عنوان مقاله [English]
Human civilization has always evolved throughout history with direct access to water resources. Water plays an important role in economic and social developments with its quantitative and qualitative effects. Water has been the axis of sustainable development, which in nature, like energy, is neither created nor destroyed, but transforms from one form to another. One of the problems of the contemporary century that threatens the future of human life is the problem of water shortage. The water crisis is one of the challenges facing the world today. Due to the development of cities and increasing per capita water consumption, a large volume of wastewater is produced. Proper use of this huge water source in non-potable urban uses, in addition to preserving drinking water resources, also prevents environmental pollution.
Reuse of treated wastewater for various uses in accordance with environmental standards as a sustainable solution to optimize the management of water consumption in the country is important. The present study is a review study whose data has been obtained through library studies. The purpose of this study is to present and discuss in relation to the sources and types of non-potable urban uses, distribution line guidelines, water quality parameters and the rate of treatment required for wastewater reuse to non-potable urban uses, as well as sociocultural aspects of wastewater reuse. Finally, it must be acknowledged that Iran, as one of the Middle Eastern countries, has experienced a shortage of renewable water resources and is approaching the brink of a water crisis. Therefore, proper management of water resources, optimal use of renewable resources, observance of consumption pattern, use of unconventional water and effluent from wastewater treatment for non-urban drinking purposes, including, irrigation of green space, flash tank toilets, ventilation construction Air conditioning, and firefighting is essential.
Access to safe drinking water is one of the important and essential indicators of urban development and social welfare. Developed and developing countries, especially our country, which are taking steps towards development, have come to the conclusion that the goal should be sustainable development, or in other words, development without destroying the environment. Requisite for sustainable development, optimum use of available resources, including water resources. Population growth, the expansion of industries, rising living standards, and the increasing emission of pollution have severely limited available water resources. Therefore, to compensate for the shortage of water resources and also environmental protection, reuse wastewater is necessary. Municipal wastewater should be introduced as the most important available and usable resource for non-potable uses, especially for irrigation purposes.
Wastewater reuse in agriculture has a long history, while the reuse of wastewater for non-potable urban purposes is relatively new. This method has been further developed by establishing dual water distribution systems. Non-potable uses in cities including firefighting, irrigation of green spaces, flash tanks of toilets, construction, recreational uses etc., which with separating them from drinking uses, will lead to significant savings in water resources. In some cities, the old water distribution system can be considered for the delivery of treated effluents and non-drinking uses. In any case, it should be noted that conventional municipal wastewater treatment (primary and secondary treatment) is often unable to provide proper water quality guidelines for reuse. Therefore, the application of advanced and tertiary treatment is essential for reuse.
The protection of natural resources is one of the basic features of sustainable development. Increasing population, as well as increasing demand for natural resources, create competition between people for food supply and the conservation and rational use of these resources. Water is the main source of agricultural production and food security. Considering acute shortages of water and high demands on these scarce resources, proper management and planning to sustain this resource are highly solicited. In the contemporary world, the water crisis is one of the most important issues because about ¼ of the world's population is facing water shortages. The excessive use of water resources, poor management of water in the agriculture sector, climate change, and pollution have led to the drying up of rivers and groundwater. With increasing water shortages, especially in the semi-arid part, drought and floods are expected to increase. Therefore, access to fresh water for human consumption has become even more essential than access to education and health services.
The scarcity of water resources is not specific to one area; more than 43 countries in the world are suffering from this crisis. The United Nations has warned that if the world consumes as much water as it does now, Approximately 1.8 billion people in the world will suffer from water shortage by 2025.
Iran is one of the arid and semi-arid regions and is currently facing a drastic water crisis. Climate change, droughts, and political and economic problems have exacerbated the water crisis. As a result, management measures are crucial to resolving the water crisis. Iran's progress and development depend on the efficient management of the country's water resources. In recent decades, the increase in population in the country as well as the limited volume of extractable water resources and serial droughts have declined renewable water resources. Iran’s renewable water supplies have dipped from 7000 m3 per inhabitant in 1956 m3 to 2160 m3 in 2000 and to 1,732 m3 in 2017. It is predicted that Iran's renewable water resources will reach about 1300-1400 m3 in 2025. Comparison of this data indicates that Iran is approaching the threshold of the water crisis.
Material: The present study is a review study whose data has been obtained through library studies. The purpose of this study is to present and to discuss in relation to the sources and types of non-potable urban uses, distribution line guidelines, water quality parameters, and the rate of treatment required for wastewater reuse to non-potable urban uses, as well as sociocultural aspects of wastewater reuse. Finally, it must be acknowledged that Iran, as one of the Middle Eastern countries, has experienced a shortage of renewable water resources and is approaching the brink of a water crisis. Therefore, proper management of water resources, optimal use of renewable resources, observance of consumption pattern, use of unconventional water and effluent from wastewater treatment for non-urban drinking purposes, including, irrigation of green space, flash tank toilets, ventilation construction Air conditioning, and firefighting is essential.
Today, many countries in the world are facing water crises for reasons such as growing population, industrial development, climate change, and climate conditions, as well as limited water resources available. Therefore, the use of new and unconventional water supply sources in order to reduce the utilization of existing water resources seems necessary. The reuse of wastewater as an unconventional source of water is an essential step to protect the country's water resources. Today, in arid and semi-arid countries such as Iran, the reuse of wastewater for non-urban drinking, industrial use, agriculture, aquaculture, environmental use and recreation, and groundwater recharge has become particularly important. It is obvious that the reuse of wastewater will be possible only with proper management and maintenance of environmental standards regarding its amount of treatment, type, and method of consumption, and otherwise, it can be the source of many diseases and environmental problems. Direct reuse for non-drinking purposes (agricultural, urban, industrial and environmental) results in significant savings in terms of conservation of fresh water and other raw water resources for drinking purposes. Therefore, this practice is considered as a strategic management method for sustainable development of communities, and reasons such as better public acceptance, lower health risks, and lower costs have caused the use of wastewater for non-drinking purposes to be further expanded in the future. According to researchers. Expansion of water supply networks in purple (the color indicates the flow of second-hand water in the pipe) in the coming years, both for countries in the arid regions of the world and other countries, will be inevitable.