Groundwater has often been plagued by persistent contaminants such as dense nonaqueous phase liquids (DNAPLs). There is a need for sustained release technologies to ensure long-term treatment in these flow systems. Innovative methods involving sustained release of a selected reagent, persulfate, through pellets made from inorganic materials such as zeolite, diatomite, and silica flour are reported through a proof-of-concept study. Efficacy of the method relies on the preservation of the reagent without decreasing the treatment potential that would otherwise occur with organic matrices. Several methods and different matrix materials for pellet fabrication are described for sustained release of persulfate as a model reagent. Some pellets (diameter: 13 mm; thickness: 2.5-2.7 mm; mass: 0.5 g) show persulfate release of >25 hours. Larger pellets are expected to provide longer release times. Different pellet types and fabrication methods offer a range of ease of pellet construction, as well as reagent release times for sustained release. Trichloroethylene (TCE), a DNAPL, was selected as the model contaminant for testing this sustained release approach. Treatment of 15 mg L^-1 (ppm) TCE solutions showed 99% degradation, and the pellets remained intact afterwards. The current work demonstrates the potential feasibility of sustained persulfate release from inert matrices for groundwater treatment.

地下水经常受到持久性污染物的困扰，例如致密的非水相液体（DNAPLs）。需要持续释放技术以确保这些流动系统中的长期治疗。通过概念验证研究，报告了涉及通过无机材料（例如沸石，硅藻土和硅粉）制成的颗粒持续释放选定试剂过硫酸盐的创新方法。该方法的有效性取决于试剂的保存而不降低有机基质原本会发生的处理潜力。描述了用于丸粒制造的几种方法和不同基质材料，用于持续释放过硫酸盐作为模型试剂。一些粒料（直径：13 mm；厚度：2.5-2.7 mm；质量：0.5 g）显示过硫酸盐释放时间> 25小时。较大的药丸有望提供更长的释放时间。不同的颗粒类型和制造方法提供了一系列易于构建的颗粒，以及用于持续释放的试剂释放时间。DNAPL三氯乙烯（TCE）被选为测试这种持续释放方法的模型污染物。治疗15毫克升^-1（ppm）TCE溶液显示99％的降解，此后沉淀仍保持完整。当前的工作证明了从惰性基质持续释放过硫酸盐用于地下水处理的潜在可行性。