Biological Degradation and Transformation Characteristicsof Total Petroleum Hydrocarbons by Oil Degradation Bacteria Adsorbedon Modified Straw

摘要

We report a simple and “green” method for the fabrication of polymer-modified straw-supported oil degradation bacteria (PMS-ODB) for biological degradation of total petroleum hydrocarbons (TPHs) in water. The modification of straw was achieved by in situ copolymerization of styrene and butyl methacrylate using methylene-bis-acrylamide as a cross-linker in an aqueous solution containing straw powders. Compared with the control group (ODB loaded on untreated straw), the results obtained from the experimental group show that the polymer-modified straw is beneficial to the growth of microorganisms. As a result, the degradation rate of TPHs reaches 90.12%, which is 50.54 and 7.08% higher than that of the blank group (ODB only) and the control group, respectively. A study on the transformation characteristics of PMS-ODB shows that the degradation rate of alkanes with low, medium, and high carbon number is higher than 90%. w(∑C21–)/w(∑C22+) (the mass ratio of normal alkanes of high carbon/low carbon), w(pr)/w(ph) (the ratio of pristane/phytane), and OEP (the mass ratio of normal alkanes of odd carbon/even carbon) forTPHs in the experimental group were measured to be 0.6186, 0.7248,and 1.4356, respectively, all of which are the largest value amongthe blank group, control group, and experimental group. These findingsindicate that compared with the control group, the modification ofstraw could enhance the comprehensive biological degradation performancefor TPHs, even those highly stable organics, such as carbon n-alkanes and isoprenoid hydrocarbon, which may open a newpossibility for degradation of oils or toxic organics in an enhancedbiological manner.