School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
Biomed Res Int. 2013;2013:365163. doi: 10.1155/2013/365163. Epub 2013 Jun 11.
In this study, adsorption of zinc onto the adsorbent (untreated rice husk and NaOH-treated rice husk) was examined. During the removal process, batch technique was used, and the effects of pH and contact time were investigated. Langmuir isotherm was applied in order to determine the efficiency of NaOH-treated rice husk used as an adsorbent. The zinc adsorption was fast, and equilibrium was attained within 30 min. The maximum removal ratios of zinc for untreated rice husk and NaOH-treated rice husk after 1.5 h were 52.3% and 95.2%, respectively, with initial zinc concentration of 25 mg/L and optimum pH of 4.0. Data obtained from batch adsorption experiments fitted well with the Langmuir isotherm model. Maximum adsorption capacity of zinc onto untreated rice husk and NaOH-treated rice husk was 12.41 mg/g, and 20.08 mg/g respectively, at adsorbent dosage of 1 g/L at 25°C. The nature of functional groups (i.e., amino, carboxyl, and hydroxyl) and metal ion interactions was examined by the FT-IR technique. It was concluded that the NaOH-treated rice husk had stronger adsorption capacity for Zn(2+) compared with the untreated rice husk. The NaOH-treated rice husk is an inexpensive and environmentally friendly adsorbent for Zn(2+) removal from aqueous solutions.
在这项研究中，考察了吸附剂（未经处理的稻壳和 NaOH 处理的稻壳）对锌的吸附作用。在去除过程中，使用了批量技术，并研究了 pH 值和接触时间的影响。应用 Langmuir 等温线来确定 NaOH 处理的稻壳作为吸附剂的效率。锌的吸附速度很快，在 30 分钟内达到平衡。在初始锌浓度为 25mg/L 和最佳 pH 值为 4.0 的条件下，未经处理的稻壳和 NaOH 处理的稻壳在 1.5 小时后的最大锌去除率分别为 52.3%和 95.2%。批量吸附实验得到的数据与 Langmuir 等温线模型拟合良好。在 25°C 下，当吸附剂用量为 1g/L 时，未经处理的稻壳和 NaOH 处理的稻壳对锌的最大吸附容量分别为 12.41mg/g 和 20.08mg/g。通过傅里叶变换红外（FT-IR）技术研究了功能基团（即氨基、羧基和羟基）和金属离子相互作用的性质。结果表明，与未经处理的稻壳相比，NaOH 处理的稻壳对 Zn(2+)具有更强的吸附能力。NaOH 处理的稻壳是一种廉价且环保的吸附剂，可用于从水溶液中去除 Zn(2+)。
