Building multi-system nexuses in low-carbon transitions: Conflicts and asymmetric adjustments in Norwegian ferry electrification.

While nexus research in sustainability science has investigated the consequences of connected systems, it has paid less attention to the processes of building nexuses which is becoming increasingly important in low-carbon transitions because these often require the creation of new connections between multiple consumption-production systems. Building on multi-system research in the sustainability transitions literature, this paper introduces a conceptual system interface perspective on nexus-building which considers four dimensions (technology, actors, institutions, and resources) that are useful for analyzing nexus-building dynamics. We apply our framework to the case of electrification of ferries in Norway which requires the building of a new interface between the electricity system and the maritime transport system. The case study shows that the system interface was initially characterized by conflicts and tensions in all dimensions, which actors then attempted to resolve through cross-system intermediation and adjustment activities. These activities were asymmetrical because of differences in external pressures, urgency, unequal power relationships, and different degrees of interest in cross-system nexus building. Because important tensions remained unresolved, ferry actors started implementing sub-optimal workaround solutions in the diffusion phase.

Comparison of actigraphy-measured and parent-reported sleep in association with weight status among preschool children.

This study compared weekday and weekend actigraphy-measured and parent-reported sleep in relation to weight status among preschool-aged children. Participants were 3-6 years old preschoolers from the cross-sectional DAGIS-study with sleep data for ≥2 weekday and ≥2 weekend nights. Parents-reported sleep onset and wake-up times were gathered alongside 24 h hip-worn actigraphy. An unsupervised Hidden-Markov Model algorithm provided actigraphy-measured night time sleep without the guidance of reported sleep times. Waist-to-height ratio and age-and-sex-specific body mass index characterised weight status. Comparison of methods were assessed with consistency in quintile divisions and Spearman correlations. Associations between sleep and weight status were assessed with adjusted regression models. Participants included 638 children (49% girls) with a mean ± SD age of 4.76 ± 0.89. On weekdays, 98%-99% of actigraphy-measured and parent-reported sleep estimates were classified in the same or adjacent quintile and were strongly correlated (rs = 0.79-0.85, p < 0.001). On weekends, 84%-98% of actigraphy-measured and parent-reported sleep estimates were respectively classified and correlations were moderate to strong (rs = 0.62-0.86, p < 0.001). Compared with actigraphy-measured sleep, parent-reported sleep had consistently earlier onset, later wake-up, and greater duration. Earlier actigraphy-measured weekday sleep onset and midpoint were associated with a higher body mass index (respective ß-estimates: -0.63, p < 0.01 and -0.75, p < 0.01) and waist-to-height ratio (-0.004, p = 0.03 and -0.01, p = 0.02). Though the sleep estimation methods were consistent and correlated, actigraphy measures should be favoured as they are more objective and sensitive to identifying associations between sleep timing and weight status compared with parent reports.

Electrified Solar Zero Liquid Discharge: Exploring the Potential of PV-ZLD in the US.

Current brine management strategies are based on the disposal of brine in nearby aquifers, representing a loss in potential water and mineral resources. Zero liquid discharge (ZLD) is a possible strategy to reduce brine rejection while increasing the resource recovery from desalination plants. However, ZLD substantially increases the energy consumption and carbon footprint of a desalination plant. The predominant strategy to reduce the energy consumption and carbon footprint of ZLD is through the use of a hybrid desalination technology that integrates renewable energy. Here, we built a computational thermodynamic model of the most mature electrified hybrid technology for ZLD powered by photovoltaic (PV). We examine the potential size and cost of ZLD plants in the US. This work explores the variables (geospatial and design) that most influence the levelized cost of water and the second law efficiency. There is a negative correlation between minimizing the LCOW and maximizing the second-law. And maximizing the second-law, the states that more brine produces, Texas is the location where the studied system achieves the lowest LCOW and high second-law efficiency, while California is the state where the studied system is less favorable. A multiobjective optimization study assesses the impact of considering a carbon tax in the cost of produced water and determines the best potential size for the studied plant.

Water rights trading planning and its application in water resources management: A water-ecology-food nexus perspective.

