Used water, which contains contaminants and becomes unsuitable for domestic and industrial use is called wastewater.
Types of wastewater
Depending on where the water has been used, there are some types of wastewater. Depending on the source, different types of wastewater have different characteristics. Major types of wastewater and their respective characteristics are as follows.
Domestic wastewater
Wastewater generated from households is known as domestic wastewater. It includes water from washrooms, kitchens, toilets, laundry etc. This wastewater usually contains organic matter, nutrients, soaps, detergents, and some household chemicals. This wastewater is relatively easy to treat.
Industrial wastewater
The wastewater produced from any type of industry is called industrial wastewater. This wastewater comes from cleaning, processing, and manufacturing units. Depending on the type of industry the characteristics of wastewater vary significantly. Mostly industrial wastewater is rich in organic matter, heavy metals, chemicals, and complex organic compounds. This wastewater is considered difficult to treat to meet effluent standards.
Municipal Wastewater
The wastewater of a city or community which carries a combination of domestic wastewater, industrial wastewater, stormwater, and surface runoff, is called municipal wastewater. Municipal wastewater has a high load of suspended solids and organic content. The characteristics of municipal wastewater vary with weather. On rainy days, stormwater dilutes the municipal wastewater and reduces per unit pollution load.
Agricultural wastewater
Wastewater generated from agricultural areas, majorly as irrigation runoff, is called agricultural wastewater. It is usually rich in nutrients since irrigation runoff carries fertilizers and pesticides along. After nutrients, other notable pollutants include sediments and chemicals. Agricultural wastewater is hard to treat because of its high salinity and organic load.
Other types of wastewater include stormwater (rainwater that runs off), medical wastewater (generated from healthcare facilities), radioactive wastewater (generated from nuclear power facilities), and leachate (generated from solid waste dumping sites/landfill sites).