Action A.1: Status analysis in the targeted area
This preparatory action includes the benchmarking of common routines in wastewater handling in fruit industry. Information will be collected through the distribution of questionnaires and personal audits to representative fruit-packaging and fruit processing units in Greece and Spain. The questionnaire shall include general information (water load used, quantity of fruits which are processed annually, recording of annual use of post-harvest pesticides and other chemicals) and data on wastewater handling and routes of disposal. Key information is the amount of spent liquid and solid waste produced per ton of processed fruit, the duration of the annual processing cycle, the cost of disposal per ton of fruit and per year and possible differences in the handling practices depending on the commodity. Apart from for pre-filled topics the stakeholders will be prompted to share their standpoint on relevant aspects of water management and safe disposal of wastewater. The last sequence of question will aim at stimulating possible future interest and, if possible, commitment to future activities.
Action Progress: This preparatory action includes the benchmarking of common routines for wastewater handling in fruit/vegetables industry. In order to gather accurate information, a questionnaire was designed and administered to selected fruit-packaging/processing units in Greece and Spain. The initial call for participation was made in March-May via the Google Forms web application. The total number of invitations was 169 and 292 in Greece and Spain, respectively. As a second step, due to the low initial correspondence, a line of communication with key stakeholders in Greek prefectures (Greece) and the Association of Food and Vegetable Producers of Almeria (COEXPHAL, Spain) was launched. The questionnaire was reviewed by the Sympraxis Team (external partner undertaking the socioeconomic study of the Project), hence a more user-friendly version was prepared. Personal communication (phone or face-to-face interview) with executive officers of selected agro-industries in both States was initiated. The LIFE PureAgroH2O conference, which was hosted in Athens in mid-January of this year, was deemed as an opportunity to establish personal contact with representatives from the Greek Food Industry and collect information related to the objectives of this Action. Furthermore, the industry’s position regarding the adoption of innovative technologies was explored. The paper-and-pencil questionnaire was distributed to the participants and was filled by industry representatives. A future step is the establishment of cooperation with the Federation of Hellenic Food Industries (SEVT) and COEXPHAL, in fields of interest for the industry, such as water re-use, as part of a future close collaboration with the program.
Deliverable A1.1: List of food packaging/processing industries
Three lists of packaging/processing industries from Greece (2) and Spain (1) are provided in the format of excel files.
Deliverable A1.2: Report of the baseline situation regarding water use and wastewater
management in fruit-packaging and fruit-processing industry
In the context of this preparatory action, a survey was launched to gain insight into wastewater recycling and disposal practices in fruit-packaging/processing industry in Greece and Spain. An extensive list of packaging/processing industries in the two target States was initially prepared (Deliverable D-A1.1). A draft questionnaire was distributed internally and was reviewed by all beneficiaries. It was agreed that the questionnaire will be concise and include information on the industry/processed commodities, the water use in the facilities, the amount of wastewater produced, and the wastewater disposal/reuse/recovery practices employed.
The initial call for participation was done in March-May through the Google Forms web application The questionnaire was reviewed by socioeconomic experts and a personal communication with executive officers of selected agro-industries in both States was initiated. The LIFE PureAgroH2Ο workshop, which was hosted in Athens in mid-January of 2020, was used as an opportunity to establish personal contact with representatives from the Greek food industry and gather information related to the objectives of this Action.
All available responses were analysed. The enterprises in Spain were described as packaging or processing or mixed processing/packaging. Replies from Greece mainly concerned the packaging industry (80% of the responses). The size of the enterprises was typically small or medium, with a high variability of the annual tonnage within each State. The type of common operation routine is variable and usually includes a combination of more than one processes, washing being the most prevalent in the two States. There seems to be significant difference in the cost of water disposal between enterprises. Thirty three percent of the industries declared their interest in the innovative purification/reclamation technology, which may be considered as an early indication of potential interest of a considerable fraction of the agro-industry for the PNFR technology.
For more info, please contact Dr E. Markellou (e.markellou@bpi.gr).
Action A.2: Conceptual process design (CPD) and optimisation
CPD studies have as target to implement the mathematical description of the PNFR process and other competitive technologies (reference cases) and to establish the mass and energy balance equations, incorporating Key Performance Indicators KPIs of the process (system productivity per time and volume, pressure drop, liquid velocity, water permeability, solute rejection efficiency, and kinetics of organic molecules photodegradation). The developed CPD tools will allow assessing the PNFR for the removal of a multitude of organic and inorganic pollutants, bacteria and pathogenic organisms in representative applications. The Fruit & Vegetables Processing industry will be a priority, under the needs of the preparatory actions for process design and optimisation. NCSRD will conduct fast screening tests in the available (patented) lab scale PNFR reactor using wastewater feeds that will be provided by ZAGORIN. To support the replicability and transferability of the novel PNFR technology, NCSRD will construct a pre-pilot scale replicate of the existing lab scale PNFR (1.5 m³ /day) which will be sent at UAL (Spain) and be placed in CITRICOS del Andarax S.A. industry to perform experimental testing using wastewater from juices, gazpacho, soups and vegetable creams processing.
Action Progress: The Preparatory Phase of LIFE PureAgroH2O included the Action A2 related to the Conceptual Process Design (CPD) of the PNFR technology and its optimization, with the targets to achieve energy mitigation and reduction of the capital and operational cost (Sub-Action A2.1), along with benchmarking the novel PNFR technology against state of the art technologies such as adsorption on powdered and granular activated carbons (PAC & GAC), ozonolysis, as well as nanofiltration and photocatalysis when applied as stand-alone processes (Sub Action A2.2). These activities took place from July until the end of 2018 and have concluded into two important deliverables:
D-A2.1: Configurations of the PNFR technology, in an industrial operation.