Nexus approach provides an effective perspective for implementing synergetic management of water resources. In this study, an interval two-stage chance-constrained water rights trading planning model under water-ecology-food nexus perspective (ITCWR-WEF) is proposed to analyze the interaction between water trading and water-ecology-food (WEF) nexus, which fills in the water resources management gaps from a novel nexus perspective. ITCWR-WEF incorporates hydrological simulation with soil and water assessment tool (SWAT), water rights configuration with interval two-stage chance-constrained programming (ITCP), and multi-criterion analysis with Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). The developed ITCWR-WEF is applied to a real case of Daguhe watershed, which has characteristics of water scarcity, food producing areas and fragile ecosystem. Initial water rights allocation is addressed before the trading. Mechanisms analysis is designed to reveal mutual effect of water rights trading and WEF nexus. Optimal water management scenario is identified through multi-criterion analysis. Results reveal that the mechanism of water rights trading with WEF nexus under low constraint-violation risk level of water availability and environment capacity is recommended to promote the rational water resources allocation to balance the economic goals, water environment and water supply security, as well as ecological and food water demand guarantees.

'Forgotten crises' as forgotten sites of knowledge production for building lasting peace.

'Forgotten crises' constitute a permanent background to any present and future global humanitarian and development efforts. They represent a significant impediment to promoting lasting peace given concurrent catastrophes exacerbated by climate change. Yet, they are routinely neglected and remain unresolved. Building on critical and feminist approaches, this paper theorises them as forgotten sites of local knowledge production. It asks: what is local knowledge of and from forgotten crises? How can it be recovered and resignified, and what lessons can such knowledge provide at the global level? Drawing on examples from the intersections of conflict, disasters, and pandemics in the Philippines, the paper makes a case for valuing local knowledge arising from forgotten crises because of its potential contribution to adapting global humanitarian and development systems to address crises on multiple fronts. Such epistemic margins are generative of vantage points that can present a fuller account of how different crises interact and how best to respond to them.

Effectiveness of implementation strategies for increasing clinicians' use of five validated imaging decision rules for musculoskeletal injuries: a systematic review.

BACKGROUND: Strategies to enhance clinicians' adherence to validated imaging decision rules and increase the appropriateness of imaging remain unclear. OBJECTIVE: To evaluate the effectiveness of various implementation strategies for increasing clinicians' use of five validated imaging decision rules (Ottawa Ankle Rules, Ottawa Knee Rule, Canadian C-Spine Rule, National Emergency X-Radiography Utilization Study and Canadian Computed Tomography Head Rule). DESIGN: Systematic review. METHODS: The inclusion criteria were experimental, quasi-experimental study designs comprising randomised controlled trials (RCTs), non-randomised controlled trials, and single-arm trials (i.e. prospective observational studies) of implementation interventions in any care setting. The search encompassed electronic databases up to March 11, 2024, including MEDLINE (via Ovid), CINAHL (via EBSCO), EMBASE (via Ovid), Cochrane CENTRAL, Web of Science, and Scopus. Two reviewers assessed the risk of bias of studies independently using the Cochrane Effective Practice and Organization of Care Group (EPOC) risk of bias tool. The primary outcome was clinicians' use of decision rules. Secondary outcomes included imaging use (indicated, non-indicated and overall) and knowledge of the rules. RESULTS: We included 22 studies (5-RCTs, 1-non-RCT and 16-single-arm trials), conducted in emergency care settings in six countries (USA, Canada, UK, Australia, Ireland and France). One RCT suggested that reminders may be effective at increasing clinicians' use of Ottawa Ankle Rules but may also increase the use of ankle radiography. Two RCTs that combined multiple intervention strategies showed mixed results for ankle imaging and head CT use. One combining educational meetings and materials on Ottawa Ankle Rules reduced ankle injury imaging among ED physicians, while another, with similar efforts plus clinical practice guidelines and reminders for the Canadian CT Head Rule, increased CT imaging for head injuries. For knowledge, one RCT suggested that distributing guidelines had a limited short-term impact but improved clinicians' long-term knowledge of the Ottawa Ankle Rules. CONCLUSION: Interventions such as pop-up reminders, educational meetings, and posters may improve adherence to the Ottawa Ankle Rules, Ottawa Knee Rule, and Canadian CT Head Rule. Reminders may reduce non-indicated imaging for knee and ankle injuries. The uncertain quality of evidence indicates the need for well-conducted RCTs to establish effectiveness of implementation strategies.

