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Compound microbial fertilizer (CMF) uses organic waste as a raw material and is an environmentally friendly alternative to conventional chemical fertilizers. However, further analyses of the environmental performance of CMF production are necessary. This study first evaluated the environmental impacts of CMF made from chemical fertilizers, organic wastes, and microorganisms, as well as economic costs. A case study, whose scope encompassed raw materials, transportation, and manufacturing stages was conducted on a fertilizer company in the Hubei Province of China through a combined “cradle-to-gate” life cycle assessment and life cycle cost methodology. Normalization of midpoint results indicated that impacts on fossil resource scarcity, water consumption, and terrestrial acidification are key contributors to the total impacts. The key stage analysis highlighted that the raw materials stage played a critical role (more than 48%) in the environmental performance of the CMF life cycle, followed by the transportation and manufacturing stages (less than 15%). Key substance analysis showed that monoammonium phosphate use is a hotspot and significantly increases the environmental burden of CMF production. Moreover, bentonite and pig manure were also identified as the key substances. Future improvements in the supply chain should focus on monoammonium phosphate, bentonite production, and pig manure extraction. Results of the sensitivity analysis confirmed that controlling pollution from monoammonium phosphate and bentonite should be a priority in realizing clean production. Additionally, an economic analysis indicated that the life cycle cost of CMF was 675.75 CNY/t and that raw material costs contributed the most to the total life cycle cost (over 70%). On the basis of these results, possible recommendations were proposed, such as promoting green procurement of main raw materials, improving the collection technology of pig manure, and extending the scale of CMF enterprises. This study can be significant in assisting relevant stakeholders with decision-making to ensure a balanced tradeoff between an environmentally friendly option and an economically feasible option.

Due to the gradual scarcity of global phosphorus resources and water pollution problem caused by animal excreted phosphorus, feed grade mono-dicalcium phosphate is expected to gradually replace other feed phosphates with its high phosphorus absorption rate, low phosphorus pollution and good economic benefits advantages. This work employs a cradle-to-gate life cycle assessment and life cycle costing methodology to evaluate the environmental impacts and economic costs of feed grade mono-dicalcium phosphate production. Additionally, a detailed analysis of mono-dicalcium phosphate production using process analysis in the quantification of material and energy usage was done. The normalization of midpoint results showed that the predominate environmental impact was identified as human toxicity, followed by fossil depletion, marine ecotoxicity and particular oxidant formation. The contributions analysis results highlighted that beneficiation, sulfuric acid synthesis and phosphoric acid synthesis are the processes with serious environmental pollution. In addition, key substances which can bring serious environmental burdens were identified as sulfur and electricity, beneficiation reagent and tailings as well as phosphogypsum in this study. The results of sensitivity analysis confirmed that decreasing electricity and sulfur consumption should be priority to realize clean production. The results indicated that 1-ton target product would lead to 11460.96 MJ and 306.92 US $ in energy consumption, life cycle cost. Importantly, when the available phosphate ore grade decreases from 25% to 15% because of gradual phosphate resources depletion, cost related to mono-dicalcium phosphate production was computed as from 300.76 to 332.35 US $. It will provide useful guidance for phosphate enterprises in China under different market price. Based on these results, this work makes interpretations and gives possible recommendations such as optimizing national power structure, improving the sulfur raw material consumption efficiency and increasing the recycled rate of waste heat for operational improvements in mono-dicalcium phosphate production.