Biodegradability of chlorophenol wastewater enhanced by solar photo-Fenton process.
The combination of solar irradiation and Fenton reagent have been used to enhance the biodegradability (BOD(5)/COD) of chlorophenol wastewater, including 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), and 2,4-dichlorophenol (2,4-DCP). Results showed that the solar photo-Fenton process improved significantly the biodegradability of chlorophenol wastewater. Basically, increasing initial H(2)O(2) dosage was much more beneficial for increasing biodegradability of wastewater than increasing initial Fe(2 + ) dosage. Among the conditions studied, the optimum condition of increasing biodegradability of chlorophenol wastewater was found with a [H(2)O(2)](0)/[Fe(2 + )](0)/[chlorophenol](0) ratio of 10.0/0.2/1.0, 10.0/0.3/1.0, and 10.0/0.2/1.0 for 2-CP, 4-CP, and 2,4-DCP, respectively. As a result, the value of BOD(5)/COD was increased from 0 for untreated solution up to 0.231, 0.248, and 0.193 for 2-CP, 4-CP, and 2,4-DCP, respectively with a 15-min treatment. Under the operation of optimum conditions, the oxidative state of chlorophenol wastewater could be easily controlled into a higher biodegradability stage. The COD and TOC degradation efficiency could be in excess of 90% on the whole as the preoxidized chlorophenol solution was treated by a following batch-type biological unit. In the meanwhile, the microtoxicity of wastewater reduced more than 95%.
Kuo
W S
WS
Department of Safety, Health, and Environmental Engineering, National United University, Miao-Li, 360, Taiwan, China. wsk@nuu.edu.tw
Lin
I T
IT
D002733:Chlorophenols / Q000737:chemistry* / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D015394:Molecular Structure; D055668:Photochemical Processes / Q000528:radiation effects*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism*
D002733:Chlorophenols; C045076:Fenton's reagent; D014874:Water Pollutants, Chemical; D006861:Hydrogen Peroxide; D007501:Iron