The alum sludge which is also known as water treatment residual or waterworks sludge contains high amount of aluminium due to usage of Al compound as the coagulant. Annually about 80,000 tons of the alum sludge waste is produced from water treatment plants. Management of the alum sludge has become important Environmental Sciences issue due to stringent Environmental Sciences regulation and increasing public awareness. Reuse of the alum sludge as building, construction and cementitious materials; land improvement additives such as structural soil improver have been known. Also, for removal of carbon dioxide (CO2 ), an undesirable greenhouse gas which creates operational and economic issues, there is a need for effective and inexpensive CO2 removal technologies. High efficiency, cost effective and novel sorbent/filter for removal of carbon dioxide (CO2) using drinking water treatment plant sludge. The removal efficiency of CO2 was evaluated at lab scale and using real vehicle exhaust gas.