title: Modeling and optimization of trihalomethanes formation potential of surface water (a drinking water source) using Box-Behnken design.
abstract: OBJECTIVE
  The present research aims to investigate the individual and interactive effects of chlorine dose/dissolved organic carbon ratio, pH, temperature, bromide concentration, and reaction time on trihalomethanes (THMs) formation in surface water (a drinking water source) during disinfection by chlorination in a prototype laboratory-scale simulation and to develop a model for the prediction and optimization of THMs levels in chlorinated water for their effective control.
  
  
  METHODS
  A five-factor Box-Behnken experimental design combined with response surface and optimization modeling was used for predicting the THMs levels in chlorinated water. The adequacy of the selected model and statistical significance of the regression coefficients, independent variables, and their interactions were tested by the analysis of variance and t test statistics.
  
  
  RESULTS
  The THMs levels predicted by the model were very close to the experimental values (R(2) = 0.95). Optimization modeling predicted maximum (192 μg/l) TMHs formation (highest risk) level in water during chlorination was very close to the experimental value (186.8 ± 1.72 μg/l) determined in laboratory experiments. The pH of water followed by reaction time and temperature were the most significant factors that affect the THMs formation during chlorination.
  
  
  CONCLUSIONS
  The developed model can be used to determine the optimum characteristics of raw water and chlorination conditions for maintaining the THMs levels within the safe limit.
authors.affiliation: Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Council of Scientific and Industrial Research, Lucknow, India. kpsingh_52@yahoo.com
authors.forename: Kunwar P
authors.initials: KP
authors.lastname: Singh
authors.forename: Premanjali
authors.initials: P
authors.lastname: Rai
authors.forename: Priyanka
authors.initials: P
authors.lastname: Pandey
authors.forename: Sarita
authors.initials: S
authors.lastname: Sinha
mesh_terms: D001965:Bromides / Q000032:analysis / Q000737:chemistry; D002244:Carbon / Q000032:analysis / Q000737:chemistry; D002713:Chlorine / Q000032:analysis / Q000737:chemistry; D004203:Disinfection / Q000379:methods*; D060766:Drinking Water / Q000032:analysis* / Q000737:chemistry; D054879:Halogenation; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D022882:Trihalomethanes / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D001965:Bromides; D060766:Drinking Water; D009930:Organic Chemicals; D022882:Trihalomethanes; D014874:Water Pollutants, Chemical; D002713:Chlorine; D002244:Carbon