Styrene bioremediation and polyhydroxyalkanoate (PHA) production : analytical methods development and microbial study

Abstract

Styrene is a principal waste effluent produced from polystyrene (PS) plastic-related industries, and imposes significant environmental and public health burden. Aerobic biological treatment methods are most effective and widely-applied for remediating styrene, but typically generate high biomass by-product volumes, resulting in high management/disposal cost. Optimizing the bioprocesses to bioconvert styrene into commercially-valuable medium-chain-length polyhydroxyalkanoate (MCL-PHA) biopolymer could alleviate pollution and off-set biomass disposal cost. PHA production cost may be reduced, bringing it closer to commercialization. Separately, improving methods for styrene wastewater and PHA analyses is important in facilitating the work of field engineers and researchers. This PhD study developed new analytical methods, which simplified and reduced analysis prices for styrene wastewater and PHA analyses. This study also characterized the aqueous styrene-degrading bacterial community, and increased the pool of styrene-degrading cum MCL-PHA-producing bacteria. The new microbial findings are anticipated to aid future selection of seeding sludge, bioaugmentation strategies and formulation of defined microbial cocktails for enhancing styrene bioremediation and extending the process to concurrent MCL-PHA production.