| Title |
A Study on the Parameters of Bed Depth Service Time Equation in Removing NO3 - N by Ion Exchange |
| Authors |
최승일 ; 김정민 ( Suing Il Choi ; Jung Min Kim ) |
| Abstract |
The maximum contamination level of NO₃-N which is known to causes methemoglobinimea to baby at high concentration is set as 10 ㎎/ℓ. Although biological denitrification has been used to remove NO₃-N in wastewater, it may cause some trouble in drinkingh water treatment. An ion exchange process could be an alternative for drinking water treatment. The bed depth-service time equation by Thomas has been used as a design tool to predict and/or evaluate the performance of ion exchange column. To utilize the equation, the kinetic rate constant K₁ and the maximum solid phase concentration q_0 should be determined from the pilot study. However, there has not been enough understanding on the behavior of K₁ and q_0 according to the change of the flow rate and influent concentration. Thus the research has been conducted to investigate the behavior of K₁ and q_0 by the change of influent concentration, flow rate, and the presence of humic acid. A commercially available NO₃-N selective anion exchange resin has been used and the results are summarized as; 1. The influent nitrate concentration has not affected the rate constant K₁ and the maximum solid phase concentration q_0. But the flow rate has changed the rate constant K₁ significantly although its influence on the maximum solid phase concentration q_0 is almost neglegible. 2. The difference in the sodium concentration in the regeneration solution has not affected the maximum solid phase concentration q_0. 3. It seems that the humic acid reduce the rate constant K₁ and increase the maximum solid phase concentration q_0. However the effect of humic acid and other organic matters on the NO₃-N ion exchange should be investigated more thoroughly to reveal the effect clearly. This study has increased the understanding of the behavior of kinetic rate constant K₁ and maximum solid phase concentration q_0 in the Thomas` BDST equation. The result could be used in utilizing the equation for designing ion exchange column, especially for NO₃-N removal. |