Department of Environmental Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Environmental Applications of Recycled and Natural Materials Laboratory (EARN), Khon Kaen University, Khon Kaen, 40002, Thailand.
Sci Rep. 2023 Feb 1;13(1):1873. doi: 10.1038/s41598-023-29055-4.
The discharging of lead-contaminated wastewater is a concern because of its toxicity to living organisms and water quality resulting in dangerous water consumption, so it is highly recommended to remove lead from wastewater to be below water quality standards for a safe environment. Zeolite A sugarcane bagasse fly ash powder (ZB), zeolite A sugarcane bagasse fly ash powder mixed iron(III) oxide-hydroxide (ZBF), zeolite A sugarcane bagasse fly ash beads (ZBB), zeolite A sugarcane bagasse fly ash powder mixed iron(III) oxide-hydroxide beads (ZBFB), and zeolite A sugarcane bagasse fly ash beads coated iron(III) oxide-hydroxide (ZBBF) were synthesized and characterized in various techniques. Their lead removal efficiencies were investigated by batch experiments, adsorption isotherms, and kinetics. The specific surface area, pore volume, and pore size of ZB were close values to zeolite A standard (STD), and ZBF had the highest specific surface area and the smallest pore size than others. ZB and ZBF demonstrated crystalline phases whereas ZBB, ZBFB, and ZBBF were amorphous phases. The surface morphology of ZB was a cubic shape similar to STD. ZBF demonstrated an agglomerated formation of ZB and iron(III) oxide-hydroxide whereas ZBFB and ZBBF had sphere shapes with coarse surfaces. Si, Al, O, Fe, Na, Ca, O-H, (Si, Al)-O, HO, and DR were detected in all materials. The surface charges of all zeolite A materials had negatively charged at all pH values, and their surfaces increased more negatively charged with increasing pH value which pH 5 illustrated as the highest negatively charged in all materials. Their lead removal efficiencies were higher than 82%. Langmuir isotherm and pseudo-second-order kinetic models were well explained for their adsorption patterns and mechanisms. Finally, ZBBF is a good offer for applying in industrial wastewater treatment systems because of its easy operation and saving costs than ZBF.
含铅废水的排放令人担忧，因为它对生物体有毒，而且会导致水质变差，从而危及人们的用水安全。因此，强烈建议从废水中去除铅，使其浓度低于水质标准，以确保环境安全。本文合成并采用多种技术对沸石 A 甘蔗渣飞灰粉（ZB）、沸石 A 甘蔗渣飞灰粉混合三价铁氢氧化物（ZBF）、沸石 A 甘蔗渣飞灰珠（ZBB）、沸石 A 甘蔗渣飞灰粉混合三价铁氢氧化物珠（ZBFB）和沸石 A 甘蔗渣飞灰珠负载三价铁氢氧化物（ZBBF）进行了表征。通过批量实验、吸附等温线和动力学研究了它们的除铅效率。ZB 的比表面积、孔体积和孔径与沸石 A 标准（STD）接近，ZBF 的比表面积最高，孔径最小。ZB 和 ZBF 表现出结晶相，而 ZBB、ZBFB 和 ZBBF 则为非晶相。ZB 的表面形态为类似于 STD 的立方形状。ZBF 表现为 ZB 和三价铁氢氧化物的团聚体形成，而 ZBFB 和 ZBBF 具有粗糙表面的球形。所有材料均检测到 Si、Al、O、Fe、Na、Ca、O-H、（Si、Al）-O、HO 和 DR。所有沸石 A 材料的表面电荷在所有 pH 值下均带负电荷，随着 pH 值的增加，其表面带负电荷的程度增加，其中 pH 值为 5 时所有材料的表面带负电荷最多。它们的除铅效率均高于 82%。Langmuir 等温线和准二级动力学模型很好地解释了它们的吸附模式和机制。最后，ZBBF 是一种很有前途的应用于工业废水处理系统的材料，因为它的操作简单，成本低于 ZBF。
