Wastewater is water that has been contaminated at home, in agricultural activities, industrial establishments, and other areas, its content has changed, and some or all of its properties have changed. Water, which is the main source of life for living things, is abundant in the world, but not all of these waters are sufficient and unlimited to meet the needs of living things. People need water to meet their needs in many areas. This need for water is increasing day by day due to the rapid population growth and the changing need, and the increasing use of areas depending on this need. Water resources, which are limited in nature, are now in danger of being exhausted for such reasons. In addition to this, it will become more and more difficult for living things to reach the water that they can use when it is added that the wastewater that is polluted by using it is given directly to nature. Therefore, wastewater treatment systems are of vital importance both for the protection of existing water resources and for water savings.
Wastewater treatment plants are facilities that enable the water of varying content to be polluted for various reasons to be purified and discharged to nature by using some methods. Wastewater facilities perform this treatment process depending on the pollution rate of the water, the wastewater content, and the area in which the treated wastewater will be used. The water to be treated and reintroduced to nature must adapt to the characteristics of the environment in which it is given and not disturb the ecological balance. Therefore, wastewater treatment systems are improving their methods day by day. In other words, the development of wastewater treatment plants is directly related to increasing the quality of wastewater treatment and recycling of water. Wastewater has been treated and used in many areas. Especially the rapid increase of the population has jeopardized the continuity of the limited amount of water. This situation brought the issue of treating the water they polluted by using people in various fields to the agenda. By treating water in wastewater treatment facilities, it allows the water to be used in different areas by recovering some or all of its lost properties. Nowadays, it is possible to treat and reuse wastewater. Wastewater has begun to be used in agricultural activities and park and garden irrigation in cities around the world by treating it. With this increasingly widespread method, savings in water consumption have been achieved, and it has also contributed to the solution of the wastewater problem that causes water pollution.
Wastewater changes in the content day by day according to the ever-changing needs of people.
Domestic wastewater can be defined as the water polluted by people in their homes for different purposes. This wastewater contains organic or inorganic substances as dissolved, suspended, or colloidal. The content of these wastewater changes according to the living standards of people, the climatic characteristics of the region where the water is consumed, and the cultural characteristics of the region. Another factor that changes the content of domestic wastewater is the discharge of industrial wastes into the city sewage system. This situation drastically changes the content of the wastewater. The nature and content of domestic wastewater may vary not only from country to country but even in different settlements in a city. It may even show an hourly change according to the hours where water is used more. Domestic wastewater can be classified as black water and gray water. Domestic wastewater Water coming from homes, hospitals, schools, hotels, and places that are common areas of people creates domestic wastewater.
Blackwater: It is the wastewater that is used and polluted in the toilets of the houses and comes from here. In other words, it is defined as the water coming from the toilet, except for the kitchen, shower, sink, dishwashers, and washing machines.
Gray water: The water that goes to the sewer by using other than toilets in homes is gray. It is the type of wastewater with the cleanest content among wastewater. It is the wastewater with the least polluting substance. The source of this type of wastewater, which is described as gray water from domestic wastewater, can be counted as the water coming from the kitchen bathroom sinks, the water coming from the dishwasher, and the washing machine. Gray waters constitute a large part of domestic wastewater in terms of quantity. Nitrogen is the substance that affects and increases the pollution degree of domestic wastewater the most. Nitrogen is the most difficult to clean substance in drinking water. Most of the nitrogen amount in wastewater comes from black water. In gray water, the amount of nitrogen is very low. Therefore, gray water is cleaned more easily and faster than black water.
Industrial wastewater is water discharged from industrial establishments or any commercial activity. Other wastewater from homes or settlements other than rainwater.
Industrial wastewater may differ from industry to industry, even in the same industrial establishments, depending on the place of production. The difference in raw materials used in industrial establishments and other reasons are the main reasons for this diversity.
Wastewater treatment plants use treatment methods according to different industrial establishments. Because the content of wastewater from industrial organizations is very variable and treatment should be done according to the content. Besides, the wastewater from these institutions is degraded during storage and in the disposal facilities. Therefore, all these reasons should be taken into consideration when treating.
Since the organic and inorganic substances contained in wastewater originating from the food industry reduce the amount of oxygen in the water, when they are given to rivers, they adversely affect and damage the living life and water quality there. Food industry wastewater can be treated and used for irrigation. However, there may be color and content problems in these waters due to their ingredients. It may be necessary to add nutrients during treatment. The biggest problem in wastewater in the textile industry is the color from the dyeing department. Machine oils are another contaminant. The typical effect in this wastewater is taste and odor problems. They can cause poisoning from industrial wastes.