(Reflow-ESR5) Struvite precipitation from organic waste

Apr 24, 2019
May 10, 2019
Organization Type
University and College
Full Time
Job description

This Early Stage Researcher position is part of the European Training Network REFLOW entitled Phosphorous Recovery for Fertilisers from Dairy Processing Waste. A key part of the REFLOW project is to:
  • mitigate the environmental impact of dairy processing waste on soil and water,
  • provide safe environmentally-sustainable, cost-effective closed-loop solutions for crop nutrient management
  • meet the demand for skilled professionals to support the technical, regulatory and commercial development of the market for recycled phosphorous fertiliser products.

The ESR will be required to undertake PhD studies and must fulfil the requirements of the university's doctoral training programme. They will have opportunities to visit other network partners for secondments, and attend the research and training events of the network. All costs will be fully funded (100% employment) for a period of three (3) years by the Marie Sklodowska-Curie Actions programme which also offers highly competitive and attractive salary and working conditions. The REFLOW Training Network is coordinated by the University of Limerick.

Position Details

Phosphorus (P)-rich biosolids can be either applied directly to land or mineralized and the P recovered as struvite or phosphoric acid (H3PO4). There is evidence that P supplied as EBPR biosolids is as effective for crops as mineral P but biosolids are bulky to transport, require specialist spreading equipment and have low %P compared to mineral fertilizer. Some reports suggest that AD decreases P availability for plants. Direct application also carries the risk of contamination either from pathogens, heavy metals or persistent organic pollutants (POPs). Sterilization and POP destruction can be achieved thermochemically by hydrothermal carbonization with subsequent P recovery as H3PO4 or struvite. Hydrothermal carbonization (HTC) is a thermochemical processing operation undertaken with relatively low (25%) solids content waste feedstocks such as sludge at moderate temperatures (160-315C), and pressures up to 15MPa. HTC is a qualifying STRUBIAS technology, typically used for treating wet wastes producing a hydrochar (HC) and a liquor (HCL). There are no reports of P recovery from HTC of dairy processing waste. REFLOW will investigate the recovery of Struvite from the liquors produced from HTC.

Position Objectives
  1. Investigate the effects of processing conditions (temperature 150-315C, pressure, retention time 10-60 minutes), pH (2-9)) on hydrothermal carbonization of dairy processing waste.
  2. Establish the yield of hydrochar, speciation of alkali metals, organic pollutants and phosphorous mineralization within the hydrochar
  3. Characterise the liquid fraction from HC and develop an understanding of the partitioning of organic P and mineral components between the hydrochar and HC liquor
  4. Characterize the hydrochar and hydrothermal carbonization liquor for sugars, organic acids and heavy metals.

Expected Outcomes/ Results

Precipitation of struvite with phosphorus removal efficiency 70-95%; Evaluation of struvite properties as fertilizer - P205 content >35%,(Ca = Mg)/P > 0.8 (molar ratio), Organic Carbon
Planned Secondments

The Researcher will be required to spend extended periods of time (secondments) at the premises of other beneficiaries and Partner Organisations which will be relevant and beneficial for the researchers and in line with the project objectives. Secondments will contribute to the inter-sectoral experience and also contribute to the multi/inter-disciplinary experience of the researchers. Secondments will not exceed 30% of the fellowship's duration. They will represent between 6 to 12 months of the ESRs contracted time.

  • Excellent institutional environment, a stimulating high profile research programme with international focus
  • Measures for career development opportunities (training programme, secondments)
  • Salary corresponding to 2018 European Training Network (including living, mobility and family allowances) [€35560,05 - €2,468.85 euro gross pay per month + mobility allowance (600 euro per month) + family allowance (500 euro per month, if relevant) before taxes and other deductions are made].
  • A full-time contract

At the core of the MSCA-ETNs is researcher mobility. The recruited Early-Stage Researcher (ESR) must not have resided or carried out his/her main activity in the country he/she will be employed for more than 12 months in the 3 years immediately prior to the recruitment date.

Candidates must be in the early stage of their research career (first four years, full time equivalent) and not in possession of a doctoral degree.

Application Process

Applicants are requested to submit their application in English until May 10th 2019 via the application website. The application shall comprise a letter of motivation (at least one page), a curriculum vitae, copies of diplomas and language skills, a transcript of records, a nominated referee that can be contacted and a paper or a publication (if applicable).


Shortlisted candidates will be invited for the interview with the position starting between June and September 2019.

Selection Criteria
  • Criteria 1: proven previous experience in the filed of struvite precipitation - 20%
  • Criteria 2: authorship of articles - 20%
  • Criteria 3: analytical skills - 30%
  • Criteria 4: willing to publish obtained results, focus on the effect- 30%

For additional information please visit the website www.etn-reflow.eu