Wastewater is water that has already been used and must be treated before it can be discharged into another body of water to avoid further contamination of the water source. Wastewater comes from a variety of sources. Everything you flush down the toilet or flush down the drain is wastewater. Rainwater, runoff, and various pollutants enter street drains and end up in wastewater treatment facilities. Wastewater can also come from agricultural and industrial sources. Some wastewater is more challenging to treat than others; for example, industrial wastewater can be difficult to treat, while domestic wastewater is relatively easy to treat (although treating domestic waste is becoming more difficult due to the increasing amount of pharmaceuticals and personal care products found in domestic wastewater)
What are the three stages of wastewater treatment?
The wastewater treatment process is divided into three main stages: primary, secondary, and tertiary water treatment. In some applications, more advanced treatment is required, known as quaternary water treatment. This stage deals with pollution in the parts per million to parts per billion range and usually involves oxidation or fine filtration. Each stage treats a different contaminant, and the water becomes cleaner as it passes through these stages.
In primary treatment, wastewater is temporarily retained in a settling tank where the heavier solids sink to the bottom, and the lighter ones float to the surface.
Once settled, this material is stopped, and the remaining liquid is discharged or transferred to the more rigorous second stage of wastewater treatment.
These large tanks are also usually equipped with mechanical scrapers, which continuously convey the sludge collected at the bottom of the tank to a hopper then pumped to the sludge treatment facility.
What is secondary wastewater treatment?
Secondary treatment of wastewater is more intensive than primary treatment and is designed to significantly reduce the biological content of the waste through aerobic biological processes.
Completing secondary wastewater treatment allows for a safer release into the local environment, reducing common biodegradable pollutants to safe levels.
It is accomplished in one of three ways.
1. Biofiltration
Biofiltration uses sand filters, contact filters, or trickling filters to remove any additional sediment from the wastewater.
2. Aeration
Aeration is a lengthy process that increases oxygen saturation by introducing air into the wastewater. Typically, the aeration process can last up to 30 hours but is very effective.
3. Oxidation basins
This method is usually used in warmer climates and uses natural bodies of water such as lagoons, allowing the wastewater to pass through for some time and then retaining it for two to three weeks.
Granular sludge vs activated sludge
AGS differs from activated sludge in its physical, chemical and microbiological properties, providing a compact and economical treatment method for removing oxidizing and reducing pollutants from wastewater.AGS sequencing batch reactors have shown their utility in treating slaughterhouses, livestock, rubber, landfill leachate, dairy products, breweries, textiles, and other effluents.
What is tertiary wastewater treatment?
Tertiary wastewater treatment aims to improve water quality to domestic and industrial standards or to meet specific requirements around the safe discharge of water. For water treated by municipalities, the tertiary treatment also includes the removal of pathogens to ensure that the water is safe to drink.
At Arvia Technology, we specialize in industrial tertiary and quaternary wastewater treatment. Our specialist solutions target the most difficult contaminants to ensure compliance with safe discharge or water reuse regulations.
We work in life sciences, chemicals, agrochemicals, and specialty chemicals. The Nyex™ system can be used as a stand-alone treatment or bolted onto an existing treatment system to provide more advanced and targeted treatment when required.