Membrane Research Laboratory, Department of Chemical Engineering, National Institute of Technology, Tiruchirappalli, 620015, India.
Membrane Research Laboratory, Department of Chemical Engineering, National Institute of Technology, Tiruchirappalli, 620015, India.
Environ Res. 2022 Jun;209:112820. doi: 10.1016/j.envres.2022.112820. Epub 2022 Jan 25.
Lignin valorization is essential in proposing an economic perspective as a raw material for valuable compounds. The bio-refineries require adequate processing to improve the high purity of lignin. Meanwhile, nanofiltration is fascinated attention to obtain high purity value-added products. The effect of alumina nanoparticles on the fabrication of mixed matrix membranes (MMM) has contributed to improvising filtration performance. However, incorporating nanoparticles is a significant issue regarding appropriate size and shape integrated into membrane for better filtration efficiency. The influence of shapes of alumina nanoparticles has been investigated into polysulfone (PSf) membranes for salt and lignin separation. The morphology of alumina was tailored with spindle, cubic, and spherical shapes synthesized at a different calcination temperature of 250, 500, 700 and 900 °C, respectively. The phase transitions were confirmed in X-ray diffraction (XRD) analysis, and the shape of the nanoparticles was observed in a high-resolution transmission electron microscope (HRTEM). The separation efficiency of membranes was tested with salt rejection using sodium sulfate, calcium chloride, potassium sulfate, and sodium chloride. The lignin was extracted from prehydrolysed sawdust, and the synthetic lignosulfonic acid sodium salt solution was separated. The higher lignin rejection of 98.6% and 97.9% were obtained for cubic shaped gamma phase alumina mixed matrix membrane. The high rejection of lignin occurred due to narrow pores channels that could resist the transfer of lignin through the membrane. The results proved that the controllable organization of PSf/alumina mixed matrix membranes could apply for lignocellulose compounds with good efficiency.
木质素的增值对于提出作为有价值化合物原料的经济观点至关重要。生物精炼厂需要进行适当的处理以提高木质素的高纯度。同时，纳滤吸引了人们的注意，以获得高纯度的增值产品。氧化铝纳米粒子对制备混合基质膜（MMM）的影响有助于改善过滤性能。然而，将纳米粒子掺入膜中以获得更好的过滤效率是一个涉及适当尺寸和形状的重大问题。氧化铝纳米粒子的形状对聚砜（PSf）膜中盐和木质素分离的影响进行了研究。通过在不同的煅烧温度 250、500、700 和 900°C 下分别合成纺锤形、立方体形和球形，对氧化铝的形态进行了调整。通过 X 射线衍射（XRD）分析证实了相转变，并用高分辨率透射电子显微镜（HRTEM）观察了纳米粒子的形状。通过用硫酸钠、氯化钙、硫酸钾和氯化钠进行盐截留测试来测试膜的分离效率。木质素是从预水解木屑中提取的，分离出合成的木质素磺酸钠溶液。立方相γ相氧化铝混合基质膜的木质素截留率高达 98.6%和 97.9%。木质素的高截留率是由于窄的孔道可以阻止木质素通过膜的传递。结果证明，PSf/氧化铝混合基质膜的可控组织可以有效地应用于木质纤维素化合物。
