A review of interconnected challenges in the water-energy-food nexus: Urban pollution perspective towards sustainable development

The swift growth of cities worldwide poses significant challenges in ensuring a sufficient water, energy, and food supply. The Nexus has innovated valuable systems to address these challenges. However, a crucial issue is the potential for pollution resulting from these systems, which directly and indirectly impacts public health and the overall quality of urban living. This study comprehensively reviews the interconnected challenges of the water-energy-food (WEF) nexus and various forms of pollution in cities. The primary focus of this review article is to showcase the findings of WEF nexus studies regarding various pollutions across different geographical regions and spatial scales. It aims to examine the problems resulting from these pollutions, specifically their effects on human health and urban life. It also delves into the sources of pollution as identified in these studies. Furthermore, the article will highlight the proposed solutions from the research aimed at effectively mitigating pollution in each sector studied. This article is a systematic review which analyses research sources from the Scopus database. It extensively reviewed 2463 peer-reviewed published articles and focused explicitly on articles related to the WEF nexus that discussed pollution. Our study emphasizes, firstly, raising awareness about the crucial link between the WEF nexus, pollution, urban environments, and human health among policymakers and key stakeholders, including urban planners, industry partners and municipalities. This is to promote the development of policies that encourage sustainable practices and key stakeholders. Secondly, it evaluates WEF nexus and pollution research methods and findings, aiding in identifying research gaps technological innovation and potential, as well as enhancing decision-making. Lastly, it outlines future research challenges, providing a roadmap for researchers and policymakers to advance understanding in this domain and identify opportunities for resource efficiency and collaboration between different sectors.

Assessing environmental sustainability of a vital crop in a critical region: Investigating climate change impacts on agriculture using the SWAT model and HWA method

Drought is an occurrence that brings about significant changes to the structure of areas. Its influence is especially noticeable in important regions with dry and semi-dry weather patterns, leading to a range of difficulties including interruptions in food distribution systems, lack of water, health problems, economic declines, increased migration, and inadequate energy supply. The Ardabil plain, located in Asia and the northern-western region of Iran, plays a pivotal role in crop productions within an arid environment and holds significant political importance for the country. The main objective of this study is to enhance environmental sustainability in this critical and vulnerable region, particularly in anticipation of imminent droughts. The study focuses on examining the financial impacts on agriculture and selection a crop using the SWAT model, HWA method and climate scenarios under the RCP8.5 pathway for the future period (2040-2050). Results for the near future indicate a notable decline in rainfall of around 38 %, a reduction in wheat production by approximately 25 %, and an increase in temperature of around 30 %. At present, the Ardabil Plain produces a total of 284,182 tons of wheat, with 204,980 tons from irrigated crops and 79,202 tons from rain-fed crops. However, the projected future scenario indicates a decrease in total wheat production to 202,926 tons, with 153,855 tons from irrigated crops and 49,071 tons from rain-fed crops. This decline in production is expected to lead to a total net income loss of approximately -$139,372,437, with -$87,690,344 attributed to irrigated crops and -$51,682,092 to rain-fed crops. The comprehensive hierarchy of crop choices yielded by the HWA method is outlined as follows: barley holds a superior position, followed by wheat, soybeans, and potatoes. The study findings suggest that the availability of water sources in certain regions may prompt a shift in farming land from the north to the south of the plain to promote environmental sustainability.

Highly Mesoporous Hybrid Transition Metal Oxide Nanowires for Enhanced Adsorption of Rare Earth Elements from Wastewater

Removal of rare earth elements (REEs) from industrial wastewater is a continual challenge. To date, several approaches to the synthesis of nanoadsorbants for this application have been reported, although these are characterized by insufficient adsorption capacity and limitations in cycling stability. The present work reports the fabrication and performance of hierarchical hybrid transition metal oxide (TMO) nanowires deposited on carbon fibers. An ordered assembly of hybrid TMO nanowires exhibits an outstanding adsorbance of 1000 mg·g^-1 of REEs with 93% recyclability. This superior performance is attributed to the unique mesoporous architecture of the nanowires, which exhibits a high surface area of 122 cm³·g^-1. Further, rapid adsorption/desorption of the REEs reveals minimal morphological alteration and hence high structural stability of these hybrid TMO nanowires after multiple cycles. The ready accessibility of the adsorption sites at crystallite boundaries and the surfaces as well as rapid adsorption of the REEs on the mesoporous nanostructure facilitate considerable adsorption capacity, improved structural stability, and extended cyclability, all of which suggest the potential for this material in REE extraction.