Comparison of hydrolysis and acidification performance and microbial characteristics of refinery wastewater at mesophilic and psychrophilic temperatures
The performance of hydrolysis and acidification under mesophilic and psychrophilic conditions were compared,as well as the microbial community structure and function were analyzed.Hydrolytic acidification at 35℃was more favorable for COD removal(40.51%)and improvement of biodegradability(0.53 of BOD5/COD).COD removal efficiency and BOD5/COD was only 20.96%and 0.26 under psychrophilic condition,respectively.Mesophilic condition facilitated for the hydrolysis and bioconversion of refractory organic compounds(O3S1 and O4S1).Mesophilic hydrolytic acidification could generate more micromolecular organic compounds in comparison of psychrophilic one.Metagenomic sequencing of hydrolytic acidification microorganisms indicated that mesophilic temperature was more favorable for microbial growth,with higher abundance of organic degrading bacteria of unclassified_p_Chloroflexi and hydrolase secretion bacteria of unclassified_o_Bacteroidales.Moreover,mesophilic condition enriched functional genes of ko00643(styrene degradation),ko00633(nitrotoluene degradation),ko00622(xylene degradation),ko00364(fluorobenzoate degradation),ko00642(ethylbenzene degradation)and ko00365(furfural degradation),which promoted the degradation of aromatic and nitrogenous pollutants as well as improvement of the effluent biodegradability.This study revealed the variation of water quality and the characteristics of microbial community under mesophilic and psychrophilic hydrolytic acidification of refinery wastewater.
refinery wastewaterhydrolysis and acidification at mesophilic and psychrophilic temperaturesorganic compositionmetagenomeanaerobicbiotechnology