Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-kuang Road, Taichung 402, Taiwan.
Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-kuang Road, Taichung 402, Taiwan.
J Hazard Mater. 2022 Oct 5;439:129657. doi: 10.1016/j.jhazmat.2022.129657. Epub 2022 Jul 21.
The presence of trichloroethylene (TCE) dense non-aqueous phase liquid (DNAPL) in the subsurface can generate a dissolved phase plume in groundwater. This study developed an alkaline activated sodium persulfate (SPS) sustained release oxidation rod (alkaline SPS SR-Rod) for long-term in situ chemical oxidation accelerated treatment of TCE dissolved from TCE DNAPL, by creating a greater concentration gradient at the TCE DNPL boundary. The dissolution of TCE DNAPL (1 mL) in water (280 mL) generated ~700 mg L, with a volumetric mass transfer coefficient (ka) of 0.0187 d. The alkaline SPS SR-Rod system had a ka of 0.013 d for TCE dissolution at early stage, and thereafter aqueous TCE concentration remained below ~10 mg L over 60 d of reaction. An SPS SR-Rod life-span of 186 d, for 90% of SPS released from the rod, was estimated. In the soil-water system, aqueous TCE was maintained < 3 mg L throughout the reaction and the soil oxidant demand was determined to be ~4 g-SPS/kg-soil in the alkaline SPS SR-Rod system. These results revealed that the use of the alkaline SPS SR-Rod can be effective as a method of treating dissolved TCE released from DNAPL contamination, and thereby accelerating TCE DNAPL removal.
三氯乙烯（TCE）致密非水相液体（DNAPL）存在于地下水中会生成溶解相羽流。本研究开发了一种碱性激活过硫酸钠（SPS）持续释放氧化棒（碱性 SPS SR-棒），通过在 TCE DNAPL 边界处创造更大的浓度梯度，用于加速 TCE 从 TCE DNAPL 中溶解的原位化学氧化处理。TCE DNAPL（1 毫升）在水中（280 毫升）的溶解生成了约 700 毫克/升，体积传质系数（ka）为 0.0187 天。碱性 SPS SR-棒系统在早期 TCE 溶解时的 ka 为 0.013 天，此后在 60 天的反应中，水相 TCE 浓度保持在 10 毫克/升以下。预计 SPS SR-棒的使用寿命为 186 天，其中 90%的 SPS 从棒中释放出来。在土壤-水系统中，水相 TCE 在整个反应过程中保持<3 毫克/升，并且确定碱性 SPS SR-棒系统中的土壤氧化剂需求约为 4 克-SPS/千克-土壤。这些结果表明，使用碱性 SPS SR-棒可以有效地作为处理从 DNAPL 污染中释放的溶解 TCE 的方法，从而加速 TCE DNAPL 的去除。
