Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran.
Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran, Iran; Modares Environmental Research Institute, Tarbiat Modares University, Tehran, Iran.
Chemosphere. 2024 Mar;352:141408. doi: 10.1016/j.chemosphere.2024.141408. Epub 2024 Feb 7.
Waste liquid crystal displays (LCDs) are one of the most substantial and rapidly growing e-waste streams that contain a notable amount of critical, precious, and toxic elements. This study presented a novel thermal-biological hybrid method for resource recovery from waste LCDs. Through the design of a multistage thermal treatment process with the addition of optimized 20 wt% BO to waste, the LCD's glass structure was separated into two interconnected phases, resulting in the transfer of metals from the LCD's glass phase to the BO phase that can solubilize in the acid solution. Following the thermal treatment step, the biometabolites of Aspergillus niger were used for bioleaching of In, Sr, Al, and As from the obtained thermally treated product. The optimal bioleaching parameters were a pulp density of 10 g/L, temperature of 70 C, and leaching time of 2 days, which led to the highest extraction of 82.6% Al, 70.8% As, 64.5% In, and 36.2% Sr from thermally treated LCD waste, representing a multifold increase in Al, As, and Sr extraction levels compared to untreated waste. This study demonstrated that the proposed hybrid method could successfully overcome waste complexities and ensure effective element extraction from discarded LCDs.
废弃液晶显示器（LCD）是数量最多且增长最快的电子废物之一，其中含有相当数量的关键、珍贵和有毒元素。本研究提出了一种从废弃 LCD 中回收资源的新型热-生物混合方法。通过设计具有添加优化 20wt%BO 的多阶段热处理工艺，LCD 的玻璃结构被分离成两个相互连接的相，从而将金属从 LCD 的玻璃相转移到 BO 相中，BO 相可以溶解在酸溶液中。在热处理步骤之后，黑曲霉的生物代谢产物用于从获得的热处理产物中浸出 In、Sr、Al 和 As。最佳生物浸出参数为纸浆密度为 10g/L、温度为 70°C 和浸出时间为 2 天，这导致从热处理的 LCD 废物中提取出 82.6%的 Al、70.8%的 As、64.5%的 In 和 36.2%的 Sr，与未经处理的废物相比，Al、As 和 Sr 的提取水平提高了数倍。本研究表明，所提出的混合方法可以成功克服废物的复杂性，并确保从废弃的 LCD 中有效提取元素。
