Department of Physics, Kangwon University, 1 Kangwondaehak-gil, Chuncheon-si, Gangwon-do, 24341, Republic of Korea.
Department of Health and Environment, Catholic Kwandong University, Beomil-ro 579, Gangneung-si, Gandwon-do, 25601, Republic of Korea.
J Environ Manage. 2018 Mar 1;209:382-392. doi: 10.1016/j.jenvman.2017.12.080.
The aim of this study was to investigate heavy metal removal using waste biomass adsorbent, persimmon leaves, in an aqueous solution. Persimmon leaves, which are biomaterials, have a large number of hydroxyl groups and are highly suitable for removal of heavy metals. Therefore, in this study, we investigated the possibility of removal of Cu, Pb, and Cd in aqueous solution by using raw persimmon leaves (RPL) and dried persimmon leaves (DPL). Removal of heavy metals by RPL and DPL showed that DPL had a 10%-15% higher removal than RPL, and the order of removal efficiency was found to be Pb > Cu > Cd. The pseudo-second order model was a better fit to the heavy metal adsorption experiments using RPL and DPL than the pseudo-first order model. The adsorption of Cu, Pb, and Cd by DPL was more suitable with the Freundlich isothermal adsorption and showed an ion exchange reaction which occurred in the uneven adsorption surface layer. The maximum adsorption capacity of Cu, Pb, and Cd was determined to be 19.42 mg/g, 22.59 mg/g, and 18.26 mg/g, respectively. The result of the adsorption experiments showed that the n value was higher than 2 regardless of the dose, indicating that the heavy metal adsorption on DPL was easy. In the thermodynamic experiment, ΔG° was a negative value, and ΔH° and ΔS° were positive values. It can be seen that the heavy metal adsorption process using DPL was spontaneous in nature and was an endothermic process. Moreover, as the temperature increased, the adsorption increased, and the affinity of heavy metal adsorption to DPL was very good. This experiment, in which heavy metals are removed using the waste biomass of persimmon leaves is an eco-friendly new bioadsorbent method because it can remove heavy metals without using chemicals while utilizing waste recycling.
本研究旨在探讨利用柿叶这种生物废料吸附剂从水溶液中去除重金属。柿叶作为生物材料，含有大量的羟基，非常适合去除重金属。因此，在本研究中，我们考察了利用生柿叶（RPL）和干柿叶（DPL）从水溶液中去除 Cu、Pb 和 Cd 的可能性。RPL 和 DPL 对重金属的去除实验表明，DPL 的去除率比 RPL 高 10%-15%，且去除效率的顺序为 Pb > Cu > Cd。与准一级动力学模型相比，拟二级动力学模型更适合 RPL 和 DPL 对重金属吸附的实验。DPL 对 Cu、Pb 和 Cd 的吸附更符合 Freundlich 等温吸附模型，表明发生在非均匀吸附表面层的离子交换反应。确定 DPL 对 Cu、Pb 和 Cd 的最大吸附容量分别为 19.42、22.59 和 18.26 mg/g。吸附实验结果表明，无论剂量如何，n 值均高于 2，表明 DPL 对重金属的吸附很容易。在热力学实验中，ΔG°为负值，ΔH°和ΔS°为正值。可以看出，DPL 吸附重金属的过程是自发的，是一个吸热过程。此外，随着温度的升高，吸附增加，重金属对 DPL 的吸附亲和力非常好。本实验利用柿叶的废生物质去除重金属，是一种环保的新型生物吸附剂方法，因为它可以在不使用化学物质的情况下去除重金属，同时利用废物回收。
