Method selection for sustainability assessments: The case of recovery of resources from waste water

Sustainability Assessment of Water Resources Use in 31 Provinces in China: A Combination Method of Entropy Weight and Cloud Model

As a fundamental and strategic resource, water is a crucial controlling element of ecosystem and natural environment and it plays an irreplaceable role in maintaining and promoting the sustainable development of the economy and society. To achieve the sustainable development of society, the economy and ecology, it is necessary to assess and improve the sustainability of water resources use. Based on the Human-Resource-Nature approach, this paper constructed an indicator system for the sustainability assessment of water resources use (ISSAWRU) in China from three perspectives: water resources condition, socio-economy and ecological environment. A five-level hierarchy of assessment indicators was established. Based on the entropy weight method and the cloud model which took both fuzziness and randomness into account, this paper established an entropy-cloud-based assessment model for the sustainability assessment of water resources use in 31 provinces in China in 2019. The assessment results were compared with results obtained by the TOPSIS method to test their reliability. Finally, a comprehensive and in-depth analysis of the sustainability of water resources use in China was conducted. According to the results, water resources per capita had a weighting of 0.306 and the greatest impact on the sustainable use of water resources. In addition, water structure, agricultural water use efficiency, forest coverage, and so on, had a significant impact on the sustainable use of water resources in China. The overall level of sustainability of water resources use in 31 provinces in China was not high-42% of the regions have unsustainable water resources use and there was a clear spatial distribution trend. The sustainability level of water resources use was higher in the southeast and economically developed regions. Therefore, each region should develop measures to guarantee water security based on the local conditions. This research helps policy makers to figure out the contributing factors associated with sustainability of water resources use and to set relevant rules and regulations to promote the use of water resources in a sustainable way.

Improved science-based transformation pathways for the development of safe and sustainable plastics

Projected plastic production volumes are rising, as is societal and political attention to plastic pollution and possible health impacts. In line with ambitions for climate mitigation and the circular economy, various national and international policies and action plans address the reduction of impacts of plastics. Quantitative scenario analyses show that even if current ambitious targets to reduce plastics are achieved, plastics will remain a source of millions of tons of environmental pollution annually. To achieve a sustainable transformation of the global plastics economy, 'extraordinary effort' and 'coordinated global action' beyond current ambitions are needed. While mapping knowledge gaps for the effects of micro and nano plastics (MNP) is crucial, mapping alone is not enough to achieve the needed transition. In this communication, we propose a scope for the exploration of societal transformation pathways to safe and sustainable plastics. To see which efforts are needed globally we need to advance in the following three areas: (i) embedding risk assessment methodologies in wider cost-benefit and life cycle analyses; (ii) using safe-and-sustainable design strategies that include alternative solutions and look at multiple life cycles, and (iii) reflecting on the societal transformation pathways with stakeholders by using co-created quantitative models. We believe that these practices are crucial in the coming decade to realise the extraordinary effort of defining safe and sustainable plastics.

Challenges and opportunities for more efficient water use and circular wastewater management. The case of Campania Region, Italy

By 2050, global demand for water is expected to increase by some 55% due to population growth and urbanization. The utilization of large amounts of freshwater in the world, generate huge volumes of wastewater of which, globally, more than 80% is discharged without treatment, thus causing impacts on aquatic ecosystems, human health and economic productivity. More sustainable practices of wastewater management are expected as a way towards circular bioeconomy (CBE) processes, whose goal is to implement closed systems promoting the systematic use of recycling, reuse and recovery of bioproducts and by-products and the reduction of waste generation. This approach, if adopted in the water and wastewater sector, can ensure environmental, economic and social benefits. The reuse of wastewater, on the one hand, reduces the volume of wastewater and the pressure on water bodies; on the other hand, the recovery of nutrients (P or N) and/or other high value bioproducts (biogas, cellulose, biopolymers) from wastewater offers numerous advantages in terms of supplying new raw bio-based materials that can be refed back to supply chains (thus substituting fossil resources) and, at the same time, producing cleaner water to be reused. Nevertheless, while in Europe many industries have demonstrated the ability to recycle and reuse water, in many regions of Italy the sustainable management of water and wastewater is not yet consolidated. In this study we explore the available technological, economic and environmental options concerning water use and wastewater treatment and we apply them to design appropriate scenarios for improved use efficiency and circular management. A comprehensive literature review of the most promising wastewater treatment processes for resources and energy valorization was conducted. The recovery of PHAs, struvite, nitrogen and algal biomass, as potential substitutes for conventional PET, phosphate and nitrogen chemical fertilizers and electricity, respectively, in addition to reusable treated water, were hypothesized and carefully discussed. Resulting scenarios are tested against the present situation of Campania Region (situated in Southern Italy) based on population and demand statistics, in order to develop strategies and policies potentially applicable locally and elsewhere.

