A two-phase partitioning airlift bioreactor for the treatment of BTEX contaminated gases

✍ Scribed by Jennifer V. Littlejohns; Andrew J. Daugulis

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 394 KB
• Volume: 103
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.22343

✦ Synopsis

Abstract

This investigation characterizes a novel 11 L airlift two‐phase partitioning bioreactor (TPPB) for the treatment of gases contaminated with a mixture of benzene, toluene, ethylbenzene, and o‐xylene (BTEX). The application of the TPPB technology in an airlift bioreactor configuration provides a novel technology that reduces energy intensity relative to traditional stirred tank TPPB configurations. The addition of a solid second phase of silicone rubber beads (10%, v/v) or of a liquid second phase of silicone oil (10%, v/v) resulted in enhanced performance of the airlift bioreactor relative to the single phase case, with 20% more BTEX being removed from the gas phase during an imposed transient loading. During a 4 h loading step change of three times the nominal loading (60 g m^−3^ h^−1^), overall removal efficiencies for the airlift TPPBs containing a liquid or solid phase remained above 75%, whereas the single phase airlift had an overall removal efficiency of 47.1%. The airlift TPPB containing a silicone rubber second phase was further characterized by testing performance during steady‐state operation over a range of loadings and inlet gas flow rates in the form of a 3^2^ factorial experimental design. Optimal operating conditions that avoid oxygen limitations and that still have a slow enough gas flow rate for sufficient BTEX transfer from the gas phase to the working volume are identified. The novel solid–liquid airlift TPPB reduces energy inputs relative to stirred tank designs while being able to eliminate large amounts of BTEX during both steady‐state and fluctuating loading conditions. Biotechnol. Bioeng. 2009;103: 1077–1086. © 2009 Wiley Periodicals, Inc.