Citation: | LIANG Kai, LUO Yinghua, PENG Meixun, ZHAO Hongwei. Study on Effects of Acid Modification or Heat Treatment on Formaldehyde Adsorption of Sepiolite in Air and the Related Mechanisms[J]. Conservation and Utilization of Mineral Resources, 2022, 42(2): 120-125. doi: 10.13779/j.cnki.issn1001-0076.2022.02.016 |
In order to regenerate HCHO adsorption, both types of sepiolite stirred at 15% HCl for 8.5 h or heated at 100~600 ℃ for 5 h were applied to static adsorption experiments in high concentration HCHO to research the HCHO adsorption effects, and X-ray diffraction, infrared adsorption spectroscopy, thermogravimetry, BET specific surface area analysis and scanning electronic microscopy were adopted to research the adsorption mechanisms. The results revealed that the sepiolite heated at ≤450 ℃ held favorable HCHO adsorption capacities, while those modified by acid or heated at ≥500 ℃ had significantly reduced HCHO adsorption capacities. It is inferred that the crystalliferous water in sepiolite could chemically absorb HCHO and the structural microhole, basically composed of zeolite holes, could be occupied by HCHO through physical adsorption. Subjected to acid modification, large part of Al3+ and Mg2+ in the sepiolite structure were replaced by H+, then the crystalliferous water bonded with Mg2+ lost and the structural layers were dismantled. The micropore area significantly reduced due to the structural microhole collapsed, and the HCHO absorption capacity drastically declined. The sepiolite heated at ≥500 ℃ lost its HCHO adsorption ability for the sepiolite phase was decomposed with the crystalliferous water completely lost and the structural microhole collapsed also. The research affirmed continuously removing HCHO in the air with sepiolite by heating at reasonable temperature that could not only eliminate the absorbed HCHO and regenerate the adsorption capacity.
[1] | 崔维怡, 王希越, 谭乃迪. 甲醛催化氧化反应机理的研究进展[J]. 精细化工, 2020, 37(10): 1978-1985. CUI W Y, WANG X Y, TAN N D. Research progress in the mechanism of catalytic oxidation of formaldehyde[J]. Fine Chemicals, 2020, 37(10): 1978-1985. |
[2] | 张永航. 空气中甲醛净化处理的研究进展[J]. 广州化工, 2020, 48(22): 24-27+89. ZHANG Y H. Research progress on formaldehyde purification in air[J]. Guangzhou Chemical Industry, 2020, 48(22): 24-27+89. |
[3] | 黄慧娟, 尚莉莉, 马建锋, 等. 锰氧化物催化分解室内甲醛的研究进展[J]. 材料导报, 2019, 33: 521-525. HUANG H J, SHANG L L, MA J F, et al. Advances on catalytic oxidation of formaldehyde by manganese oxide[J]. Materials Reports, 2019, 33: 521-525. |
[4] | 王濮, 潘兆橹, 翁玲宝, 等. 系统矿物学(中册)[M]. 北京: 地质出版社, 1987: 419-421. WANG P, PAN Z L, WEN L B, et al. Systemic Mineralogy(middle volume)[M]. Beijing: Geology Press, 1987: 419-421. |
[5] | CORUH S, GEYIKEI F, ELEVLI S. Adsorption of neutral red dye from an aqueous solution onto natural sepiolite using full factorial design[J]. Clays and Clay Minerals, 2011, 59(6): 617-625. doi: 10.1346/CCMN.2011.0590607 |
[6] | 鲁旖, 仇丹, 章凯丽. 海泡石吸附剂的应用研究进展[J]. 宁波工程学院学报, 2016, 28(1): 17-22. LU Y, QIU D, ZHANG K L. Research progress on application of sepiolite absorbent[J]. Journal of Ningbo University of Technology, 2016, 28(1): 17-22. |
[7] | 贺洋. 低品质海泡石提纯及吸附性能研究[J]. 非金属矿, 2019, 42(4): 56-57. HE Y. Purification of low quality sepiolite and adsorption capacity research[J]. Non-Metallic Mines, 2019, 42(4): 56-57. |
[8] | 周鹏. 改性海泡石制备及其对甲醛的吸附行为研究[D]. 武汉: 武汉理工大学, 2019. ZHOU P. Preparation of modified sepiolite and adsorption behavior to formaldehyde[D]. Wuhan: Wuhan University of Technology, 2019. |
[9] | 宋公保, 彭同江, 董发勤, 等. 海泡石的红外光谱研究[J]. 矿物学报, 1998, 18(4): 525-532. doi: 10.3321/j.issn:1000-4734.1998.04.019 SONG G B, PENG T J, DONG F Q, et al. Infrared spectrometric study of sepiolite[J]. Acta Mineralogica Sinica, 1998, 18(4): 525-532. doi: 10.3321/j.issn:1000-4734.1998.04.019 |
[10] | 王艳, 王多君, 易丽. 空气气氛中滑石的热分解动力学试验研究[J]. 中国科学院大学学报, 2015, 32(1): 70-73. WANG Y, WANG D J, YI L. Experimental study on thermal decomposition kinetics of talc under the condition of air[J]. Journal of University of Chinese Academy of Sciences, 2015, 32(1): 70-73. |
[11] | 聂利华, 刘德忠, 姚守拙. 海泡石的物化特性[J]. 湖南大学学报, 1990, 17(1): 106-113. NIE L H, LIU D Z, YAO S C. Physichemieal Properties of sepiolite of Liuyang County in Hunan Province[J]. Journal of Hunan University, 1990, 17(1): 106-113. |
[12] | 梁伟朝. 海泡石改性及其吸附挥发性有机物机理与过程研究[D]. 石家庄: 河北科技大学, 2016. LIANG W C. Adsorption mechanism and process of VOCs on Modified sepiolite[D]. Shijiazhuang: Hebei University of Science and Technology, 2016. |
XRD patterns of adsorbents
FTIR spectrum for absorbents
TGA curves for sepiolite sample and the acidized sepiolite
BET surface areas, micropore areas and exteral surface areas for adsorbents
Adsorption average pore diameter and average particle size for absorbents
SEM morphologies for sepiolite (a, b) and acidized sepiolite(c, d)
Effects of sepiolite/HCHO mass ratio on adsorption capacity
Effects of HCHO concentration on adsorption capacity
Effects of adsorption time on adsorption capacity
Effects of heating temperature on adsorption capacity