College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
Molecules. 2021 Sep 20;26(18):5690. doi: 10.3390/molecules26185690.
Removing toxic heavy metal species from aqueous solutions is a point of concern in our society. In this paper, a promising biomass adsorbent, the modified waste shrimp shell (MS), for Cu (II) removal was successfully prepared using a facile and simple one-step modification, making it possible to achieve high-efficiency recycling of the waste NaOH solution as the modification agent. The outcome shows that with the continuous increase in pH, temperature and ion concentration, the adsorption effect of MS on Cu (II) can also be continuously improved. Adsorption isotherm and adsorption kinetics were fitted with the Langmuir isotherm model and the pseudo-second-order model, respectively, and the maximum adsorption capacity of Cu (II) as obtained from the Langmuir isotherm model fitting reached 1.04 mmol/g. The systematic desorption results indicated that the desorption rate of Cu (II) in the MS could reach 100% within 6 min, where HNO is used as the desorption agent. Moreover, experiments have proven that after five successive recycles of NaOH as a modifier, the adsorption capacity of MS on Cu (II) was efficient and stable, maintaining tendency in 0.83-0.85 mmol/g, which shows that waste NaOH solution can be used as a modification agent in the preparation of waste shrimp shell adsorbent, such as waste NaOH solution produced in industrial production, thereby making it possible to turn waste into renewable resources and providing a new way to recycle resources.
从水溶液中去除有毒重金属物种是我们社会关注的焦点。本文成功制备了一种有前途的生物质吸附剂，即用简便的一步法改性废弃虾壳（MS），用于去除 Cu（II），使得高效回收作为改性剂的废弃 NaOH 溶液成为可能。结果表明，随着 pH、温度和离子浓度的不断增加，MS 对 Cu（II）的吸附效果也可以不断提高。吸附等温线和吸附动力学分别拟合了 Langmuir 等温线模型和准二级动力学模型，从 Langmuir 等温线模型拟合得到的 Cu（II）最大吸附容量达到 1.04mmol/g。系统解吸结果表明，在 6 分钟内，用 HNO 作为解吸剂，MS 中 Cu（II）的解吸率可达到 100%。此外，实验证明，经过五次连续循环使用 NaOH 作为改性剂，MS 对 Cu（II）的吸附容量是高效稳定的，保持在 0.83-0.85mmol/g 之间，这表明可以将废 NaOH 溶液用作制备废弃虾壳吸附剂的改性剂，例如工业生产中产生的废 NaOH 溶液，从而使废物转化为可再生资源，并为资源回收提供了新途径。
