啤酒糟生物炭吸附固定化功能菌强化去除多环芳烃特性

Removal Characteristics of PAHs in Water by Immobilized Functional Bacteria Adsorbed onto Brewer’s Grains Biochar

文章采用不同热解温度制备的啤酒糟生物炭载体吸附固定化特征降解菌(SZ-3),分析啤酒糟生物炭理化性质与形貌表征对功能菌固定化能力的影响,探究菲、荧蒽、芘3种多环芳烃化合物(PAHs)的微生物降解效能强化以及反应周期内功能菌的增殖与酶活特性。结果表明,500℃热解温度制备的啤酒糟生物炭亲水性强,比表面积及孔径分别为2.505 m^(2)/g、23.928 nm,炭材料表面官能团以羧基、脂肪醚为主,电子传递性能优良,对功能菌的吸附量达到825.71 nmol P/g。批次实验条件下,优化制备的啤酒糟生物炭固定化功能菌对水中菲、荧蒽、芘的去除率分别为71%、38%和35%,相较于单独生物炭和游离功能菌体系,固定化降解菌对PAHs化合物去除率提升范围为8%~34%,且菲的生物降解效能强化最为显著。同时,啤酒糟生物炭固定化降解菌体系中的功能菌生长数量和邻苯二酚双加氧酶活性也较大提高。采用啤酒糟生物炭作为微生物固定化载体强化难降解有机物去除具有良好的实际意义。

Biochar prepared at different pyrolysis temperatures from brewer’s grains was used as a carrier for the adsorption and immobilization of the PAHs(polycyclic aromatic hydrocarbon)degrading bacteria named SZ-3,whose physicochemical properties and morphology characterization,and their affects on the immobilization of functional bacteria were analyzed.Furthermore,the enhanced microbial degradation efficiency of three species of PAHs(phenanthrene,fluoranthene and pyrene),and their proliferation and enzymatic activity of the functional bacteria during the reaction cycle were investigated.The results indicated that the brewer’s grain biochar prepared at a pyrolysis temperature of 500℃was of high hydrophilic property,with a specific surface area and pore size of 2.505 m^(2)/g and 23.928 nm,respectively;most of the functional groups on the surface of the carbon material were carboxyl groups and fatty enzymes,which had excellent electron transfer properties and possessed a large functional bacteria adsorption capacity of 825.71 nmol P/g;and in the case of the batch experiment,it was showed that the removal rates of phenanthrene,fluoranthene,and pyrene by the optimized SZ-3,which had been prepared from brewer’s grain,could attain up to 71%,38%and 35%,respectively.On the whole,in comparison with the sole biochar and free functional bacteria systems the increase of removal rates of PAHs compounds by use of SZ-3 ranged from 8%to 34%,and particularly,the bio-degradation efficiency of phenanthrene was significantly enhanced.Additionally,the count of functional bacteria increased,and the activity of catechol dioxygenase in the brewer’s grain biochar fixed SZ-3 also significantly improved.To conclude,application of brewer’s grains biochar as a microbial immobilization carrier is of practical significance in terms of the removal of refractory organic matter.