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Phosphorus REcovery for FertiLisers frOm dairy processing Waste

Periodic Reporting for period 1 - REFLOW (Phosphorus REcovery for FertiLisers frOm dairy processing Waste)

Reporting period: 2019-01-01 to 2020-12-31

REFLOW is an interdisciplinary cross-sectoral European Training Network combining world-leading scientists and key stakeholders in dairy processing, fertilizer production and phosphorous recycling with early-stage researchers (ESRs) to address important technical and socio-economic challenges associated with the recovery of phosphorous from dairy processing waste water and its recycling into fertilizer products enabling sustainable expansion of the dairy industry in Europe.

Phosphorous (P) is essential for life, however the industrialization of food production, in order to feed a rapidly expanding population, is giving rise to serious leakage of P throughout the global agricultural food system. The production of dairy products, such as cheese and yogurt, give rise to P-rich dairy processing waste (DPW) and phosphorous leakage from the dairy industry is causing environmental damage and putting public health at risk. As a whole, the dairy industry is the EU’s largest industrial food wastewater source and one of the main sources of P-rich industrial effluent. The abolition of EU milk quotas (2015) resulted in a subsequent 2.8% annual growth in milk production with a corresponding increase in DPW. If the way in which DPW is managed does not change, then the leakage of nutrients will continue to intensify, leading to environmental problems such as the eutrophication of water bodies by phosphorous run-off from soil.

A key component of both the EU Farm-to-Fork Strategy and Circular Economy Action Plan requires member states to develop “an Integrated Nutrient Management Plan (INMAP) to ensure more sustainable application of nutrients (NPK) and to stimulate the markets for recovered nutrients” for implementation. The key pillars of INMAP are
• Reducing nutrient loses (Farm-to-Fork) (by at least 50%, 2030)
• Nutrient recycling (Circular Economy) with key priority to monetize environmental and social benefit, (particular focus on wastewater treatment.

The overall REFLOW objectives are aligned with the EU strategies and are to:
1. Develop and demonstrate processes for the recovery and reuse of phosphorous (P) products from DPW;
2. Establish the fertilizer value and optimum application rates through laboratory protocols and field trials of the recovered phosphorous (P) products from DPW;
3. Address the environmental, social, food safety and economical challenges, ultimately finding market-driven solutions for the new processes and fertilizer products.
The key aim of the first period of the REFLOW project was to recruit into the REFLOW Training Network thirteen Early-Stage Researchers (ESR), enrol the recruited ESRs into PhD positions, put in place the supervisory teams and structures needed for them to undertake the tasks and obtain the training set out in the REFLOW Grant Agreement. The culmination of this initial stage of activity is the production of a Career Development Plan by each ESR. Work undertaken to-date has included comprehensive Literature Reviews of the ESRs research subject areas. Two training schools took place during the reporting period.

The structure of the Scientific work within the REFLOW ETN is broken into 3 Work Packages (WP):
• WP1 Phosphorous accumulation, mineralisation, and purification
• WP2 Crop yield and Soil Health
• WP3 Economic and Environmental Sustainability

Each ESR is assigned to a work package and is undertaking an individual programme of work which will integrate with other ESRs work within the WP. The Work Packages are also interconnected to achieve the objective of the project. The work undertaken within WP1 includes steps to develop and demonstrate processes for the recovery and reuse of phosphorous (P) products from DPW through the design of pilot plants to meet project objectives. Within WP2 recycled fertiliser components have been used in pot trials to benchmark their: fertiliser value relative to conventional mineral fertilisers; effects effects on soil microbiology; and on soil greenhouse gas emissions. The frameworks for processing the outputs from WP1 and WP2 are being currently being developed by the WP3 ESRs.
Key Scientific Developments to-date
• A significant milestone has been achieved in the production of Enhanced biological phosphorus removal (EBPR) biosolids.
• An anaerobic digester specific to dairy waste incorporating membrane technology and novel drying techniques has been designed and is currently being validated.
• Process parameters for optimised hydrothermal carbonisation have been established.
• Mineral Phosphate (Struvite) has been recovered from hydrothermal carbonisation (HTC) liquors.
• Initial REFLOW fertiliser efficacy has been established as an Fertiliser Equivalence Value (FEV) for use within field trials.
• The identification of specific sustainability indicators for phosphate recovery from waste waters

Expected Project Results and Impacts
• An EBPR technology specific to Dairy Waste Water will be developed, eliminating harmful chemical flocculants within the sludge.
• A HTC Process specific to Dairy Waste Water will be developed. The hydrochar output will contain a mixture of fast and slow release phosphate.
• HTC Liquors, which are normally considered a waste, will be efficiently cleaned through recovery of its mineral phosphate (Struvite).
• Dairy waste sludge incineration will be optimised to enable the recovery of phosphate from the ashes through acid leeching.
• The development of a software application for calculating the correct amount of REFLOW fertiliser for use on grassland and forage crops.
• Calculation of the Life Cycle cost and environmental components of the REFLOW fertilisers.
• The establishment of a model that will help determine a pricepoint at which the REFLOW fertilisers can be economically sustainable.

The development of a range of technological solutions for Phosphate recovery that can be tailored to the size of individual sites and location.
The solutions will provide optimised processes for the recovery of Phosphorus from Dairy Processing Waste Waters and its incorporation into fertilisers.
Processes that farmers can easily follow to effectively and efficiently fertlise their lands with REFLOW fertiliser.

The benefits of recovering phosphate efficiently and economically from dairy waste water will have wide socio-economic impacts including:
reduced importation of mineral fertilisers; greater circularity within both local and national bio economies; job creation through local fertiliser production;
reduced carbon footprint associated with grassland used for dairy production; cleaner dairy waste water;
increased environmental and circular economy awareness within dairy industry including farmers and dairy plant employees