In Silico Phototoxicity Prediction of Drugs and Chemicals by using Derek Nexus and QSAR Toolbox.

Phototoxicity testing is crucial for evaluating the potential harmful effects of pharmaceuticals and chemicals on human skin when exposed to sunlight. Traditional in vivo models involving mice, rats, guinea pigs, as well as in vitro assays such as the 3T3 Neutral Red Uptake phototoxicity assay and methods based on the use of reconstructed human epidermis, have been established for phototoxicity testing. While these approaches are extremely valuable, they are costly in terms of both time and resources. Consequently, in silico approaches based on the use of predictive software tools can offer more rapid and cost-effective phototoxicity screening solutions. With this goal in mind, the current study evaluated two in silico tools - Derek Nexus 6.1.0/Derek Knowledge Base 2020 1.0 (Lhasa Limited, UK) and the QSAR Toolbox (v 4.5) developed by the Organisation for Economic Co-operation and Development (OECD) - for their capacity to predict the phototoxicity of several substances from diverse classes. Derek Nexus and the QSAR Toolbox were both found to be very useful for predicting the phototoxicity of drugs and other chemicals. Derek Nexus predicted phototoxicity of the compounds, with a sensitivity of 63%, specificity of 93%, Positive Predictive Values of 90% and Negative Predictive Value of 69%, overall accuracy of 77% and balanced accuracy of 78%. The QSAR Toolbox achieved sensitivity of 73%, specificity of 85%, Positive Predictive Value of 85% and Negative Predictive Value of 74%, overall accuracy of 79% and balanced accuracy of 79%. The results show that Derek Nexus and the QSAR Toolbox can be usefully incorporated in the workflow of phototoxicity testing for pharmaceuticals and chemicals.

Applying a climate-biodiversity-health framework to support integrated food systems planning and policy.

Food systems impact different aspects of sustainability and human life, such as pollution, health, climate change, biodiversity loss, water shortage, and soil infertility. However, in many places, food systems are neither resilient nor sustainable. Integrated planning approaches can help to overcome fragmented strategies and policies in ways that improve the sustainability and resilience of food systems. This study explores such an approach by applying a climate-biodiversity-health (CBH) nexus to local and regional food systems in the Comox Valley region, British Columbia, Canada. The CBH nexus is used as an analytical lens to identify systems relationships among food systems, climate change, biodiversity and health issues and strategies in the region. The employs a place-based approach entailing semi-structured interviews with provincial, regional, and local stakeholders in order to develop a holistic understanding of planning challenges, strategies and their outcomes through the CBH lens. Outcomes of this work include a system map that can be used as a framework for elucidating how various strategies align or conflict with different CBH imperatives and can be used to support integrated community sustainability planning and policy-making efforts. The framework is developed within the Comox Valley context, but it can be adapted to other communities. This paper details the development of this framework, the interconnections between different components, and how this framework can be adopted in other communities.

Sustaining ex-mining lake-converted constructed wetlands as nature-based solutions: A comprehensive assessment of the carbon-water nexus in Paya Indah Wetlands, Malaysia.

