title: Mineralization of some natural refractory organic compounds by biodegradation and ozonation.
abstract: The objective of this study was to explore the extent of mineralization, reduction in color and reduction of COD of gallic acid, tannin and lignin by ozonation and a combination of aerobic biodegradation and ozonation. Ozonation of pure aliquots (phase I experiments) resulted in the decline in TOC, COD, COD/TOC ratio, UV absorbance at 280 nm and color of the three model compounds investigated, with COD removals of greater than 80% and high removals (>90%) of UV absorbance at 280 nm and color observed in all cases at an ozone dose of 6 mg ozone/mg initial TOC or higher. Aerobic biodegradation of pure gallic acid, tannin and lignin aliquots resulted in COD decline of approximately 36-38%. Subsequent ozonation (phase II experiments) resulted in further decline in TOC, COD, COD/TOC ratio, and increase in UV absorbance at 280 nm and color removals. COD and TOC removals comparable to phase I experiments were obtained with 30-40% lower ozone absorption in phase II experiments. The biodegradation step was quite effective in removing specific UV absorbance at 280 nm, with up to 75% removal observed. Subsequent ozonation increased overall specific UV absorbance at 280 nm to greater than 90%.
authors.affiliation: Environmental Engineering and Management Programme, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
authors.forename: Devendra P
authors.initials: DP
authors.lastname: Saroj
authors.forename: Arun
authors.initials: A
authors.lastname: Kumar
authors.forename: Purnendu
authors.initials: P
authors.lastname: Bose
authors.forename: Vinod
authors.initials: V
authors.lastname: Tare
authors.forename: Yashodhan
authors.initials: Y
authors.lastname: Dhopavkar
mesh_terms: D001420:Bacteria, Aerobic / Q000378:metabolism; D001673:Biodegradation, Environmental; D002244:Carbon / Q000032:analysis; D003116:Color; D005707:Gallic Acid / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D010083:Oxidants, Photochemical / Q000032:analysis / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis / Q000737:chemistry; D010126:Ozone / Q000032:analysis / Q000737:chemistry*; D013634:Tannins / Q000378:metabolism*; D014865:Waste Disposal, Fluid; D018508:Water Purification / Q000379:methods
chemical_list: D010083:Oxidants, Photochemical; D013634:Tannins; D005707:Gallic Acid; D010126:Ozone; D002244:Carbon; D008031:Lignin; D010100:Oxygen