Removal of dissolved natural organic matter in granular activated carbon column – application on Catalan drinking water treatment plant

In this study, granular activated carbon (GAC) adsorption on dissolved natural organic matter (DNOM) was studied. Experiments were divided into two stage. At first stage experiments, the effects of temperature, pH, adsorbent amount, influent organic matter concentrations on treatment efficiency, and adsorption isotherms in GAC adsorption on DNOM process, were tried to be defined. On the conclusions, it was observed that adsorption efficiency increased within increasing temperature and adsorbent amount, and decreasing pH. Best efficiency was reached at 35 0C as 91 %, at pH 4.0 as 91 % and at 0,8 gr/L adsorbent amount as 91 %. Equilibrium time was detected as 60 minutes. Langmuir R2 value was found as 0,8905 and Freundlich R2 value was found as 0,9739. Also it was detected that multi-layer adsorption and film diffusion were found to be effective in adsorption process. At second stage experiments, the effects of adsorbent amount, bed depth, empty bed contact time (EBCT), and influent organic matter concentrations on treatment efficiency of DNOM, were studied in fixed bed-continious flow GAC columns and datas were exhibited. Data were used in model equations, and full-scale adsorption column design parameters were calculated. According to calculations, for 250000 m3 flow rate and 2,13 mg/L DNOM raw water; 15 numbers columns which have 4,33 m radius - 7 m bed depth, full operation time 22 days specifications, should be built for efficiency treatment of inlet water. Column outflow target DNOM level was selected as 1,5 mg/L according to previous regulations.