Department of Food Science and Technology, School of Agriculture, Forestry and Natural Environment, Aristotle University, 541 24, Thessaloniki, Greece.
Environ Sci Pollut Res Int. 2021 May;28(19):24230-24244. doi: 10.1007/s11356-019-07277-2. Epub 2019 Dec 21.
Several materials have been investigated for the adsorption of olive mill wastewater phenolic compounds. However, researchers have focused on the development of novel, low-cost, with high adsorption capacity adsorbents, originated from the food industry as by-products. The aim of this work was the investigation of the effectiveness of a juice industry by-product, pomegranate seed, for the adsorption of olive mill wastewater phenols. Furthermore, chemical activation and thermal activation of the adsorbent took place in order to improve total phenols uptake and afterwards, desorption process in hydrochloric acid was studied. After the determination of equilibrium time, the effects of temperature (20-60 °C), solution's pH (4.0-8.0), initial sorbate concentration (50-500 mg/L), sorbent mass concentration (0.01-0.05 g/mL OMW), and sorbent particle size (0.149-1.180 mm) on adsorption yield were studied performing batch experiments. The maximum phenols uptake observed was 92.8% after 10 min, at 30 °C and a pH of 5.0, with an initial sorbate concentration of 162.5 mg/L, a sorbent mass concentration of 0.02 g/mL, and a sorbent particle size of 0.922 mm. Langmuir, Freundlich, and Temkin isotherms were developed for the equilibrium description, while pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were applied to investigate adsorption kinetics. The experimental data were best fitted to the Langmuir model, whereas the kinetic data followed the pseudo-first-order kinetic model. The results of the study were promising indicating that pomegranate seed could be used as a novel and low-cost biosorbent. Graphical abstract.
几种材料已被用于吸附橄榄厂废水中的酚类化合物。然而，研究人员专注于开发新型、低成本、高吸附能力的吸附剂，这些吸附剂源于食品工业的副产品。本工作的目的是研究一种果汁工业的副产品——石榴籽，对橄榄厂废水中酚类物质的吸附效果。此外，对吸附剂进行了化学和热活化，以提高总酚类物质的吸附量，随后研究了在盐酸中的解吸过程。在确定平衡时间后，研究了温度（20-60°C）、溶液 pH 值（4.0-8.0）、初始吸附质浓度（50-500mg/L）、吸附剂质量浓度（0.01-0.05g/mL OMW）和吸附剂粒径（0.149-1.180mm）对吸附率的影响，通过分批实验进行。在 30°C 和 pH 值为 5.0 的条件下，初始吸附质浓度为 162.5mg/L，吸附剂质量浓度为 0.02g/mL，吸附剂粒径为 0.922mm 时，观察到最大吸附率为 92.8%，吸附时间为 10min。建立了Langmuir、Freundlich 和 Temkin 等温线来描述平衡，同时应用伪一级、伪二级和内扩散模型来研究吸附动力学。实验数据最符合 Langmuir 模型，而动力学数据则符合伪一级动力学模型。研究结果很有前景，表明石榴籽可用作新型、低成本的生物吸附剂。
