Evaluation of heavy metal fixation ability from drilling waste of oil and gas wells using treated sugarcane bagasse

Introduction The drilling industry is one of the main sectors of the oil industry, and oil drilling is one of the most specialized industrial activities. Large-scale production of sugarcane bagasse in Khuzestan Province creates an environmental opportunity to utilize this agricultural byproduct in different sections as a valuable byproduct. This study aimed to investigate the ability of the raw form of bagasse and its transformed structure in heavy metal fixation in drilling mud and to investigate the efficiency of crude bagasse, processed bagasse, and biochar adsorbents in removing heavy metals from the drilling mud residues of Ahvaz oil field. Methods Sampling of drilling mud waste from Mishan Geological Formation (MGF) and Aghajari Geological Formation (AGF) was done on a vibrating sieve. The treatments examined in this research include the contact time in six levels (30, 60, 90, 120, 150, and 180 min), amount of the adsorbent in three levels (0.1, 0.5, and 1 g), adsorbent type in three levels (crude bagasse, processed bagasse, and biochar), and the formation type in two levels (Aghajari and Mishan). After chemical digestion, the samples were placed in contact with crude bagasse, processed bagasse, and biochar according to the designed conditions. Then, the removal percentages of Ba, Ni, V, Cd, Fe, and Pb were calculated. Means were compared using Duncan’s test at the 1% level. Results and Discussion The results showed that the biochar adsorbent is the most efficient compared to other adsorbents. The maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 72.53%, 68.89%, 79.49%, 76.88%, 49.42%, and 85%, respectively. In addition, the results showed that the maximum removal percentages of heavy metals Ba, Ni, V, Cd, Fe, and Pb by crude bagasse are 81/72%, 83/89%, 86/67%, 83/44%, 64/41%, and 90.72%, respectively. The maximum efficiency of biochar for adsorbing heavy metals Ba, Ni, V, Cd, Fe, and Pb is 90.70%, 91.84%, 88.89%, 88.75%, 78.59%, and 97.75%, respectively. The maximum amount of heavy metals adsorbed by all adsorbents was 1 gr/L, and the adsorption efficiency increased by increasing the amount of the adsorbent from 0.2 to 1 gr/L. In examining the effect of contact time, the maximum removal percentage of heavy metals barium and cadmium was obtained in 120 min, nickel and lead in 90 min, and vanadium and iron in 60 min. After the above contact times, there was no increase in the maximum percentage of metal removal.