Water is used in food production for cleaning, sanitation, and manufacturing processes. Effluents of these processes often contain a mixture of components, e.g., starch, proteins, nutrients, and high amounts of salts. The proper treatment of these effluents brings the opportunity not only to recycle water but also to recover compounds with potential to be reused.
One of the most used methods to treat food industry effluents is biological fermentation, i.e., anaerobic digestion (AD), in which organic compounds are converted into methane, carbon dioxide, ammonium, and short/medium chain fatty acids. Digestates produced with this process are commonly used to extract nutrients and produce fertilizers. However, nutrient extraction often requires a trend of processes to selectively remove target compounds from the complex digestate matrix. Additionally, pre-treatment options, the high amount of waste-activated sludge generated, and its disposal, are some of the factors to consider when applying AD processes.
Nature and technology complement each other
A combination of membrane technologies and nature-based solutions (NBS) can be used to achieve a comprehensive treatment of food industry effluents. This type of hybrid treatment can enhance the separation of organic compounds, nutrient removal, biomass recovery, and overall water quality fit for being reused. Additionally, coupling separation technologies with NBS offers the possibility to decrease energy consumption and CO2 emission in the treatment process.
In this project, we will work on developing an integrated process to recover water and decrease the emission of nutrients and other compounds to the environment from residual streams from the food industry. Potential feedstocks for the process are residual flows from food processing, which can include digestates before/after the removal of nutrients. The process will integrate:
- membrane technologies to separate non-charged organics, such as starch, from small charged compounds. The concentrated stream generated will contain nutrients, such as ammonium and phosphate, and other salts.
- nature-based solutions, i.e., microalgae and helophyte filters, as a polishing step to take up nutrients from either of the streams produced during membrane separation steps.
With regards to the use of microalgae, in the proposed process, we will look into the use of this biomass as a renewable source of plant bio-stimulants.
Collaborating with industrial partners
We welcome food-producing and processing companies interested in recovering water and other potentially valuable compounds from their residual water flows, currently considered waste streams. We are also looking for technology providers looking into optimizing the application of their products.