One of the major purification process used commonly is adsorption using activated carbon. The effluent stream after passing through the bed of regenerated or reused activated carbon shows a rapid increase in the pH ranging from 3-4 units. This undesired increase in the pH leads to adverse effects in the effluent stream. This affects the soil grade in the nearby area and it also poses a major threat to the aquatic life. Such effluent streams cannot be let directly into the environment without any further downstream processes. This innovative method of making pH stable when activated carbon is used ensures that the pH of the stream is maintained without any adverse change. From experiments carried out it is seen that the deviation of pH is within unity. This method exploits the acidic property of a carboxylic acid. The activated carbon composition is prepared by immersing activated carbon in an aqueous solution of a carboxylic acid containing compound. Here citric acid has been employed as it is non toxic and cheap. The effluent solution to be treated is passed through the bed and the purified effluent from the bed has a pH differential less than. ±1pH.
Keywords: adsorption, activated carbon, pH, carboxylic acid, citric acid
