March 5, 2009

Chicken manure can biodegrade crude oil

Chinese scientists say they've discovered chicken manure can be used to biodegrade crude oil in contaminated soil.

Bello Yakubu, Huiwen Ma and ChuYu Zhang of Wuhan University said they determined bacteria contained in the manure breaks down 50 percent more crude oil than in soil lacking the manure.

The scientists said current approaches to remove soil contaminated by crude oil caused by equipment failure, natural disasters or human error come with additional environmental costs. Detergents, for instance, become pollutants themselves and can persist in the environment long after any remediation exercise is complete, they said. And bioremediation -- the use of natural or engineered microbes to metabolize the organic components of crude oil -- can be expensive and result in soil hardening and a loss of soil quality.

Ma and colleagues suggest animal waste, and in particular chicken manure, might provide the necessary chemical and microbial initiators to trigger biodegradation of crude oil. One important factor, they said, is that chicken manure raises the pH of soil to the range 6.3 to 7.4, which is optimal for the growth of known oil-utilizing bacteria.

The research is reported in the International Journal of Environment and Pollution.