Abstract:
Most industries produce effluents which are environmental hazards due to presence of color and
recal
citrant COD. One useful way of remediating these effluents is by using them in production of
biofuels through fermentation process. The use of industrial effluents as substrate for producing
biofuels is advantageous in that on top of producing energy, the
effluent is bioremediated before
discharge. However, in many occasions, the production process is limited by its low energy yields and
productivity due to presence of toxicants and refractory substances. This necessitates some form of
substrate pretreatmen
t like; biological, physical
-
chemical and the advanced oxidation processes
(AOPs). Ozonation is one of the AOP process applied in industrial effluent pretreatment. The current
study reviews the use of ozonation is used to enhance biofuel fermentation proce
ss and remove the
colored recalcitrant substances before its discharge. Ozonation was found to increase the
biodegradability of recalcitrant and toxicants in substrates for higher bioenergy yields. In pretreatment
of solid substrates like the sludge, the
process solubilizes the particulate substrate with minimal effects
on energy contents of the substrates. Our data on digested distillery effluent indicate that the process
can be used to remediate the color before the effluent is discharged. Though the pro
cess produced some
increase in biodegradability, it was observed that the use of ozone overdose caused reduction in the
biodegradability enhancement possibly due to production of toxic intermediates. Ozonation is one of
the most selective AOP to unstable b
onds. Its application in treatment of colored textile effluent results
in almost complete color removal but with low COD elimination. More studies are required on
integration of ozonation with other processes with the aim of enhancing both technical and ec
onomic
cost
-
effectiveness of bioenergy production and the color removal
