| 热水环境中Na+活化斜发沸石吸附钙离子除硬过程研究 |
| 摘要点击 2191 全文点击 984 投稿时间：2014-06-27 修订日期：2014-09-13 |
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| 中文关键词 斜发沸石 活化 热水 吸附 钙离子 |
| 英文关键词 clinoptilolite activation hot-water adsorption calcium ion |
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| 中文摘要 |
| 本实验以Na+活化天然斜发沸石为吸附剂模拟研究其在工业热水环境中对钙离子(Ca2+)吸附除硬,考察了吸附剂的活化/再生条件、溶液pH等影响因素,并对Ca2+吸附动力学和热力学行为进行了分析探讨. 结果表明:①该吸附过程具有准二级动力学特征且更符合Langmuir吸附等温模型; ②温度升高可有效提升Ca2+吸附效率,而对其最大吸附量影响较小; ③过程属化学吸附且为自发、吸热的熵增反应; ④建议溶液pH控制在6~10之间,且当初始Ca2+浓度小于20 mg·L-1时活化斜发沸石可再生高效使用9次以上. 研究证明活化斜发沸石是一种工业热能动力系统高温在线除硬的理想吸附剂. |
| 英文摘要 |
| This work investigated adsorptive removal of calcium ion (Ca2+) by virtue of Na+-conditioned clinoptilolite simulating the process of softening for industrial hot-water system. Influential factors such as the activation/regeneration of sorbent and solution pH were tested. The kinetics/thermodynamics for adsorption of Ca2+were analyzed and discussed. Results showed that: ① The adsorption rate was in good agreement with the pseudo-second order kinetic models, and the process of adsorption better followed the Langmuir model; ② Higher solution temperature allowed an enhanced efficiency on Ca2+ removal, albeit the maximum adsorption capacity of Na+-conditioned clinoptilolite was hardly affected; ③ The process of adsorption was dominated by chemisorption, and also characterized by entropy increase with spontaneous/endothermic nature; ④ Solution temperature was suggested to be controlled within the range of 6 to 10, and more than 9 times of sorbent regeneration could be ensured for an effective adsorption towards Ca2+ with initial concentration less than 20 mg·L-1. It was demonstrated that the activated clinoptilolite should be a promising alternative adsorbent for industrial hot-water softening. |
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