D-A2.2: Design and technical performance of the integrated process-design of the PNFR technology in the FVP industry.
As mentioned in the detailed technical description of the project’s actions, CPD studies necessitate the knowledge of several Key Performance Indicators (KPIs) of the process and properties of the photocatalytic nanofiltration membranes. These included the system productivity per time and volume, the pressure drop, the liquid velocity, the water permeability, the solute rejection efficiency, the surface charge, the kinetics of organic molecules photodegradation and their dependency on the feed composition, the intermediate products, the presence of inorganic cations and anions (NO3-, ammonium, heavy metal cations), the pH, the temperature and the irradiation intensity.
Therefore, the CPD studies had to be assisted by experimental data under realistic conditions at the “pre-pilot” level, exploiting the testing facilities committed to the project by NCSRD.
Images from the process of the development of polymer hollow fibers with integrated photocatalytic nanoparticles. The wet / dry phase inversion technique was used in large scale fiber assembly.
Deliverable A2.1: Configurations of the PNFR technology, in an industrial operation.
Demokritos had to conduct the Conceptual Process Design (CPD) of the PNFR technology and its optimization, with the targets to achieve energy mitigation and reduction of the capital and operational cost. The CPD study pertains to the preparation of a preliminary flow-diagram of the overall process, including the boundaries of the wastewater treatment system and the way to retrofit the fruit washing process at ZAGORIN with the PNFR technology. Accordingly, an estimation of the dimensions of each component of the process has been implemented based on the targets for daily water production and purity. This encompassed: (i) the dimensions and number of PNFR reactor modules; (ii) definition of the most effective pretreatment process of the wastewater effluent, (iii) number and dimensions of multi-channeled ceramic monoliths in each PNFR module and the most effective method for their modification to photocatalyticmonoliths, (iv) number and dimensions of the porous hollow fibers embedding TiO2 nanoparticles, (v) design and engineering of reactor’s internals, (vi) design, engineering, construction, and operation of a small prototype, including just one set of the reactors’ internals to test all the components, (vii) design of the irradiation system, (viii) relative position of the photocatalytic monoliths, the glass sleeves for the UV lamps and the porous hollow fibers with embedded TiO2 nanoparticles to safeguard effective irradiation.
Achievements:
o Definition of an optimized wash coating method to develop the photocatalytic monoliths (/membranes) and of an optimized wet/dry spinning, phase inversion method in a pilot spinneret setup, to produce the porous polymeric hollow fibers with embedded TiO2 nanoparticles.
o Characterization of the materials in the lab and extraction of the key performance indicators (KPIs) required in the CPD study. These include the permeability of the membranes and their pollutant removal efficiency, as well as the reaction rate constant and the dependence of the reaction rate on the concentration of the pollutant in the presence of several scavengers.
o Mathematical description of the PNFR process and establishment of mass and energy balances. Validation of the software tools’ outcome developed in gPROMS platform.
o Effective utilization of the above data and implementation of process optimization and integration at a first, conceptual design level. Conduction of process simulation studies and estimation of the performance and energetic features of the most promising equipment and process designs.
o Report that describes the design of the PNFR technology, including indicative dimensions and geometry of the main equipment involved and addressing important design parameters.
o Report describing the process concept of the PNFR wastewater treatment technology embedded in and integrated with the FVP industry and other industrial sectors, which includes a process flow diagram, mass and energy balances, short-cut equipment design, definition of control and safety issues, preliminary piping and instrument diagrams and overall performance data and energetic features.
Deliverable A2.2: Design and technical performance of the integrated process design of the PNFR technology in the FVP industry
Demokritos had to describe the process concept of the PNFR wastewater treatment technology by scheduling a process flow diagram, establishing the mass and energy balances, concluding to a short-cut equipment design, defining control and safety issues, implementing preliminary piping and instrument diagrams and elaborating the overall performance data and energetic features. This deliverable constitutes a significant input for the environmental and technoeconomic analysis (B4) and supports the activity B1.1, as it contains all data needed to conduct the Front End Engineering Design (FEED) and detailed engineering and deliver the blue prints of the process.
Achievements:
o The concept of the PNFR process is reported highlighting the innovative aspects, how the synergy between photocatalysis and nanofiltration is achieved, what major problems of conventional processes are solved with this synergy and what basic ideas and knowledge motivated us to select the active photocatalytic membranes and materials enclosed in the PNFR reactor modules.
o A first short-cut equipment design of the PNFR reactor and its internals has been implemented based on the output of the conceptual design study. Exploiting in parallel the SOLIDWORKS platform, we have managed to transform our draft designs to a detailed reactor design.
o The process flow diagram has been finalized with some changes from the initial plans which were found necessary by considering the analytical findings of the several sampling campaigns that were conducted at ZAGORIN during this first phase of the project. Other changes were relevant to the needs of the new FVP installation of ZAGORIN (sorting/grading process) that is expected to be committed and operate during the LIFE project and were introduced in order to improve the capacity of the PNFR process and its adaptability to comply with the new requirements and specifications.
o Mass and energy balances have been established (in sub-section A2.1-g), based on process simulations in gPROMS, that have been implemented for the newly developed wash-coated photocatalytic membranes, taking also into account the key performance indicators as obtained from the experimental campaigns o Actions A2.1-b and A2.1d as well as the new requirements and specifications that arose during the project. Therefore, we have implemented energy and mass balances calculations and defined the inputs and outputs of the targeted system.
For more info, please contact Dr E. Markellou (e.markellou@bpi.gr).