title: para-Chlorophenol inhibition on COD, nitrogen and phosphate removal from synthetic wastewater in a sequencing batch reactor.
abstract: COD, nitrogen, phosphate and para-chlorophenol (4-chlorophenol, 4-CP) removal from synthetic wastewater was investigated using a four-step sequencing batch reactor (SBR) at different sludge ages and initial para-chlorophenol (4-CP) concentrations. The nutrient removal process consisted of anaerobic, oxic, anoxic and oxic phases with hydraulic residence times (HRT) of 1/3/1/1 h and a settling phase of 0.75 h. A Box-Wilson statistical experiment design was used considering the sludge age (5-25 days) and 4-CP concentration (0-400 mg l(-1)) as independent variables. Variations of percent COD, NH4-N, PO4-P and 4-CP removals with sludge age and initial 4-CP concentration were investigated. Percent nutrient removals increased with increasing sludge age and decreasing 4-CP concentrations. Low nutrient removals were obtained at high initial 4-CP concentrations especially at low sludge ages. However, high sludge ages partially overcome the adverse effects of 4-CP and resulted in high nutrient removals. COD, NH4-N, PO4-P and 4-CP removals were 76%, 72%, 26% and 34% at a sludge age of 25 days and initial 4-CP concentration of 200 mg l(-1). Sludge volume index (SVI) also decreased with increasing sludge age and decreasing 4-CP concentrations. An SVI value of 104 ml g(-1) was obtained at a sludge age of 25 days and initial 4-CP of 200 mg l(-1).
authors: Department of Environmental Engineering, Dokuz Eylul University, Buca, Izmir, Turkey. fikret.kargi@deu.edu.tr
authors: Fikret
authors: F
authors: Kargi
authors: Ahmet
authors: A
authors: Uygur
authors: Huseyin Savas
authors: HS
authors: Baskaya
mesh_terms: D000150:Acinetobacter / Q000378:metabolism; D019149:Bioreactors; D002733:Chlorophenols / Q000378:metabolism*; D009576:Nitrobacter / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D009606:Nitrosomonas / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D013053:Spectrophotometry; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D002733:Chlorophenols; D010710:Phosphates; C029107:4-chlorophenol; D009584:Nitrogen; D010100:Oxygen