2,4-Dichlorophenol removal in a solid-liquid two phase partitioning bioreactor (TPPB): kinetics of absorption, desorption and biodegradation

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• 作者：M. Concetta Tomei ; M. Cristina Annesini ; Andrew J. Daugulis
• 刊名：New Biotechnology
• 出版年：2012
• 出版时间：15 November, 2012
• 年：2012
• 卷：30
• 期：1
• 页码：44-50
• 全文大小：379 K

文摘

The applicability of a sequencing batch two phase partitioning bioreactor (TPPB) to the biodegradation of a highly toxic compound, 2,4-dichlorophenol (DCP) (EC₅₀ = 2.3-40 mg L^?1) was investigated. A kinetic study of the individual process steps (DCP absorption into the polymer, desorption and biodegradation) was performed and, based on favourable absorption/desorption characteristics (DCP diffusivity of 6.6 ¡Á 10^?8 cm² s^?1), the commercial polymer Tone P787 (Dow Chemical), was utilized as the sequestering phase for TPPB operation. Batch kinetic biodegradation tests were performed in both single- and two-phase modes, and the Haldane equation kinetic parameters were estimated (m>km> = 1.3 ¡Á 10^?2 mgDCP mgVSS^?1 h^?1, m>Km>_I = 35 mgDCP L^?1 and m>Km>_s = 18 mgDCP L^?1), confirming the highly toxic nature of DCP. Consistent with these findings, operation of the single-phase system showed that for an initial DCP concentration of 130 mg L^?1 the biomass was completely inhibited and DCP was not degraded, while the two-phase system achieved near-complete DCP removal. In sequencing batch mode the TPPB had a removal efficiency of 91 % within 500 min for a feed of 320 mg L^?1, which exceeds the highest concentration previously degraded. These results have confirmed the effectiveness of the use of small amounts (5 % , v/v) of inexpensive commercial polymers as the partitioning phase in TPPB reactors for the treatment of a highly toxic substrate at influent loads that are prohibitive for conventional single-phase operation, and suggest that similar detoxification of wastewater influents is achievable for other target cytotoxic substrates.