There are many types of wastewater. These include rainwater, seawater, and domestic and industrial wastewaters in the sewage system. Greywater is domestic water that comes from homes and is used for cleaning and bathing. Blackwater is made up of water and other liquids from street drains, lavatories, and industrial sites. It is very important to maintain resource recovery in any industry.
These require more processing and may include material from cesspools or latrines. Water treatment also includes water runoff from snow and highway deicing. The sewage is further broken down into organic and inorganic substances, some of which are pathogenic and loaded with heavy metals.
Water treatment is designed to remove contaminants from water and allow bacteria to grow rapidly. This allows water to be reused. This requires the use of a lot of equipment. There is also a need for settling ponds that allow inorganic deposits to be drawn by gravity to the bottom. Pumps are used to add more air to the mixture, which helps it decompose faster and return to a neutral pH level. This is how nearly three-quarters of Israel's irrigation water needs are supplied.
This is only one example of the many types of irrigation and water reuse. Ozone treatment is a relatively new treatment that allows ozone to be produced and circulated throughout the system. This increases the process of decontaminating the water.
The first or primary treatment step for sewage and lighter waste products is the settling tanks. These may include light oils and grease, as well as solids that are floating to the surface. They are then skimmed off and treated further. The water leftover is then ready for the second stage, which involves the removal of small biological materials and microbes.