Arsenic removal by household-based ceramic filters: Evaluating mode of operations and influence of groundwater compositions

Abstract

Household-based ceramic filters amended with metal iron showed great potential to remove arsenic (As) from groundwater (GW) due to their low cost and minimal maintenance requirements. The present study assessed the As removal performance of iron amended ceramic filters (CFs) with two different filter configurations including single unit ceramic filter (SUCF) and double unit ceramic filter (DUCF). Fifteen SUCFs and one DUCF were tested at different households in the Khulna-Bagerhat region of Bangladesh with freshly withdrawn GW having As and Fe concentrations ranging from 141 to 585 μg/L and 0–16 mg/L, respectively. SUCFs achieved As effluents below the standard level (50 μg/L) from medium As GW (41–231 μg/L). Whereas, DUCF was efficient for high As GW (288–585 μg/L) removing As (86%) and Fe (99%) below the standard limit. Principal component analysis (PCA) demonstrated that As removal efficiency was positively influenced by Fe and Ca and negatively by As concentrations. Fe2+ released from the amended iron net has a significant contribution to the As removal in the CFs. X-ray photoelectron spectroscopy (XPS) analysis detected the presence of Fe3+, P, Si, and Ca on the surface of the iron net leading to insufficient Fe dissolution to remove As. Overall, it is recommended to use SUCFs for low to medium As GW and DUCFs for high As GW. The CFs with affordable cost, easy operation, and minimal maintenance can produce sufficient quantity (60–80 L/d) to fulfill the daily drinking water demand in the rural households of developing countries.