Airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 for treatment of lubricants in wastewater

• Published in: Journal of hazardous materials 2012-04, Vol.213-214, p.466-473
• Main Authors: Khondee, Nichakorn, Tathong, Sitti, Pinyakong, Onruthai, Powtongsook, Sorawit, Chatchupong, Thawach, Ruangchainikom, Chalermchai, Luepromchai, Ekawan
• Format: Article
• Language: English
• Subjects: Absorption; Airlift loop reactor; Biodegradation; Biodegradation, Environmental; Bioreactors; Chitosan - chemistry; Chromatography, Gas; Chromatography, Thin Layer; Equipment Design; Flame Ionization; Immobilization; Lubricant; Lubricants - chemistry; Microscopy, Electron, Scanning; Oily wastewater; Oxygen - chemistry; Polycyclic Aromatic Hydrocarbons - analysis; Sphingomonadaceae - chemistry; Sphingomonadaceae - metabolism; Waste Disposal, Fluid - methods; Water Pollutants, Chemical - chemistry
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2012.02.018

► Sphingobium sp. P2 effectively degraded various lubricant samples. ► Efficiency of Sphingobium sp. P2 increased after immobilization on chitosan. ► High removal efficiency was due to both sorption and degradation processes. ► The immobilized bacteria (4gL−1) were applied in internal loop airlift bioreactor. ► The bioreactor continuously removed lubricant from emulsified wastewater. An internal loop airlift bioreactor containing chitosan-immobilized Sphingobium sp. P2 was applied for the removal of automotive lubricants from emulsified wastewater. The chitosan-immobilized bacteria had higher lubricant removal efficiency than free and killed-immobilized cells because they were able to sorp and degrade the lubricants simultaneously. In a semi-continuous batch experiment, the immobilized bacteria were able to remove 80–90% of the 200mgL−1 total petroleum hydrocarbons (TPH) from both synthetic and carwash wastewater. The internal loop airlift bioreactor, containing 4gL−1 immobilized bacteria, was later designed and operated at 2.0h HRT (hydraulic retention time) for over 70 days. At a steady state, the reactor continuously removed 85±5% TPH and 73±11% chemical oxygen demand (COD) from the carwash wastewater with 25–200mgL−1 amended lubricant. The internal loop airlift reactor's simple operation and high stability demonstrate its high potential for use in treating lubricants in emulsified wastewater from carwashes and other industries.