Samenvatting

Total organic carbon (TOC) is often found in natural water sources, and also may come from (chemical) water treatment processes or from sewage. It may react with disinfectants to produce DBPs (disinfection by-products), which are harmful to water systems and public health. Besides, in industrial systems applying high pressures and temperatures, TOC may convert to acids, which causes corrosion and damage to the plants. Thus, reducing the concentration of TOC is essential in practice. In addition to the traditional chemical treatment technology, IX (ion exchange) resins have become widely accepted and feasible in recent decades. It has the positive ability to remove organic matter with charge (ions).
In order to apply this method and achieve maximum efficiency, it is necessary to know what factors influence the behavior of the IX treatment process. IX is a batch process including operation and regeneration. Ions will be exhausted by unwanted ions, in this case TOC, then it need to be regenerated. This research concentrated on how regenerant concentration (NaOH), contact time and flow rate affect the regeneration part through performing TOC removal experiments. The purpose of the research was to find the optimized regeneration parameters of the resins offered by Evides.
A strong basic anion resin in OH- form and a strong acid cation resin in H+ were used in this research to compare the performance under several experimental conditions. An initial set of experiments with standard regeneration settings determined the baseline settings and residual TOC concentration indicated removal efficiency of resins. After experiments, a response surface model was set up to analyze the relationship among the mass of removed TOC, NaOH concentration and flow rate, and further to find optimal parameters.
The conclusion of this study is that practically, the optimal flow rate is 4 m/h and regenerant (NaOH) concentration is 4% at 20℃. While the theoretical optimal flow rate is 4 m/h, regenerant (NaOH) concentration is 3.5% at 20℃ from response surface model in regeneration phase to achieve the best TOC removal efficiency.