Batch Adsorption Processes of Chloride and Sulphate Anions from Aqueous Solutions Using Natural Stone Powder

Pumice is a natural rock that has many applications. It has been used as an abrasive material, as a mold release agent in different industries like textiles and plastics, as a filler in painting and coating industries, and as an aggregate and stone in the construction industry. The current work investigates the possibility of using pumice as an adsorbent in water treatment for removing chlorides and sulphates ions using laboratory batch adsorption experiments. The adsorption capacity is detected from the decrease in electrical conductivity of the aqueous salt solutions brought in contact with the surface of pumice. The method is fast and simple and requires only the use of an electrical conductivity meter. The effect of the adsorbent content, initial salts solutions concentration, salts solutions pH, temperature, and contact time on filtrates conductivity is investigated. The results showed that conductivity decreases with increasing contact time and pH, and increases with increasing the initial ions concentration, temperature and the adsorbent content. This study gives valuable information about the adsorption process for chloride and sulphate ions removal from their aqueous solutions using pumice that could be considered as a technically workable and economically viable adsorbent in water desalination.