Shi Bingfang, Zuo Weiyuan, Zhang Jinlei, Tong Haijuan, Zhao Jinhe
J Environ Qual. 2016 May;45(3):984-92. doi: 10.2134/jeq2014.12.0533.
The removal of heavy metals, especially from wastewater, has attracted significant interest because of their toxicity, tendency to bioaccumulate, and the threat they pose to human life and the environment. Many low-cost sorbents have been investigated for their biosorption capacity toward heavy metals. However, there are no reports available on the removal of Pb(II) from aqueous solution by of L. seed husk ash. In this work, use of seed husk ash for the removal of Pb(II) from wastewater was investigated as a function of contact time and the initial pH of the solution. Kinetics and equilibrium constants were obtained from batch experiments. Our study shows that the adsorption process follows pseudo-second-order kinetics. Moreover, the Langmuir absorption model gave a better fit to the experimental data than the Freundlich equation. The maximum adsorption capacity of the husk ash was 263.10 mg g at 298 K and pH 5.0, and this is higher than the previously reported data obtained using other sorbents. The results obtained confirm that seed husk ash is an effective sorbent for the removal of Pb(II) from aqueous solution. Analysis of infrared spectra of the husk ash after absorption of Pb(II) suggested that OH, C=O, C-O, Si-O-Si, and O-Si-O groups were important for the Pb(II) ion removal. Moreover, practical tests on this biosorbent for Pb(II) removal in real wastewater samples successfully demonstrated that seed husk ash constitutes an efficient and cost-effective technology for the elimination of heavy metals from industrial effluent.
由于重金属具有毒性、生物累积倾向以及对人类生命和环境构成威胁，从废水中去除重金属，尤其是去除重金属，已引起了人们的极大关注。许多低成本吸附剂已被研究其对重金属的生物吸附能力。然而，目前尚无关于利用L.种子壳灰从水溶液中去除Pb(II)的报道。在这项工作中，研究了利用种子壳灰从废水中去除Pb(II)与接触时间和溶液初始pH值的关系。通过批量实验获得了动力学和平衡常数。我们的研究表明，吸附过程遵循准二级动力学。此外，与Freundlich方程相比，Langmuir吸附模型对实验数据的拟合效果更好。在298 K和pH 5.0条件下，壳灰的最大吸附容量为263.10 mg/g，这高于先前报道的使用其他吸附剂获得的数据。所得结果证实，种子壳灰是从水溶液中去除Pb(II)的有效吸附剂。对吸附Pb(II)后的壳灰进行红外光谱分析表明，OH、C=O、C-O、Si-O-Si和O-Si-O基团对Pb(II)离子的去除很重要。此外，在实际废水样品中对这种生物吸附剂去除Pb(II)的实际测试成功表明，种子壳灰构成了一种从工业废水中去除重金属的高效且经济有效的技术。
