ABSTRACT
Development of sustainable and technically accessible treatment alternatives of As-rich groundwater suitable for low-income populations is a relevant research field, mostly in locations relying on wells as drinking water source. Use of limestones for arsenic removal is specially promising in groundwater contaminated areas with limestone outcrops. This study was carried out with the aim to determine the influence of groundwater major anions on As removal by limestones through column experiments. Treatment experiments were carried out during 18 weeks with water containing As, fluoride and each of the main anions in concentrations corresponding to the most polluted well (As = 1.2 mg/L) at Zimapán, México. Results indicated that chloride and fluoride do not influence As removal that decreases more than 80%. Meanwhile, although As diminished to values below the Mexican drinking water standard (0.025 mg/L) in the solutions containing sulfate and bicarbonate since the 2nd week, it started to increase since the 12th week and 7th week respectively. This behavior may be due to a decrease of sorption sites due to their retention on limestones. Results of the study may be used to design a home filter to treat the contaminated water, and further exported to other locations.
