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What Are the Steps Involved in Sludge Treatment?
Monday, September 20, 2021

Most of us go about our daily lives without thinking about or wanting to think about wastewater and sludge. However, properly treating our wastewater is essential.

Prior to the 1950s, most communities in the U.S. discharged their wastewater into local streams and rivers with little treatment. As the population boomed, waterways became overwhelmed.

This led to environmental concerns on how to treat wastewater. In the following years, wastewater treatment plants were built. However, these plants created sludge, which also needed treatment.

That’s where sludge treatment methods come in.

What Is Sludge Treatment?

Sludge is a semi-solid byproduct, usually from wastewater treatment, that contains organic and inorganic matter. Sludge treatment refers to a variety of processes used to reduce the health risks associated with sludge. These processes also aim to remove water from sludge and reduce its bulk.

The best sludge treatment will recover water, minimize health risks, and create valuable byproducts such as agriculture fertilizer and biogas.

Ideally, proper sludge treatment allows for a circular economy.

Sludge Treatment Steps

Sludge wastewater treatment steps vary from one location to another. Generally speaking, there are four steps to the process.

Sludge Thickening

The first step of sludge treatment is to thicken the sludge. This process forms more solids, minimizing water waste.

There are a few different ways of thickening the sludge. Methods may vary from one wastewater treatment plant to another.

Some use dissolved air flotation, which uses air bubbles to allow solid masses to float to the top. Others may go the opposite route and use tanks with sloped designs to allow solids to collect at the base of the tank.

Sludge Digestion

During the digestion step, sludge is treated to reduce the among of organic matter and toxic microorganisms. Usually, this is done either by anaerobic digestion (without oxygen) or by aerobic digestion (with oxygen). Both are bacteria-driven processes that can reduce sludge and provide biogas as a byproduct.

Water Removal

Water removal can reduce the weight and volume of sludge. Dewatering sludge can occur through sludge drying beds, or through centrifugation. Centrifugation has become a more popular method in recent years, as it easily separates water from solid waste.

Disposal and Reuse

The final step in sludge treatment is to either dispose of it or reuse it.

Sludge disposal means the sludge can be buried underground, or possibly incinerated and turned into ash. The method used depends on the toxicity of the sludge.

If the sludge is non-toxic, it can even become fertilizer.

Wastewater treatment facilities have continued to improve, with new technologies increasing their efficiency and allowing them to become resource recovery facilities.

Smart Wastewater Monitoring

In order for sludge treatment to occur properly, facilities need to monitor it. That’s where EchoSmart comes in.

Entech Design’s EchoSmart monitors sludge in industrial and municipal wastewater. The digital analyzer technology provides real-time monitoring for clarifiers in water treatment systems.

For more information about EchoSmart, contact us.