Landfilling is the main method to manage municipal solid waste (MSW) in Latin America due to the economic, technological and political characteristics of the region. The disposal of MSW in landfill sites may affect the quality of the environment and compromise a considerable share of the municipal budgets. The selection of suitable sites reduces the environmental and economic impact of landfills. In the present study the sustainable location index (SLI) is proposed as a methodology to assess environmentally, and economically, sanitary landfill site selection in the Metropolitan Area of Monterrey, a representative large-size city of Latin America. EVIAVE methodology was modified to include administrative and economic dimensions, which are assessed as a sustainable approach using together the SLI integrated with geospatial and multicriteria analysis tools. The assessment showed that the zones with the lowest SLI changes drastically when the importance of the economic or environmental factor varies. This result suggest that the inclusion of sustainability in landfill site selection decision-making is complex and it may requires the inclusion of local particularities such as municipal budgets, policies of MSW management and public perception about environmental deterioration.

In this study, an environmental and economic assessment of hydrogen production from biowaste and biomass is performed from a life cycle perspective, with a high degree of primary life cycle inventory data on materials, energy, and investment flows. Using SimaPro LCA software and CML-IA, 2001 impact assessment method, ten environmental impact categories are analyzed for environmental analysis. Economic analysis includes capital and operational expenditures and monetization cost of life cycle environmental impacts. The hydrogen production from biowaste has a high climate impact, photochemical oxidant, and freshwater eutrophication than biomass while it performs far better in ozone depletion, terrestrial ecotoxicity, abiotic depletion-fossil, abiotic depletion, human toxicity, and freshwater ecotoxicity. The sensitivity analysis of LCA results indicates that feedstock to biogas/pyrolysis-oil yields ratio and the type of energy source for the reforming process can significantly influence the results, particularly climate change, abiotic depletion, and human toxicity. The life cycle cost (LCC) of 1 kg hydrogen production has been accounted as 0.45–2.76 € with biowaste and 0.54–3.31 € with biomass over the plant's lifetime of 20 years. From the environmental impacts of climate change, photochemical oxidant, and freshwater eutrophication hydrogen production from biomass is a better option than biowaste while from other included impact categories and LCC perspectives it’s biowaste. This research contributes to bioresources to hydrogen literature with some new findings that can be generalized in Europe and even globally as it is in line with and endorse existing theoretical and simulation software-based studies.

Long-term sustainable biogas production requires different raw material alternatives, especially when reducing the most desirable organic substrate, food waste, which has been set as a goal in the 2030 Agenda. In Sweden, horse manure (HM) is generated in large quantities, and due to its physical and chemical characteristics, it has the potential to be used as a raw material to produce biogas through anaerobic digestion (AD). In order to investigate the challenges that HM digestion can impose in terms of methane yield and/or digestate quality, the modified ORganic WAste REsearch (ORWARE) AD model was applied. The aim was to study the effects of different substrates and combinations of these on the AD process during a full-scale solid-state (SS)-AD. In this sense, the model allows for the analysis of the digestion process of multicomponent substrates at the element level. The simulation results suggested that the replacement of green waste (GW) by HM with wood chips as bedding material gave the best improvement in terms of energy turnover; the liquid fraction of the digestate of this mixture of substrates presented the highest concentration in all the nutrients analyzed, specifically in total carbon-biological and phosphorus. The nutrient concentrations in the digestate from the aforementioned scenario are in line with the SPCR120 certification.

Biofuels policy instruments are important in the development and diffusion of biogas as a transport fuel in Sweden. Their effectiveness with links to geodemographic conditions has not been analysed systematically in studying biogas development in a less urbanised regions, with high potential and primitive gas infrastructure. One such region identified is Gävleborg in Sweden. By using value chain statistics, interviews with related actors, and studying biofuels policy instruments and implications for biogas development, it is found that the policy measures have not been as effective in the region as in the rest of Sweden due to different geodemographic characteristics of the region, which has resulted in impeded biogas development. In addition to factors found in previous studies, the less-developed biogas value chain in this region can be attributed particularly to undefined rules of the game, which is lack of consensus on trade-off of resources and services, unnecessary competition among several fuel alternatives, as well as the ambiguity of municipalities’ prioritization, and regional cultural differences. To strengthen the regional biogas sector, system actors need a strategy to eliminate blocking effects of identified local factors, and national policy instruments should provide mechanisms to process geographical conditions in regulatory, economic support, and market formation.

The creation of pathways toward a societal transition to clean energy requires the engagement of multiple stakeholders with different and sometimes conflicting interests. In this connection, stakeholder analysis (SA) offers a technique for identifying, assessing and structuring different needs, interests and concerns related to different stakeholders within the context of sustainability. This article aims to present the findings from a qualitative stakeholder analysis (QSA) by using a thematic network approach (TNA), with the help of the ATLAS.ti software. It focuses on Project X, which was aimed at engaging multiple stakeholders and creating favorable conditions for small and medium-sized companies in a region situated in the central part of Sweden, with the potential to start biogas production. In this work, the findings and discussions of the QSA using TNA are structured by using the political, economic, social, technological, environmental and legal (PESTEL) themes of the model. The present study concludes that for the small-scale biogas industry to successfully develop an understanding of the possibilities of the biogas value chain, it is necessary to have analyzed the nature of the main themes by which various stakeholders relate to biogas production and envision their contribution to creating a sustainable society. Herein, we demonstrate that QSA by a TNA, combined with the application of a PESTEL model, are valuable analytical tools in sustainable project management. The lessons from Project X can be applied to other local biogas initiatives, as many identified threats and opportunities are shared by others. 

