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Adsorption-degradation of polycyclic aromatic hydrocarbons in soil by immobilized microorganisms in loofah |
Received:August 06, 2019 |
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KeyWord:microorganisms;immobilization;PAHs;adsorption;degradation |
Author Name | Affiliation | E-mail | WANG Tian-jie | School of Environmental Science, Liaoning University, Shenyang 110036, China | | SU Dan | School of Environmental Science, Liaoning University, Shenyang 110036, China | sudan1980@126.com | LI Xue | School of Environmental Science, Liaoning University, Shenyang 110036, China | | PU Yu | School of Environmental Science, Liaoning University, Shenyang 110036, China | | WANG Xin | Key Laboratory of Regional Environment and EcoRemediation, Ministry of Education, Shenyang University, Shenyang 110044, China | wx1979@126.com |
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Abstract: |
To fully understand the bioadsorption-degradation behavior of polycyclic aromatic hydrocarbons(PAHs) during bioremediation, Pseudomonas sp.SDR4(S4) and Mucormucedo sp.SDR1(S1) were used as research objects to study the adsorption and degradation of PAHs in soil by immobilized microorganisms. The adsorption mechanism, degradation kinetics, and relations between adsorption and degradation of the immobilized microorganisms to PAHs in soil were examined. The results showed that after 60 d, the dynamic equilibrium adsorption of modified loofah(CK), dead immobilized S1(S1-D), dead immobilized S4(S4-D), and dead immobilized mixed bacteria S1 and S4(S1+S4-D) to phenanthrene(Phe) was 5.28, 6.82, 5.73, and 7.46 μg, respectively, and the dynamic equilibrium adsorption of pyrene (Pyr) was 4.17, 4.72, 4.53, and 5.00 μg, respectively. The adsorption of dead immobilized microorganisms to Phe and Pyr was subject to quasi-second-order dynamics. The dynamic adsorption capacities of living fungi S1, bacteria S4, and mixed bacteria S1+S4 to Phe were 2.32, 2.01, and 2.76 μg, respectively, and the dynamic adsorption amount of Pyr was 2.79, 2.41, and 3.14 μg, respectively. Quasi-first and quasi-second-order kinetics of Phe and Pyr adsorbed by living immobilized microorganisms in soil showed little difference in R2 fitting results. The degradation rates of S1, S4, and S1+S4 to Phe were 54.34%, 61.45%, and 64.23% respectively, and the degradation rates of Pyr were 38.42%, 35.02%, and 42.43%, respectively. Following treatment with S1, S4, and S1+S4, the half-lives of the degradation of Phe were 38.88, 29.41, and 25.63 d, respectively. The half-lives of the degradation of Pyr were 64.76, 69.02, and 59.28 d, respectively. The research shows that chemical action is the main factor that controls the adsorption rates of immobilized microorganisms of loofah to PAHs. The enhanced degradation ability of microorganisms can increase the influence on the migration of PAHs in soil. The synergistic effect between fungi and bacteria can improve the degradation efficiency of Phe and Pyr. |
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