Mercury (Hg) is a major environmental pollutant when they present in high concentration in soil and have toxic effects on plants growth, environmental quality and human health. This experiment was performed as a completely randomized design (factorial) with three replications. For this purpose, columns containing 6 kg of saline soil was treated with humic acid (HA) and zeolite (Zol) both at concentrations of 0 and 0.5 mg/kg soil. Treated soil columns were irrigated with three mercury levels of 0, 75, and 150 mg/L using mercuric chloride salt. Irrigation with mercuric chloride was done every five days with equal amounts of prepared solution to each column. After 20 days, the total mercury was determined in 5 sections of soil with 10 cm thickness (D1…D5). The results indicated that increasing Hg levels enhanced Hg concentration in all soil sections, highest was noted in D1 compared to other sections. Both humic acid and zeolite treatments played an important role in controlling Hg in saline soil. Further, total Hg retention in saline soil was increased by humic acid and zeolite treatments. Accordingly, humic acid (HA) treatment in D1–D4 sections proved to be superior to zeolite (Zol) treatment in more retention of total Hg in saline soil. All in all, the positive impact of humic acid treatment was greater than that of zeolite treatment.

Keywords