How Sustainable Is It To Extract Nutrients From Food Industry Wastewater?

Today, we are facing two challenges related to nutrients. On one hand, phosphorus is considered a critical raw material. On the other hand, nutrient loss into water bodies leads to severe environmental issues. In her doctoral thesis, Marta Behjat explores the sustainability of innovative technologies developed to recover nutrients, that can then be utilised in agriculture rather than being lost into the environment.

What challenges do you focus on in your research?
“Over the past few years, I have explored and evaluated early-stage technologies designed for nutrient recovery. Specifically, I focused on methods for recovering struvite from dairy wastewater and capturing nitrogen and phosphorus from fish farm wastewater using biochar as a filter. Since these technologies are still in their early stages, limited data and information are available. Gathering data for something that does not yet fully exist is challenging.”

How do you address the problem?
“Noting the above, there was a lack of specific data available and therefore, the collected data had to be scaled up from lab scale to pilot scale, and then refined based on experimental observations and engineering assumptions.”

What are the main findings?
“To assess these technologies, I utilised established sustainability assessment methods, such as LCA, and also developed and adapted additional assessment methods. In this work, I discovered that when evaluating innovative technologies, we cannot utilise solely the established methods. Methods like meta-analysis and circularity indicators also provided useful insights into the recovery efficiency and performance of these innovative technologies. The circularity assessment results illustrate and quantify the significant role that recovered products can play in nutrient management, thus reinforcing the circularity of the systems. Furthermore, the environmental assessment results showed that installing nutrient recovery as part of or after food wastewater treatment would not incur a large environmental impact; the main hotspots in the recovery process are related to chemical production and atmospheric ammonia emissions during sludge treatment.”

What do you hope your research will lead to?
“I hope the methodology that I developed or adapted for my research can be useful in the future for other similar studies, such as assessing technologies at an early stage and contributing to their development. Furthermore, I hope that the results on environmental impact and recovery efficiency of nutrients will be used to promote more sustainable agriculture.”