炼化污水中低温水解酸化性能及微生物特性对比

Comparison of hydrolysis and acidification performance and microbial characteristics of refinery wastewater at mesophilic and psychrophilic temperatures

以炼化污水为研究对象,对比了中温和低温条件下的水解酸化性能、微生物群落结构和功能。中温(35℃)水解酸化更利于COD去除(40.51%)和水质可生化性提高(BOD_(5)/COD提高至0.53),而低温(15℃)COD去除率和BOD_(5)/COD仅为20.96%和0.26。中温条件有助于难降解化合物(O_(3)S_(1)和O_(4)S_(1))的水解转化,与低温水解酸化相比,中温条件能够产生更多种类的小分子有机物。水解酸化微生物的宏基因组测序结果表明中温条件更利于微生物生长,有机物降解菌unclassified_p_Chloroflexi和可分泌水解酶的unclassified_o_Bacteroidales丰度较高。中温水解酸化富集了ko00643(苯乙烯降解)、ko00633(硝基甲苯降解)、ko00622(二甲苯降解)、ko00364(氟苯甲酸酯降解)、ko00642(乙苯降解)和ko00365(糠醛降解)等功能基因,促进了芳香类及含氮污染物的降解和出水可生化性能的提高。本研究揭示了炼化污水中低温水解酸化的水质变化及微生物特性。

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 BOD_(5)/COD).COD removal efficiency and BOD_(5)/COD was only 20.96%and 0.26 under psychrophilic condition,respectively.Mesophilic condition facilitated for the hydrolysis and bioconversion of refractory organic compounds(O_(3)S_(1)and O_(4)S_(1)).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.