Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (5): 1375-1383.doi: 10.1016/j.cjche.2020.02.012

• Energy, Resources and Environmental Technology • Previous Articles     Next Articles

Single and competitive adsorption affinity of heavy metals toward peanut shell-derived biochar and its mechanisms in aqueous systems

Rui Shan1,2,3,4, Yueyue Shi1,5, Jing Gu1,2,3,4, Yazhuo Wang1,2,3,4, Haoran Yuan1,2,3,4   

  1. 1 Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;
    2 Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou), Guangzhou 511458, China;
    3 CAS Key Laboratory of Renewable Energy, Guangzhou 510640, China;
    4 Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;
    5 Nano Science and Technology Institute, University of Science and Technology of China, Suzhou 215123, China
  • Received:2019-05-16 Revised:2020-01-28 Online:2020-05-28 Published:2020-07-29
  • Contact: Haoran Yuan
  • Supported by:
    This research was financially supported by State's Key Project of Research and Development Plan, China (y804091001), National Natural Science Foundation of China (51776211), Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML2019ZD0101).

Abstract: Converting peanut shells into biochar by pyrolysis was considered an environmentally friendly and efficient method for agricultural solid waste disposal. The properties of peanut shell-derived biochar (PBC) under different temperature and its adsorption capacity of heavy metals were investigated. It was found that PBC400 exhibited the highest cumulative capability for heavy metals elimination in single solute because of its high specific surface area and rich functional groups. Furthermore, the competitive adsorption revealed that PBC had a substantial difference in adsorption affinity from diverse heavy metal ions, sorption capacity decreased as Pb2+ > Cu2+ > Cd2+ > Ni2+ > Zn2+, which was lower than in a single solute. The adsorption process using selected biochar was optimized with respect to pH, reaction time, adsorbent dose, and initial concentration of heavy metals. The kinetic data was well fitted with PSO model, and the Langmuir model was adopted for adsorption equilibrium data in both cases of single solutes and mixed solutes for all heavy metals, which indicated that the removal course was primarily explained by monolayer adsorption, and chemical adsorption occupied an important role. Therefore, peanut shells derived biochar could be a potential and green adsorbent for wastewater treatment.

Key words: Pyrolysis, Biochar, Heavy metal removal, Competitive adsorption