title: Effect of electric intensity on the microbial degradation of petroleum pollutants in soil.
abstract: Electro-bioremediation is an innovative method to remedy organic-polluted soil. However, the principle of electrokinetic technology enhancing the function of microbes, especially the relationship of electric intensity and biodegradation efficiency, is poorly investigated. Petroleum was employed as a target organic pollutant at a level of 50 g/kg (mass of petroleum/mass of dry soil). A direct current power supply was used for tests with a constant direct current electric voltage (1.0 V/cm). The petroleum concentrations were measured at 3275-3285 nm after extraction using hexane, the group composition of crude oil was analyzed by column chromatography. The water content of soil was kept 25% (m/m). The results indicated the degradation process was divided into two periods: from day 1 to day 40, from day 41 to day 100. The treatment of soil with an appropriate electric field led the bacteria to have a persistent effect in the whole period of 100 days. The highest biodegradation efficiency of 45.5% was obtained after treatment with electric current and bacteria. The electric-bioremediation had a positive effect on alkane degradation. The degradation rate of alkane was 1.6 times higher in the soil exposed to electric current than that treated with bacteria for 100 days. A proper direct current could stimulate the microbial activities and accelerate the biodegradation of petroleum. There was a positive correlation between the electric intensities and the petroleum bioremediation efficiencies with a coefficient of 0.9599.
authors.affiliation: Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. tingting.li2006@yahoo.com.cn
authors.forename: Tingting
authors.initials: T
authors.lastname: Li
authors.forename: Shuhai
authors.initials: S
authors.lastname: Guo
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
authors.forename: Fengmei
authors.initials: F
authors.lastname: Li
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Niu
mesh_terms: D001673:Biodegradation, Environmental; D019149:Bioreactors; D010578:Petroleum / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D010578:Petroleum; D012989:Soil Pollutants