Influence of the methodological approaches adopted on the food waste generation ratios

Food waste (FW) accounting methodology is of paramount importance in Europe. The European Commission established a common methodology and minimum quality requirements for its measurement. Although these guidelines represents a great advance, important questions as the definition of flows, the Food Supply Chain (FSC) stages considered or the measurement methodology depending on the availability of resources remain open. The study aim is to analyze the implications of these approaches on the FW ratios, based on 109 ratios from different European frameworks obtained by literature review. Among these aspects, the considered FSC stages and the measurement methodology stand out as factors that influence the results; while the direct methods give more accurate values, the indirect methods tend to overestimate the generation. Highlight as significant result, the creation of a superstructure that collects the different approaches used in FW generation ratios and it serves as a tool for benchmarking.This work has been financially supported by the Government of Cantabria R&D project entitled “Obtaining, treatment and dissemination of data related to production and management of waste, and adjustment of the existing indicators system to the valid waste plan of Cantabria”

Sustainable management strategy for solidification/stabilization of zinc plant residues (ZPR) by fly ash/clay-based geopolymers

ABSTRACT: Solidification/stabilization (S/S) of acid waste using Ordinary Portland Cement (OPC) is widely implemented, but, due to the impact on climate change, alternative methods are being investigated. In this work, first, the feasibility of using coal fly-ash/clay-based geopolymers for the S/S of Zn plant residues (ZPR), Cadmium Sponge (CS), and Anode Mud (AM) is proposed as a treatment prior to disposal in landfills. Different variables, such as the type of processing, molding (as-received waste), and pressing (dried waste), and activators, a commercial and an alternative residual sodium carbonate, have been studied. The technical and environmental assessments of the S/S process by means of compressive strength and the leaching of critical pollutants have been monitored. Immobilization efficiencies of Cd and Zn higher than 99% have been obtained by dosing 50% of the acid waste, 6 M NaOH solution (20 min contact time), cured at 75 °C (48 h) and at room temperature (28 days), achieving in the leachates pH values of 7 to 10 and [Cd] and [Zn] < 1 and 2.5 mg/kg, respectively. However, alkaline activation increases As leaching, mainly associated with the clay. Secondly, removing clay from the geopolymer formulation, the optimization of geopolymer parameters, acid waste/geopolymer ratio, liquid/solid ratio, and NaOH molar concentration enables obtaining a significant reduction in the release of As and Cd, and Zn is kept at acceptable values that meet the non-hazardous waste landfill disposal limits for the S/S of both acid wastes.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund by means of the research project RTI2018-097612-B-C22

Methodology proposed for estimating biowaste generation using municipal rurality indexes

The separated collection and management of biowaste (BW) must be implemented in next years in the European countries. In order to define a proper BW strategy, it is necessary to estimate the generation at a municipal level, since depending on the amount to be treated, the strategy may notably vary. The aim of this study is to develop a methodology to estimate BW generation at municipal level taking into account the characteristics of the region, the Municipal Solid Waste management applied, and diferent socio-economic variables that defne the level of rurality of a municipality. A model to estimate the BW generation for each type of municipality has been developed using Multiple Linear Regression Analysis. As input data, results from a Waste Compositional Analysis executed by the regional government to samples collected on 38 municipalities and data related to infuential socio-economic variables have been used. Signifcant infuence of socio-economic variables on BW generation is observed for the rural municipalities. The evolution of these characteristics, as well as the greater awareness of society with food waste, have change the consumption patterns. Therefore, it is not recommended to use static ratios, but models that allow including socio-economic changes in the estimation of waste generation.This work has been financially supported by the Government of Cantabria R&D project entitled “Obtention, treatment and dissemination of data related to production and management of waste, and adjustment of the existing indicators system to the valid waste plan of Cantabria”. The public company MARE S.A. has provided the MSW generation data, as well as the WCA characterisations used to develop the statistical modellin

Self-organizing maps to assess the recycling of waste in ceramic construction materials

