Enhanced biodegradation of azo dyes using an integrated elemental iron-activated sludge system: I. Evaluation of system performance.
The objective of this research is to evaluate an integrated system coupling zero-valent iron (Fe(0)) and aerobic biological oxidation for the treatment of azo dye wastewater. Zero-valent (elemental) iron can reduce the azo bond, cleaving dye molecules into products that are more amenable to aerobic biological treatment processes. Azo dye reduction products, including aniline and sulfanilic acid, were shown to be readily biodegradable at concentrations up to approximately 25 mg/L. Batch reduction and biodegradation data support the proposed integrated iron pretreatment and activated sludge process for the degradation of the azo dyes orange G and orange I. The integrated system was able to decolorize dye solutions and yield effluents with lower total organic carbon concentrations than control systems without iron pretreatment. The success of the bench-scale integrated system suggests that iron pretreatment may be a feasible approach to treat azo dye containing wastewaters.
Department of Civil and Environmental Engineering, University of Delaware, Newark 19716, USA.
Jennie Perey
JP
Saxe
Brian L
BL
Lubenow
Pei C
PC
Chiu
Chin-Pao
CP
Huang
Daniel K
DK
Cha
D000332:Aerobiosis; D000693:Anaerobiosis; D001391:Azo Compounds / Q000737:chemistry / Q000378:metabolism*; D001420:Bacteria, Aerobic / Q000502:physiology; D001421:Bacteria, Anaerobic / Q000502:physiology; D001673:Biodegradation, Environmental; D002851:Chromatography, High Pressure Liquid; D007501:Iron / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods; D018508:Water Purification / Q000379:methods*
D001391:Azo Compounds; D007501:Iron