Epimedium Herbal Residue as a Bulking Agent for Lignite and Spent Mushroom Substrate Co-composting

• Published in: Waste and biomass valorization 2023-08, Vol.14 (8), p.2547-2555
• Main Authors: Pan, Xiong, Deng, Ting-fei, Zhang, Lin, Ge, Li-juan, Li, Liang-qun, Yang, Li-shou, Gao, Ming, Cao, Jia-fu, Wei, Fu-xiao, Liu, Xiao-lan, Yan, Yan-fang, Juan-Yang, Yang, Xiao-sheng
• Format: Article
• Language: English
• Subjects: Accumulation; Cadmium; Carbon/nitrogen ratio; Composting; Composts; Electrical conductivity; Electrical resistivity; Engineering; Environment; Environmental Engineering/Biotechnology; Epimedium; Fertilizers; Germination; Industrial Pollution Prevention; Lignite; Mushrooms; Organic matter; Original Paper; Phosphorus pentoxide; Renewable and Green Energy; Residues; Seed germination; Soil amendment; Substrates; Temperature profiles; Waste Management/Waste Technology; Weight; Yard waste
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-022-02018-y

Purpose This study aimed to assess Epimedium herba residue (EHR) as a bulking agent for lignite and spent mushroom substrate (SMS) co-composting to develop a soil amendment/fertilizer as an alternative to current management practices (disposal in landfalls). Methods Composting was performed in a 150-L composting box using different ratios of EHR (0, 10%, 20% and 30% of the sum of lignite and SMS, named the T1, T2, T3 and T4 groups, respectively). Finally, the produced compost was used in pepper cultivation to evaluate the effect of the produced compost on cadmium accumulation in pepper fruits through pot experiments. Results Composting worked best in T4. Characteristic temperature profiles consisting of a 2-day mesophilic phase, an 8-day thermophilic phase (maximum of 50–63 °C) and a 20-day second mesophilic phase (27–50 °C) were observed in T4, while T1 showed a 0-day thermophilic phase. After composting for 30 days, a stabilized and mature fertilizer (pH 7.5–7.6; total organic matter 454.8–468.9 g kg −1 ; 1.7% N; 8.9–9.1 g kg −1 P 2 O 5 ; 8.9–9.2 g kg −1 K 2 O; C/N ratio of 15–16; electrical conductivity 2.9–3.4 mS cm −1 and seed germination index 153–199) was obtained in T3 and T4. The final compost of T3 and T4 greatly reduced the accumulation of cadmium in pepper. Conclusion EHR as a bulking agent for lignite and SMS co-composting provides a safe and sustainable approach to deal with the EHR. The best percentage of EHR was recommended at a dry weight ratio of 20–30% (percentage of total weight of lignite and SMS). Graphical Abstract