Efficiency of pseudomonas aeruginosa and Escherichia coli to treatment of effluent petroleum wastewater from AI-Nasiriya refinery – Iraq

Abstract

Fourbacteria isolated from the soil contaminated with petroleum hydrocarbon and wastewaters from the refinerylocated in the south part of AI-Nasiriya city in Iraq,by using dilution method.The results showed that Pseudomonas aeruginosawas more dominant with 100% in soil and wastewaters in inside of refinery,and 93%,95% in soil and wastewaters in outside the refinery respectively.The results showed that the second dominant of bacteria was Esherchia coil with 92%,98% in soil and wastewaters in inside the refinery,and 83%,88% in soil and wastewaters in outside of refinery.The remaining two species of bacteria isolated with a very low frequency,these bacteria were Bacillus subtilis and Klebsiella sp., B.subtilis was obtained with 10%,8% in soil and wastewaters in inside the refinery,and 10%,3% in soil and wastewaters in outside of refinery .In the same time that Klebsiella sp. Was obtained with 10% in soil and wastewaters in inside the refinery,and 8%,3% in soil and wastewaters in outside the refinery.The results showed that mixed two bacteria (high frequency)were more efficient to decrease Biological Oxygen Demande(BOD)with 59% in pH 4,0.5gm / I salt (NaCI) concentration.Chemical Oxygen Demande (COD) was decreased to 75%.The results showed that the Total Acidity(TA) in wastewater were increased to 82%mg / I in 40c o ,pH 8 and 2.0 gm/ I NaCI , and Total Suspended Solid (TSS) was decreased to 50 mg / I in 40c o , pH 8,2.0 gm / I NaCI . The results showed that the Total Petroleum Hydrocarbon (TPH) was removal with 99.99%, and in the same time the numbers of mixed bacteria were increased to 5x10 8 after incubation 48h in 40c o .