Soil Sciences Department, College of Food & Agricultural Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Kingdom of Saudi Arabia.
Soil Sciences Department, College of Food & Agricultural Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Kingdom of Saudi Arabia.
Environ Pollut. 2023 Oct 15;335:122319. doi: 10.1016/j.envpol.2023.122319. Epub 2023 Aug 4.
Extensive production and utilization of plastic products have resulted in the generation of microplastics (MPs), subsequently polluting the environment. The efficiency of biochars (BCs) derived from jujube (Ziziphus jujube L.) biomass (300 °C and 700 °C) for nylon (NYL) and polyethylene (PE) removal from contaminated water was explored in fixed-bed column trials. The optimum pH for the removal of both MPs was found 7. Both of the produced biochars demonstrated >99% removal of the MPs, while the sand filter exhibited a maximum of 78% removal of MPs. BC produced at 700 °C (BC700) showed 33-fold higher MPs retention, while BC produced at 300 °C (BC300) exhibited 20-fold higher retention, as compared to sand filters, indicating the higher efficiency of BC produced at higher pyrolysis temperature. Entrapment into the pores, entanglement with flaky structures of the BCs, and electrostatics interactions were the major mechanism for MPs retention in BCs. The efficiency of MPs-amended BCs was further explored for the removal of Pb(II) and Cd(II) in fixed-bed column trials. BC700 amended with PE and NYL exhibited the highest 50% breakthrough time (2114.23 and 2024.61 min, respectively, for Pb(II) removal and 2107.92 and 1965.19 min, respectively, for Cd(II) removal), as compared to sand filters (38.07 and 60.49 min for Pb(II) and Cd(II) removal, respectively). Thomas model predicted highest adsorption capacity was exhibited by BC700 amended with PE (584.34 and 552.80 mg g, for Pb(II) and Cd(II) removal, respectively), followed by BC700 amended with NYL (557.65 and 210.59 mg g for Pb(II) and Cd(II) removal, respectively). Therefore, jujube waste-derived BCs could be used as efficient adsorbents to remove PE and NYL from contaminated water, while MPs-loaded BCs can further be utilized for higher adsorption of Pb(II) and Cd(II) from contaminated aqueous media. These findings suggest that BC could be used as an efficient adsorbent to remove the co-existing MPs-metals ions from the environment on a sustainable basis.
大量生产和使用塑料制品导致了微塑料（MPs）的产生，进而污染了环境。本研究采用枣（Ziziphus jujube L.）生物质制备的生物炭（BC），在固定床柱试验中探索了其对尼龙（NYL）和聚乙烯（PE）从受污染水中去除的效率。发现去除两种 MPs 的最佳 pH 值为 7。两种生物炭的 MPs 去除率均大于 99%，而沙滤的 MPs 去除率最大为 78%。与沙滤相比，在 700°C 下制备的生物炭（BC700）对 MPs 的保留率高 33 倍，在 300°C 下制备的生物炭（BC300）对 MPs 的保留率高 20 倍，表明较高的热解温度制备的生物炭具有更高的效率。BC 中 MPs 的主要保留机制是被截留进入孔隙、与片状结构缠结以及静电相互作用。进一步在固定床柱试验中探索了添加 MPs 的 BC 对 Pb(II)和 Cd(II)的去除效率。添加了 PE 和 NYL 的 BC700 对 Pb(II)和 Cd(II)的 50%穿透时间最长（分别为 2114.23 和 2024.61 分钟和 2107.92 和 1965.19 分钟），而沙滤的 50%穿透时间最短（分别为 38.07 和 60.49 分钟）。Thomas 模型预测，添加 PE 的 BC700 对 Pb(II)和 Cd(II)的吸附容量最高（分别为 584.34 和 552.80 mg g），其次是添加 NYL 的 BC700（分别为 557.65 和 210.59 mg g）。因此，枣废弃物衍生的 BC 可作为去除受污染水中 PE 和 NYL 的有效吸附剂，而负载 MPs 的 BC 可进一步用于从受污染的水介质中吸附更高浓度的 Pb(II)和 Cd(II)。这些发现表明，BC 可作为一种有效的吸附剂，以可持续的方式从环境中去除共存的 MPs-金属离子。
