title: Integrated hydraulic and organophosphate pesticide injection simulations for enhancing event detection in water distribution systems.
abstract: As a complementary step towards solving the general event detection problem of water distribution systems, injection of the organophosphate pesticides, chlorpyrifos (CP) and parathion (PA), were simulated at various locations within example networks and hydraulic parameters were calculated over 24-h duration. The uniqueness of this study is that the chemical reactions and byproducts of the contaminants' oxidation were also simulated, as well as other indicative water quality parameters such as alkalinity, acidity, pH and the total concentration of free chlorine species. The information on the change in water quality parameters induced by the contaminant injection may facilitate on-line detection of an actual event involving this specific substance and pave the way to development of a generic methodology for detecting events involving introduction of pesticides into water distribution systems. Simulation of the contaminant injection was performed at several nodes within two different networks. For each injection, concentrations of the relevant contaminants' mother and daughter species, free chlorine species and water quality parameters, were simulated at nodes downstream of the injection location. The results indicate that injection of these substances can be detected at certain conditions by a very rapid drop in Cl2, functioning as the indicative parameter, as well as a drop in alkalinity concentration and a small decrease in pH, both functioning as supporting parameters, whose usage may reduce false positive alarms.
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel. Electronic address: t2rafi@gmail.com.
authors.forename: Rafi
authors.initials: R
authors.lastname: Schwartz
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel. Electronic address: agori@tx.technion.ac.il.
authors.forename: Ori
authors.initials: O
authors.lastname: Lahav
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel. Electronic address: ostfeld@tx.technion.ac.il.
authors.forename: Avi
authors.initials: A
authors.lastname: Ostfeld
mesh_terms: D004390:Chlorpyrifos / Q000032:analysis*; D003198:Computer Simulation; D004784:Environmental Monitoring; D007306:Insecticides / Q000032:analysis; D008962:Models, Theoretical; D010278:Parathion / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality; D014881:Water Supply / Q000032:analysis*
chemical_list: D007306:Insecticides; D014874:Water Pollutants, Chemical; D010278:Parathion; D004390:Chlorpyrifos
keywords: Chlorpyrifos; Contamination events; EPANET-MSX; Event detection; Parathion; Water distribution systems