Urban air pollution caused by transport, traffic congestion, and high energy use is considered one of the major challenges in megacities. This paper presents a study on the effect of using nanocoating on the buildings’ facades to improve air quality in cities. It also highlights the types and uses of nanocoating in various countries through a comparative analysis of global case studies. The objective of this work focuses on titanium dioxide as a self-cleaning photo-catalytic to mitigate pollution and improve indoor air quality. The methodology depends on inductive and analytical approaches: the first part includes a review on the nanotechnology and nanocoating, whereas the analytical part encompasses an assessment of global models for nanotechnology. The study analysed different buildings around the world that applied different types of Nanocoatings. The review of these buildings were divided according to their types of nanocoating, the country where most common types of buildings used and the country that has similar matching to Egypt’s climatic conditions. By analysing each building facades, it was helpful to extract the nanotechnologies, especially self-cleaning (photo-catalytic) that mitigate air pollution. In addition, assessments of the percentage of pollutants worldwide to identify the most important pollutants that are classified as top contaminants threatening human health, if the concentration in the internal spaces exceeds the limits recommended globally were highlighted. Finally, a review of the report of Ministry Environment, Egypt, and the maximum limits of pollutants at the global scale was also conducted, which led to the extraction of requirements to reduce contaminants in the internal spaces of buildings using titanium dioxide as self-cleaning (photo-catalytic). Results show the potential of titanium dioxide as a self-cleaning (photo-catalytic) to mitigate the level of pollution to enhance livability in cities.

River dams are generally constructed for several purposes such as: to generate hydropower; storing water for irrigation and for long-term uses during low flooding and drought years; and both for hydropower generation and saving water. The beneficial side effects of the river dams are to control the river destruction power during high flooding years, to prevent the siltation in irrigation canal, and finally to save water from being wasted in the sea. The collective benefits of Aswan High Dam (AHD) are increasing the Egyptian water resource, controlling and regulating floods, protecting Egypt from potential frequent droughts, increasing agriculture productivity, and completely regulating the river water. The benefits also include preventing siltation in the irrigation delivery systems, enhancing the agriculture extension and desert greening, changing the agricultural pattern to intensive and continuous cultivation, and increasing the cultivation area of high water-consuming crops such as rice, sugarcane, sugar beet, and green clover. The AHD dam is also responsible for generating 2.1 MW of clean sustainable and environmental friendly power, improving navigation and enhancing tourism which create Nile cruise ship hotels, transforming/alternating the agricultural pattern toward having more cash and export crops, increasing fishery and fish productions, and saving the Nile water from being wasted in the Mediterranean Sea. The dam also has a lot of positive economic effects that can help in improving some infrastructure issues as well as the quality of drinking water.