Samad Sabrin A, Arafat Abul, Lester Edward, Ahmed Ifty
Advanced Materials Research Group, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
Department of Nuclear Engineering, Faculty of Engineering, University of Dhaka, Dhaka 1000, Bangladesh.
Materials (Basel). 2022 Aug 23;15(17):5809. doi: 10.3390/ma15175809.
Each year about 7.6 million tons of waste glasses are landfilled without recycling, reclaiming or upcycling. Herein we have developed a solvent free upcycling method for recycled glass waste (RG) by remanufacturing it into porous recycled glass microspheres (PRGMs) with a view to explore removal of organic pollutants such as organic dyes. PRGMs were prepared via flame spheroidisation process and characterised using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Mercury Intrusion Porosimetry (MIP) analysis. PRGMs exhibited 69% porosity with overall pore volume and pore area of 0.84 cm/g and 8.6 cm/g, respectively (from MIP) and a surface area of 8 m/g. Acid red 88 (AR88) and Methylene blue (MB) were explored as a model source of pollutants. Results showed that removal of AR88 and MB by PRGMs was influenced by pH of the dye solution, PRGMs doses, and dye concentrations. From the batch process experiments, adsorption and coagulation processes were observed for AR88 dye whilst MB dye removal was attributed only to adsorption process. The maximum monolayer adsorption capacity (q) recorded for AR88, and MB were 78 mg/g and 20 mg/g, respectively. XPS and FTIR studies further confirmed that the adsorption process was due to electrostatic interaction and hydrogen bond formation. Furthermore, dye removal capacity of the PRGMs was also investigated for column adsorption process experiments. Based on the Thomas model, the calculated adsorption capacities at flow rates of 2.2 mL/min and 0.5 mL/min were 250 mg/g and 231 mg/g, respectively which were much higher than the batch scale Langmuir monolayer adsorption capacity (q) values. It is suggested that a synergistic effect of adsorption/coagulation followed by filtration processes was responsible for the higher adsorption capacities observed from the column adsorption studies. This study also demonstrated that PRGMs produced from recycled glass waste could directly be applied to the next cyclic experiment with similar dye removal capability. Thus, highlighting the circular economy scope of using waste inorganic materials for alternate applications such as pre-screening materials in wastewater treatment applications.
每年约有760万吨废玻璃未经回收、再利用或升级改造就被填埋。在此，我们开发了一种无溶剂升级改造方法，将回收玻璃废料（RG）再加工成多孔回收玻璃微球（PRGMs），以探索去除有机染料等有机污染物。PRGMs通过火焰球化工艺制备，并使用扫描电子显微镜（SEM）、X射线衍射（XRD）、布鲁诺尔-埃米特-泰勒（BET）和压汞孔隙率法（MIP）分析进行表征。PRGMs的孔隙率为69%，总体孔体积和孔面积分别为0.84 cm/g和8.6 cm/g（来自MIP），表面积为8 m/g。以酸性红88（AR88）和亚甲基蓝（MB）作为污染物模型来源进行研究。结果表明，PRGMs对AR88和MB的去除受染料溶液pH值、PRGMs剂量和染料浓度的影响。从间歇过程实验中可以观察到，AR88染料的去除过程包括吸附和凝聚过程，而MB染料的去除仅归因于吸附过程。AR88和MB的最大单层吸附容量（q）分别为78 mg/g和20 mg/g。XPS和FTIR研究进一步证实，吸附过程是由于静电相互作用和氢键形成。此外，还对PRGMs在柱吸附过程实验中的染料去除能力进行了研究。基于托马斯模型，在流速为2.2 mL/min和0.5 mL/min时计算得到的吸附容量分别为250 mg/g和231 mg/g，远高于间歇规模的朗缪尔单层吸附容量（q）值。这表明吸附/凝聚后接过滤过程的协同效应是柱吸附研究中观察到的较高吸附容量的原因。该研究还表明，由回收玻璃废料制成的PRGMs可直接应用于下一个循环实验，且具有相似的染料去除能力。因此，突出了将废弃无机材料用于替代应用（如废水处理应用中的预筛选材料）的循环经济范围。
