Anootnara Talkul Kuster and Anthony Charles Kuster

DOI: 10.14456/sjst-psu.2017.54

pp. 497 - 507

Abstract

The purpose of this research was to compare five water quality parameters (BOD, TSS, total zinc, TKN, and fecal
coliform) in wet-weather flow of a combined sewer catchment against dry-weather flow, while making a distinction between
direct and delayed inflow, which has often not been made. Correlations and event mean concentrations (EMCs) were also
calculated. A total of 38 samples were collected from Khon Kaen’s combined sewer system between March and August 2015.
Concentrations in direct inflow of three parameters: total zinc ( x = 0.24 mg/L, IQR = 0.12-0.34), TSS (240 mg/L, 176-356),
and BOD (59.7 mg/L, 42.4-77.8) were higher than delayed inflow ( x = 0.04 mg/L, 36 mg/L, and 23.7 mg/L, respectively).
Concentrations of delayed inflow were similar to or lower than dry-weather flow. Pollutant concentrations for particulatebased pollutants were much higher during the direct inflow phase of rain events compared to the delayed inflow phase.
Dissolved-phased nutrients, however, were not different.