Citation:

Lamolinara, B., A. Pérez-Martínez, E. Guardado Yordi, C. Guillén Fiallos, K. Diéguez-Santana, AND G. Ruiz-Mercado. Anaerobic digestate management, environmental impacts, and techno-economic challenges. WASTE MANAGEMENT. Elsevier Science Ltd, New York, NY, 140:14-30, (2022). https://doi.org/10.1016/j.wasman.2021.12.035

Impact/Purpose:

Nutrient pollution from anthropogenic organic waste is a major global climate disruptor, threatening the sustainability and resilience of humankind and ecosystems. Some nutrient pollution impacts include harmful algal blooms (HABs), hypoxia, and eutrophication. A sustainable way to mitigate these environmental challenges is by converting organic waste into renewable energy by anaerobic digestion (AD). AD converts organic waste into valuable resources, thus contributing to the economy while reducing greenhouse gas (GHG) emissions, water pollution, and the volume of waste that goes into landfills. 90-95% of what was fed into the AD process is a nutrient-rich by-product called digestate.This review article provides state-of-the-art current and novel uses of digestate in terms of management, processing technologies, generation, product recovery characterization, environmental impacts, policy and regulations, and techno-economic challenges. Also, this contribution offers stakeholders feasible and efficient alternatives for organic waste management, nutrient pollution prevention, recycling, and reuse. This review manuscript addresses the following questions: What are the characteristics of the digestate feedstock and its influence on the digestate characterization? What are the advantages and disadvantages of the technologies for recycling and reuse? Are the digestate characteristics determining its upcycling use? What worldwide regulations or incentives influence digestate quality and use? What economic and environmental challenges of digestate are influencing its repurposing?Therefore, to address these concerns, this work analyses and combines the findings from more than two hundred journal articles, books, and reports. The review outcomes allow academic, industry, government, and community stakeholders to enhance education and training programs and achieve a more favorable perception and understanding of the anaerobic, aerobic, and co-digestion of organic waste. Moreover, this work's findings promote the use of digestate in a circular economy and as a promising feedstock for producing different value-added products through multiple upcycling pathways. Finally, this review identifies further research, development, and standardized international regulation needs for the safe and sustainable management of digestate and nutrient pollution prevention.

Description:

Digestate is a nutrient-rich by-product from organic waste anaerobic digestion but can contribute to nutrient pollution without comprehensive management strategies. Some nutrient pollution impacts include harmful algal blooms, hypoxia, and eutrophication. This contribution explores current productive uses of digestate by analyzing its feedstocks, processing technologies, economics, product quality, impurities, incentive policies, and regulations. The analyzed studies found that feedstock, processing technology, and process operating conditions highly influence the digestate product characteristics.

URLs/Downloads:

Record Details: