Difference Between Primary and Secondary Treatment of Wastewater

Written by AOS Treatment Solutions on June 26, 2018
difference between primary and secondary treatment of wastewater


Many differences exist between the primary and secondary treatment of wastewater. The critical difference involves how these treatments are processed.

The primary treatment of wastewater occurs through sedimentation with filtering out large contaminant particles within the liquid. The contaminants separate as they are passed through several tanks and other filters. Leftover sludge filters through a digester to suspend solids from the wastewater.

The secondary treatment of wastewater happens through biofiltration, aeration, oxidation ponds and the interaction of waste through these processes.

What is the Primary Treatment of Wastewater?

primary treatment of wastewater

Through the primary treatment, it is possible to remove materials that float and settle on top of water. Through primary treatment, it is possible to implement screening water treatment, reduce particles to fragments, remove grit and initiate sedimentation.

The primary treatment pushes sewage through screens into the comminutor for grip disposal with the grit chamber. After this point, the waste may process through the secondary treatment.

What is the Secondary Treatment of Wastewater?

Secondary treatment of wastewater further purifies the wastewater through additional processes. The first is biofiltration that uses filters with sand, contact filters or trickling filters that remove sediment from the sewage.

Aeration is the next step. It mixes the wastewater with a microorganism solution. Then, this treatment uses an oxidation pond to pass the wastewater through a body for up to two or three weeks. Other items involved in the secondary treatment of wastewater include activated sludge wastewater treatment and water treatment disinfection.

Primary and Secondary Wastewater Treatment Processes

secondary treatment of wastewater

The primary wastewater process utilizes equipment to break up larger particles and then uses sedimentation or a floating process for extraction. Many treatments that use the primary method then proceed to the secondary treatment process. In this stage, the organic matter and other sludge are pushed for removal that the primary treatment did not catch.

The removal in the secondary wastewater treatment process generally occurs through a biological process with consumption of impurities in water by microbes, converting the matter into energy, carbon dioxide gases, and water.

AOS can help with municipal wastewater treatment services in both primary and secondary processes.

Difference between Primary and Secondary Treatment of Wastewater

The principal difference in primary and secondary treatment is the process that breaks down the sewage in wastewater. In the primary method, the waste processes through a physical procedure with equipment and filtration. While secondary treatment may use similar items, this method uses biological treatment through microbes.

The initial and primary water treatment process removes large matter from wastewater while the secondary treatment will remove smaller particles already dissolved or suspended. Sedimentation and filtration are the processes involved in the primary treatment method while biological breakdown occurs through aerobic or anaerobic units in secondary processes.

Another difference between these processes is how much time they take to complete. The primary treatment takes a shorter period to finish, but the secondary takes much longer as organic microbes consume the waste.

Contact AOS Treatment Solutions

You should contact AOS Treatment Solutions for primary or secondary wastewater treatment services within a local community to treat the body of water of contaminants. A representative of AOS will have more information on how to proceed with the service and what the treatment entails.

The process is complicated, but a representative can explain possible wastewater treatment methods and how to manage the body of water for future use so that you are aware of all of the benefits.


Posted Under: Wastewater Treatment Solutions