Isolation of A PAHs-Degrading Bacterium and Analysis of Its PAHs-Degrading Effect in Water

A high efficiency PAHs-degrading strain W3,which could use naphthalene,phenanthrene,fluorene,pyrene,fluoranthene as the sole carbon and energy source,was isolated from the activated sludge of Wuhan Petrochemical Works by the water-silicon oil biphasic system.W3 was indentified as Pseudomonas citronellolis according to the phylogenetical analysis results of 16S rDNA sequence.In the mineral salts-silicon oil medium under PAHs initial concentration of 30 mg·L-1,the degradation rate of naphthalene,phenanthrene,fluorene,pyrene,fluoranthene was(94.00±2.83)%,(81.15±1.63)%,(87.65±4.71)%,(91.65±1.63)% and(87.20±2.12)%,respectively after five days.In the research on application of W3 in South Lake water,with inoculation amount of 3% and bacterial density of 3.15×106 cfu·mL-1 by bioaugmentation,five days later,the degradation rate of naphthalene,phenanthrene,fluorene,pyrene,fluoranthene reached(34.07±7.07)%,(24.78±0.51)%,(56.95±5.06)%,(19.67±3.18)% and(35.10±5.22)%,respectively;and bacterial density of 4.76×107 cfu·mL-1 by bioaugmentation,five days later,the degradation rate of naphthalene,phenanthrene,fluorene,pyrene,fluoranthene reached(59.27±8.54)%,(44.35±10.79)%,(66.64±2.35)%,(26.40±6.36)% and(53.86±4.07)%,respectively.