Treatment of particle board industry wastewater by chemical and electrooxidation methods and optimization

In this study, the hybrid treatment of particle board industry wastewater with electrooxidation (EO) processes after chemical pretreatment was investigated. Flo30, iron (III) chloride and anionic potato starch (APS) were used for the coagulation process. In the EO process carried out in batch mode, graphite and mixed metal oxide (MMO) coated electrodes as the anode electrode material, stainless steel as the cathode were used. The results are optimized with response surface method (RSM) and artificial neural networks (ANN) techniques. In chemical pretreatment using iron (III) chloride/APN; initial pH (6, 7, 8), coagulant dose (2, 3, 4 g/L), flocculant dose (10, 20, 30 ml/L) were selected; COD (Chemical Oxygen Demand), TSS (Total suspended solids) and color removal efficiencies were 70,9%, 98,36% and 97,51%, respectively, while the average cost was calculated as 47,36 USD/m3. In chemical pretreatment using Flo30/APN; initial pH (5, 6,5, 8), coagulant dose (6, 9, 12 ml/L), flocculant dose (10, 20, 30 ml/L) were selected; while the COD, TSS and color removal efficiencies were 56,83%, 96,07% and 83,2%, the average cost was calculated as 17,79 USD/m3. Independent variables and levels for both anodes in the EO process were; initial pH (4, 6, 8), sodium sulfate concentration (2, 3, 4 g/L), current (2, 3,5, 5 A), time (60, 120, 180 min). In the maximum removal conditions of the experimental studies performed with graphite/stainless steel electrodes after chemical pretreatment, the COD and color removal efficiencies were 90,41% and 96,52%, respectively, and the average cost was 76,46 USD/m3. In the maximum removal conditions of the experimental studies performed with KMO/stainless steel electrodes after chemical pretreatment, the COD and color removal efficiencies were 50,05% and 96,15%, respectively, and the average cost value was 59,53 USD/m3.