant removal was also achieved, although at a lower rate than with aqueous solutions (k = 0.117 min−1 for atrazine; k = 0.061 min−1 for lindane)