Impact of Cold Shock on the Intrinsic Qualities of a Bioremediated Petroleum Hydrocarbon-Polluted Soil

Abstract

The present study investigated the effects of cold shock on the intrinsic qualities of a bioremediated petroleum hydrocarbon- polluted soil. Into already perforated buckets were measured 5kg sun-dried top soil (0-10cm). Waste engine oil (WEO) was added to soil and mixed thoroughly to obtain similar concentrations of 5 % w/w oil in soil. The entire setup was divided into 5 treatment sets, depending on the interval of exposure to a total of 250ml of ice pellets at a time;daily exposure (1PD), twice per week at equal intervals (2PW), once weekly (1PW), fortnightly (2PM), and once monthly (1PM). The control soil did not receive any cold treatment. Results showed significant reductions in heavy metal and polyaromatic hydrocarbon concentrations. Immediately after soil was contaminated with waste engine oil concentration of vanadium 0.08mg/kg, but was beyond detectable limit in all the treatment and control at after exposure to cold shocks 3 months later (MAP).
Total PAH at 3 MAP was 142.81mg/kg in 1PD, 96.27mg/kg in 2PW, 196.31 mg/kg in 1PW and 147.39mg/kg in 1PM, compared to 1055.15mg/kg
immediately after soil was contaminated with WEO. It is therefore demonstrated that exposing soils to low temperature shocks at most twice in a week offered comparatively better remediative capabilities for the soil.