Treatment of bactericide wastewater by combined process chemical coagulation, electrochemical oxidation and membrane bioreactor.
Bactericide wastewater (BIW) contains isothiazolin-ones, high salinity, toxicity and non-biodegradable organic concentrations. In order to enhance biodegradable capacity, chemical coagulation and electrochemical oxidation were applied to pretreatment processes. FeSO(4).7H2O, pH 12 and 20 mmol/l were determined as optimal chemical coagulation condition; and 15 mA/cm2 of current density, 10 ml/min of flow rate and pH 7 were chosen for the most efficient electrochemical oxidation condition at combined treatment. The wastewater which consisted mainly of isothiazolin-ones and sulfide was efficiently treated by chemical coagulation and electrochemical oxidation. The optimal pretreatment processes showed 60.9% of chemical oxygen demand (COD), 99.5% of S(2-) and 96.0% of isothiazolin-ones removal efficiency. A biological treatment system using membrane bioreactor (MBR) adding powder-activated carbon (PAC) was also investigated. COD of the wastewater which was disposed using a MBR was lower than 100 mg/l.
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
Wei-Qing
WQ
Han
Lian-Jun
LJ
Wang
Xiu-Yun
XY
Sun
Jian-Sheng
JS
Li
D000900:Anti-Bacterial Agents / Q000032:analysis*; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004573:Electrolytes; D004867:Equipment Design; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D009930:Organic Chemicals / Q000032:analysis; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D013844:Thiazoles / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
D000900:Anti-Bacterial Agents; D004573:Electrolytes; D009930:Organic Chemicals; D013844:Thiazoles; D014874:Water Pollutants, Chemical; C512915:isothiazolidinone; D002244:Carbon; D010100:Oxygen