Activated Sludge Systems for Biological Wastewater Treatment

What is Activated Sludge?

Activated Sludge uses beneficial microorganisms to treat wastewater for both industrial and municipal applications. This involves aeration, biodegradation, separation, and recirculation.

How the Activated Sludge Process Works

Wastewater is mixed with activated sludge in an aeration tank, where air is supplied to support microbial activity. The mixture then flows to a clarifier, where the sludge settles and the treated water is separated. A portion of the sludge is recycled back to the aeration tank, while the excess is removed for further processing. 

How Activated Sludge Improves Wastewater Treatment

Efficient organic matter removal is achieved as microorganisms consume and break down pollutants, significantly reducing biological oxygen demand (BOD).

 

Nutrient reduction occurs through biological processes that help remove nitrogen and phosphorus preventing harmful eutrophication.

 

Improved solids separation results from the production of settleable biomass, which can be effectively removed in secondary clarifiers to produce clearer effluent. 

 

Adaptable to varying loads, this process can handle fluctuations in flow and pollutant concentrations with consistent performance.

 

Supports water reuse, generating high-quality treated water suitable for irrigation, industrial use, or safe environmental discharge.

 

Cost-effective treatment is possible through naturally occurring microbes, reducing the need for chemical additives.

 

Scalable design makes it suitable for applications ranging from small community systems to large municipal treatment plants.

Activated Sludge for California Treatment Facilities

Activated sludge systems designed for California treatment facilities fully comply with state wastewater regulations and effluent discharge standards. These systems are proven and adaptable to handle a wide range of flow conditions effectively. They reduce pathogens, solids, and nutrients to protect public health and the environment. Additionally, they can be customized to enhance nutrient removal, improve energy efficiency and support water reuse initiatives. 

Applications of Activated Sludge in Wastewater Treatment

Decentralized or Rural

Reliable treatment for small, remote, or off-grid communities.

 

Food and Beverage

Handles high-strength wastewater from production and cleaning operations.

 

Industrial Manufacturing

Supports compliance by treating complex, variable-strength industrial flows.

 

Institutional Facilities

Used at schools, prisons, and healthcare centers for consistent effluent quality.

 

Municipal Wastewater

Common in small to mid-sized municipal systems with tight effluent limits.

 

Resorts and Campgrounds

Compact and efficient treatment for seasonal or fluctuating populations. 

 

Wineries

Tailored for organic-rich wastewater with low operational impact.

Innovations and System Variations

Activated Sludge systems have advanced with several innovative configurations to boost efficiency, adaptability, and treatment performance. Common variations include the following. 

 

Extended Aeration, which uses longer aeration times to stabilize sludge, reduce odors, and eliminate the need for separate digestion.

 

Sequencing Batch Reactors (SBRs) treat wastewater in time batches within a single tank, allowing precise control and flexibility for variable flows and compact sites.

 

Membrane Bioreactors (MBRs) combine biological treatment with membrane filtration for high-quality effluent that meets strict discharge and reuse standards.

 

Package Plants are modular, compact systems ideal for small to mid-size facilities or remote locations, offering easy installation and operation.

Nviro's Activated Sludge Solutions

Nviro designs and supports activated sludge systems tailored for municipal, industrial, and decentralized wastewater applications. Our solutions provide reliable BOD, TSS, and nutrient reduction, optimized for performance, ease of operation, and regulatory compliance.