Abstract
Soil aquifer treatment (SAT) is one of the most important methods for reusing wastewater. This study evaluated the influence of 300 cm vadose zone thickness on the removal of wastewater contaminants Physicochemical parameters and heavy metal were assessed at 0, 30, 60, 100, 150, 200, and 300 cm soil depth. Results showed that the upper 300 cm soil layer effectively removed some contaminants from wastewater. An increase in soil pH with depth from 7.38 to 8.25. The removal efficiency of COD and BOD was 83.27% and 83.24%, respectively. TSS decreased from 146.7 to 76.5 mg/l, with a removal efficiency of 47.9%. A high removal efficiency of 91.4% was observed for TDS. Removal of TC and FC concentrations were high, with a maximum reduction of 99.5% and 99.4%. On the other hand, B concentration increased from 0.15 to 0.5 mg/l. Removal efficiencies for cations were 84.5%, 43.5%, and 15%, for Mg+2, Na+, and Ca+2, respectively. Heavy metal concentrations within the soil layer were restricted to several centimetres. The removal efficiency was as follow; Cd2+ (100%)> Zn2+ (59.8%)> pb(2+) (52.9%)> Mn2+ (10.8%)> Cu6+ (8.9%)> Al3+ (5.53%). Moreover, no significant removal values were obtained for chromium (Cr6+) concentration.