Commonalities and asynchronous experiences of realizing zero-waste of water, energy, and food resources between the world and China have critical global importance to support sustainable development, especially for Guangdong-Hong Kong-Macao Greater Bay Area (GBA) urban agglomeration. In this study, a comprehensive assessment framework for the zero-waste city was proposed to evaluate zero-waste construction in the world (e.g., San Francisco, New York, and Tokyo) and China (e.g., Beijing, Shanghai, and GBA) from the perspective of water, energy, and food. The results showed that the zero-waste construction level of the GBA cities was weaker than that of the benchmark city and other world-class cities. The average score of the GBA cities was the lowest, 2.5% lower than the benchmark city and 11.8% lower than other world-class cities. Macao had apparent advantages in the social-economic and ecological-environment system, while the Pearl River Delta cities were considerably better than Macao and Hong Kong in the water and food systems. Future work could improve the level of zero-waste construction by learning from foreign zero-waste cities’ advanced experience, increasing efforts to promote the implementation of a circular economy, and building an all-around government sharing mechanism with public participation.

Lanthanide-doped nanoparticles exhibit unique optical properties and have been widely utilized for different sensing applications. Herein, the Eu³⁺:SrSnO₃@APTS nanosensor was synthesized and its optical properties were analyzed using UV-Vis and photoluminescence spectroscopy. The TEM images of the synthesized nanophosphor Eu³⁺:SrSnO₃@APTS exhibited peanut-like morphology, composed of two or more spherical nanoparticles with an average diameter ∼33 nm. Effects of environmental pH values and doping concentrations as well as amino functionalization on the structure of Eu³⁺:SrSnO₃ were investigated. The as-synthesized optical nanosensor was used for determination of copper ions based on a fluorescence quenching approach. Red emission with a long lifetime was obtained in the case of the 0.06 mol Eu³⁺:SrSnO₃@APTS sample. Under the optimal experimental conditions, a Stern–Volmer plot exhibited a good linearity for copper ions over the concentration (0.00–10.8) × 10⁻¹¹ mol L⁻¹ with a correlation efficient of 0.996 and a limit of detection 3.4 × 10⁻¹² mol L⁻¹. The fluorescent sensor was dynamically quenched via a coulombic interaction mechanism between the Eu³⁺ (⁵L₆) and Cu²⁺. The Eu³⁺:SrSnO₃@APTS nanosensor with the optimal Eu³⁺ dopant concentration of 0.06 mol was applied for copper determination in food and real drink water samples with high recovery values. We believe that the developed nanosensor probe can also be used for the detection of other toxic compounds, with high selectivity and sensitivity.

Mammals in drylands are facing not only increasing heat loads but also reduced water and food availability as a result of climate change. Insufficient water results in suppression of evaporative cooling and therefore increases in body core temperature on hot days, while lack of food reduces the capacity to maintain body core temperature on cold nights. Both food and water shortage will narrow the prescriptive zone, the ambient temperature range over which body core temperature is held relatively constant, which will lead to increased risk of physiological malfunction and death. Behavioural modifications, such as shifting activity between night and day or seeking thermally buffered microclimates, may allow individuals to remain within the prescriptive zone, but can incur costs, such as reduced foraging or increased competition or predation, with consequences for fitness. Body size will play a major role in predicting response patterns, but identifying all the factors that will contribute to how well dryland mammals facing water and food shortagewill copewith increasing heat loads requires a better understanding of the sensitivities and responses ofmammals exposed to the direct and indirect effects of climate change. | The South African National Research Foundation (NRF), the Carnegie Corporation of New York, the Claude Leon Foundation, the Global Change System for Analysis, Research and Training (START), the Oppenheimer Memorial Trust, the Tswalu Foundation, the University of the Witwatersrand, and the Australian Research Council. | http://jeb.biologists.org | am2022 | Anatomy and Physiology | Centre for Veterinary Wildlife Studies | Paraclinical Sciences