Circular economy promotes the use of waste materials into new production processes as a key factor for resource efficiency. The construction sector, and specifically the fired clay industry, is able to assimilate large amounts of waste in their processes, without significantly altering the technical properties of products. The introduction of different waste in ceramic products at the laboratory level has been extensively studied in the literature, but most of these studies have not yet been scaled-up to industrial production. Differences in processing with respect to laboratory conditions introduces uncertainty in relation to the expected properties of the final products. This paper uses a Self-Organizing Map (SOM)-based methodology for analysing and assessing the incorporation of industrial waste, Waelz slag (WS) and foundry sand dust (FSD), in ceramic products obtained sequentially at laboratory, semi-industrial and industrial level, over technological properties and metals release. As a result, from the SOM analysis, a clustered map of the samples developed is obtained that highlights the most important parameters affecting the technological and environmental properties to be the type of clay and therefore, the firing temperature; secondly, the Waelz slag content, being independent of the foundry sand addition; and finally, the type and level of processing (laboratory-pressing, semi-industrial extruder, industrial extruder).This work has been partially supported by (a) the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund by means of the research project RTI2018-097612-B-C22; (b) the BEFESA STEEL R&D, S.L.U.C. Company at Asua, Vizcaya, Spain

Waste indicators of primary sector and health & veterinary services for regional planning

When there is a need to move smoothly and effectively from an abundance of detailed field data to summarized information, indicators and indices are used. Indicators are important tools that assist decision-makers in formulating and implementing plans for the management of waste at different geographic levels. In Cantabria, a northern Spanish region, all waste streams generated are covered through four specific Waste Plans recently adopted. The present study is focused on the Primary Sector, Health & Veterinary Services Waste Plan (PHWP), which is the framework to the decision-making processes related to the generation and management of forest, agricultural, livestock, food industry and health & veterinary wastes. In this work, 16 indicators have been proposed to track the evolution over time of the management of these waste streams in the region and the degree of achievement of the policy objectives. This article discusses the way to obtain, analyse and evaluate valuable information to build the indicators, finding that only eight indicators can be applied at short term. In addition, a summary of these indicators is included, showing in general, a good trend of the evolution of primary sector, health & veterinary waste management. Finally, different actions to improve the quality of data used for the indicators development are proposed in order to obtain more useful waste indicators to the stakeholders

Influence of unburned carbon on environmental-technical behaviour of coal fly ash fired clay bricks

ABSTRACT: The incorporation of coal fly ash (CFA) in fired clay bricks (FCBs), as a clay replacement, contributes toward cleaner production practices. CFA disposal is an important issue worldwide due to its huge volume and to its potential negative environmental impacts, and currently does not have a recovery route due to its high concentration in unburned materials. In this study, the impact of the incorporation of two CFA, with different content of unburned carbon, FAA (low LOI) and FAB (high LOI) in FCBs, from a technical and environmental point of view was conducted. Unburned carbon plays an important role on the final properties of FCBs. The thermal decomposition during the firing process promotes an increase of water absorption, decreasing the flexural strength as the porosity increases, although the technical and mechanical properties of samples containing up to 30% FAA and percentages of 20% FAB are acceptable. The leaching behaviour showed an immobilisation of Cr and Se in FCBs while Mo reduced its mobility to values below non-hazardous limits. Acid gas emission values do not exceed the reference emission value, except for SO2 emissions while the level of CO2 emissions must be estimated based on the total annual production of the ceramic factory.This work was presented at the workshop “Engineering and circular economy: the road to sustainability” funded as a part of the ECO-MET-AL Project (PID2019-109520RB-I00), “Can industrial and mining metalliferous wastes produce green lightweight aggregates" Applying the Circular Economy” funded by the Spanish Ministry of Science, Innovation, and Universities and ERDF funds, framed in the “Grants for “R&D&I Projects” in the framework of the State Programmes for the Generation of Knowledge and Scientific and Technological Strengthening of the R&D&I System and R&D&I oriented to the Challenges of Society, Call 2019”

Waelz slag-based construction ceramics: effect of the trial scale on technological and environmental properties