Application of Internet of Things and Naive Bayes in Public Health Environmental Management of Government Institutions in China

As the builder and maintainer of the city appearance and environment, the city appearance and environmental service industry provides urban residents with a beautiful, livable, and comfortable living environment and is also responsible for providing city appearance and environmental public health services for the economic and social functions carried by the global cities task. Based on this problem, this study has carried out the work of government agencies' public health environmental management and influencing factors based on the Internet of Things and edge computing. This study analyzes the influencing factors of public health environmental management of government agencies based on traditional research and conducts data analysis through the Naive Bayes algorithm. On this basis, the study combines the Internet of Things technology to construct system architecture for public health environmental management. The proposed management system is used to manage government agencies, which meets security, privacy and efficiency, and data security requirements. Experimental results prove that after algorithm optimization and architecture design, the evaluation level of the public health environment is significantly improved.

Sustainability assessment of organic waste management in three EU Cities: Analysing stakeholder-based solutions

This study focuses on a comprehensive sustainability assessment of the management of the organic fraction of municipal solid waste in Ghent (Belgium), Hamburg (Germany) and Pécs (Hungary). A sustainability assessment framework has been applied to analyse social, environmental, and economic consequences at the midpoint level (25 impact categories) and at the endpoint level (5 areas-of-protection). For each case study, the reference scenario was analysed, along with three solutions to improve the sustainability performance, which were selected and developed with the collaboration of local stakeholders. The solutions focus on food waste prevention, collection (increasing separate collection and household composting) and/or valorisation treatment (insect breeding, bioplastic production and improvement of centralised treatment). The results show that food waste prevention results in substantial improvements in all areas of protection when a significant quantity of food is saved. Solutions proposing innovative treatments such as insect breeding do not show clear improvements at the endpoint level, given current technology development level, but appear promising for some categories such as Revenues, Ecotoxicity, Land Use or Particulate Matter if the substituted products compensate the impact of the treatment (e.g., energy and water use). Enhancing the separate collection of organic waste can improve sustainability, but trade-offs may arise, e.g., decreased environmental savings from energy recovery at incineration. For this, the influence of the electricity mix (more or less decarbonised) should be carefully considered in future studies. The application of the solutions proposed to other cities should also consider potential bottlenecks such as legislation barriers, public acceptance, or management costs.

Implications for Sustainability of the Joint Application of Bioeconomy and Circular Economy: A Worldwide Trend Study

The joint application of bioeconomy (BE) and circular economy (CE) promotes the sustainable use of natural resources, since by applying a systemic approach, it improves the efficiency of these resources and reduces the impact on the environment. Both strategies, which belong to the area of green economy, provide a global and integrated approach towards environmental sustainability, as regards the extraction of biological materials, the protection of biodiversity and even the primary function of food production in agriculture. The objective was to analyze the implications for sustainability of BE and CE joint application. A systematic and bibliometric review has been applied to a sample of 1961 articles, selected from the period 2004–May 2021. A quantitative and qualitative advance is observed in this field of study. The expansion of scientific production is due to its multidisciplinary nature, since it implies technical, environmental and economic knowledge. The main contribution of this study is to understand the state of research on the implications for sustainability that BE and CE have when combined, in relation to their evolution, the scientific collaboration between the main driving agents, and the identification of the main lines of research developed.

Low-Carbon Urban Water Systems: Opportunities beyond Water and Wastewater Utilities?

The provision of urban water and wastewater services contributes to greenhouse gas (GHG) emissions. Urban water supply and wastewater utilities can potentially achieve low-carbon or carbon-neutral operation through many "utility opportunities". Outside the jurisdiction of water utilities, many water-related "wider opportunities" can also contribute to GHG emissions abatement for cities. This study aims to explore the GHG emissions abatement potential, cost effectiveness, and enabling factors of implementing wider opportunities in cities. Using Amsterdam as a case study, we developed a marginal abatement cost curve to compare the abatement potential and cost effectiveness of both utility and wider opportunities. The results show that many wider opportunities related to thermal energy, water end use, and life cycle are cost-effective with significant abatement potential, compared to utility opportunities. This case study and emerging worldwide examples show that the water industry has a role to play to support wider water-related opportunities in cities. This vision can be supported by developing mechanisms to credit utilities for wider opportunity initiatives, building inter- and intrasectoral partnerships for utilities, accounting for scope 3 emissions of utilities, and being open to extend utilities' role beyond water and wastewater services providers.

Quantitative sustainability assessment of household food waste management in the Amsterdam Metropolitan Area

Food waste represents the largest fraction of the municipal solid waste generated in Europe and its management is associated to suboptimal performance in environmental, health, and social dimensions. By processing detailed multi-fold local data as part of a comprehensive and broadly understandable sustainability framework, this study quantifies the environmental and socio-economic impacts of household food waste management in the Amsterdam Metropolitan Area based on priorities set by local stakeholders. Five alternative short-term management options have been assessed against the current system, relying on poor separate collection and incineration. Four options involve separate collection of food waste followed by biological treatments (home/centralised composting and anaerobic digestion) while one involves a mix of separate collection and centralised mechanical-biological treatment followed by anaerobic digestion. Among these, separate collection followed by anaerobic digestion coupled with effective nutrient and energy recovery is, according to our findings, the preferred option to improve the sustainability of the current system in all dimensions considered, except for the economic pillar due to the collection costs. Home and centralised composting as well as mechanical-biological treatment are associated to more adverse impacts based on our findings. The study informs local stakeholders and authorities on the potential consequences of their options, thereby allowing them to make sound choices for a future waste and circular economy strategy.

