How Does Wastewater Sludge Treatment Work
By: Tom Frankel
Post Date: July 10th 2024
Wastewater contains organic and inorganic materials, chemicals, plant nutrients and even pathogens. These components can be toxic to humans and the environment, which is why wastewater treatment is important.
The process of treating wastewater creates sludge, also known as biosolids. Sludge is a byproduct of wastewater that may be in solid, semisolid or slurry form. This substance is divided into two main classifications — primary and secondary. Primary sludge comes from the primary sedimentation treatment of wastewater, while secondary sludge is the activated waste that results from biological treatments.
Like wastewater, sludge undergoes a treatment process. The main purpose of sludge treatment is to reduce sludge volume and weight and ultimately minimize the costs of transportation and disposal. It also destroys pathogens that may carry potential health risks.
List of Sludge Treatment Processes
Sludge treatment typically consists of four main processes:
- Thickening: Usually the first step in the sludge treatment process, this is where primary or secondary sludge gets stirred with clarifying agents to create larger, solid aggregates.
- Dewatering: Dewatering is reducing water content in sludge through centrifugation, filtration or evaporation. Sludge with 50% to 75% water is handled as a solid material, while sludge with more water undergoes further treatment.
- Digestion: The digestion process involves reducing the amount of microorganisms and organic matter in solid sludges. This process is further classified into three methods — aerobic digestion, anaerobic digestion and composting.
- Disposal: As the final step of sludge management in water treatment, this is where the dewatered sludge gets transported to designated disposal sites. Landfills, where sludge is usually buried underground, are the most common sites for disposal. Other sludge disposal methods include reclamation, incineration and land application.
The Importance of Wastewater Sludge Treatment
In the United States, wastewater undergoes treatment as mandated by the U.S. Environmental Protection Agency. This process includes sludge treatment and the observance of proper sludge disposal methods.
Wastewater treatment is necessary to remove pollutants from the wastewater and prevent the contamination of natural resources. It also makes treated sludge viable for other uses, such as fertilizer for gardens and parks, soil erosion control, landscaping, heating and cooking, and generating energy in the form of alternative fuels.
Explore Sludge Treatment Equipment for Diverse Applications
SSI Aeration, Inc. develops sludge control systems for wastewater treatment plants. Our innovative solutions ensure maximum efficiency in your treatment processes and help you adhere to environmental standards.
To learn more about our products and services, contact us at 845-454-8171 or fill out our contact form.
Mr. Frankel co-founded SSI in 1995 with experience in design and distribution of engineered systems. He is in charge of sales, marketing and operations in the company. Mr. Frankel holds multiple US patents related to diffusers. He is a graduate of Washington University in St. Louis.