• Literature
  • NOM
  • DBPs
  • NOM
  • Analytical
  • Chloramines
• Systems
  • Drinking Water
  • Watersheds
• UMass Resources
  • Courses
    • CEE 577
    • CEE 680
    • CEE 684
    • CEE 772
  • Lab Instruments
• UMass Research
  • Water Treatment
    • Unregulated DBPs
    • Ferrate
  • Wastewater Treatment
  • Natural Systems
• Other

 

Low Level Ozonation to Control Discharges of Organic Chlorine Compounds from Municipal Wastewater Treatment Plants

Massachusetts Division of Water Pollution Control, 9/1/86-8/31/89

PI: Reckhow
Students: Eric Lehan, R.V. Rajan, Chris Hull & Diana King

The purpose of this study was to evaluate the extent to which ozone treatment prior to final disinfection with chlorine can limit the formation of hazardous TOX, and under what conditions it is most effective

Proposal, Plans and Reports

• Proposals: preliminary, Full

• Progress Reports: Dec 86, May 87, Sept 87, Jan 88, Apr 88, Jun 88, Oct 88

• Final Report: Lehan & Reckhow, 1989

Project Data

• TOX comparison through 12/87
• 1st quarter 88

 

Jounal Publications based on this work

• Reckhow, D.A., D.W. Ostendorf and M.E. Billa, "Combined Residual Chlorine Fate and Transport in Small Stream," ASCE, Journal of the Environmental Engineering Division, 116:6:1125-1142 (1990). [CN22]

• Reckhow, D.A., C. Hull, E. Lehan, J.M. Symons, H.-S. Kim, Y.-M. Chang, L. Simms, R.C. Dressman, and H. Pourmoghaddas, "Determination of Total Organic Halide in Water: An Interlaboratory Comparative Study of Two Methods," International Journal of Environmental Analytical Chemistry, 38:1-7 (1990). [CN20]

Conference presentations based on this work

Theses/Dissertations based on this work

• Billa, M., "Monochloramine Transport and Fate in Small Streams," MS Thesis, 1988
• Hull , C.S., "Removal of DOX and DOX Precursors in Municipal Wastewater Treatment Plants," MS Thesis, September, 1989.
• Rajan, R.V., "Characterization and Fate of Halogenated Organic Compounds in a Biologically Treated Secondary Fiber Mill Wastewater," Ph.D. Dissertation, September, 1992.

 

Additional Background: Chlorine reacts very rapidly with ammonia and some of the highly nucleophilic organics present in treated municipal wastewaters to give chloramines and stable organohalides (TOX). Chlorinated organic by-products of this sort have been associated with toxicity to aquatic organisms, mutagenicity, and carcinogenicity in laboratory tests. To date much research has focused on the control of these TOX compounds in chlorinated drinking waters and power plant cooling waters, but the domain of municipal wastewater has barely been touched. One promising pretreatment for the purposes of reducing TOX formation in municipal wastewater is pre-ozonation. Ozone has the capability. of reacting specifically with the same nucleophilic organics that react with chlorine (but it does not react with ammonia). The ozone pretreatment would then preclude their subsequent reaction with chlorine during disinfection.

The problem was investigated in the laboratory using samples of non-nitrified or partially nitrified secondary wastewater effluent. A brief preliminary survey of TOX concentrations in the chlorinated effluents of several local wastewater treatment plants was conducted in order to identify a suitable treatment plant for this study. Samples of the designated wastewater was then be collected just upstream from terminal chlorination and brought to the laboratory when needed for the chlorination and ozonation experiments. First, the wastewater was chlorinated (constant pH) at a variety of chlorine doses on both sides of the breakpoint. These were compared with similar studies where pure solutions of monochloramine are added directly, thus avoiding the effects of a momentary free chlorine residual. Then the wastewater was given small doses of ozone at various pH's and free radical scavenger concentrations and retested for the formation of organohalides.

 

 

See other MDWPC R&D Projects

 

Return to Dave Reckhow's home page.