AWWA WQTC71390

To maintain an adequate source of water treatment chemicals and to protect against increasing chemical costs, Memphis Light, Gas and Water (MLGW) decided to search for a practical alternative to bulk sodium hypochlorite. This paper discusses MLGW's approach to on-site-generation of sodium hypochlorite including the pros and cons of switching from bulk manufactured to on-site-generated. Some inherent advantages to on-site-generation are low bleach strength, slow bleach decay rate, highly available raw materials, and multiple sources and delivery options. Some of the intrinsic disadvantages of on-site-generation are large initial capital costs, increased operator skill set, large equipment foot print, and a soft water treatment requirement. Finally, environmental issues have to be considered with any project. These include electrolytic cell cleaning waste disposal and process production of bromates, chlorates, and hydrogen gas. MLGW concluded that the potential savings were outweighed by the large initial costs and the potential change in water aesthetics. Includes 4 references, tables.