Water and carbon, essential for Earth's well-being, face imminent threats from human activities that fuel climate change. This study investigates nature-based solutions, focusing on the carbon-water nexus of ex-mining lake-converted constructed wetlands, specifically in Malaysia's Paya Indah Wetlands (PIW). Addressing research gaps, it assesses the ecosystem services of these wetlands, emphasising integrated evaluations for informed land management and employing a top-down conservation approach. Methodologically, spatial assessments, soil and water sampling, carbon quantification, water quality index calculations, land cover classification and stakeholder surveys were conducted. Results underscore the significant carbon sequestration and water quality improvement potential of constructed wetlands, with soil and sediment carbon accumulation reaching 1553.11 Mg C ha-1 (equivalent to 5700 Mg CO2 ha-1), translating to an annual sequestration capacity of 67.5 Mg C ha-1 year-1. Water quality index values ranged from 58 to 81 (Classes II to III). PIW's establishment led to a reduction of over 90% in barren land, with increases in water bodies (36%) and vegetation-covered land (38%), boosting wildlife populations by 30%. Spatial variations in organic carbon density and water quality underscore the complexity of the carbon-water nexus and its impacts on ecosystem health and water security. Despite land use changes, PIW demonstrates resilience, contributing to climate change mitigation. Stakeholder perceptions vary, emphasising the need for adaptive strategies. The study proposes transdisciplinary conservation initiatives and adaptive plans, stressing the pivotal role of ex-mining lake-converted constructed wetlands in enhancing climate resilience.

Effectiveness of conservation messages to reduce households' GHG emissions: A serious-gaming experiment.

Households play a critical role in reducing greenhouse gas emissions. However, there have been few studies of household conservation from the perspective of the nexus of food, energy, and water (FEW) consumption. This study's objective is to understand the effects of different types of intervention messages for inducing conservation of FEW resources and reducing carbon emissions at the household level in the U.S. Employing a serious-gaming approach, we developed the HomeRUN (Home Role-play for Understanding the Nexus) game, which allows players to act as homeowners and take behavioral and technological upgrade actions in a computer-simulation setting. The types of messages tested include social comparisons and resource-reduction measures across FEW sectors as well as information about the health, economic, and environmental impacts of FEW consumption. A game experiment with U.S. university students finds that social-comparison messages on food and energy consumption, but not on water, lead to significant reductions in household carbon emissions. In addition, messages associated with each type of FEW resource tend to lead to an immediate action corresponding to the particular FEW domain. These insights support a prioritization of intervention messaging for coordinated FEW conservation efforts at a household level.

An approach to complex transboundary water management in Central Asia: Evolutionary cooperation in transboundary basins under the water-energy-food-ecosystem nexus.

Water-related issues in transboundary basins are generally complicated by the challenges of climate change, the historical evolution of the basin characteristics, and the different interests of the riparian countries. Therefore, dealing with water-sharing and water cooperation problems among basin countries needs to be based on multi-factor system analysis in the context of regional water, energy, food (land) resources, and ecosystems. In the present study, the Aral Sea basin in Central Asia, where transboundary water problems are extremely prominent and complex, was selected as the research area. Firstly, the characteristics of the water-energy-food-ecosystem nexus of the Aral Sea basin are analyzed. Then, based on the game theory, a multi-objective game model is constructed, and the multi-objective evolutionary game process and evolutionary stable strategies (ESSs) of both the upstream and downstream countries are explored. Finally, the evolutionary stable strategy under the intervention of the basin commission is simulated. The results show that there are obvious reciprocal feedbacks among water, land, energy, and ecosystem in the Aral Sea basin, and the uneven distribution of natural resources, fragile ecosystems, and conflicting demands of multiple actors lead to the unstable evolution of the nexus. Driven by the maximization of upstream and downstream countries' respective interests, the optimal stabilization strategy of the system cannot be realized. Whereas, the introduction of the basin commission intervention and its restraint mechanism is conducive to promoting cooperation and maximizing the overall benefits of the basin. The incentives and penalties of the basin commission have significant effects on whether the system can reach Pareto optimality, and higher incentive coefficient and penalty coefficient help the system converge to the ideal state more quickly. The evolution of the water-energy-food-ecosystem nexus based on the perspective of the whole basin can provide theoretical support for dealing with the transboundary water conflicts, and the cooperation strategy aiming at maximizing the overall benefits of the basin can provide decision-making basis for promoting transboundary water cooperation and synergistic development of the water-energy-food-ecosystem nexus.

Exploring Dynamics of Water, Energy, and Food Systems in Agricultural Landscapes Using Mental Modeling: A Case of Varamin Plain, Iran.