The construction industry has already begun the transition to circular economy and intensive research has been conducted over the last decades at laboratory scale to assess the potential use of waste in ceramic applications. However, industrial trials to prove its scale up have been performed to a lesser extent. This work studies the effect of trial scale on the technological and environmental properties of high quality ceramic products incorporating Waelz slag (WS), an industrial by-product from the recovery of electric arc furnace dust. To this aim, three groups of ceramics have been produced varying the WS content and the process parameters, moulding water and pressure, at laboratory and industrial scale. Preliminary laboratory scale tests were used to optimize WS content and process conditions using the software GAMS (General Algebraic Modeling System). Optimum ceramic products were processed at both laboratory and industrial scale and tested for their technological and environmental properties. Results from the laboratory and industrial trials were compared to evaluate the scale effect on the ceramic properties. The introduction of WS in clay bricks seems to be easily scaled-up for additions of WS ≤ 10wt%, but higher percentages of WS promotes relevant differences in the properties of the laboratory and industrial bricks.This work has been funded by the Spanish Ministry for Education and Science (Project CTM 2009-11303). The authors gratefully acknowledge fnancial support for this research from BEFESA STEEL R&D, S.L.U.C. Company at Asua, Vizcaya, Spain

Primary sector waste indicators for regional planning

Decisions are made based on information of different kinds and several tools have been developed to facilite the inclusion of environmental aspects in decision-making. One of these tools is the indicators that have become a vital component of environmental impact assessments and "state of the environmental" reporting. In Cantabria, a northern Spanish region, a specific set of indicators has been developed to monitor the degree of implementation of waste policies recently adopted in the region, identified in the Cantabria Regional Waste Plan 2010- 2014. This Regional Planning covers all waste streams generated: There is a Regional Waste Plan developed through four Sectorial Waste Plans on: (i) Primary Sector and Sanitary Waste; (ii) Industrial, Construction and Demolition, and Mining Waste; (iii) Special Waste, and (iv) Municipal Waste. At the present time, the primary sector waste flows in Cantabria are outstanding, since it is a region where the primary sector is one of the driving forces of the economy together with the tourism. The 86% of municipalities are classified as rural or semirural, and there, it is producing a large rural development from traditional craft production to intensive farms in which waste management is becoming a problem. In this work the methodology developed by European Environmental Agency has been used as a starting point in developing a set of Specific Indicators on the primary sector waste. Eleven indicators have been developed to evaluate the generation and management of forest, agricultural, livestock and food industry waste. These indicators allow not only monitoring the primary sector waste management, but also they highlight the precarious situation in relation to knowledge of actions undertaken in the sector in relation to their waste and with the information flows. Therefore, in this paper the analysis of difficulties for management the available information has been carried out

Case study about the student perceptions of the flipped classroom model in engineering subjects. Design and implementation of a questionnaire

RESUMEN: La incursión de las Nuevas Tecnologías de la Información y la Comunicación en las aulas universitarias, ha potenciado y favorecido el desarrollo de modalidades pedagógicas alterativas a las tradicionales. La Flipped Classroom, se ha configurado como un modelo adecuado para la enseñanza de las asignaturas de ingeniería, optimizando el tiempo de trabajo en el aula y preparando materiales para el aprendizaje de los estudiantes fuera del mismo. En este estudio, se presenta una experiencia basada en el modelo Flipped Classroom desarrollada con 151 estudiantes de ingeniería. A través de un cuestionario diseñado ad hoc, se han recogido sus percepciones sobre la experiencia respecto a los materiales y recursos, las ayudas docentes y el rol del estudiante. Los principales resultados señalan que el modelo favorece el rol activo por parte de los estudiantes, y les exige un mayor esfuerzo y seguimiento diario. Igualmente, se presentan algunas propuestas de mejora para su futuro desarrollo.ABSTRACT: New Technologies of Information and Communication in the university classrooms have promoted the development of alternative pedagogical modalities to the traditional ones. The Flipped Classroom, has been considered as a suitable model for teaching engineering subjects, due to it is useful for optimizing the time of work in the classroom and preparing materials for students learning outside it. In this study, an experience based on the Flipped Classroom model developed with 151 engineering students is presented. Through an ad hoc designed questionnaire, their perceptions about the experience have been collected experience with materials and resources, teaching aids and the role of the student. The main results suggest that the model favors an active role for the students, and demands a greater effort and daily follow-up. Likewise, some proposals for improvement are presented for its future development