School of Civil, Environmental and Infrastructure Engineering, Southern Illinois University Carbondale, Carbondale, IL, USA.
Paul H. O'Neill School of Public and Environmental Affairs, Indiana University Bloomington, Bloomington, IN, USA.
Environ Technol. 2024 Jun;45(14):2879-2890. doi: 10.1080/09593330.2023.2192367. Epub 2023 Mar 29.
The overall objective of this study was to develop cost-effective treatment processes for 1,4-dioxane removal that were safe and easy to scale up. Degradation of 1,4-dioxane was conducted and compared for the first time by heterogeneous photocatalysis and a photo-Fenton-like process under cool white fluorescent light in mild conditions, using two types of commercial nanoparticles-titanium dioxide (TiO) and nanoscale zero-valent iron (nZVI), respectively. Both types of nanoparticles removed >99.9% of 1,4-dioxane in a short period of time. Hydroxyl radicals (·OH), superoxide radicals (O), and hydrogen peroxide (HO) were detected in both degradation processes; photogenerated holes (h) were critical in the degradation of 1,4-dioxane by the photocatalytic process using TiO. 1,4-Dioxane can be degraded at pH 7 in TiO/light system and at pH 3 in nZVI/light system, and faster degradation of 1,4-dioxane at even higher concentration was achieved in the former system. Increase in light intensity accelerated 1,4-dioxane degradation, which followed first order kinetics in both systems. In wastewater effluent, the removal of 1,4-dioxane was slower than that in deionised water, which likely reflected the complex compositions of the wastewater effluent. Under combined UVA and visible light illumination, a two-stage degradation process was proposed for 1,4-dioxane for the first time by TiO nanoparticles; this study also demonstrated for the first time 1,4-dioxane degradation by the photo-Fenton-like process using nZVI. The cost-effective solutions using commercial nanoparticles under fluorescent light developed in this study can be potentially applied to treat water contaminated by high concentrations of 1,4-dioxane in large-scale.
本研究的总体目标是开发具有成本效益的 1,4-二恶烷去除处理工艺，这些工艺安全且易于放大。首次在冷白光荧光灯下，通过非均相光催化和类芬顿光化学过程，使用两种商业纳米粒子-二氧化钛（TiO）和纳米零价铁（nZVI），分别进行了 1,4-二恶烷的降解，并进行了比较。两种类型的纳米粒子在短时间内去除了>99.9%的 1,4-二恶烷。在两种降解过程中均检测到了羟基自由基（·OH）、超氧自由基（O）和过氧化氢（HO）；光生空穴（h）在 TiO 光催化过程中对 1,4-二恶烷的降解至关重要。1,4-二恶烷可在 TiO/光体系中 pH 为 7 和 nZVI/光体系中 pH 为 3 的条件下进行降解，并且在前一体系中，即使在更高浓度下，1,4-二恶烷的降解速度也更快。增加光强会加速 1,4-二恶烷的降解，这在两种体系中都遵循一级动力学。在废水流出物中，1,4-二恶烷的去除速度比去离子水中慢，这可能反映了废水流出物的复杂组成。在 UVA 和可见光联合照射下，首次提出了 TiO 纳米粒子的 1,4-二恶烷两阶段降解过程；本研究还首次证明了使用 nZVI 的类芬顿光化学过程中 1,4-二恶烷的降解。本研究中使用商业纳米粒子在荧光灯下开发的具有成本效益的解决方案，可潜在应用于处理高浓度 1,4-二恶烷污染的大规模水体。
