Treatment and Operational Efficiencies of Several Natural and Synthetic Sands on Treating Arsenic Through Adsorption

With the aim of exploring a best adsorbent from locally available sands for removing arsenic from water, eight different adsorbents are tested through column experiments using those materials as filter bed. Based on earlier batch experimental results five locally available sands (Scoria, Skye, iron ore, NT red and TGS), one commercial sand (GFH) and two synthetic sands iron oxide-coated sand and aluminium oxide-coated sand (IOCS and IOCS-AOCS) were selected for the column experiments. Target was to treat arsenic from water up to WHO standard level of 10 μg/L for a considerable period. It is found that Skye sand is capable to treat arsenic-contaminated water to the WHO standard for the longest period, followed by TGS, iron ore and NT red sands. Scoria sand is unable to treat water up to the WHO standard. Although, GFH, IOCS and IOCS-AOCS are capable to remove arsenic to an excellent level, however practically not suitable as they get clogged due to accumulation of finer particles in the filter bed. Also, it is found that artificial coatings enhance the arsenic removal capabilities, however susceptible to clogging.