WEC Logo
Linked In


Which Sewage Treatment Technology And Process Is Best?

Sewage Treatment Technology
There are many different technology and process options for sewage treatment available today, each with their own advantages and disadvantages. As experts in the supply of sewage treatment solutions, WEC Projects explore several of these options in this article.

Matching the technology with the volume to be treated

Fundamental to your technology selection is the sheer volume (hydraulic load) of sewage to be treated, the degree of contamination of the effluent and the treated effluent discharge requirements. If full nutrient removal is a requirement in terms of the discharge with the treated water specifications being high, a system with nutrient removal capability needs to be selected. Options include your conventional activated sludge (CAS) system that includes anaerobic, anoxic and aeration zones with the requisite recycles. Nereda® has enhanced biological nutrient removal capabilities with the added advantage of a smaller footprint and reduction in the energy requirements compared to CAS systems.

Our “Model R” extended aeration activated sludge treatment plant is considered a packaged plant as a result of the hydraulic load it generally treats (350kl/day to 1,5MLD in single modules) and because the concept is duplicable. We therefore have pre-engineered much of the concept, which needs to be modified to suit specific effluent and site conditions. The Model R however does provide for full nutrient removal and we have utilised it successfully in applications where special discharge limits were a requirement.

For smaller flows, we employ our model A through D range of packaged sewage treatment plants. The hydraulic loading design limit ranges from 10kl/day through to 350kl/day depending on the specific model selected. This range of packaged plants is modular, which provides the client with an easy expansion option should the capacity requirements increase.

WEC Projects also provide sequential batch reactors which differ from our continuous flow options, in that SBR’s are a batch process type. There are different variations on the theme but all SBR’s operate on the same fundamental premise of reactors being fed in batches. While one tank is accepting effluent, another is in the settle/decant mode or in fill and aerate mode.

Biological trickle filters are also designed, built and supplied by WEC Projects. A biological trickle filter is a low energy, low maintenance option where the discharge standards may not be as stringent

The extra benefits of WEC Projects systems

One vital aspect that sets our sewage treatment systems apart is that we offer options for both general and special discharge limits. That means that we can design and install the system to achieve additional goals such as full nutrient removal. Nutrient removal is especially important in settings with high amounts of nitrogen and phosphorus, preventing these from killing aquatic life.

Proper maintenance and operation is key.

The key to continuously meeting discharge requirements and high-quality effluent is proper operation and maintenance of the plant. That is why WEC Projects also has an operation and maintenance division, WECAssist, which assists in making sure that our clients have access to the knowledge and skills that ensure the quality of their sewage systems and effluent remains up to legislative standards.

Contact us for information on our products, including the innovative Nereda® sewage treatment system, and any other services you may require which we offer. Take your next step towards improving our precious water sources with WEC Projects.