Design Of Recovery System Of Ammonium Sulphate From Effluent Containing Ammonical Nitrogen

Abstract

Numerous wastewater treatment processes are currently available for nitrogen removal or am- monia conversion to nitrate. Those that are economically feasible are Biological nitri cation- denitri cation, Ion exchange method, Break point Chlorination and Air stripping. Mostly on microbiological processes, which are only e ective when the microorganisms remain in a healthy state. If a biological process upset was to occur, due to a toxic shock load or cold weather, it may result in a discharge of ammonia or total nitrogen into the receiving water body. The impact of such a discharge could have deleterious e ects on aquatic life or human health. In the ion exchange method the ammonium ion contained in drainage is adsorbed in an ion exchange such as natural or synthetic zeolite and then the ammonium ion is eluted in the alkali salt or alkali hydroxide solution from the ion exchange substance. In the method of break point chlorination, adjustment of pH decreased by the direct addition of chlorine to the drainage and treatment of chloramines, formed as by-product with active carbon and of remaining residual chlorine in the drainage are necessary. The air stripping process can be simply de ned as a unit process in which water and air are brought into contact with each other with the purpose of transferring volatile substances from water to air. This process has been e ectively used in water and wastewater treatment to strip dissolved gases such as hydrogen sulphide, carbon dioxide and ammonia. In other applications, it has been successfully used to strip and reduce the concentration of taste and odour producing compounds and trace volatile organics. Air stripping is competitive with other methods both in terms of performance and cost. The Henry's law constant is a primary indicator of a compound's potential for removal by air stripping. The counter-current packed-tower type air stripper o ers greater interfacial surface area for mass transfer of volatile compounds than do other gas-stripping processes. This method therefore o ers signi cant advantages in e ciency and overall cost when used for the removal of volatile compounds from potable or wastewater streams. In case of air stripping, it is feasible to achieve a high degree of removal. Once the ammonia is stripped it is recovered from the air ow by absorption in a sulfuric acid solution, yielding ammonium sulphate which can be obtain in an appropriate concentration. Each of the processes discussed has its advantage and dis-advantage but compare to other processes Air Stripping is superior to others both in terms of performance and economics because, If the concentration of ammonical nitrogen is more i.e. in thousands of ppm, than only air stripping can work e ciently compare to other processes and it is economical because of recovery of Ammonium sulphate as by- product. The main objective of this project is to reduce the level of ammonical nitrogen from e uent as per GPCB norm by air stripping process and simultaneously to design ammonia recovery system for manufacturing ammonium sulphate as by-product. It is an experimental and analytical method in which based on the results of laboratory work the design of ammonia stripper and absorption column will take place.