title: Application of a continuously stirred tank bioreactor (CSTR) for bioremediation of hydrocarbon-rich industrial wastewater effluents.
abstract: A continuously stirred tank bioreactor (CSTR) was used to optimize feasible and reliable bioprocess system in order to treat hydrocarbon-rich industrial wastewaters. A successful bioremediation was developed by an efficient acclimatized microbial consortium. After an experimental period of 225 days, the process was shown to be highly efficient in decontaminating the wastewater. The performance of the bioaugmented reactor was demonstrated by the reduction of COD rates up to 95%. The residual total petroleum hydrocarbon (TPH) decreased from 320 mg TPH l(-1) to 8 mg TPH l(-1). Analysis using gas chromatography-mass spectrometry (GC-MS) identified 26 hydrocarbons. The use of the mixed cultures demonstrated high degradation performance for hydrocarbons range n-alkanes (C10-C35). Six microbial isolates from the CSTR were characterized and species identification was confirmed by sequencing the 16S rRNA genes. The partial 16S rRNA gene sequences demonstrated that 5 strains were closely related to Aeromonas punctata (Aeromonas caviae), Bacillus cereus, Ochrobactrum intermedium, Stenotrophomonas maltophilia and Rhodococcus sp. The 6th isolate was affiliated to genera Achromobacter. Besides, the treated wastewater could be considered as non toxic according to the phytotoxicity test since the germination index of Lepidium sativum ranged between 57 and 95%. The treatment provided satisfactory results and presents a feasible technology for the treatment of hydrocarbon-rich wastewater from petrochemical industries and petroleum refineries.
authors.affiliation: Laboratoire des Bioprocédés Environnementaux, Pôle d'Excellence Régional AUF-LBPE, Centre de Biotechnologie de Sfax, Université de Sfax, BP 1117, 3018 Sfax, Tunisia.
authors.forename: Boutheina
authors.initials: B
authors.lastname: Gargouri
authors.forename: Fatma
authors.initials: F
authors.lastname: Karray
authors.forename: Najla
authors.initials: N
authors.lastname: Mhiri
authors.forename: Fathi
authors.initials: F
authors.lastname: Aloui
authors.forename: Sami
authors.initials: S
authors.lastname: Sayadi
mesh_terms: D001419:Bacteria / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D019149:Bioreactors; D006838:Hydrocarbons / Q000378:metabolism*; D007220:Industrial Waste / Q000517:prevention & control*; D059013:Microbial Consortia; D010578:Petroleum / Q000378:metabolism*; D018675:Toxicity Tests; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D006838:Hydrocarbons; D007220:Industrial Waste; D010578:Petroleum