粉末活性炭对水中嗅味物质IPMP和IBMP的吸附特性

安娜¹，谢茴茴¹，高乃云¹，楚文海¹，张可佳²，蒋金¹

(1. 同济大学 污染控制与资源化研究国家重点实验室，上海，200092；
2. 浙江大学 建筑工程学院(紫金港校区)，浙江 杭州，310058)

摘 要：研究粉末活性炭(PAC)对水中嗅味物质2-甲氧基-3-异丙基吡嗪(IPMP)和2-甲氧基-3-异丁基吡嗪(IBMP)的吸附特性，考察pH、共存离子、本底值和预氯化对吸附作用的影响，并分析吸附动力学和等温吸附模型。研究结果表明：PAC对IPMP和IBMP吸附效果较好，当投加量为25 mg/L时，对IPMP和IBMP的去除率分别为88.74%和95.31%， IBMP比IPMP更容易被吸附；在试验浓度范围内，吸附等温线符合修正的Freundlich方程，吸附速率符合二级反应动力学模型，以化学吸附为主；pH对吸附有一定影响，强酸性环境对吸附有明显的抑制作用，最佳吸附pH为10；对于IBMP，共存离子均有利于吸附；PAC对于IPMP，Ca²⁺ 有利于吸附，Na⁺和Cl^-不利于吸附；在原水中，两者的吸附容量明显降低，主要是小分子有机物产生竞争吸附；余氯对PAC吸附IPMP和IBMP有明显抑制作用；随着氯质量浓度增大，抑制作用加强。

关键词：粉末活性炭；嗅味物质；2-甲氧基-3-异丙基吡嗪；2-甲氧基-3-异丁基吡嗪；预氯化

Adsorption characteristics of taste and odor compounds IPMP and IBMP by powder activated carbon in aqueous system

AN Na¹, XIE Hui-hui¹, GAO Nai-yun¹, CHU Wen-hai¹, ZHANG Ke-jia², JIANG Jin¹

(1. State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China;
2. College of Civil Engineering and Architecture, Zhejiang University (Zijingang Campus), Hangzhou 310058, China)

Abstract:The adsorption characteristics of powdered activated carbon (PAC) for two taste and odor compounds 2-isopropyl-3-methoxy pyrazine (IPMP) and 2-isobutyl-3-methoxy pyrazine (IBMP) in drinking water were investigated. The effects of pH, co-existed anions, background water and pre-chlorination on adsorption, adsorption kinetics and adsorption isotherm models were studied. The results show that the adsorption of IPMP and IBMP by PAC works well, and the removal rates are 88.74% and 95.31% respectively with the dosage of 25 mg/L. IBMP is more easily absorbed than IPMP. The adsorption isotherm fits the amendatory Freundlich equation best, and the adsorption process follows second order kinetics in the range of experimental concentration, chemical adsorption mainly. Strong acidic condition has negative effect on adsorption, and the best pH value is 10. Co-existed anions are good for adsorption of IBMP, but for IPMP, Ca²⁺ is beneficial and Na⁺, and Cl^- is unfavorable. The adsorption capacities in raw water significantly decrease due to the competitive adsorption effects of small organic compounds. Adsorption of IPMP and IBMP by PAC is significantly inhibited by residual chlorine, and the inhibition is strengthened with the increase of Cl₂ concentration.

Key words:powdered activated carbon; taste and odor compounds; 2-isopropyl-3-methoxy pyrazine; 2-isobutyl-3- methoxy pyrazine; pre-clorination