Overcoming substrate inhibition during biological treatment of monoaromatics: recent advances in bioprocess design

Abstract

The biological removal of monoaromatic compounds from contaminated environments, usually arising from industrial activity, is challenging because of the inherent toxicity of these compounds to microorganisms, particularly at the concentrations that can be encountered in industrial waste streams. A wide range of bioprocess designs have been proposed and tested with the aim of achieving high removal efficiencies, with varying degrees of technical success, and potential for practical implementation. This review reports on the progress on variations of well-known themes made in the last 3-4 years, as well as new bioprocess technologies that address the cytotoxicity of monoaromatics directly. Areas for further research are also proposed.

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

“…Commercial polymers have proven to be effective in TPPBs for the treatment of phenolic compounds (i.e. 4-nitrophenol, 3,4-dimethylphenol) [19,20] but have not yet been tested for the biodegradation of highly toxic halogenated aromatics (chlorophenols). The objective of this study was to perform a series of tests on the different process steps involved (i.e.…”

A first principles approach to identifying polymers for use in two‐phase partitioning bioreactors

“…The history of this bioprocess technology has recently been reviewed. 1 The first embodiment of this technology used immiscible organic solvents as the carrier phase. Although a prescriptive list of desirable solvent properties was formulated to aid in selecting appropriate organic solvents, 2 the most important are biocompatibility, non-biodegradability, and affinity for the target molecule.…”

Biodegradation Kinetic Studies on Phenol in Internal Draft Tube (Inverse Fluidized Bed) Biofilm Reactor UsingPseudomonas fluorescens: Performance Evaluation of Biofilm and Biomass Characteristics

“…Several different types of biofilm reactors have been studied, including rotating disk bioreactors, fixed bed reactors, and three-phase fluidized bed bioreactors (Kaymaz, Babaoglu, and Pazarlioglu 2012). The latter are considered superior because of large biofilm support surface, appropriate hydrodynamic conditions, high mass transfer rates of both oxygen and substrate, and excellent contact between the liquid and solid phases (Schugerl 1997;Reese et al 1999;Toumi, Fedailaine, and Allia 2008;Daugulis, Tomei, and Guieysse 2011). However, one significant problem in practically all types of biofilm reactors, including fluidized bed reactors, is uncontrolled biofilm growth, which limits the diffusion of oxygen and/or the organic substrate to the deeper layers of the biofilm (Sokol 2010).…”