Environmental assessment of soils contaminated with heavy metals in the oil field areа of Zhanaozen

The present work was performed with the aim of investigating heavy metal contamination of soils in the Zhanauzen oilfield, Kazakhstan. For this study, ۲۰ soil samples were collected from industrial and residential areas around the oilfields and the concentrations of heavy metals lead, cadmium, nickel, and zinc were measured using atomic absorption spectrometry. The results of the laboratory analyses showed that the average lead concentration was ۸۹ mg kg-۱, and cadmium was ۱.۴۲ mg kg-۱, which were ۴.۸ and ۵.۷ times higher than the natural background levels of the area, respectively. Calculation of pollution indices showed that ۸۰% of the samples were in the moderate to highly polluted category. Based on the ecological risk index, cadmium was found to be the most critical metal due to a risk coefficient as high as ۳۷۸ in some places. Samples S۰۴ and S۰۷ can be considered as those require urgent attention due to the highest levels of contamination. The strong correlation between the concentrations of lead, cadmium, and zinc (correlation coefficients above ۰.۹) indicates that the source of contamination is common. The outcomes of the present investigation indicate the significant impact of oil industry activities on soil pollution in the region and necessitate the implementation of continuous monitoring programs and management strategies to reduce pollution.

کلیدواژه ها:

Soil pollution ، Heavy metals ، Ecological risk assessment ، Zhanauzen oilfield