摘要
采用批量实验研究了荔枝皮对水中重金属Ni2+吸附的影响因素(如接触时间、pH和吸附剂量)、吸附等温线、吸附动力学和吸附热力学等,并讨论了其吸附机理。结果表明,未改性荔枝皮和改性荔枝皮对Ni2+的吸附平衡时间均为30min;最适pH为6.0~7.0;最佳吸附剂量均为20 g/L。吸附过程均能用Langmuir和Freundlich等温线模型来很好地描述,且均符合假二次动力学模型。改性荔枝皮和未改性荔枝皮对Ni2+的最大比吸附量分别为11.88和5.19 mg/g。此外,热力学研究结果表明,未改性荔枝皮和改性荔枝皮吸附Ni2+均属于非自发的放热过程。
The influencing factors(such as contact time,pH and adsorbent dose),adsorption isotherm models,kinetics and thermodynamics of Ni2 +adsorption by litchi pericarps were investigated by batch assays, and the adsorption mechanism was also discussed. The results showed that the adsorption equilibrium time,optimal pH and adsorbent dose were all 30 min,6. 0 ~ 7. 0 and 20 g/L for the raw and modified litchi pericarp,respectively. The adsorption processes of Ni2 +on the raw and modified litchi pericarp could be well described by Langmuir and Freundlich models,and adsorption kinetics conformed to pseudo-second-order model. The maximum adsorption capacities of Ni2 +in aqueous solution were 11. 88 and 5. 19 mg/g for the modified and raw litchi pericarp,respectively. Additionally,the thermodynamics results showed that the adsorption processes of Ni2 +by the raw and modified litchi pericarp were all non-spontaneous and exothermic.
出处
《环境工程学报》
CAS
CSCD
北大核心
2014年第6期2277-2282,共6页
Chinese Journal of Environmental Engineering
基金
国家自然科学青年基金项目(51208174)
关键词
荔枝皮
吸附
NI2+
litchi pericarp
adsorption
Ni2+