Acta Scientiarum Naturalium Universitatis Pekinensis ›› 2017, Vol. 53 ›› Issue (6): 1122-1131.DOI: 10.13209/j.0479-8023.2017.130

• Orginal Article • Previous Articles     Next Articles

Single and Competitive Adsorption of Cu(Ⅱ), Pb(Ⅱ), Ni(Ⅱ) and Cd(Ⅱ) onto Biochar

Qi WANG, Binwei WANG, Guangcai TAN, Nan XU()   

  1. Shenzhen Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055
  • Received:2016-05-26 Revised:2016-06-07 Online:2017-11-20 Published:2017-11-20

生物炭对Cu(Ⅱ)、Pb(Ⅱ)、Ni(Ⅱ)和Cd(Ⅱ)的单一及竞争吸附研究

王棋, 王斌伟, 谈广才, 许楠()   

  1. 深圳市重金属污染控制与资源化重点实验室, 北京大学深圳研究生院环境与能源学院, 深圳 518055
  • 基金资助:
    农业部面源污染控制重点实验室开放基金(2014-37)资助

Abstract:

Two kinds of materials including corn stalks and diary manure were used to produce the biochars (BC and DMBC) by pyrolysing at temperature of 500ºC under the protection of nitrogen atmosphere. The single and competitive adsorption characteristics of Cu2+, Pb2+, Ni2+ and Cd2+ ions onto these biochars were investigated to reveal the interaction among the metal ions on the biochar. Experimental results show that the biochars have different elemental composition. BC has a larger specific surface area, and DMBC has a bigger average pore diameter. For the single metal adsorption, the kinetics on BC are similar, but obvious differences of adsorption rates were observed on DMBC. Langmuir isotherm model well fits the sorption data of the four metal ions, and the order of sorption capacity is Pb2+>Cu2+>Cd2+>Ni2+. Through the competitive adsorption experiments it is found that the competitive sorption capacity of Pb2+ is the strongest, and Cu2+ follows, while the sorption of Ni2+ and Cd2+ are weaker and easy to be suppressed by other divalent metal ions.

Key words: biochar, single adsorption, competitive adsorption, divalent metal ion

摘要:

分别以玉米秸秆、牛粪为原料, 在500ºC氮气保护的无氧气氛下热解生成玉米秸秆生物炭(BC)和牛粪生物炭(DMBC), 分别探讨两种生物炭对水溶液中4种二价重金属离子(Cu2+, Pb2+, Ni2+和Cd2+)的单一吸附效果, 并进行4种重金属在生物炭上的竞争吸附实验, 探讨金属离子间在生物炭上的相互作用关系。结果显示, 两种生物质原料具有不同的元素组成, BC具有较大的比表面积, DMBC的平均孔径更大。在单一吸附过程中, BC对金属的吸附动力学过程具有相似性, 而DMBC对不同金属的吸附速率差异较大。4种重金属离子在生物炭上的等温吸附过程可以用Langmuir方程较好地拟合, 吸附容量的顺序为: Pb2+>Cu2+>Cd2+>Ni2+。通过金属之间的竞争吸附实验, 发现在生物炭上Pb2+的竞争吸附能力最强, Cu2+次之, 而Ni2+和Cd2+竞争吸附能力较弱, 其吸附过程容易受到其他二价金属离子的抑制。

关键词: 生物炭, 单一吸附, 竞争吸附, 二价金属离子