Arsenic and heavy metals removal by iron-impregnated ceramic granules: A household-scale

Abstract

Clean water for drinking and cooking has been a serious issue in rural areas of Vietnam, which is mainly due to high-cost treatment of the available water sources in such areas. In order to reduce the treatment cost, iron impregnated ceramic granules (IICGs) was synthesized using a mixture of locally available montmorillonite and crushed rice husk (with the rice husk size < 0.2 mm, IICGs size 0.2 mm – 0.45 mm). This material was used as a simple and efficient adsorbent of pollutants in groundwater in this present work. The household-scale drinking water treatment unit (capacity of 0.13 L/h) consists of an air stripper, a slow sand filter and an adsorption column packed IICGs. This system was operated with the inlet flow comprising of total iron ion (1.10.1 mg/L), arsenic (300 ppb) copper ion (6.15 mg/L), cadmium ion (8.1mg/L), lead ion (0.41 mg/L), and zinc ion (0.515 mg/L). The derived IICG adsorbent was observed to significantly remove a wide array of dissolved metals including iron (99.3%), arsenic (99.92%), zinc (99.48%), copper (97.03%), lead (98.6%) and cadmium (99.6%). The effluent concentrations of most dissolved metals after the household-scale drinking water treatment unit were about ten times lower the Vietnamese standard for drinking water.