Arsenic removal in groundwater by integrated ozonation and adsorption by activated carbon and zeolite

Abstract

In this study, we investigated the effectiveness of arsenic removal from groundwater with a hybrid process integrating oxidation with ozone and adsorption with activated carbon and zeolite in a 2 L volume batch reactor. Artificial ground water was used in this study, using sodium arsenite (NaAsO2) as an As (III) source. Artificial ground water is made to resemble natural groundwater conditions which contain 3 mg / L arsenic. The experiment shows that the arsenic adsorption efficiency in integrated ozonation-adsorption process is higher than individual adsorption process. For individual adsorption process, either with GAC or zeolite, both reached maximum removal in 2 hours. For integrated ozonation-adsorption process, adsorption efficiency reached maximum removal in 45-90 minutes. Maximum removals for individual adsorption with adsorbent dose 12.5 g/L are 69% and 55% for GAC and zeolite respectively. Maximum removal for integrated ozonation-adsorption process with adsorbent dose 12.5 g/L and ozone dose 10.1 mg/minute is 99,97% for both cases of ozone-GAC and ozone-zeolite. Total arsenic concentration in solution reached <0.001 mg/L in 90 minutes for both cases of ozone-GAC and ozone-zeolite with adsorbent dose 10 g/L.