Carbon-Hydrogen-Oxygen Symbiosis Networks (CHOSYNs) enable the centralized use of major atoms among substances.Previous decision-making in CHOSYNs researches always neglect the perspectives of multi-stakeholder, who have a claim on the cash flow of projects and may affect the sustainable operations of CHOSYNs. Hence, this paper proposes a system framework with the Multi-stakeholder decision method to balance the conflicts between stakeholders in the development of a CHOSYN. Multi-stakeholder decision method, which considers the benefits of each stakeholder, can gain a high satisfaction solution by using the dissatisfaction percentage (%D) and weight (ω). First, baseline the sources to get candidates by the multi-scale atomic targeting method. Then the simple objective and the multi-objective optimization method are used to obtain the Utopian point and the Nadir point respectively. Finally, the Multi-stakeholder decision method is used to select the optimal solution. A case study is solved to exhibit the advantages of the framewor

Conductive materials (CM) have recently attracted research interest in the anaerobic digestion of food waste to achieve reduction and resource utilization. Fe-metal organic frameworks (Fe-MOF) and Ketjen Black (KB), the conductive materials (CMs), were added for the enhancement of food waste digestion. This study therefore, is intended to fill in this knowledge gap and clarify the underlying mechanism of CM-promoted performance. Batch experiments revealed that the optimal additions of Fe-MOF and KB were 0.5 g·L–1 and 0.2 g·L–1, respectively. The biogas production increased by 27.50% and 29.45% compared with the blank group, and the removal efficiency of volatile solids (VS), total solids (TS), and chemical oxygen demand (COD) increased by 18.28%, 40.52%, and 15.31%. The lag period was shortened from 3.042 to 2.006 and 1.544 days, respectively. Mechanism studies revealed that Fe-MOF and KB were beneficial to food waste digestion, and the functional groups of Fe-MOF and KB increased the buffer capacity of the system to pH and ammonia nitrogen. The physicochemical properties of Fe-MOF and KB promote the activity of the electron transfer system (ETS); the ETS activity was about 2 times the 11.32 mg·(g·h)−1 of the blank group. Zeta potential and electrical conductivity were beneficial to the establishment of intermicrobial direct interspecies electron transfer (DIET).