Li Dongyi, Kumar Rajat, Johnravindar Davidraj, Luo Liwen, Zhao Jun, Manu M K
Institute of Bioresource and Agriculture, Sino-Forest Applied Research Centre for Pearl River Delta Environment and Department of Biology, Hong Kong Baptist University, Hong Kong, Hong Kong.
Environ Technol. 2023 Jan 2:1-11. doi: 10.1080/09593330.2022.2161950.
Food waste digestate (FWD) disposal is a serious bottleneck in anaerobic digestion plants to achieve a circular bioeconomy. FWD could be recycled into nitrogen-rich compost; however, the co-composting process optimisation along with bulking agents is required to reduce nitrogen loss and unwanted gaseous emissions. In the present study, two different-sized bulking agents, namely, wood shaving (WS) and fine sawdust (FS), were used to investigate their impact on FWD composting performance along with the nitrogen dynamics. The mixing of FWD with different bulking agents altered the physiochemical characteristics of composting matrix and the effective composting performance was observed through reduced ammonium nitrogen and increased seed germination index during 28 days of composting. The carbon loss of 19-22% through CO emission indicated similar carbon mineralisation with both types of sawdust; however, the nitrogen transformation pathways were different. Only WS treatment demonstrated the nitrification process, whereas the nitrogen loss was higher with FS. A total nitrogen loss of ∼15% was observed in treatments with FS, whereas WS treatments displayed a nitrogen loss of 12%. The outcome of the present study could significantly contribute to the practical aspect of the FWD composting operation with the promotion of the bio-recycling economy.
食物垃圾消化物（FWD）的处理是厌氧消化厂实现循环生物经济的一个严重瓶颈。FWD可被回收制成富氮堆肥；然而，需要与膨松剂一起优化共堆肥过程，以减少氮损失和有害气体排放。在本研究中，使用了两种不同尺寸的膨松剂，即刨花（WS）和细木屑（FS），来研究它们对FWD堆肥性能以及氮动态的影响。FWD与不同膨松剂的混合改变了堆肥基质的物理化学特性，并且在28天的堆肥过程中，通过减少铵态氮和提高种子发芽指数观察到了有效的堆肥性能。通过CO排放造成的19 - 22%的碳损失表明，两种木屑的碳矿化情况相似；然而，氮转化途径不同。只有WS处理显示出硝化过程，而FS处理的氮损失更高。在FS处理中观察到总氮损失约为15%，而WS处理的氮损失为12%。本研究结果可通过促进生物循环经济，对FWD堆肥操作的实际应用做出重大贡献。
