This comprehensive review explores aquaponics as an environmentally friendly solution aligned with SDGs and food sovereignty, assessing various aspects from system design to automation, and weighing social, economic, and environmental benefits through literature and case studies. However, challenges persist in obtaining organic certification and legislative recognition, hindering its growth. Achieving remarkable water use efficiency, up to 90%, relies on adaptable fish species like Nile tilapia and carp. Nutrient-rich fish feeds notably benefit low-nutrient-demanding greens. Ensuring water quality and efficient nitrification are pivotal, supported by IoT systems. Despite its efficiency, integrating Industry 4.0 involves complexity and cost barriers, necessitating ongoing innovation. Economies of scale and supportive horticultural policies can bolster its viability. Aquaponics, known for its efficiency in enhancing crop yields while minimizing water use and waste, is expanding globally, especially in water-scarce regions. Aquaponics, pioneered by the University of the Virgin Islands, is expanding in Europe, notably in Spain, Denmark, Italy, and Germany. Asia and Africa also recognize its potential for sustainable food production, especially in water-limited areas. While it offers fresh produce and cost savings, challenges arise in scaling up, managing water quality, and meeting energy demands, particularly for indoor systems. Egypt’s interest in desert and coastal regions highlights aquaponics’ eco-friendly food production potential. Despite the associated high costs, there is a quest for practical and affordable designs for everyday integration. Research in arid regions and industry advancements are crucial for aquaponics’ global food production potential. Deeper exploration of intelligent systems and automation, particularly in large-scale setups, is essential, highlighting the industry’s promise. Practical application, driven by ongoing research and local adaptations, is a key to fully harnessing aquaponics for sustainable food production worldwide.

Multiple uses of water aquaculture-integrated agriculture systems (AIAS) are inevitable to produce more food per drop of water to address water shortage, food insecurity, and climate change. This survey intends to outline the multiple-use water in pond-based AIAS in light of legal regulations and water salinity. Scenarios for pond-based AIA and their impact on the environment were presented and discussed. Pond-based AIA has been demonstrated to have many social, economic, and environmental benefits. Moreover, international and national experiences and attempts for genuine applications were exhibited. Throughout, pond-based AIA farming practices are seen as a proficient utilization of water that aids food sustainability. It was concluded that pond-based AIA could aid in increasing productivity, income for food producers and soil fertility, ecosystem maintenance, and adaptation to environmental change. AIAS helps adapt to and mitigate climate change by reducing waste and greenhouse gas emissions, reducing pressure on water resources, and recycling nutrients. Finally, developing and promoting the expansion of rotation of wheat-fish and pond-based AIA in the desert and encouraging global collaboration for information and knowledge transfer among different countries were discussed.

The objective of this article is to review the historical development of rice–aquatic species (RASp) integration and analyze the factors that affect its performance. Compared to rice monoculture, the integration of the rice–aquatic species system has a more significant impact on farm production, income, land (L), water use efficiency (WUE), net revenue, and labor use efficiency (LBUE) reduction. Although concurrent and alternate cultivations of rice–aquatic species increase unit water efficiency, concurrent cultivation requires 26% more water than monoculture. Furthermore, RASp farming promotes environmentally-friendly rice cultivation by reducing the use of pesticides (insecticides and herbicides), decreasing CH₄ emissions by approximately 14.8–22.1%, and enhancing water quality. These findings suggest that fish integration in rice fields could be integrated into extensive aquaculture. Finally, global cooperation is necessary to transfer knowledge about this technology, particularly from China, and more research is needed to evaluate the effects of rice–aquatic species integration in the context of climate change and practical water use efficiency. Additionally, a robust development program at the national and global levels, with regulatory and non-administrative bodies’ guidance and strategy, is needed to embrace the expansion of the rice–aquatic species practice.

The present investigation was conducted to study the leaching characteristics, speciation and fractionation of trace and major elements from fly ash. Five liquid-to-solid ratios (L/S) were selected, ranging from 0.5 to 1. The releasing of trace and major elements from fly ash increased as L/S ratios increased or over time (at pH=2.88). γ-Al(OH)3, Cd3(PO4)2, azurite, jarosite, MnCO3, Pb(OH)2, quartz (SiO2) and ZnCO3 are the solid phases that control Al, Cd, Cu, Fe, Mn, Pb, Si and Zn activities in fly ash leachates. The sequential chemical extraction tests showed that Al, Cd, Cu, Fe, Mn, Pb, Si and Zn were mainly present in the last three fractions, which were Fe–Mn oxides, organics and residual fractions and their leachability could be well-controlled in common natural environment. According to risk assessment code (RAC); Cd, Cu, Mn and Pb show a medium risk, while Zn and Fe shows low risk level, but Al and Si are considered safe to our environment

This project investigated the relative efficiencies of three pilot-scale constructed columns for enhancing drainage wastewater treatment processes to ensure compliance with Egyptian and international water quality criteria. In this investigation, basic materials (sand and gravel) and variable natural clay minerals zeolite (Z), diatomite (D) and bentonite (B) were utilized as packing materials to build up a Z column (ZC), D column (DC) and B column (BC), respectively. The three columns’ ability to remove pollutants from waste water for re-use in irrigation was investigated throughout one year (12 trials). The results revealed that the influent water had 211 mg/L total suspended solids, 6.09 mg/L total nitrogen, 36.67 mg/L biochemical oxygen demand, 56 mg/L chemical oxygen demand, 1700 mg/L total dissolved solids, 0.97 mg/L copper (Cu²⁺), 1.12 mg/L iron (Fe²⁺), 1.07 mg/L manganese (Mn²⁺), 1.02 mg/L lead (Pb²⁺), 1.05 mg/L zinc (Zn²⁺), and 46 × 10³ CFU/mL fecal coliforms. These parameters were higher than the values permitted by Egyptian and international licenses. The range of removal efficiency of these pollutants by ZC was 96–21%, by BC was 99–29.8%, and by DC was 99–19.80%. Regeneration studies for the spent adsorbents demonstrated that the percentages of pollutant removal were sufficiently high. The treated effluent produced by the three columns was suitable for irrigation purposes, especially at a contact time of four hours, with the order for column treatment efficiency being BC ˃ DC ˃ ZC. Treated water was classified for irrigation suitability according to the Agrifood Water Quality Index (AFWQI) as marginal from the ZC, very good from the DC, and excellent from the BC. Treatment of such drainage water using the BC and DC appears feasible, because the process is easily operated and leads to final treated effluent of high quality for agricultural uses. The economic cost also confirms the feasibility of this treatment.