School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China; Key Laboratory for Water Quality Security and Protection in Pearl River Delta, Ministry of Education, Guangzhou 510006, PR China.
School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China.
Bioresour Technol. 2024 Apr;398:130533. doi: 10.1016/j.biortech.2024.130533. Epub 2024 Mar 5.
Liquid digestate of food waste is an ammonium-, ferric- and sulfate-laden leachate produced during digestate dewatering, where the carbon source is insufficient for nitrogen removal. A two-stage partial nitrification-anammox/denitrification process was established for nitrogen removal of liquid digestate without pre-treatment (>300 d), through which nitrogen (95 %), biodegradable organics (100 %), sulfate (78 %) and iron (100 %) were efficiently removed. Additional ammonium conversion (20 %N) might be coupled with ferric and sulfate reduction, while produced nitrite could be further converted to di-nitrogen gas through anammox (75 %) and denitrification (25 %). Notably, since increasingly contribution of hydroxylamine producing nitrous oxide, and up-regulated expression of electron transfer and cytochrome c protein, the enhanced ammonium oxidation was probably conducted through extracellular polymeric substances-mediated electron transfer between sulfate/ferric-reducers and aerobic ammonium oxidizers. Thus, the established partial nitrification-anammox/denitrification process might be a cost-efficient nitrogen removal technology for liquid digestate, benefitting to domestic waste recycling and carbon neutralization.
液态食物垃圾消化物是一种铵、铁和硫酸盐含量高的浸出液，在消化物脱水过程中产生，此时碳源不足以进行氮去除。通过建立两段式部分硝化-厌氧氨氧化/反硝化工艺，可以在无需预处理（>300 天）的情况下去除液态消化物中的氮，该工艺的氮去除率高达 95%，生物降解有机物去除率为 100%，硫酸盐去除率为 78%，铁去除率为 100%。此外，可能会有 20%的铵转化（N）与铁和硫酸盐的还原耦合，而生成的亚硝酸盐可以通过厌氧氨氧化（75%）和反硝化（25%）进一步转化为氮气。值得注意的是，由于羟胺产生一氧化二氮的贡献越来越大，以及电子转移和细胞色素 c 蛋白的表达上调，增强的铵氧化可能是通过硫酸盐/铁还原菌和需氧铵氧化菌之间的细胞外聚合物介导的电子转移来进行的。因此，所建立的部分硝化-厌氧氨氧化/反硝化工艺可能是一种经济高效的液态消化物氮去除技术，有利于国内废物回收和碳中和。