This study applies the mental model and cognitive mapping method to involve stakeholders in delineating the mutual relations between sources of water, energy, and food (WEF) production in the Varamin Plain (VP). Through involving farmers and managerial experts, the approach facilitates the deployment of community communication patterns to recognize and comprehend problems and move from single-loop learning to double-loop learning. The dynamic model was driven from the final mental model of the participants to reflect changes in the systems over time. The system dynamic (SD) model incorporates three scenarios for enhancing irrigation efficiency, managing groundwater extraction, and satisfying environmental needs. The results uncovered that the surface and underground water resources of the VP will gradually decrease within the next two decades in the range of 158 and 2700 million cubic meters (MCM) per year. Also, the plain suffers from water insecurity and a 162 MCM shortage. Consequently, focusing on understanding the nexus and nexus governance can enhance resource management and achieve sustainable development goals. Essentially, promoting collaborative governance, such as creating cooperative organizations and implementing double-loop learning, and instituting a water market, regulatory governance, and monitoring laws can improve the state of Varamin Plain's resources. These results carry important policy implications for using mental models to consider dynamics for discussions on participatory management of the WEF system nexus and environmental management.

Sense of Place and Perceived Impacts in the Rural Industrialized Nexus: Insights for Sustainability Pathways.

As representative of the water-energy-food nexus, fossil fuel development and industrial agriculture are rural industries that continue to expand and increasingly occur in the same areas. Being a top agricultural export county and the fossil fuel capital of California while ranking among the worst in the US for industrial pollution, Kern County is a poster child of rural nexus development and, thus, an essential place for initiating sustainability transitions. Such transitions rely on policy support and the adoption of methods by individuals and communities who may disagree with such changes. While sense of place and impact perceptions are recognized as playing critical roles in sustainability management, they have yet to be utilized in nexus research. A survey (N = 256) of the perceived impacts of nexus industries with place meaning and place attachment as possible drivers for perceptions was conducted in nexus industry pollution exposure risk zones. Factor analysis and bivariate correlations showed that place meaning and place attachment are drivers for perceptions while also being drivers for concern for changes in nexus industries. While perceptions of impacts indicated contested place meanings, participants strongly perceive the economy and environment as being in decline. To build support for sustainability policy, directing funds from Kern County's renewable energy industry to local sectors of society, implementation of regenerative agriculture, cooperative management, and nurturing place meaning as aligned with nature's restorative quality are important paths forward. These nexus management foci could strengthen place attachment, build trust in government, and repair environmental alienation.

A holistic approach for performance evaluation of wastewater treatment plants: integrating grey water footprint and life cycle impact assessment.

Wastewater treatment plants (WWTPs) have positive and negative impacts on the environment. Therefore, life cycle impact assessment (LCIA) can provide a more holistic framework for performance evaluation than the conventional approach. This study added water footprint (WF) to LCIA and defined ϕ index for accounting for the damage ratio of carbon footprint (CF) to WF. The application of these innovations was verified by comparing the performance of 26 WWTPs. These facilities are located in four different climates in Iran, serve between 1,900 and 980,000 people, and have treatment units like activated sludge, aerated lagoon, and stabilization pond. Here, grey water footprint (GWF) calculated the ecological impacts through typical pollutants. Blue water footprint (BWF) included the productive impacts of wastewater reuse, and CF estimated CO2 emissions from WWTPs. Results showed that GWF was the leading factor. ϕ was 4-7.5% and the average WF of WWTPs was 0.6 m3/ca, which reduced 84%, to 0.1 m³/ca, through wastewater reuse. Here, wastewater treatment and reuse in larger WWTPs, particularly with activated sludge had lower cumulative impacts. Since this method takes more items than the conventional approach, it is recommended for integrated evaluation of WWTPs, mainly in areas where the water-energy nexus is a paradigm for sustainable development.

Africa and the Nexus of poverty, malnutrition and diseases.

