Wastewater is water that is no longer fit for purpose - whether it be wastewater from homes and businesses, or from sources such as acid rain.
Water is never created from new - all the water in the world is recycled and used over and over again. Because of this, wastewater management techniques are used in order to produce safe, clean water for use in homes and industries around the world, or returned back into the water cycle with as little impact on the environment as possible.
Water management is carried out via a process of water reclamation
Reclaimed water can be used for a number of purposes including:
- Surface water and groundwater
- Drinking water
Water quality standards vary depending on the purpose of the reclaimed water. For example, irrigation water used for watering crops requires a lower quality standard than drinking water which needs to be cleaned and disinfected to strict standards in order for it to be safe for human consumption.
Wastewater management explained
The primary reason for wastewater management is to protect public health and the environment.
Once the wastewater leaves homes or businesses to continue its journey down the drain, it joins the municipal sewers. Then, it travels through a conveyance system to water treatment plants where it undergoes a series of treatments.
Preliminary treatment process
Firstly, the wastewater is subject to a preliminary treatment process to remove items that cannot be treated biologically, such as:
- Rubber goods
- Inorganic materials e.g. sand and rocks
If this process is not followed, problems may occur in the downstream and the water treatment process overall. Machinery or equipment can be damaged, resulting in costly repairs. In addition, downtime in treating water can cause a water shortage which can have a number of negative consequences for those dependant on the water supply.
Primary treatment process
This is the first stage in the treatment process where most of the organic material is separated from the water - solids are separated from the liquid. Solids that are denser and therefore heavier will sink to the bottom and materials like grease and scum rise to the top. The clean water then flows to the next stage of the treatment process, while the remaining solids are removed and sent on for further processing.
Secondary treatment process
Ammonia in the wastewater is converted to nitrogen gas through a series of biological processes and the water is disinfected with chlorine or bleach. The disinfectant is then removed from the water and the clean and disinfected water exits the wastewater treatment plant back into the environment for re-use.
Much of the world’s wastewater comes from industrial and commercial sources and local water authorities are putting in further measures for businesses to reduce the levels of fats, oils and grease (FOG) and TSS (total suspended solids) in their wastewater.
Find out more about NCH Asia’s range of solutions to ensure safe and sustainable water is generated.