AWWA ACE70836

A comprehensive summary of dechloramination technologies is currently not available, and therefore aliterature review was undertaken with the objectives of recommending the most feasible and cost-effectivedechloramination alternative and presenting a conceptual design of dechloramination processfor treatment of the filter backwash and filter-to-waste wastewater.The dechloramination alternatives examined in this study include: dechloramination with passive nonchemicalmethods; dechloramination using regular dechlorination chemicals; dechloraminationwith activated carbon filters; dechloramination with UV light; dechloramination with breakpointchlorination and dechlorination; and, dechloramination using proprietary dechloraminators.Dechloramination using a regular dechlorination chemical, such as sodium bisulfite, was recommendedas the most feasible and cost-effective alternative for chloramine removal from Evansville WFP filterbackwash and filter-to-waste process wastewater. Preliminary design of the dechloramination systemis summarized in this paper following a characterization of the process wastewater flows, pH, andfree and combined chlorine concentrations. As ammonia is released as a byproduct of the chemicaldechloramination process, the concentration of un-ionized ammonia (which is toxic to many aquaticorganisms) under the worst case scenario of total ammonia nitrogen release was evaluated underdifferent pH and temperature conditions to assess its potential adverse effects on the receiving waters and aquatic organisms. Methods for minimizing the concentrations of un-ionized and total ammonianitrogen, should future plant discharge permit set such limits, are also discussed. Includes 15 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

64

File Size:

1 file , 1.3 MB