Wang Chi-Wei, Liang Chenju
Department of Environmental Engineering, National Chung Hsing University, 145 Xingda Rd., South Dist., Taichung 402202, Taiwan.
Department of Environmental Engineering, Da-Yeh University, 168 University Rd., Dacun, Changhua 515006, Taiwan.
ACS Omega. 2025 Jul 29;10(31):34321-34330. doi: 10.1021/acsomega.5c01779. eCollection 2025 Aug 12.
Organochlorine pesticides (OCPs), such as lindane, persist as toxic pollutants in river sediments, necessitating operative and effective remediation. An alkaline green tea (GT)/Fe system shows promise for chemical reductive degradation of lindane through sustained polyphenol release. This study developed a novel in situ capping material (ISCM) composed of tea leaves, bentonite, sodium alginate, and pyrite. The GT ISCM exhibits strong water absorption, swelling, extended polyphenol release, and a stable reducing environment. Using the Taguchi method (L9 orthogonal array), the ISCM formulation was systematically optimized, and Analysis of Variance identified the optimal composition as 10 g bentonite, 0.5 g tea leaves, 0.25 g pyrite, and 0.1 g sodium alginate. Utilizing tea polyphenols as reducing agents, it immobilized lindane and promoted its degradation while preventing the formation of 1,3,4,5,6-pentachlorocyclohexene and trichlorobenzene, byproducts produced during alkaline hydrolysis. Under simulated field conditions, the ISCM significantly reduced lindane release from contaminated sediments into the aqueous phase, demonstrating high removal efficiencies. These findings underscore the potential of GT ISCM as a sustainable strategy for stabilizing and degrading lindane in contaminated sediments, providing a green alternative for OCP remediation.
有机氯农药（OCPs），如林丹，作为有毒污染物长期存在于河流沉积物中，因此需要有效可行的修复方法。碱性绿茶（GT）/铁体系有望通过持续释放多酚对林丹进行化学还原降解。本研究开发了一种由茶叶、膨润土、海藻酸钠和黄铁矿组成的新型原位覆盖材料（ISCM）。GT ISCM具有很强的吸水性、膨胀性、延长的多酚释放能力和稳定的还原环境。采用田口方法（L9正交表）对ISCM配方进行了系统优化，方差分析确定最佳组成为10克膨润土、0.5克茶叶、0.25克黄铁矿和0.1克海藻酸钠。利用茶多酚作为还原剂，它固定了林丹并促进其降解，同时防止了碱性水解过程中产生的副产物1,3,4,5,6-五氯环己烯和三氯苯的形成。在模拟现场条件下，ISCM显著降低了林丹从受污染沉积物向水相的释放，显示出高去除效率。这些发现强调了GT ISCM作为一种可持续策略在稳定和降解受污染沉积物中林丹方面的潜力，为OCP修复提供了一种绿色替代方案。
