Assessing pollution removal efficiencies of some selected parameters by applying different remediation techniques for petroleum oily sludge

Abstract

The present work was carried out to find a suitable eco-friendly sustainable technique for remediation of oily sludge generated from the petroleum industry. Hence, three experimental sets, one with simple land degradation serving as C- set (control), the second one with compost (C+ set), and the third one with silver (Ag) nanoparticles (N set) was used to study the remediation of oily sludge. The three experimental sets each with 500 g of sample were sampled initially at 0 days followed by 15, 30, 45, and 60 days for quantifying pH, conductivity, heavy metals (Pb, Ni, As, and Fe), and total petroleum hydrocarbon (TPH). Our study found that the C+ set (compost) has the highest removal efficiency for heavy metals namely Fe (91.77%), Pb (54.44%), Ni (76.11%), and As (33.48%) as well as TPH (65.52%). All the sets exhibited a positive correlation between pH and TPH as well as between As (Arsenic) and Fe (Iron) and a negative correlation between conductivity and TPH. The pollution index (PI) of As (Arsenic) was between 6.7 to 10.7 exhibiting a very strong level of pollution for all the sets under study. The potential ecological risk index depicted a low level of risk for Pb (0.5–0.30) and Ni (0.043–0.064) whereas moderate level of risk for As (67) in N set and a higher level of risk for C- (88) and C+ (107) set. Based on the results of the present experiment, the application of compost for remediation of oily sludge is better than using nanoparticles and simple land degradation. However, the experiment needs to be carried on for a long period to conclude.