The Role of pH in Nitrate-reducing Conditions in Degradation of Polycyclic Aromatic Hydrocarbons in Contaminated Soil Extract

Degradation of polycyclic aromatic hydrocarbons (PAHs) was investigated by applying different NaNO3 mass at varying pH levels (2.0, 4.0, 6.0 and 8.0) to contaminated soil extract. Results obtained indicated that using 2 g NaNO3, 31.1% of 2-methylnaphthalene was regarded as the overall highest PAH degraded (pH 6.0), while 1.4% anthracene at pH 2.0 was the overall lowest degraded PAH. However, using 4 g NaNO3, 20% of 2- methylnaphthalene was degraded as the highest PAH at pH 6.0, while 1.0% of acnaphthalene (pH 2.0) was observed as the least degraded PAH. A general increase in trend in PAH degradation was noted using 2 g NaNO3 as the pH was increased from 2.0 to 6.0, though, at pH 8.0 there was a remarkable decrease in PAHs degradation. The trend in PAHs degradation observed using 2 g NaNO3 was replicated using 4 g NaNO3 except for phenanthrene, fluoranthrene and pyrene. It was also found that increasing the mass of NaNO3 from 2 to 4 g didn’t have any positive impact on the rate of degradation of PAHs

Author(s): Luke N. Ukiwe, Ugochukwu U. Egereonu

Abstract | PDF

Share This Article