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过程工程学报 ›› 2021, Vol. 21 ›› Issue (7): 794-806.DOI: 10.12034/j.issn.1009-606X.220204

• 反应与分离 • 上一篇    下一篇

响应曲面法优化木薯酒精污泥基活性炭制备及对没食子酸的吸附性能

张智霖1, 丁磊1,2*, 周强1, 余剑1, 郭昌进1, 张德伟2,3
  

  1. 1. 安徽工业大学建筑工程学院,安徽马鞍山243032
    2. 生物膜法水质净化及利用技术教育部工程研究中心,安徽马鞍山243032
    3. 安徽华骐环保科技股份有限公司,安徽马鞍山243071

  • 收稿日期:2020-06-28 修回日期:2020-09-01 出版日期:2021-07-28 发布日期:2021-07-27
  • 通讯作者: 丁磊 dinglei1978@163.com
  • 基金资助:
    基于燃料沉积演化机制的火烧油层启动与控制;安徽省高校优秀拔尖人才培育项目

Optimization of preparation of cassava alcohol sludge-based activated carbon by response surface methodology and its adsorption properties for gallic acid

Zhilin ZHANG1, Lei DING1,2*, Qiang ZHOU1, Jian YU1, Changjin GUO1, Dewei ZHANG2,3   

  1. 1. School of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan, Anhui 243032, China
    2. Engineering Research Center of BiomembraneWater Purification and Utilization Technology, Ministry of Education, Ma'anshan,
    Anhui 243032, China
    3. Anhui Huaqi Environmental Protection Technology Co. Ltd., Ma'anshan, Anhui 243071, China
  • Received:2020-06-28 Revised:2020-09-01 Online:2021-07-28 Published:2021-07-27

摘要: 以木薯酒精厂生产过程中产生的脱水污泥为原料,采用响应曲面法 Box-Behnken模型优化了木薯酒精污泥基活性炭的制备工艺,同时对最优成品进行一系列表征分析,并将其应用于没食子酸废水的处理研究。活性炭的最优制备条件为活化温度489℃,浸渍时间14 h,活化时间51 min,氯化锌浓度21.53%,该条件下样品的碘吸附值达521.64 mg/g。表征分析显示其表面布有众多孔壁较薄、大小不一的孔洞,金属含量较小,BET比表面积达441.86 m2/g,平均孔径为2.50 nm,拥有丰富的微孔结构,表面富有较多的含氧官能团。考察了活性炭投加量、pH、接触时间、溶液温度对样品去除水中没食子酸的影响。结果表明,样品能够高效去除没食子酸,且随着投加量的增加和pH值降低,没食子酸的去除率呈增长趋势。木薯酒精污泥基活性炭对没食子酸的吸附符合pseudo second-order动力学模型和Freundlich等温模型,最大吸附量为126.72 mg/g。扩散机理显示除颗粒内扩散外也包含液膜扩散过程。热力学分析表明该吸附反应是自发进行的吸热且熵增的过程。本研究将为制备高性能污泥活性炭并应用于高浓度天然有机物废水处理提供理论基础。

关键词: 木薯酒精污泥, 活性炭, 响应曲面法, 没食子酸, 吸附

Abstract: The dewatered sludge from the production process of cassava alcohol plant was used as raw material. Response surface methodology was applied to optimize the preparation of cassava alcohol sludge activated carbon. At the same time, a series of characterization analysis was carried out for the optimal product, which was applied to the treatment of gallic acid wastewater. The results showed that the optimal preparation conditions were: activation temperature of 489℃, impregnation time of 14 h, activation time of 51 min, zinc chloride concentration of 21.53%, the adsorption iodine value under this condition was 521.64 mg/g. The results of characterization to CASAC suggested that the BET surface was found as 441.86 m2/g and the average pore diameter as 2.50 nm. It was full of different sizes of small pores on the carbon surface. The activated carbon owned a low metal content but more oxygen-containing functional group after activation process. The effects of carbon dosage, pH, contact time and solution temperature on the removal of gallic acid from water were investigated. It is suggested that the sample carbon could remove gallic acid efficiently, and the removal rate of gallic acid increased with the increase of carbon dosage and the decrease of pH value. The adsorption of gallic acid by cassava alcohol sludgy-based activated carbon was in line with pseudo second-order kinetics model as well as Freundlich isothermal model. The maximum adsorption capacity was 126.72 mg/g. The diffusion mechanism showed that the adsorption process was influenced by the diffusion of liquid film in addition to the diffusion within particles. Thermodynamic analysis indicated that the adsorption of gallic acid was a spontaneous process of heat absorption and entropy increase. This study provided a theoretical basis for the preparation of high-performance activated sludge and the application of high concentration of natural organic wastewater treatment.

Key words: Cassava alcohol sludge, activated carbon, response surface methodology, gallic acid, adsorption