Mini-analyzers monitor sulfite and chlorine levelsProblem: The wastewater plants in Clarkson and Guelph, Ontario, use chlorine disinfection but have severe chlorine residual limits because the receiving stream has sensitive aquatic life. The usual approach is to feed sulfite to dechlorinate the effluent, but sulfite is an oxygen scavenger, and large residuals can result in reduced dissolved oxygen in the stream, replacing one problem with another.Solution: Two ChemScan mini-analyzers from ASA Analytics monitor sulfite/chlorine levels and address the feed control issue. A mini LowChlor chlorine analyzer with a detection limit of 0.005 mg/L monitors the chlorine residual before or after sulfite
