title: Quantitative bioregeneration of granular activated carbon loaded with phenol and 2,4-dichlorophenol.
abstract: Lignite based granular activated carbon of 20x30 mesh size was used to investigate the extent of bioregeneration of phenol and 2,4-DCP in a batch system. The adsorption isotherm fits very well with the Freundlich isotherm and it is apparent that 2,4-DCP is more adsorbable than phenol. The degree of reversible adsorption for phenol and 2,4-DCP were 32.9 and 10.6 %, respectively. The low percentages of their reversibility meant that the adsorption phenomena of both phenol and 2,4-DCP were not fully physicosorption. The microorganisms can regenerate 31.4% (21.2 mg g(-1)) of GAC loaded with phenol and 14.3% (24.8 mg g(-1)) of GAC loaded with 2,4-DCP over a period of 7-10 days. The bioregeneration of phenols closely followed the first order kinetics with the rate constant of 0.046 day(-1) at initial phenol concentration of 100 mg l(-1) and biomass concentration of 20 mg l(-1) MLVSS. The rate constant was 0.021 day(-1) at initial 2,4-DCP concentration of 200 mg l(-1) and 200 mg l(-1) MLVSS. In addition, the increasing in initial concentration of biomass in the solution shortened the time required to reach the asymptotic limit on the bioregeneration but rendered little impact on the bioregeneration percentage.
authors.affiliation: Division of Environmental Technology, School of Energy and Materials, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok, Thailand.
authors.forename: S
authors.initials: S
authors.lastname: Vinitnantharat
authors.forename: A
authors.initials: A
authors.lastname: Baral
authors.forename: Y
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: S R
authors.initials: SR
authors.lastname: Ha
mesh_terms: D000327:Adsorption; D018533:Biomass; D002244:Carbon / Q000737:chemistry*; D002733:Chlorophenols / Q000737:chemistry*; D006801:Humans; D019800:Phenol / Q000737:chemistry*; D014874:Water Pollutants, Chemical; D018508:Water Purification / Q000379:methods*
chemical_list: D002733:Chlorophenols; D014874:Water Pollutants, Chemical; D019800:Phenol; D002244:Carbon; C004762:2,4-dichlorophenol