Luo Xiaofang, Chen Lihua, Zhao Shujing, Lei Zhongchun, Xia Miaomiao, Zhang Chuantao
Experimental Teaching Department, Northwest Minzu University, Lanzhou 730030, P. R China.
College of Chemical Engineering, Key Laboratory for Utility of Environment-Friendlymicro Composite Materials and Biomass in University of Gansu Province, Northwest Minzu University, Lanzhou, Gansu 730030, P. R China.
ACS Omega. 2020 Jul 29;5(31):19402-19408. doi: 10.1021/acsomega.0c01123. eCollection 2020 Aug 11.
To enhance the degradation efficiency of oily wastewater, polyacrylamide (PAM)-sodium alginate (SA) and poly(vinyl alcohol) (PVA)-sodium alginate (SA) were mixed and used as spherical supporting materials for the immobilization of microbials, which were employed as a platform to study the degradation of total petroleum hydrocarbons (TPHs) in the oily wastewater. The degradation and evolution of normal paraffin (n-paraffin) series have been studied by determining the crude oil group composition of the residual oils by the gas chromatography-mass spectrometry (GC-MS) analysis. The results show that the half-lives of the PAM-SA-immobilized microorganisms are 6.21 days, which is 2.11 days less than that of PVA-SA, indicating that more nutrients are provided by PAM-SA for microbial growth, which can accelerate the degradation of TPHs. As can be seen from the GC-MS analysis, the main peak carbons of the n-paraffin series are moved backward after 14 days of degradation, implying the degrading advantage of n-paraffin with low carbon numbers. The ∑C21/∑C22 value of PAM-SA was measured to be 0.749, which is greater than that of PVA-SA (0.051), indicating that PAM-SA has a superior ability to degrade normal paraffins with high carbon numbers. After 14 days of degradation, an odd-even predominance (OEP) (the mass ratio of normal alkanes of odd carbon/even carbon) value of 1.075 for PAM-SA was obtained, which is slightly larger than that of PVA-SA (0.967), indicating a better degradation performance of PAM-SA, especially for the degradation of the even-carbon normal paraffins with high carbon numbers. The Pr/Ph of PAM-SA is 0.938, which is also greater than that of PVA-SA (0.844), indicating that the ability of PAM-SA for the degradation of isoprenoids is superior to that of PVA-SA under the immobilized conditions. Based on these results, in terms of immobilization of microorganisms, PAM-SA, instead of PVA-SA, is more advantageous for the degradation of TPH in the oily wastewater.
为提高含油废水的降解效率，将聚丙烯酰胺（PAM）-海藻酸钠（SA）和聚乙烯醇（PVA）-海藻酸钠（SA）混合用作固定化微生物的球形载体材料，以此作为研究含油废水中总石油烃（TPHs）降解的平台。通过气相色谱-质谱联用（GC-MS）分析确定残留油的原油族组成，研究了正构烷烃系列的降解与演化。结果表明，PAM-SA固定化微生物的半衰期为6.21天，比PVA-SA的半衰期短2.11天，这表明PAM-SA为微生物生长提供了更多养分，可加速TPHs的降解。从GC-MS分析可以看出，降解14天后，正构烷烃系列的主峰碳向后移动，这意味着低碳数正构烷烃具有降解优势。测得PAM-SA的∑C21/∑C22值为0.749，大于PVA-SA的（0.051），表明PAM-SA具有更强的降解高碳数正构烷烃的能力。降解14天后，PAM-SA的奇偶优势（OEP）（奇数碳正构烷烃与偶数碳正构烷烃的质量比）值为1.075，略大于PVA-SA的（0.967），表明PAM-SA的降解性能更好，尤其是对高碳数偶数碳正构烷烃的降解。PAM-SA的Pr/Ph为0.938，也大于PVA-SA的（0.844），表明在固定化条件下，PAM-SA降解类异戊二烯的能力优于PVA-SA。基于这些结果，在微生物固定化方面，对于含油废水中TPH的降解，PAM-SA比PVA-SA更具优势。
