Chlorination Safety, Reliability, and Efficiency April 2012
Chlorination Safety, Reliability, and Efficiency
Vol. 1, No. 1 Reported independently as Catalytic Objective Synthesis™* April, 2012
City Takes Advantage of Special NaOCl Dosing Unit for Reliable
and Cost-Effective Replacement of Gas Chlorination System
Operations management for a municipal direct water filtration plant reports achievement of a reliable and cost-effective change in chlorination systems that has continued to provide for effective disinfection, while better meeting safety and efficiency criteria.
The plant has a treatment capacity of about 150 MGD. Average flow is about 50 MGD. For chlorination, the plant previously relied on three chlorinators capable of feeding 2000 lb. of chlorine each, 24/7, with typically 12 chlorine cylinder tanks delivered every two weeks, and 18 cylinders on site at a time.
In 2006, they switched to a special, vacuum-driven sodium hypochlorite (NaOCl) delivery system that includes four 11,000 gal. tanks for storage. The bulk-purchased NaOCl is delivered by 4500-gal. tanker truck, and six patented, metered feeders provide a total of 1300 gal./day for their treatment train, via 9 different application points.
“We had always wanted to do something that was safer, even though we never had any incidents, and especially after OSHA and EPA emergency preparation requirements got more rigorous,” recalled the senior plant operator. “We heard of municipal treatment plants going to sodium hypochlorite. We wanted to find out what was the newest equipment; how to feed it safely and efficiently, without failures, using the feed equipment, from storage to delivery point.”