Chayapat Hassapak, Pakamas Chetpattananondh, Sininart Chongkhong and Tanit Chalermyanont

pp. 55 - 63

Abstract

Zinc is one of the important contaminants in groundwater. Removal of zinc by iron filings, activated sludge and lateritic
soil was studied with batch test. The lowest optimum pH for removal of zinc by iron filings, activated sludge and lateritic soil
was 6. From isotherm studies iron filings and activated sludge were chosen as media for permeable reactive barrier (PRB).
The PRB of 0.5-m thick was simulated in the unconfined aquifer with the distance of 21.5 m downgradient of the zinc contaminated site having constant concentration of 100 mg/l. The groundwater flow in the site was induced by the hydraulic gradient
of 0.02. Simulation results indicated that the concentration of zinc of treated groundwater was less than 5 mg/l, which met
Thai Groundwater Quality Standard for Drinking Purposes. The continuous PRBs using iron filings and activated sludge
could treat zinc for 2,170 and 2,248 days, respectively.

Keywords

• permeable reactive barrier
• zinc
• iron filings
• activated sludge
• lateritic soil