How Does a Sewage Treatment Plant Work?

A sewage treatment plant processes wastewater through several stages to remove contaminants before discharging it into the environment. Here's a general overview:

Screening & Grit Removal:

Incoming sewage is filtered through large screens to remove solid objects like rags and sticks, preventing equipment clogging. The sewage then enters grit chambers where heavier inorganic materials like sand and gravel settle at the bottom.

Primary Treatment:

In sedimentation tanks or clarifiers, heavier solid particles (sludge) settle to the bottom while lighter materials (scum) float to the surface. These materials are removed for further treatment or disposal.

Secondary Treatment:

• Biological Treatment: The remaining liquid is mixed with microorganisms in an aerated tank. These microorganisms break down the organic matter, converting it into carbon dioxide, water, and more microorganisms.
• Secondary Sedimentation: The mixture from biological treatment goes through sedimentation tanks where microorganisms settle as sludge, leaving clear liquid effluent.

Tertiary Treatment (Optional):

Additional processes may be used to achieve higher effluent quality:

• Filtration: Effluent is passed through filters to remove remaining suspended solids.
• Disinfection: Effluent is treated with disinfectants like chlorine or UV light to kill pathogens.
• Nutrient Removal: Processes such as nitrification and chemical precipitation remove excess nutrients.

Sludge Treatment:

Sludge from primary and secondary treatments is further processed to reduce volume and stabilize it. Methods include anaerobic digestion, aerobic digestion, composting, and dewatering.

Effluent Discharge:

Treated effluent that meets quality standards is discharged into a water body. The treated liquid, about 95% clean water, can be safely returned to a natural watercourse. The remaining sludge is periodically removed by specialized companies.

Features & Benefits of Sewage Treatment Plants

• Odourless: Advanced technology activates wastewater with oxygen immediately, producing clear, odourless water ready for extraction via a soakaway or underground pipe.
• Sustainable: Achieving up to 99% efficiency, our wastewater treatment plants ensure sustainable discharge values, preparing for stricter future legal requirements.
• Environmentally Friendly: Lightweight and simple construction reduces energy consumption and running costs, featuring an energy-optimised membrane compressor and economical motor valve. Transported in stackable half-shelves, cutting freight costs by 80%.
• Easy Installation & Maintenance: Lightweight treatment tanks are easy to transport and install, requiring minimal space. The tank can be installed in groundwater, and the lid fits flush with the ground. Maintenance is simplified with an integrated self-cleaning sampling container.
• Long Lasting: Our sewage treatment plants come with a minimum 10-year structural warranty and a minimum 2-year warranty on the technology, typically exceeding these durations.

Sizing of Sewage Treatment Plants

Sized based on the number of occupants, we offer sewage waste treatment systems for up to 18-person occupancy. For larger requirements, please contact us.

Soakaway Requirements

Soakaway crates should not be used with sewage treatment plants or septic tanks as they are not designed for untreated wastewater and could contaminate public drinking water sources.

Emptying Requirements

Sewage treatment plants require periodic emptying, typically recommended annually to manage sludge buildup. Specific intervals vary; consult your supplier. Some tanks have alarms to indicate when emptying is needed.

Pumped and Gravity Fed Options

Most plants offer gravity or pumped outlet options. While gravity-fed systems are preferred, pumps are required for locations on gradients. Adding a pump introduces additional maintenance requirements.

Delivery Information

For delivery and returns, refer to the delivery & returns tab. Contact us if offload facilities are unavailable onsite, which may incur additional costs.

Note: Our sewage treatment plants do not qualify for Spend & Save volume discounts. For more information, please contact us.