Types of Wastewater Treatment Plants

Written by AOS Treatment Solutions on August 7, 2018
types of sewage treatment plant


Wastewater and sewage treatment plants are responsible for processing approximately 34 gallons of wastewater in the United States each day. Wastewater treatment plant power consumption can range anywhere from 50k BTU/gallon each day to less than 5k, depending on the types of water treatment plants in question.

Several different types of sewage treatment plants are currently in operation across the country, each of which varies in the way it treats wastewater.

4 Types of Sewage Treatment Plants

In this article, we’ll examine how each type of facility manages wastewater and the requirements for operating a municipal wastewater treatment plant.

Activated Sludge Plant (ASP)

ASP sewage treatment plant

An activated sludge plant, also known as an activated sewage plant or ASP, uses a wastewater treatment process that involves adding oxygen and microorganisms to organic pollutants.

These microorganisms used in wastewater treatment cause the pollutants to oxidize, creating a sludge type substance biologically.

Examples of ASP sewage treatment plants include:

  • Vortex
  • Crystal Eco
  • WPL Diamond
  • BioPure
  • Conder ASP
  • Bison
  • Biodigester

Rotating Disc System

Rotating disc-system wastewater treatment plants offer a reliable and robust solution that delivers high-quality effluent. They are suitable for all applications and can also be retrofit to existing wastewater management systems.

They are the ideal solution for populous areas as they offer minimal noise pollution and have a small footprint. Unlike some other types of wastewater treatment plants, rotating disc systems only need to be de-sludged once every 12-18 months. They also do not require a full-time attendant to carry out raking duties.

Examples of rotating disc system treatment plants include:

  • Tuke and Bell
  • Klargester Biodisc
  • Clearwater Rotoclear

Due to the nature of the mechanical and internal moving parts, rotator disc systems must be maintained by a qualified engineer. Depending on the size of the system, servicing should be performed every 6-12 months.

Submerged Aerated Filter System

types of wastewater treatment plants

Submerged aerated filter systems, also known as SAFs, are a popular choice of wastewater treatment system. These systems require little in the way of maintenance, have few moving parts, and are simple to operate.

For companies looking to reduce overhead without affecting effluent quality, SAF is a good option. SAFs require no regular operator to be present and can be used for both industrial and domestic wastewater processing.

Examples of submerged aerated filter systems include:

  • Falcon
  • Acorn
  • Conder SAF
  • Clearwater Aeroclear
  • Matrix

As mentioned previously, these systems have few moving parts and therefore require minimal maintenance. SAFs also benefit from an automated desludging function for hassle-free operation.

Sequencing Batch Reactors

Sequencing batch reactors, also known as fill and draw systems, process wastewater using a sequence of steps. All steps take place within the same tank reactor. These systems are extremely flexible and allow the treatment of a range of different wastewater types, from very dilute to very strong.

Examples of sequencing batch reactors include:

  • Fluidyne
  • Argos
  • Lakeside

Due to their relatively small footprint and ease of operation, these types of reactors used in wastewater treatment require minimal maintenance and also save on capital costs due to the elimination of clarifiers and other equipment.

Requirements for Operating All Types of Wastewater Treatment Plants

While all the sewage treatment plants detailed above operate differently, the end result is very similar. All facilities will need to comply with legislation and regulations governing the processing of wastewater in the United States.

These requirements are as follows:

  • A valid EN 12566-3 test certificate
  • A Permit to Discharge from the Environment Agency or a valid exemption.
  • A plant that’s capable of producing an effluent quality that complies with the legislation outlined in the Permit to Discharge. Typically, this is 20mg/l of suspended solids, 20mg/l of Ammoniacal Nitrogen (NH4) and 30mg/l of biochemical oxygen demand (BOD)

To find out more about maintaining plant efficiency from our wastewater treatment consulting expertscontact AOS Treatment Solutions today. We offer a range of services designed to optimize the wastewater treatment process and would be delighted to offer our services.


Posted Under: Technical Applications, Wastewater Treatment Solutions