Phosphorus recovery from municipal wastewater treatment: Critical review of challenges and opportunities for developing countries

The aim of this paper is to provide guidance in selecting phosphorus recovery options within the municipal wastewater treatment sector regarding developing countries. This critical review includes a brief contextualization of the resource-oriented sanitation paradigm, the discussion of processes for phosphorus recovery based on methods at full-scale, pilot-scale and laboratory-scale, and a concise discussion of the environmental impacts and benefits associated with phosphorus recovery strategies. Finally, the main challenges related to the implementation of resource recovery strategies, especially for phosphorous, were identified and discussed. According to the results, some of the main drivers for phosphorus recovery are the limited availability of phosphorus, increasing cost of phosphate fertilizers and reduction of maintenance costs. Currently, most of the operational processes are based on crystallization or precipitation from the digester supernatant. Struvite is the most common recovered product. The recovery rate of phosphorus from the liquid phase is lower (10-60% from wastewater treatment plant influent), than from sludge (35-70%) and from sludge ashes (70-98%). Phosphorus recovery remains challenging, and some barriers identified were the integration between stakeholders and institutions, public policies and regulations as well as public acceptance and economic feasibility. In developing countries, the implementation of nutrient recovery systems is challenging, because the main concern is on the expansion of sanitation coverage. Resource recovery approaches can provide benefits beyond the wastewater treatment sector, not only improving the sustainability of wastewater treatment operations, but generating revenue for the utility provider.

Planning for achieving low carbon and integrated resources recovery from sewage treatment plants in Minas Gerais, Brazil

There is an enormous deficit in sanitation infrastructure in most Brazilian cities. To tackle this challenge, it is crucial to conceive the new sanitation infrastructure based on sustainability principles, including an integrated approach for the management of the liquid, solid and gaseous phases. This study aimed at developing sustainable sewage treatment flowsheets for different scales and regional scenarios in the state of Minas Gerais. Two watersheds were chosen as study areas, due to their remarkable regional importance and socioeconomic and environmental diversity, i.e. Rio das Velhas and Jequitaí-Pacuí. Currently available processes for sewage treatment and resources recovery were assessed based on: literature review and benchmarking of operational practices, experiences reported by sanitation companies, techno-economic feasibility of resource recovery and carbon footprint assessment of anaerobic-based technologies. Social acceptance was also considered. A total of 15 sustainable flowsheets were proposed, comprising passive/natural systems (stabilization ponds, constructed wetlands and controlled land application), anaerobic process combined with natural systems (UASB reactors followed by controlled land application, constructed wetlands or polishing ponds) and compact anaerobic/aerobic systems (UASB reactors followed by activated sludge or trickling filters). Processes selected for small-scale sewage treatment plants (STPs) (people-equivalent - PE < 10,000 inhab.) intended to be integrated into local communities and economic activities. Large-scale STPs (especially those with PE > 100,000 inhab.) were conceived as industries, where a wide range of resources (e.g. sand for non-structural concrete, biogas for electricity, sludge for thermal energy) could be recovered from the influent sewage. Results obtained from the current study could serve as support for decision-making on the planning and implementation of new sustainable sanitation solutions in the state of Minas Gerais and possibly in other regions of Brazil and other developing countries.

Employing SWOT Analysis and Normal Cloud Model for Water Resource Sustainable Utilization Assessment and Strategy Development

Water Resource Sustainable Utilization (WRSU) is becoming increasingly important, given growing water resource shortages and widening gaps between water supply and demand. Most existing studies have focused on WRSU levels without a dedicated strategy-oriented framework. In addition, uncertainties occur in the process of indicator quantification and grading, leading to a lack of accuracy in the assessment results. Therefore, in this study, stemming from water resource, societal, economic, and environmental dimensions, an indicator system with qualitative description was introduced by Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis to enable development and selection of sustainable water use strategies. A normal cloud model that is capable of addressing uncertainties was used to determine WRSU levels. The comprehensive evaluation results can both reflect the WRSU levels and select the most suitable strategy. The model’s utility was demonstrated by applying it to the case of Shandong province in China. Based on the results, most areas of Shandong province appear to be facing serious unsustainable issues. Appropriate development strategies based on the WRSU levels were provided for improving sustainable use of water resources. The proposed method offers an efficient means for WRSU assessment and strategy development. Moreover, it has the potential to be applied to other water resource issues.