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Refused derived fuel (RDF) is one of the products of the MSWs that is effectively used as an energy source, especially in the cement industry. This work discusses the role of the RDF in the achievement of the United Nations Sustainable Development Goals (SDGs) and the circular economy. Moreover, the barriers that challenge the widespread of the RDF are indicated. The RDF positively contributes to the most SDGs. However, the main contribution would be in SDG l: no poverty, SDG 3: good health and well-being, SDG 6: SDG 6: clean water and sanitation, SDG 7: affordable and clean Energy, SDG 8 decent work and economic growth, SDG 9: industry, innovation and infrastructure, SDG 11: sustainable cities and communities, SDG 12: responsible consumption and production, SDG 14: life below water and SDG 15: life on land. While in the main contribution of the circular economy comes from its ability to reuse municipal solid wastes, industrial solid waste, non-recyclable plastics, waste tires, biomass, paper/card, waste oils, and waste textiles. In addition, RDF will reduce the CO 2 by up to 2155.3 106 Kt CO 2 /year and recover heat content from 2 to 5.5 Gcal/t. Moreover, the RDF will save up to 15% of the fuel that equals 4.92 tons/h. Such fuel reduction will save 486 USD/h in petcoke costs, with 2.27 tons/h of CO 2 being emitted into the atmosphere at a net saving of 389 USD/h. The results guide academic researchers, policymakers, and stakeholders worldwide to evaluate solid wastes as alternative fuels concerning their overall sustainability and cheapness. Moreover, this work introduces some future research directions to involve solid wastes in circular economy and SDGs. Furthermore, a set of indicators are proposed to guide the stakeholder to increase the RDF contribution to SDGs and lower the possible trade-off. [ABSTRACT FROM AUTHOR]

Membrane-based technologies are recently being considered as effective methods for conventional water and wastewater remediation processes to achieve the increasing demands for clean water and minimize the negative environmental effects. Although there are numerous merits of such technologies, some major challenges like high capital and operating costs. This study first focuses on reporting the current membrane-based technologies, i.e., nanofiltration, ultrafiltration, microfiltration, and forward- and reverse-osmosis membranes. The second part of this study deeply discusses the contributions of membrane-based technologies in achieving the sustainable development goals (SDGs) stated by the United Nations (UNs) in 2015 followed by their role in the circular economy. In brief, the membrane based processes directly impact 15 out of 17 SDGs which are SDG1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16 and 17. However, the merits, challenges, efficiencies, operating conditions, and applications are considered as the basis for evaluating such technologies in sustainable development, circular economy, and future development. [Display omitted] • Membrane-based technologies for water and wastewater remediation were summarized. • Challenges facing the development of Membrane-based technologies were discussed. • The role of Membrane-based technologies in achieving SDGs was introduced. • The role of Membrane-based technologies in the circular economy was analyzed. [ABSTRACT FROM AUTHOR]

• An assessment of the different production methods of green ammonia was analyzed. • The various barriers facing widespread of green ammonia were discussed. • The contribution of green ammonia in achieving SDGs was elaborated. Fossil fuels are no longer accepted as the sole energy source with their environmental impacts and fluctuating price. Green hydrogen is considered a potential candidate for fossil fuel soon—however, hydrogen is facing the challenges of storage and transportation. Green ammonia, with its ease of transport and storage, is another promising alternative. Decarbonizing ammonia production is an environmental press toward achieving net-zero emissions by 2050. This work summarizes the up-to-date progress in the green ammonia production methods. An assessment of the different production methods was conducted to highlight the merits and constraints of each approach. Moreover, the promising applications of green ammonia in the energy sectors were discussed. The various barriers, i.e., technical, economic, environmental, and regulations and policies, facing the widespread of green ammonia were also discussed. Finally, the contribution of green ammonia in achieving the different sustainable development goals was elaborated, focusing on the contribution of green ammonia in achieving climate change (SDG 13), clean energy (SDG 7), and other sustainability-related goals. Low efficiencies, high cost, and negative environmental impacts are the common challenges of the various production methods. The progress in green ammonia is essential for achieving SDG2, "Zero hunger". SDG3 "healthy life and well-being" and SDG13 "Climate action", will be achieved by eliminating 3.85 kg CO 2 -eq/kg NH 3 emitted from conventional ammonia-based processes. Ease storing of green ammonia in liquid form (at 9 bar or cooling to −33°); makes it the best green energy source, i.e., achieving SDG7 "green and affordable energy". By 2050, green ammonia is expected to represent 99 % of marine fuel, thus contributing to SDG9 "Industry and Infrastructure". Moreover, green ammonia production will save 35.2 GJ of natural gas, thus achieving SDG12 "Responsible consumption/production". [ABSTRACT FROM AUTHOR]