ABSTRACT
This chapter presents a summary of the findings on the photo-assisted biodegradation, biosurfactant-facilitated dissolution, and biosurfactant-assisted biodegradation of the halogenated aromatic compounds and polyaromatic hydrocarbons (PAH) in water, soil, and sludge. The process utilized a photoreactor chamber where UV light was used to generate OH• radicals that could achieve reductive dehalogenation of the chlorinated phenolic compounds followed by complete mineralization of the products by mesophilic bacteria in the second stage. Biological remediation of most high-ring-number PAHs is limited by the bioavailability of the compounds, which exist as crystals in solid phase or as complexes with other solid matter such as soil particles. The lower organic carbon concentration observed in the sludge obtained from the semi-fed-batch system highlighted the efficiency of the plug-flow reactor with regard to the oil recovery process. The study using the fed-batch plug-flow system with differential deceleration of sludge particles showed a higher degradation of PAH impurities in the recovered oil and a lower residual.
