Ion Exchange [India] Ltd supplies Water Purifier for Rural Areas. Ion Exchange [India] Ltd. Is ISO 9001:2000 certified. The Water Purifier for Rural Areas works on the principle of siphoning. It uses Zero-B resin technology and is ideal for rural and semi-rural areas which do not have access to a tap. The Water Purifier for Rural Areas removes harmful bacteria and prevents various waterborne diseases. It purifies 4500 litres of water and does not require electricity.