Effect of Microbes, Npk Fertilizer and Cow Dung on the Biodegradation of Polycyclic Aromatic Hydrocarbons from Abattoir Wastes in Nigeria

Abstract

The biodegradation of polycyclic aromatic hydrocarbons by associated microorganisms were studied. Soil and waste water samples were collected from four abattoirs located at Egbu and Ogbe in Imo state, Trans-Amadi and Ahoada in Rivers State. Likewise, surface water and sediment samples from Otamiri River and Oginigba Creek adjoined to Egbu and Trans-Amadi abattoirs, respectively were collected using standard methods. The ability of hydrocarbon utilizing bacteria and fungi to biodegrade polycyclic aromatic hydrocarbons (PAHs) was carried out by growing the isolates in a mineral salt broth amended with PAHs and nutrients (NPK fertilizer and cow dung). Levels of polycyclic aromatic hydrocarbons (PAHs) left after incubation were determined using Gas chromatographic method. Results showed that soil samples from various abattoirs had high concentrations of PAHs ranging from 0.176 mg/kg at Ahoada abattoir to 2.44 mg/kg at Egbu abattoir. In a 21-day biodegradation test, there was a drop in the initial concentration of PAHs used as control from 0.03 mg/l to 0.024 mg/l. There was loss of low molecular weight PAHs than the high molecular weight components. It is evident from the study that both mixed cultures of bacteria and fungi can biodegrade polycyclic aromatic hydrocarbons. Results from this study have shown that abattoir wastes have high pollution strength and thus should be treated before being discharged into the environment. Of note is the fact that the microorganisms isolated from the abattoirs are potential agents of remedying environments impacted by polycyclic aromatic hydrocarbons (PAHs).