Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.
School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Chemosphere. 2024 Oct;366:143500. doi: 10.1016/j.chemosphere.2024.143500. Epub 2024 Oct 8.
Aquaculture and agricultural production generate substantial amounts of waste, including seaweed (which has plant-stimulating properties), oyster shells, and sugar residues. Through composting and appropriate management, these wastes have the potential to be converted into beneficial soil amendments. However, there is a lack of research exploring the potential of composting in promoting the conversion of seaweed into more stable humified forms, as well as in assessing whether composted seaweed retains its beneficial effects on plant growth. Additionally, studies on using oyster shells as additives to reduce waste pressure and comparing their effectiveness with biochar are relatively scarce. This study examines the impact of incorporating 5% corn stover biochar (T1), 10% biochar (T2), and 10% oyster shell powder (T3) on key physicochemical properties, product quality, and microbial community dynamics during the co-composting of seaweed and sugar residues. Results indicate that organic matter (OM) loss in T1 and T2 increased by 31.2% and 26.4%, respectively, compared to the control (CK). Moreover, Excitation-emission matrix (EEM) fluorescence spectroscopy revealed that humic substances in T1 and T2 surged by 434% and 423%, respectively, far exceeding the 289% increase in CK. The 10% biochar treatment also improved alginate degradation and seed germination index, due to the presence of biostimulants in seaweed and an increased abundance of Cobetia. Microbial analysis post-composting showed that T2 and T3 significantly enhanced the diversity and richness of bacterial communities. Notably, although oyster shell powder did not improve the humification degree of compost as significantly as biochar, it achieved effective weight reduction of waste (OM loss of 43.57%, far exceeding CK's 35.34%) without hindering the composting process. All four compost treatments retained the plant-stimulating effects of seaweed and facilitated alginate degradation. These results underscore the potential of biochar to enhance composting efficiency and utilize composting to process large quantities of oyster shell waste.
水产养殖和农业生产会产生大量的废物，包括具有植物刺激特性的海藻、牡蛎壳和糖渣。通过堆肥和适当的管理，这些废物有可能转化为有益的土壤改良剂。然而，目前缺乏研究探索堆肥在促进海藻转化为更稳定的腐殖质形式方面的潜力，也缺乏评估堆肥海藻是否保留其对植物生长有益效果的研究。此外，关于利用牡蛎壳作为添加剂来减少废物压力并比较其与生物炭的效果的研究相对较少。本研究考察了在海藻和糖渣共堆肥过程中添加 5%玉米秸秆生物炭（T1）、10%生物炭（T2）和 10%牡蛎壳粉（T3）对关键物理化学性质、产品质量和微生物群落动态的影响。结果表明，与对照（CK）相比，T1 和 T2 的有机质（OM）损失分别增加了 31.2%和 26.4%。此外，激发-发射矩阵（EEM）荧光光谱显示，T1 和 T2 中的腐殖质物质分别增加了 434%和 423%，远高于 CK 的 289%的增幅。由于海藻中存在生物刺激剂和 Cobetia 的丰度增加，10%生物炭处理还改善了褐藻胶的降解和种子发芽指数。堆肥后微生物分析表明，T2 和 T3 显著提高了细菌群落的多样性和丰富度。值得注意的是，虽然牡蛎壳粉并没有像生物炭那样显著提高堆肥的腐殖化程度，但它实现了废物的有效减重（OM 损失 43.57%，远高于 CK 的 35.34%），而不会阻碍堆肥过程。四种堆肥处理均保留了海藻的植物刺激作用，并促进了褐藻胶的降解。这些结果强调了生物炭提高堆肥效率的潜力，并利用堆肥来处理大量的牡蛎壳废物。
