Description:

We propose developing a mechanistic-based numerical model for chlorine decay and regulated DBP (THM and HAA) formation derived from (free) chlorination; the model framework will allow future modifications for other DBPs and chloramination. Predicted chlorine residual and DBP results will be compared against predictions from several other quasi-mechanistic models. We anticipate a significant improvement in prediction accuracy over existing empirical models. Several modeling hypotheses are proposed as a basis for a mechanistic-based model for disinfectant decay and DBP formation. The central modeling hypothesis is that a two-site reaction mechanism can be used to predict disinfectant decay in the presence of natural organic matter (NOM). It assumes that NOM contains both slow and fast disinfectant-reacting and DBP-forming sites. NOM site densities and concentrations are related to the concentration, size, structure and functionality of NOM. Our model will also include fitted rate constants that are a function of pH and temperature. A series of distribution functions, based upon the predicted ratios of free-bromine to free-chlorine, will be used to estimate each of the four trihalomethane species (THM₄) and each of the nine haloacetic acid species (HAA₉).

URLs/Downloads:

Final Progress Report

Record Details:

Record Type:PROJECT( ABSTRACT )

Start Date:12/15/1998

Completion Date:12/14/2001

Record ID: 52290

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Related Organizations:

Role :OWNER

Organization Name :ARIZONA STATE UNIVERSITY - MAIN CAMPUS

Citation :Tempe

State :AZ

Zip Code :85287



Role :OWNER

Organization Name :UNIVERSITY OF MASSACHUSETTS - BOSTON

Mailing Address :100 Morrissey Blvd

Citation :Boston

State :MA

Zip Code :2125



Role :OWNER

Organization Name :UNIVERSITY OF COLORADO - BOULDER

Mailing Address :Campus Box 17

Citation :Boulder

State :CO

Zip Code :80309



Role :OWNER

Organization Name :MALCOLM PIRNIE

State :NY

Project Information:

Approach :DBP experimental data from completed projects conducted by the Investigators and other researchers will be integrated into a single Unified Database. Existing empirical models and newly developed numerical models will initially be calibrated with our Unified Database. Additional experimental data will be collected since prior databases lack complete documentation of NOM characteristics before and during disinfection addition. Controlled laboratory disinfection and DBP formation studies will be conducted using water collected at several points through different water treatment plants, including raw, coagulated, softened, and pre-oxidized (ozone and/or chlorine dioxide) waters, thus the waters represent a wide range of water qualities and NOM characteristics. Experiments will investigate the affects of pH and temperature, and NOM, bromide, and free-chlorine concentrations; DBP hydrolysis studies will also be conducted.

Cost :$339,583.00

Research Component :Drinking Water

Risk Paradigm :RISK MANAGEMENT

Approach :DBP experimental data from completed projects conducted by the Investigators and other researchers will be integrated into a single Unified Database. Existing empirical models and newly developed numerical models will initially be calibrated with our Unified Database. Additional experimental data will be collected since prior databases lack complete documentation of NOM characteristics before and during disinfection addition. Controlled laboratory disinfection and DBP formation studies will be conducted using water collected at several points through different water treatment plants, including raw, coagulated, softened, and pre-oxidized (ozone and/or chlorine dioxide) waters, thus the waters represent a wide range of water qualities and NOM characteristics. Experiments will investigate the affects of pH and temperature, and NOM, bromide, and free-chlorine concentrations; DBP hydrolysis studies will also be conducted.

Cost :$339,583.00

Research Component :M/DBP (DBP)

Risk Paradigm :RISK MANAGEMENT

Project IDs:

ID Code :R826831

Project type :EPA Grant