Department of Civil Engineering, M.S. Ramaiah Institute of Technology, Bangalore, 560054, India.
Environ Sci Pollut Res Int. 2024 Sep;31(42):55022-55034. doi: 10.1007/s11356-024-34825-2. Epub 2024 Sep 2.
The technical feasibility of advanced oxidation process, in particular persulfate (PS) oxidation followed by struvite precipitation for landfill leachate treatment and nutrient recovery has been depicted in the current study. Furthermore, the impact of activation of PS with thermal and ultraviolet (UV) irradiation techniques on COD removal efficiency is also investigated. A maximum COD removal efficiency of 96% is accomplished at 65 °C together with supply of UV irradiation. The impact of persulfate dose, pH, and PS/65 °C/UV system on COD and biodegradability is also illustrated in the current study. Additionally, decomposition rate constant values are also ascertained in the present study. Afterwards, nutrient recovery using struvite precipitation is carried out for sustainable utilization of resources. Preliminary treatment of leachate with PS/65 °C/UV system is greatly conducive to recovering high quality struvite crystals. Besides, 94.9%, 83.5%, and 91.3% of PO - P, NH - N, and Mg recovery efficiency attained respectively at pH 9.5 and 1.2:1:1 molar ratio of Mg: NH - N: PO - P. Additionally, all the nutrient recovery studies are validated using chemical equilibrium model Visual MINTEQ. Later, bioavailable fraction of PO - P in the recovered struvite is also investigated for utilization as fertilizer. The presence of Cu and Zn in the recovered struvite precipitate enhanced its economic value as a fertilizer. Since Cu and Zn are vital micronutrients for growth of plants. The low soluble values of recovered struvite precipitate confirmed its utilization as slow releasing fertilizer.
本研究描述了高级氧化工艺（尤其是过硫酸盐（PS）氧化后进行鸟粪石沉淀）在处理垃圾渗滤液和回收营养物质方面的技术可行性。此外，还研究了通过热和紫外线（UV）辐照技术激活 PS 对 COD 去除效率的影响。在 65°C 并同时提供 UV 辐照的条件下，COD 去除效率最高可达 96%。本研究还说明了过硫酸盐剂量、pH 值以及 PS/65°C/UV 系统对 COD 和可生物降解性的影响。此外，本研究还确定了分解速率常数值。之后，通过鸟粪石沉淀进行了营养物质回收，以实现资源的可持续利用。渗滤液经 PS/65°C/UV 系统进行初步处理，有利于回收高质量的鸟粪石晶体。此外，在 pH 值为 9.5 和 1.2:1:1 的 Mg:NH₋N:PO₋P 摩尔比条件下，PO₋P、NH₋N 和 Mg 的回收率分别达到 94.9%、83.5%和 91.3%。此外，所有的营养物质回收研究都使用化学平衡模型 Visual MINTEQ 进行了验证。之后，还研究了回收鸟粪石中 PO₋P 的生物可利用部分，以用作肥料。回收的鸟粪石沉淀中存在 Cu 和 Zn，提高了其作为肥料的经济价值。因为 Cu 和 Zn 是植物生长所必需的微量元素。回收的鸟粪石沉淀的低可溶性值证实了其作为缓释肥料的用途。
