Water resources are essential for every development activity, not only in terms of available quantity but also in terms of quality. Population growth and urbanisation are increasing the number of users and uses of water, making water resources scarcer and more polluted. Changes in rainfall patterns threaten to worsen these effects in many areas. Water scarcity, due to physical lack or pollution, has become one of the most pressing issues globally, a matter of human, economic and environmental insecurity. Wastewater, whose value had not been appreciated until recently, is increasingly recognised as a potential ‘new’ source of clean water for potable and non-potable uses, resulting in social, environmental and economic benefits. This paper discusses the potential of recycled wastewater (also known as reused water) to become a significant source of safe water for drinking purposes and improved sanitation in support of the Sustainable Development Goals.

水资源对于每项发展活动都是必不可少的，不仅在可用数量方面，而且在质量方面。人口增长和城市化正在增加用水和用水量，使水资源稀缺和污染严重。降雨模式的变化有可能在许多地区加剧这些影响。由于人为，经济和环境的不安全问题，由于人为缺乏或污染造成的水资源短缺已成为全球最紧迫的问题之一。直到最近才意识到其价值的废水被越来越多地视为可饮用水和非饮用水用途的潜在“新”清洁水源，从而带来了社会，环境和经济利益。