Chlorine has been commonly used as a disinfectant and oxidant in drinking-water supply systems due to its germicidal effectiveness and low cost. However, chlorine can react with natural organic matter (NOM) and produce compounds known as disinfection by-products (DBPs).
In this study, a column filtration technology utilizing activated carbon (AC) as a barrier was developed and applied in the treatment of source water collected from three local communities. Total organic carbon (TOC), as a natural organic matter indicator, is identified as more reliable than ultraviolet (UV) since the UV reading can only reflect the amount of light-sensitive organic matter. Batch test results demonstrate that the use of 0.5 g (AC)/L (water) has the highest adsorption effectiveness and lowest activated carbon cost. Meanwhile, column filtration results indicate that the activated carbon barrier is effective in removing natural organic matter from the source water of Sunnyside, New-Wes-Valley, and Salvage. The follow-up chlorination experiment illustrates that the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) can be considerably reduced after the water is passed through the carbon as a filter medium.
Additionally, it was determined that New-Wes-Valley water supply had a higher potential for THM and HAA concentrations in the disinfection process due to higher concentrations of hydrophobic of natural organic matter molecules (as the greater the hydrophobic properties of the NOM, the higher the concentration of DBPs that result from the disinfection process).
Above all, the cost-effective carbon filtration technology developed in this study can potentially be applied as an affordable water treatment technology.
The full report can be found here.