In this research, an integrated approach is developed through the incorporation of systems dynamics (SD), catastrophe progression (CP), and coupled coordination degree (CCD) analysis within a general modelling framework. The developed SD-CP-CCD is then employed to simulate and evaluate relationships among the water-energy-food (WEF) and the economic systems. It will improve traditional methods for WEF nexus analysis through a) incorporating urban WEF connections and changes into the cross-system coupling analysis framework, b) evaluating its coordination with economic growth and a multi-scale and regional disparity, and c) promoting policy recommendations to ensure the guarantee of urban WEF under economic growth. The approach is then verified through WEF nexus system of Urban Agglomerations of Pearl River Delta City Cluster (PRDCC) in China. Temporal and spatial characteristics of CCD in the region were analyzed. The results revealed their performance in cities with multiple economic backgrounds. Also, the fragile factors of each city were reflected by multi-scale exploration. Regional inequality and spatial agglomeration effects were considered. The results showed that CCD has noticeable temporal and spatial differences. Geographically, CCD varied from uncoordinated to high-level coordination. The eastern cities were much better coordinated than the western cities. Due to the increasing pressure of population and economic growth in the future, the upward trend of CCD would occur in most cities. The vulnerability factors of each city were explored. Simultaneously, apparent spatial inequality and agglomeration patterns were observed, with a downward trend over time. The temporal and spatial patterns of CCD revealed in this study indicated that PRDCC policymakers should formulate policies that suit the characteristics of cities and reduce the targeted regional imbalances.

In Ethiopia, land, water, energy and food (LWEF) nexus resources are under pressure due to population growth, urbanization and unplanned consumption. The effect of this pressure has been a widely discussed topic in nexus resource literature. The evidence shows the predominantly negative impact of this: however, the impact of these factors is less explored from a local scale. As a result, securing nexus resources is becoming a serious challenge for the country. This necessitates the identification of the driving factors for the sustainable utilization of scarce LWEF nexus resources. Our study provides a systemic look at the driving factor indicators that induce nexus resource degradation. We use the Analytical Hierarchical Process (AHP) to develop the indicators’ weights, and use a Path Analysis Model (PAM) to quantitatively estimate the effect of the driving factor indicators on the LWEF nexus resources. The results indicate that social (48%), economic (19%), and policy and institutional changes (14%) are the major nexus resource driving factor indicators. The path analysis results indicate that among the social driving factor indicators, population growth and consumption patterns have a significant direct effect on the LWEF nexus, with path coefficients of 0.15 and 0.089, respectively. Similarly, the potential of LWEF nexus resources is also influenced by the institutional and policy change drivers, such as outdated legislation and poor institutional structure, with path coefficients of 0.46 and 0.39, respectively. This implies that population growth and consumption patterns are the leading social drivers, while outdated legislation and poor institutional structures are the institutional and policies change drivers which have a potential impact on LWEF nexus resource degradation. Similarly, other driving factors such as environmental, economic and technological factors also affect nexus resources to varying degrees. The findings of our study show the benefits of managing the identified driving factors for the protection of LWEF nexus resources, which have close links with human health and the environment. In order to alleviate the adverse effects of driving factors, all stakeholders need to show permanent individual and collective commitment. Furthermore, we underline the necessity of applying LWEF nexus approaches to the management of these drivers, and to optimize the environmental and social outcomes.

The nexus approach is a promising method used to address issues regarding environmental dilemmas. However, effective consumption-based and production-based nexus governance strategies are not well understood. Using data envelopment analysis and China’s provincial data for 2017, this study analysed the input–output efficiency of the water-energy-food nexus by considering production-based intensity, consumption-based intensity, and the quantity index system. The results show that policies involving consumption-based intensity metrics can be more efficient, and the efficiency of both production-based intensity (0.482) and consumption-based intensity (0.682) are much higher than the efficiency of the quantity (0.378) index system. The results also indicate that province-specific consumption-based governance strategies are crucial for 30 provinces in China. Finally, three policy directions for nexus governance in China are proposed, namely, shifting policy attention from production-based governance to consumption-based governance, focusing intensity metrics on scale efficiency and aiming quantity metrics on pure technical efficiency, and localizing province-specific management strategies. This paper compares consumption-based and production-based nexus approaches, and the results indicate that a call for consumption-based approaches in future nexus modelling and governance is appropriate. This paper also has implications for China’s nexus governance.