Both in the Central Baltic (CB) countries and Russia, there is a need to develop current education regarding resource efficiency, which is a relatively new and complex issue. The aim of the paper is to present the results of the two parallel twinning international projects "CREA-RE" (Creating aligned studies in Resource Efficiency) and "CREA-RE-RU" (Creating aligned studies in Resource Efficiency in Sweden and Russia), which has been realized from 2018 to 2020. The main goal of the projects was to produceup-to-date aligned training materials for the higher vocational education training (VET) institutions around the CB and enhance cooperation between companies and higher VET. The project promoted the mainstreaming process in the region and best practices through addressing companies and future workers, i.e. students. The overall objective has been achieved through 1) Aligning and producing learning content to be used in higher environmental VET studies; 2) Producing a channel to share aligned materials; 3) Implementing joint innovative cooperation between companies and higher VET to ensure better matching of work opportunities in sustainable business. The activities enabled the creation of a holistic view of students and companies in the theme of resource efficiency and circular economy. Based on different know-how of the partners on the relatively new and complex issues within the theme of resource efficiency and circular economy, the project created aligned e-learning material with a new perspective in the area. Joint practice-oriented case studies promoted companies’ awareness on resource efficiency and enhance their competitiveness, meanwhile enable institutions’ better understanding of the needs in the working life. New information produces a competent labor force to support the integration of the CB labor market, also including Russia. 

The configuration of the reactor influences the digestion process and thus the product yields; other factors such as the rate of biogas production or biogas loss also affect the process specifically with high solid configuration. With these in mind, the ORganic WAste REsearch (ORWARE) anaerobic digestion sub-model was modified to be able to study solid-state anaerobic digestion (SS-AD) (using plug-flow reactor). The simulation results from the updated model agreed with the operational data with respect to methane yield, digestate yield and energy turnover. The model was found to be sensitive to changes in feedstock composition but to a lesser extent to changes in process temperature and retention time. By applying the model on several cases of liquid anaerobic digestion (L-AD), it was noticed that L-AD at mesophilic condition with 25 retention days seemed to be superior to other cases of L-AD with regard to energy turnover. However, even if similar methane production were observed for L-AD and SS-AD, the model suggested higher energy turnover for the case of SS-AD at thermophilic condition, being 10% more in average in comparison with cases of L-AD.

In developing countries like Turkey, food waste has the highest share compared to other municipal solid waste components. A detailed life cycle assessment has been performed to evaluate different food waste management options (i.e., landfilling, anaerobic digestion, thermal treatment, co-treatment with municipal wastewater) for Istanbul which is the largest city of Turkey and Europe. The current waste management has the worst environmental performance compared to proposed waste management scenarios as follows: Anaerobic digestion, thermal treatment and co-treatment with municipal wastewater. The thermal treatment scenario has been found to have the best environmental performance in most of the impact categories including climate change. The anaerobic digestion scenario ranks in the first place only in freshwater eutrophication, which is attributed to avoided fertilizer use in this scenario. A drastic improvement with 866% has been found in this category if the anaerobic digestion scenario was followed. Co-treatment with municipal wastewater refers to use of food waste disposers at households and provides improvements especially in marine eutrophication and ecotoxicity. Lower effluent emissions by means of biological wastewater treatment in the co-treatment scenario compared to other proposed scenarios lead to better performance in these categories. Various sub-scenarios have also been investigated such as using biogas as vehicle fuel, replacing a combined heat and power with a condensing plant and increasing food waste addition to sewer lines. Important improvements are not achievable in the first two sub-scenarios; however, increasing food waste addition to sewer lines reduces various environmental impact categories by −41% and −60%. © 2019 Elsevier Ltd

Solid-state anaerobic digestion (SS-AD) takes place when solid content of the substrate is higher than 15%. Some advantages of this technology have been recognized as e.g., less required water added to raw feedstock and consequently minimized digester size and cost, higher volumetric organic loading rates (OLR) that may lead to higher efficiency methane yield and better acceptance of a wide range of feedstocks. However, scientific studies of SS-AD at pilot- and full-scale are very few and difficulties have been reported in operating SS-AD, especially when the system undergoes a scale-up, where methane production is the purpose. As a result, this review gives a summary of scientific studies for SS-AD processes at laboratory-, pilot- and full-scale, where a great diversity of substrate composition, reactor design and operational parameters have been categorized, and their performances in terms of methane yield have been analyzed. This, in turn, helps to identify that factors affecting methane yields at different scales arise mainly from operational conditions as well as the characteristic of feedstocks. This review even contributes to suggest several strategies for improvement of methane yield at full-scale.

Life cycle assessment (LCA) is a beneficial tool to evaluate the performance of wastewater treatment plants (WWTPs) and to compare different upgrading options. The main objective of this study is to investigate the environmental impact of upgrading options of a preliminary WWTP in Istanbul, Turkey. The preliminary plant currently consists of mechanical treatment units and various upgrading options including primary treatment and high-rate activated sludge system (HRAS) process as well as the addition of food waste to wastewater were compared. Results showed that the baseline scenario (S0) had worse performance than all future scenarios (S1-3) except for climate change. The scenario of adding food waste to wastewater (S3) has the best performance in climate change, terrestrial acidification, terrestrial ecotoxicity and fossil depletion. Increased addition of food waste was also tested in the sensitivity analysis, and major improvements were obtained especially in climate change and terrestrial ecotoxicity.