This review examines the nexus of poverty, malnutrition and diseases in Africa, the challenges, implications and their mitigation. The paper takes a critical look at available literatures on the primary causes, modes, implications and solutions to the problems of poverty, malnutrition and diseases in Africa continent. Poverty and malnutrition are outcomes of uncontrolled rapid population growth, inefficient agricultural and industrial practices, high debt profile of many African countries due to poor governance and corruption, diseases such as AIDS epidemic, malaria, Ebola virus and COVID-19 pandemic, poor and inadequate health infrastructure and armed conflicts. African poverty scenario entails non-availability of basic human needs which makes many Africans to be very poor. Despite abundance of natural resources, the gross domestic product per capita of many African countries is among the lowest of list of nations of the world. According United Nation in 2009, 22 of 24 nations among the "Low Human Development" nations of the world on the UN's Human Development Index were found in sub-Saharan Africa. Out of the 50 countries on the United Nation list of least developed countries, 34 of them were in Africa. According to FAO data over 200 million people in sub-Saharan Africa were undernourished in 2014-2016. The prevalence of undernourishment in sub-Saharan Africa rose from 181 million in 2010 to 222 million in 2016. In 2016, Africa had the highest prevalence of undernourishment in the world and estimated to be 20% of the population. While this was alarming in Eastern Africa where one-third of the population is suspected to be undernourished. In a similar data, World Bank also found that sub-Saharan Africa Poverty and Equity Data was 47% with over 500 million people in abject poverty in 2012. Poverty is the major cause of hunger and malnutrition in Africa while hunger and malnutrition escalated the problem of diseases in African continent. Poverty has continued to torment Africa as a result of poor and harmful economic policies, conflict and war, environmental factors like drought and climate change and population growth, poor leadership and greed. With the advent of COVID-19, the problem of poverty, malnutrition and diseases has been escalated and in many African countries people find it difficult to make ends meet.

Water-Energy-Carbon Nexus: Greenhouse Gas Emissions from Integrated Urban Drainage Systems in China.

Greenhouse gas (GHG) emissions from integrated urban drainage systems (IUDSs), including sewer, wastewater treatment plants (WWTPs), and receiving water systems, have not yet been integrated due to the lack of modeling tools. Here, we updated the computable general equilibrium-based System Dynamics and Water Environmental Model (CGE-SyDWEM), a recently developed model simulating the water-energy-carbon nexus at the watershed level, to calculate the direct and indirect (electricity use and external) GHG emissions from IUDSs considering carbon mitigation strategies and water engineering practices. The updated CGE-SyDWEM was applied to an estuary watershed in Shenzhen, the fourth largest city in China. With increasing socio-economic development and water infrastructure systems upgrading, GHG emissions are projected to increase from 129.2 (95% CI: 95.9-162.5) kt in 2007 to 190.7 (144.8-236.6) kt in 2025, with 89% from WWTPs (direct: 17%; electricity use: 65%; and external: 7%), 10% from the sewer (direct: 1% and electricity use: 9%) and 1% from receiving waters (direct). Carbon mitigation can reduce GHG emissions by 7% and emission intensity by 6% by 2025, with 63% contributed by external emission reduction from chemical uses. The integrated model can aid water, energy, and carbon decision-makers in finding cost-effective solutions for water and energy security in the future.

Integrated Agricultural Practices and Engineering Technologies Enhance Synergies of Food-Energy-Water Systems in Corn Belt Watersheds.

Interconnected food, energy, water systems (FEWS) require systems level understanding to design efficient and effective management strategies and policies that address potentially competing challenges of production and environmental quality. Adoption of agricultural best management practices (BMPs) can reduce nonpoint source phosphorus (P) loads, but there are also opportunities to recover P from point sources, which could also reduce demand for mineral P fertilizer derived from declining geologic reserves. Here, we apply the Integrated Technology-Environment-Economics Model to investigate the consequences of watershed-scale portfolios of agricultural BMPs and environmental and biological technologies (EBTs) for co-benefits of FEWS in Corn Belt watersheds. Via a pilot study with a representative agro-industrial watershed with high P and nitrogen discharge, we show achieving the nutrient reduction goals in the watershed; BMP-only portfolios require extensive and costly land-use change (19% of agricultural land) to perennial energy grasses, while portfolios combining BMPs and EBTs can improve water quality while recovering P from corn biorefineries and wastewater streams with only 4% agricultural land-use change. The potential amount of P recovered from EBTs is estimated as 2 times as much as the agronomic P requirement in the watershed, showing the promise of the P circular economy. These findings inform solution development based on the combination of agricultural BMPs and EBTs for the cobenefits of FEWS in Corn Belt watersheds.

