Characterization and Treatment of Urban Runoff

Abstract

The first part of the thesis focuses on the surface runoff occurring from a typical construction area in Singapore. Runoff samples were collected from 10 different storm events spanning one year over different stages of construction. The aim of study was to analyze the first flush of nutrients and trace metals from this site. It was found that most nutrients and trace metals exhibited a first flush phenomenon although on some occasions a dilution effect was also observed.This was followed by the development of a possible treatment technique to remove nutrients from water. The effectiveness of Granular Activated Carbon (GAC) as well as zinc chloride modified GAC was investigated and compared for their efficient removal of nutrients from water. The study revealed that the surface modified GAC proved to have a better adsorptive capacity than normal GAC without any preference to nitrate or phosphate ions.