(1. 華南師范大學 化學與環(huán)境學院 環(huán)境理論化學省部共建教育部重點實驗室,廣州 510006;
2. 廣東省環(huán)境科學研究院,廣州 510045)
摘 要: 采用異相合成法,以硅膠為基質、氨基硫脲為功能試劑,通過硅烷偶聯(lián)劑連接制備出一種新型吸附材料。利用FT-IR、BET、TG與XRD等分析技術對材料的性質進行表征,并進一步研究其對Pd2+的動態(tài)吸附性能。結果表明:與未改性的硅膠相比,經氨基硫脲改性后的硅膠對Pd2+的吸附性能得到大幅度提升;Thomas模型能夠準確地反映吸附過程特征,其相關性系數均大于0.930。在給定的實驗條件下,其動態(tài)最大吸附容量為0.121 mmol/g,最大回收率為55.91%;提高溶液初始濃度和吸附柱高度,或者降低流速,可提高材料的飽和吸附容量;材料經過5次循環(huán)使用后,吸附能力基本保持不變,可重復利用。
關鍵字: 硅膠;氨基硫脲;Pd2+;動態(tài)吸附
(1. Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education,
School of Chemistry and Environment, South China Normal University, Guangzhou 510006, China;
2. Guangdong Provincial Academy of Environmental Science, Guangzhou 510045, China)
Abstract:A novel thiosemicarbazide modified silica gel (SG-TSC) was prepared and characterized by Fourier transform infrared spectroscopy (FT-IR), specific surface area (BET), thermogravimetric (TG), X-ray diffraction (XRD), and so on. The property of SG-TSC of adsorbing Pd2+ from aqueous solution was studied in fixed-bed column. The results show that the adsorption ability of thiosemicarbazide modified silica gel for Pd2+ is enhanced obviously. The Thomas model is found to be suitable for describing the dynamic adsorption process with correlation coefficient more than 0.930. The dynamic highest loading capacity and recovery rate are 0.121 mmol/g and 55.91% under the specified experimental conditions. The dynamic saturation adsorption capacities increase with the increase of both influent metal concentration and bed height, but decrease with increase of flow rate. The adsorption capacity of the adsorbent is found to be apparently constant even after its repeating use for 5 cycles. The SG-TSC can be used as an adsorbent for recovery of Pd2+ ions from aqueous solution.
Key words: silica gel; thiosemicarbazide; Pd2+; dynamic adsorption


