The granular activated carbon adsorption isothermal and adsorption bed design application to remove chlorine in hemodialysis Water

• Main Authors: Zhi-Da Wang, 王子達
• Other Authors: Yen-Lin Chang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/48253110144617154353

碩士 === 中原大學 === 生物醫學工程研究所 === 99 === Abstract Chlorine/chloramine residues in water have a considerable threat to hemodialysis patients. According to relevant literature, chlorine/chloramine residues in water are related to the hemolysis phenomenon during the treatment of dialysis patients. In addition, among all the water treatment procedures of dialysis, only the activated carbon adsorption procedure can effectively eliminate chlorine/chloramine residues in water to reduce the hemolysis phenomenon of dialysis patients. The purpose of this study is to estimate the breakthrough time and filling height of the activated carbon adsorption bed by the mathematical models of the isotherm adsorption and fixed bed adsorption theories, in order to effectively remove the chlorine/chloramine residues in water and reduce the occurrence of hemolysis phenomenon of the dialysis patients during dialysis. This study conducted three types of tests using the clinically used activated carbon adsorbents. The first type test was the adsorption speed test using a fixed amount of activated carbon; the secondary test was the isotherm adsorption test of using different amounts of activated carbon in sodium hypochlorite solution of given volume, and conducted regression analysis and relevant analysis of the adsorption results to find the appropriate isotherm adsorption model; the third type of test was the fixed bed adsorption simulation test with carbon adsorption device of scaled dwon specifications for clinical use, and the adsorption results were analyzed using the fixed bed adsorption mathematical theoretical model. The results suggested that the clinically used activated adsorbents can effectively reduce the chlorine/chloramine residues in water in 5 min, and completely eliminate them in 15 min. The regression analysis of the isotherm adsorption testing results found that the clinically used activated carbon adsorbent can facilitate adsorption with the adsorption index (1/n) at 0.52. A comparison with the relevant analysis results of Langmuir and Freundlich found that the adsorbent can better fit the Freundlich isotherm adsorption model with correlation coefficient at 0.91. The fixed bed adsorption simulation results suggested that the breakthrough time of the column adsorption were 13 hr and the saturated adsorption time was 21 hr. By the mathematical model of the fixed bed adsorption theory, the column adsorption belt (δ) was 0.02 m, and the column adsorption belt moving speed (ν) was 3.04 x 10-3(m/hr), number of moving units (Nf) was 3.61 and the total capacity (Kfav) was 9925.23(1/hr). By inputting different theoretical solution concentrations into the theoretical mathematical model, it was confirmed by calculation that the theoretical adsorption time and testing time of the model have good correlation. The relevant parameters of the clinically used carbon adsorption device were input into the theoretical mathematical model to obtain the theoretical filling bed height (Z) of theoretical scaling up as 0.87 m, which was a gap of 0.13 m from the filling height bed height of 1 m, as provided by the manufacturer. The theoretical breakthrough time was 8760 hr, which was consistent with the manufacturer-suggested replacement time. By isotherm adsorption test and the fixed bed adsorption theoretical mathematical model, the breakthrough time and filling height of the activated carbon filling bed can be estimated to effectively eliminate the chlorine/chloramine residues in water to reduce the occurrence of hemolysis phenomenon of dialysis patients during dialysis.