The concept of the water-food-energy nexus has been widely studied in the past decade. In this paper we expand on this concept to include environmental, economic, and social aspects as well as life cycle assessment based thinking. We proposed a set of Environmental Footprint Assessment, Life Cycle Assessment, and Socio-Economic Assessment indicators and calculated them using a developed System Dynamic Model for Water-Land-Food-Energy-Environment-Economic-Social Nexus (SD-WLF3ESN). The developed model was applied to predict the WLF3ESN of the corn crop in the Western Lake Erie Basin (WLEB)-USA for the period 2016-2030. The prediction was based on scenarios for population, land, yield, crop use, and crop production costs and returns at the county level of WLEB. A matrix for WLF3ESN of the corn crop in WLEB was developed. This matrix can help in developing policies and strategies for managing the nexus in the basin.

We collected water samples from contaminated Buddha Nullah drain in Ludhiana district of Punjab (India) during pre- and post-monsoon seasons of the year 2017 and 2018. The soil and plant (wheat and rice) samples were also taken from fields cultivated near the water sampling sites. The drain is mainly contaminated by discharge of industrial and urban effluents from the surrounding areas and its confluence with Sutlej River (a tributary of the Indus River). Water samples were analysed for nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). Soil, rice and wheat grain samples were analysed for total metals. Besides this, soil samples were also analysed for and DTPA-extractable metals. The concentration of Cr, Pb and Fe in water exceeded the WHO guidelines during all the seasons. Total Zn, Pb, Mn, Ni and Co concentration in soils exceeded the permissible limits, whereas the average concentration of Fe, Pb, Co and Cd in rice and wheat grains exceeded the permissible limits. The bioaccumulation factor (BAF) for DTPA-extractable heavy metals was in the order: Fe > Cr > Co > Zn > Pb > Cd > Mn > Cu > Ni (BAF values > 1 for all the metals). Heavy metal toxicity load values (HMTL) in water samples were lower than the tolerable toxicity load of heavy metals. However, heavy metal pollution index (HPI) was higher than 100 in all the water samples. Based on the grading of geoaccumulation Index (Igₑₒ), total Cd concentration showed extreme contamination around the soils of Buddha Nullah. The cancer risk associated with heavy metals due to intake of wheat and rice grains and ingestion of soils were in the order: Cd > Ni > Cr. Spatial distribution maps of HPI showed the maximum contamination and health risks were around the areas having higher industrial and urban activities These results suggest that heavy metals particularly Cd cause potential health risks to urban residents and environment. The HPI and HTML for water, Igeo for soils and BAF for plants are useful for assessing heavy metal contamination. The controlling measures must be taken to reduce the heavy metal contamination in the drain by checking of the urban and industrial effluents discharged in it and cleaning of the Buddha Nullah drain should be initiated to improve the water quality of Sutlej River.

This article addresses food-energy-water-waste nexus optimization to alleviate the public health and environmental concerns from increasing food waste generation during the COVID-19 pandemic using waste-to-energy technologies. Food waste increase has become a severe global problem during the pandemic. It could alleviate health and environmental concerns by converting the food waste into electricity and heat through food-energy-water-waste nexus systems using waste-to-energy facilities, such as anaerobic digesters and combined heat and power units in wastewater treatment plants. To design efficient nexus systems, a multi-period multi-objective optimization model is proposed, while considering various impacts of the pandemic. A case study for New York State is presented. The optimized systems show a potential of reducing the food waste disposal amounts by 38%. The Pareto-optimal solutions illustrate a clear trade-off between the objectives. The minimum total cost is $27.1 million; the optimal unit processing profit is $11.9 per ton processed food waste. Spatial analyses reveal a clear correlation between facility selections and their processing capacities. Electricity price and biogas yield are the most important factors for the economic objectives, based on sensitivity analysis.

Direct determination of arsenic species in real samples is challenging due to their trace concentration and spectral interferences by coexisting ions. Herein, we proposed an ultrasound-assisted dispersive solid phase microextraction (DSPME) procedure for the analyses of the trace inorganic arsenic. The hydrothermally synthesized cadmium sulfide nanoparticles (CdS NPs) completely adsorbed both arsenic species within 20 s at the initial arsenic concentration of 100 µg L⁻¹. The detection limit (3 S/m) of the proposed method was found to be 0.5 ± 0.2 and 0.8 ± 0.2 ng L⁻¹ for As(III) and As(V), respectively. The accuracy of the method against the systematic and constant errors was confirmed by the analysis of the Standard Reference Material (SRM) (>95% recovery with <5% RSD). The Student’s t-test values were found to be less than the critical Student’s t value at a 95% confidence level. The method was successfully employed for the determination of arsenic in food samples.