Tapping the Unused Energy Potential of Solar Water Pumps in India.

India seeks to deploy millions of solar water pumps to farmers who often lack access to electricity or face an unreliable power supply. Improving the use of this technology can bolster sustainable agriculture and expand clean energy services. We investigate farm-level impacts and opportunities with primary survey data (n = 292 farmers) and a large real-time pump operational data set (n = 1106 pumps). By modeling the potential solar generation of off-grid solar water pumps, we estimate 300-400 kWh/month of unutilized solar energy per pumping system, representing up to 95% of potential generation. While farmers report increased revenues and ease of pump operation, unsolved challenges concerning the lack of panel cleaning and tracking remain. Pump operational data show pump usage in the summer and monsoon seasons and an expansion of irrigation to grow crops in the winter. Relative to emissions associated with the use of diesel pumps, solar pumps that are highly utilized reduced life cycle CO2-eq emissions by 93% on average, while the pumping systems with the lowest use result in a net increase of 26% relative to the diesel alternatives. Based on observed usage rates, approximately 70% of pumps had positive environmental benefits. The high share of unutilized solar energy provides a significant opportunity to use the energy for nonpumping purposes.

Modeling Indirect Greenhouse Gas Emissions Sources from Urban Wastewater Treatment Plants: Integrating Machine Learning Models to Compensate for Sparse Parameters with Abundant Observations.

Electricity consumption and sludge yield (SY) are important indirect greenhouse gas (GHG) emission sources in wastewater treatment plants (WWTPs). Predicting these byproducts is crucial for tailoring technology-related policy decisions. However, it challenges balancing mass balance models and mechanistic models that respectively have limited intervariable nexus representation and excessive requirements on operational parameters. Herein, we propose integrating two machine learning models, namely, gradient boosting tree (GBT) and deep learning (DL), to precisely pointwise model electricity consumption intensity (ECI) and SY for WWTPs in China. Results indicate that GBT and DL are capable of mining massive data to compensate for the lack of available parameters, providing a comprehensive modeling focusing on operation conditions and designed parameters, respectively. The proposed model reveals that lower ECI and SY were associated with higher treated wastewater volumes, more lenient effluent standards, and newer equipment. Moreover, ECI and SY showed different patterns when influent biochemical oxygen demand is above or below 100 mg/L in the anaerobic-anoxic-oxic process. Therefore, managing ECI and SY requires quantifying the coupling relationships between biochemical reactions instead of isolating each variable. Furthermore, the proposed models demonstrate potential economic-related inequalities resulting from synergizing water pollution and GHG emissions management.

Unveiling the Nexus Profile of Embodied Water-Energy-Carbon-Value Flows of the Yellow River Basin in China.

Unveiling the nexus profile of the water-energy-carbon (WEC) and value flows embodied in regional trade is essential for enhancing the co-benefits between economic development and environment conservation. However, minimal research explores the WEC and value-added nexus efficiency of the Yellow Basin River (YRB) with a comprehensive framework. Thus, this study built a nexus framework based on a multiregional input-output model (MRIO) to analyze embodied WEC and value-added flows in the nine provinces of the YRB and all 31 provinces of China, primarily in 2017 compared to 2012 and 2015. Three dimensions (space, sectors, and environmental and economic factors) depict the WEC and value-added nexus patterns. The results from these three dimensions uncovered that the YRB benefits from regional trade but suffers environmental losses, and the development imbalance among the provinces of the basin is exacerbated. The proposed integrated framework can be generalized to water-energy extended nexus analysis in other regions to portray a more complex human-environment system nexus pattern. The new knowledge of how embodied WEC interacts with concomitant economic activities within and beyond the YRB can benefit multiresource-integrated management in the YRB and coordinated regional development in China.