What is Sludge Dewatering & What is it Used For?

Tuesday, April 23, 2019
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What is Sludge Dewatering

Sludge dewatering is the practice of minimizing waste by volume to prepare for its effective disposal. Sludge originates during the process of treating wastewater before the water can be released back into the environment. Long presenting a challenge for the water treatment industry, sludge is the by-product extracted from the slurry during the process of industrial or municipal wastewater treatment. Dewatering the sludge with a dewatering filter press significantly reduces its weight and its volume before disposal.

In fact, filter presses produce excellent cake dryness and, in many cases superior cake dryness as compared to other filtration equipment.

What is “Sludge”?

Old Filtration Equipment

Simply stated, “sludge” is a semi-solid slurry that can be produced from a variety of industrial and municipal processes.

The purpose of sludge dewatering is to reliably and efficiently concentrate the wastes into high solids filter cakes for easy and cost-effective disposal. Disposal of sludge is governed by strict regulations. Most companies, municipalities, and institutions have sustainability objectives that are in line with regulatory guidelines and their own organizational and environmental requirements.

Sludge Dewatering Benefits

Waste Volume Reduction

Because sludge dewatering focuses on weight and volume reduction to minimize waste disposal costs, as the name of the method implies, water removal is the principal means to reduce volume before the sludge by-product can be economically disposed of.

Reduced Transportation Costs

Managing sludge can be a costly business. Dry, high solids cakes mean lower costs. Use of dewatering equipment is an effective tool for managing sludge accumulation, reducing both transportation costs and storage expenses.

Consistent Cake Dryness with Lower Risk of Spilling/Leaking

Use of sludge dewatering filter presses produces consistent cake dryness. The dry, high solids cakes not only mean lower costs of transport but also provide a lower risk of spilling/leaking onto the roads. This is a major issue, particularly when trucking through residential areas.

Wastewater Recycling

Recycling wastewater is another benefit of sludge dewatering. Once the treated water from sludge dewatering is free of hazards and contaminants, it can be reclaimed by industries and communities. Though the water is typically non-potable, it still has many applications. Steam powered plants are one good example of using reclaimed water to the benefit of a company or community.

Equipment is Easily Automated

A lot of folks think of filter presses as labor-intensive pieces of equipment. But, in fact, sludge dewatering presses can come with automatic cloth washers, mechanically-assisted cake release, and sophisticated control systems, allowing communication to the main plant control system, all making sludge dewatering much easier.


Finally, sludge dewatering is environmentally friendly in several ways, the first being reducing the volume of the waste to a more compact, manageable size for disposal. While the dry cakes are disposed of, the reuse of the filtrate can reduce the demand for new sources of water necessary for treatment in municipal and industrial wastewater plants, and also reduce the amount of water needed for treatment overall.

When it comes to sludge dewatering equipment, filter presses are a proven, cost-effective solution for waste minimization. Filter presses are effective for most types of sludge and are highly efficient for removing excess water from a wide variety industrial and municipal wastewater sludges.

Sludge Dewatering Equipment