title: Effects of sludge retention time and biosurfactant on the treatment of polyaromatic hydrocarbon (PAH) in a petrochemical industry wastewater.
abstract: A laboratory-scale aerobic activated sludge reactor (AASR) system was employed to investigate the effects of sludge retention time (SRT) on the removal of three polyaromatic hydrocarbons (PAHs) with low benzene rings [(acenaphthene (ACT), fluorene (FLN) and phenanthrene (PHE)] and six PAHs with high benzene rings [(benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene (DahA), benzo[g,h,i]perylene (BghiP)] in the presence of rhamnolipid (RD), emulsan (EM) and surfactine (SR) biosurfactants. This study showed that biosurfactants enhance the PAH biodegradation by increasing the biomass growth. RD exhibits a better performance than the other biosurfactants in the removal of the chemical oxygen demand (COD) and PAHs. At a RD concentration of 15 mg/L aerobic treatment for 25 days, SRT was enough to remove over 95% of total PAHs, and COD(dis). Under the same conditions 75% of COD originating from the inert organics (COD(inert)) and 96% of COD originating from the inert soluble microbial products (COD(imp)) were removed. At 25 days SRT and 15 mg/L RD concentration, about 88% of PAHs were biodegraded by the AASR system, 4% were accumulated in the system, 3% were released in the effluent, and 5% remained in the waste sludge.
authors.affiliation: Department of Environmental Engineering, Dokuz Eylul University, Buca-Izmir, Turkey. delya.sponza@deu.edu.tr
authors.forename: D T
authors.initials: DT
authors.lastname: Sponza
authors.forename: O
authors.initials: O
authors.lastname: Gok
mesh_terms: D019149:Bioreactors; D007220:Industrial Waste; D010578:Petroleum; D010865:Pilot Projects; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D012722:Sewage; D013501:Surface-Active Agents / Q000737:chemistry*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D012722:Sewage; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical