2.1. Conceptual design
Given the large number of agricultural waste produced daily, it is crucial to develop means to re-utilize these products and inspire Synergies among suppliers and demanders. In this section, the methodology followed in order to develop the conceptual design of both AgriPLaCE Waste Management Database and AgriPLaCE Synergies Tool are presented. In particular, the aim of the AgriPLaCE Waste Management Database is to provide users with information about (i) the common treatment methods of different agricultural waste streams in Greece, (ii) the economic activities and processes producing different agricultural waste streams and mainly (iii) to provide information regarding alternative agricultural waste management solutions and emerging managements techniques and finally (iv) the industrial sectors that could utilize the products deriving from the application of the alternative and emerging treatment techniques. On the other hand, the aim of the AgriPLaCE Synergies Tool is to create synergies between different actors involved in the value chain from agricultural waste production to waste treatment and new products exploitation. However, the conceptual base of both tools is the same taking into consideration that there is a common waste stream categorization and terminology and both are addressing the following user categories: waste suppliers (WS) and waste demanders (WD). At this point, it has to be mentioned that the physical persons behind the role of WS could be any industry or enterprise representative owning vegetable or fruit residues. So, besides farmers, also food industry representatives, fruit and vegetable retail trade representatives and HORECA representatives could be covered by this user category. On the other hand, owners of agricultural waste treatment technologies and industrial and enterprise representatives who would like to develop technologies to produce products derived from agricultural waste, could be covered by the role of WD. In the following paragraphs, the study of the conceptual components and their connection between each other in both tools is presented.
Waste streams categorization definition
The root of the conceptual design was based on the assumption that each user category (WS or WD) demands information from the other user category in order to cover their needs. For example, the WS wants information related to the WD, in order to find out how their waste could be exploited and the WD wants information regarding which WS could provide them with waste that could be exploitable by them. Consequently, the need for a common waste stream categorization vocabulary arose. To address this, it was necessary to investigate the agricultural waste streams as they are generated by the WSs and also, to investigate the agricultural waste streams specifications as they are required by the WDs in order to be able to receive the waste. The findings showed that rejections in agricultural fields could be categorized per kind of fruit/vegetable plants and then sub-categorized in leaves, stems, twigs and fruits/vegetables unsuitable for human consumption. Regarding the rejections in the food industry and in the HORECA sector, the stream rejections could be parts of the fruits/vegetables like pits/kernels/seed, peels and fruits/vegetables unsuitable for human consumption. Finally, regarding the rejections in the retail trade of fruits and vegetables, these could be unsuitable for human consumption. From the other side, the waste streams that could be exploitable by the WD could be constituted by:
-only one part of one specific kind of fruit/vegetable (kernel from apricot, peels from tomato, seeds from lemon) → (stream category “a”)
-one part of more than one or all kinds of fruit/vegetable plant/s (e.g. twigs from all kinds of fruit and vegetable plants, or fruits/vegetables unsuitable for human consumption deriving from all kinds of fruit/vegetable plants) → (stream category “b”)
-a total of different parts of more than one or all registered kinds of fruit/vegetable plants (leaves, twigs and seeds from all kinds of fruit/vegetable plants) → (stream category “c”)
So, it was necessary that all cases of waste streams be captured to cover the needs of both WSs and WDs. To achieve this, the waste stream categorization adopted was the following:
Table 1.
Waste classification in AgriPLaCe Platform.
Table 1.
Waste classification in AgriPLaCe Platform.
Kind of fruit/vegetable |
Waste type (part of fruit/vegetable plant) |
Kind 1 |
peels |
pits/kernels/seed |
twigs |
leaves |
stems |
fruits/vegetables unsuitable for human consumption |
Kind 2 |
…. |
……….. |
…… |
By the use of filters in the AgriPLaCE Waste Management Database, the user is able to “compose” the waste stream/s for which they would like to have information, according to their willing. For example, they can filter by type of waste (e.g. seeds and peels) and view results for a waste stream including seeds and peels from all registered fruit and vegetable plants (see
Section 2.2.3).
On the other hand, in the case of the AgriPLaCE Synergies Tool, the users -during their profile registration- are allowed to “compose” different waste streams categories, according to their willing. This can be achieved either by selecting kind of fruit/vegetables from a drop-down list and then waste type (part of fruit/vegetable plant) or by selecting only waste type/s (parts of fruit/vegetable plant) regardless of the kind of fruit/vegetable (see
Section 2.2.4).
Waste streams origin
The economic activity, the industrial sector and the processes generating different agricultural waste streams were investigated. Based on this study, information regarding the waste stream origin is provided per waste type (part of fruit/vegetable plant) of each kind of fruit and vegetable, in the AgriPLaCE Waste Management Database. This is achieved by both mentioning the NACE (the Statistical Classification of Economic Activities in the European Community) code/s of the economic activity/ies generating the different waste streams and also by providing information about the process generating each waste stream (e.g. food processing). By the use of filters, the user can view results for selected NACE codes or processes.
Regarding the AgriPLaCE Synergies Tool, when WSs register their profiles, they have to select from a drop down list the industrial sectors where they belong. The list was created based on the same study mentioned above. Consequently, the waste streams registered by WSs are connected with the sector generating them.
Agricultural waste treatments methods for bio-products creation
Regarding the agricultural waste treatment methods for valuable bio-products creation, two categories were taken into consideration. Those are:
- The established and frequently applied waste management methods in Greece; and
-The alternative agricultural waste management solutions and emerging management techniques.
Information of both categories are provided in the AgriPLaCE Waste Management Database. While the aim of the project was to promote the alternative agricultural waste management solutions and emerging management techniques, the common waste management methods in Greece (such as biogas, pellet, animal food etc.) are also provided per waste type (part of fruit/vegetable plant) for each kind of fruit and vegetable, due to the fact that there are still a lot of agricultural waste streams that are not exploited even in conventional ways and are just discarded.
However, the main part of the study was focused on defining the alternative agricultural waste management solutions and emerging management techniques. A lot of information was extracted from the literature review, regarding innovative already applied and emerging technologies for the treatment of the agricultural waste stream category “a”, “b” and “c”.
Sectors that could act as end-users for the products derived from the alternative agricultural waste management solutions and emerging managements techniques
The products derived from the methods described above could have a wide range of applications in different industrial sectors like the food, cosmetic and pharmaceutical industry, polymers production, energy etc.
Through the AgriPLaCE Waste Management Database, the sector of end-use is connected with each treatment technology, which is connected with each waste type (part of fruit/vegetable plant) of each kind of fruit and vegetable. As in other cases too, the user can use filters to view the information they desire for selected end use sectors.
Regarding the AgriPLaCE Synergies Tool, when WDs register their profiles they have to select from a drop down list their industrial sectors. The drop-down list of the WDs industrial sectors contains the sectors related to:
-the agricultural waste treatments methods for bio-products and also
- the sectors that could act as end users for the products derived from the alternative agricultural waste management solutions and emerging managements techniques.
In this way, the waste streams registered by WDs are connected with the sectors that could exploit them.
2.2. AgriPLaCE Platform Development
The completion of this research mentioned above has led to the development of the AgriPLaCE platform, an electronic system aiming to aid users with waste management applications. The AgriPLaCE platform represents the described methodology implemented into an online platform for guiding decision-makers to review existing or develop new waste management strategies and form new synergies. The platform is accessible through the following link:
https://www.agriplace.gr/. The tool was implemented considering the latest technologies in web development, through the use of open-source platforms, offering flexible access through mobile devices and personal computers so as to allow easy access and use from any user, from any device connected to the internet.
The AgriPLaCE platform offers an open waste management database tool for users providing a detailed catalogue for utilization of specific types of agricultural waste, as well as a synergies tool that operates as a host for industrial symbiosis networks by providing means of communication among users with matching profiles. During the implementation of the AgriPLaCE platform the following methodological phases were followed:
Preliminary conceptualisation of the actual methodologies, phases and steps of the tools. During this stage a conceptual model of the AgriPLaCE platform was prepared.
Preparation of PDF/PPT documents with expected visuals of the tool. Once the general concept was agreed, the desired output was drafted in electronic format.
Enrichment of the methodologies in PDF/PPT documents and development of wireframes. Based on the agreed flows and models, the content of each methodology, phase, and steps was integrated in the electronic documents depicting in more detail the actual AgriPLaCE platform content.
Drafting of mock-ups. Upon completion of the above phases a draft prototype of the actual tool and the included methodologies, phases, steps, has been outlined.
Mock-ups revision and finalization. All mock-ups were discussed and review as needed.
Development of the AgriPLaCE framework. The completion of the mock-ups was followed by the actual development of the AgriPLaCE platform.
Deployment of the AgriPLaCE platform release candidate version. A fully functional version has been deployed and provided for testing and further contribution.
Validation exercise: A validation exercise with the technical partners was organised. All comments were incorporated to the final release.
Final release of the AgriPLaCE platform.
2.2.1. AgriPLaCE Platform System Architecture
The subsystems comprising the AgriPLaCE platform stack follow a simple and intelligent architecture consisting of three layers i.e., i) the Presentation layer, ii) the Application layer, and the iii) Database layer [
24], as depicted in
Figure 1.
The user interacts with the platform by way of the Presentation layer, which provides all necessary user interfaces for performing the tools’ functionalities. Every action in the system triggers an operation on the Application layer. Conversely, when the user requests information by performing the relevant actions in the Presentation layer, the Application layer retrieves any relevant data from the Database layer, transforms it to the appropriate format, and then sends it to the Presentation layer to present the data to the user.
The Presentation layer is using javascript with VueJS as the primary framework and additionally, Vuelidate for model-based validation and Vuetify framework for the components. Vuetify is a complete user interface framework built on top of Vue.js. The goal of this approach is to provide the AgriPLaCE platform with all the necessary features needed to build a rich and engaging user experience. Additionally, Vuetify takes a “mobile first” approach to design, which means that the platform just works out of the box—whether it’s on a phone, tablet, or desktop computer.
The Application layer incorporates the Laravel Framework, a free and open-source PHP web framework intended for the development of web applications. In that manner, the web application dynamically interacts with the user providing faster and smoother transitions making the website feel more responsive [
25].
The Database layer encompasses a PostgreSQL database for computational operations [
26]. PostgreSQL is a free and open-source relational database management system that operates as a data repository for the user input data, the waste management catalogue data and the synergies tool data.
The server is the physical container that hosts the AgriPLaCE platform and makes available to the public all its functionality. On the server resides the NGINX and the Apache HTTP web server software hosting all the platform’s layers. NGINX is used as a reverse proxy server for handling static content requests and Apache as the backend to serve dynamic content, offering enhanced server performance for the web platform. Each web server software has Docker containers installed to provide all the software infrastructure to host the platform. The AgriPLaCE docker contains a standard unit of software that packages-up the AgriPLaCE code and all its dependencies in order for the application to run quickly and reliably from one computing environment to another [
27].
2.2.2. AgriPLaCE User Profile
To access the full functionality of the AgriPLaCE platform, users are prompted to register to the website by submitting relevant information regarding their waste management needs. Apart from login details they are requested to provide their enterprise type and geographical location, as well as information regarding their waste supply or needs. These data are stored in the User Data Repository and used in the Synergies Tool for calculation of the Industrial Symbiosis Matching. Based on the information stored in their profile, the users will be able to view a ranked catalogue of potential waste management partners and contact them through the Synergies Tool of the AgriPLaCE platform.
2.2.3. AgriPLaCE Waste Management Database
The AgriPLaCE Waste Management Database provides an extended list of potential utilization measures for a variety of agricultural waste types and acts as a catalogue for waste management application for its users. The Database is open to the public and users do not have to be registered to the platform to access it. The list provides detailed information related to the waste, specifically:
Kind of fruit or vegetable;
Waste Type;
Process generating waste;
Economic activity from which the waste originates (NACE2);
Conventional ways of waste management;
Emerging ways of waste management;
Products deriving from conventional and emerging waste managements;
Economic activity (NACE2) and industrial sectors valorizing products deriving from waste;
It is possible for the database users to use filters and perform an advanced search for their waste type of interest by typing keywords in the search field. The algorithm then re- categorizes the results based on the specific filtering provided. Finally, users are able to download their search results in a .xls file format for further editing.
2.2.4. AgriPLaCE Synergies Tool
The AgriPLaCE Synergies Tool is accessible only for registered users. Upon registration users are asked to provide information related to their waste supply or demand needs. This process occurs in the user profile subsystem which stores the user data input in the User Data Repository. Once the registered user enters the Synergies Tool page, the Industrial Symbiosis Matching Engine calculates the priority of each user profile stored in the user data repository and sorts all users based on their assigned priority.
Upon calculation, the user is presented with a sorted list of potential industrial symbiosis matches. Results (other platform users) with the same priority value are shown alphabetically and the user can further categorize them by performing advanced search of the results with the use of filters and search by keywords. The engine then re-categorizes the results based on the specific filtering provided and presents the updated list to the user. It is also possible to download the industrial symbiosis matching list in a .xls file format for further editing.
Finally, the Synergies Tool hosts a means of communication for registered platform users through its Contact module. Specifically, after matchmaking it is possible for the user to send a message through the platform that reaches the receiver via e-mail. The receiver’s e-mail is shared only in case of reply, thus complying with GDPR principles.
2.3. Industrial Symbiosis Matching Algorithm
Industrial Symbiosis Matching Engine of the Synergies Tool encompasses the profile matching algorithm which is based on weighted variables in a weighted sum model [
28,
29]. Specifically, there are five indexes used for ranking the potential matching of two users. Each index is assigned with one variable which receives the value 1, in case two users have a common index value and 0, in case the users have different index values.
The priority calculation formula is:
where K, W, R, U, M are the index variables, a, b, c, d, e are the weights of each variable and P is the priority value.
The five indexes and the respective variables and weights are presented in
Table 1.
The priority calculation matrix, based on the index variable values is presented in
Table 2.
Table 2.
Synergies Tool indexes with respective variables and weights.
Table 2.
Synergies Tool indexes with respective variables and weights.
Index |
Variable |
Weight |
Kind of fruit or vegetable |
K |
a = 0.35 |
Waste type |
W |
b = 0.35 |
Region |
R |
c = 0.10 |
Regional unit |
U |
d = 0.10 |
Municipality |
M |
e = 0.10 |
Table 3.
User matching priority matrix based on index variable value.
Table 3.
User matching priority matrix based on index variable value.
Priority |
K |
W |
R |
U |
M |
1 |
1 |
1 |
1 |
1 |
1 |
0.90 |
1 |
1 |
1 |
1 |
0 |
0.80 |
1 |
1 |
1 |
0 |
0 |
0.70 |
1 |
1 |
0 |
0 |
0 |
0.65 |
0 |
1 |
1 |
1 |
1 |
0.55 |
0 |
1 |
1 |
1 |
0 |
0.45 |
0 |
1 |
1 |
0 |
0 |
0.35 |
0 |
1 |
0 |
0 |
0 |
0.30 |
0 |
0 |
1 |
1 |
1 |
0.20 |
0 |
0 |
1 |
1 |
0 |
0.10 |
0 |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
Users receiving a higher priority value are then classified as more suitable candidates for waste transaction and appear higher on the Synergies Tool matching list. Users receiving the same priority value are then listed alphabetically.
Users can be waste suppliers, demanders or both based on the information they have stored on their profile. The Synergies tool provides two independent lists:
Suppliers List, presenting waste suppliers matching the user’s waste demands
Demanders List, presenting waste demanders matching the user’s waste supplies.
In case the user falls under only one category e.g. is a waste supplier, the waste supplier list shall perform the exact same algorithm showcasing the user’s competition based on the same criteria.