845-454-8171 Menu

How to Reduce Total Suspended Solids From Wastewater

By: Tom Frankel
Post Date: January 3rd 2024

Post Tags:

How to Reduce Total Suspended Solids From Wastewater


Table of Contents


Reducing total suspended solids (TSS) in wastewater increases treatment efficiency and decreases bacteria content in water discharge. Wastewater treatment plants can significantly improve their processes and release cleaner water into the environment when they reduce TSS.

Various methods help reduce TSS, preventing equipment wear and making it easier to eliminate harmful materials from wastewater before sending it back into the surrounding communities. Implementing effective procedures in your treatment processes and using high-quality equipment can help you reduce TSS and improve water quality, positively impacting your community and natural ecosystems.

Importance of Removing Total Suspended Solids

Total suspended solids are unsettled solid particles in water, and they are a crucial consideration in wastewater treatment processes. Wastewater solids come from the following sources:

Total suspended solids can reduce wastewater treatment efficiency, deplete oxygen, reduce water clarity, clog filters and pipes, and trap harmful bacteria. Reducing TSS in wastewater presents the following benefits:

Higher Oxygen Levels

The relationship between TSS and BOD reveals how reducing TSS can help increase oxygen levels in natural water bodies. TSS and biochemical oxygen demand (BOD) are two of the most essential wastewater treatment measures. BOD measures how much oxygen bacteria and microorganisms consume to degrade organic matter, and high BOD levels are harmful to aquatic ecosystems.

Natural water bodies depend on sufficient dissolved oxygen concentration to maintain aquatic life. If TSS levels are high when wastewater reaches a natural water body, microorganisms consume more oxygen as they decompose the suspended solids. Increased TSS depletes oxygen, and decreased TSS increases oxygen in water.

Maintaining low TSS levels also decreases BOD and supplies aquatic ecosystems with more oxygen to support aquatic plants and animals. You can achieve BOD reduction in an aeration tank by increasing aeration with high-quality air diffusers.

Reducing TSS also reduces chemical oxygen demand (COD). COD measures the oxygen levels necessary to oxidize organic matter in water.

Increased Water Clarity

Reducing TSS increases water clarity. The fewer suspended solids in water, the more transparent it is. Turbidity refers to cloudiness and lack of transparency in water when suspended materials are present, and it increases as TSS increases.

Protected Filters and Pipes

Reducing TSS protects industrial filters and pipes. TSS can clog and scour pipes and filters, reducing equipment efficiency and leading to costly repairs. You can make pipes and filters last longer and equipment perform better by reducing TSS.

Reduced Bacteria

Solid particles harbor bacteria, so their presence makes it difficult for treatment systems to remove all harmful substances. Reducing TSS reduces hazards present in water because it makes it easier to remove bacteria.

Increased Wastewater Treatment Efficiency and Improved Budget

Reducing TSS in wastewater helps treatment plants increase efficiency and save money. You can effectively remove harmful materials with fewer chemicals and help your equipment last longer by reducing TSS. You can also avoid high surcharges with reduced TSS and COD levels.

Compliance With Federal and State Regulations

BOD and TSS levels must adhere to environmental regulations. The government sets standards and guidelines to prevent pollution and protect the environment and human health. Publicly owned treatment works (POTWs) must follow the EPA’s secondary treatment standards, which the organization reflects as five-day BOD, pH and TSS removal.

How to Reduce Total Suspended Solids From Wastewater

Several treatment processes can help you reduce TSS in wastewater before releasing it back into natural water bodies and the surrounding community, including the following common methods.

Aerobic and Anaerobic Treatment

Aerobic and anaerobic treatment are biological wastewater treatment methods. They use microorganisms such as bacteria to break down suspended solids. Aerobic treatment requires oxygen, and anaerobic treatment requires little to no oxygen. Effective aerobic treatment depends on high-quality equipment. Quality fine bubble disc diffusers and fine bubble plate diffusers produce a uniform bubble pattern to increase oxygen transfer efficiency.

Aerobic and anaerobic treatment processes generate biological solids known as volatile suspended solids (VSS) or sludge yield. VSS generate because organic material in wastewater converts to carbon dioxide, water and biomass. Treatment plants can thicken VSS and move them off-site or use them as a compost amendment.

Coagulation and Flocculation

Coagulation and flocculation — also known as chemical precipitation — is a process that uses chemicals known as polymers to reduce TSS. During this process, polymers clump solid particles together to form larger solids that are easier to filter. Water treatment plants can use coagulation and flocculation to form larger solids and then filter them from wastewater using auto strainers, dewatering bags or filter presses.

Physical Filtration

Physical separation or filtration reduces TSS in wastewater using strainers, sediment filters, screens and depth filtration. Depth filtration is typically the best solution for wastewater with high TSS levels and small particles. If you use this method, use rotary valves instead of piston valves to prevent them from rubbing solid materials against your spacers and O-rings.


The oxidizing process destroys organic TSS with oxygen. The oxygen produces a chemical reaction that increases the suspended solids’ sizes so equipment can remove them easier. Common oxidizing solutions are aeration, ultraviolet (UV), hydroxyl radical and ozone generators.

TSS Removal Calculation

You can calculate your TSS removal efficiency percentage with a simple equation. First, subtract the effluent TSS from the influent TSS, and then divide your result by the influent TSS. Multiply this result by 100 to determine the TSS removal efficiency percentage.

Reduce TSS With High-Quality Aeration Equipment

Reduce TSS With High-Quality Aeration Equipment

Reducing TSS in wastewater decreases bacteria, increases water clarity, raises oxygen levels and increases treatment efficiency. It helps protect aquatic life and ecosystems by preventing microorganisms from consuming the oxygen plants and aquatic animals need to survive.

You can reduce TSS in wastewater with effective treatment methods and equipment. Oxidizing, physical filtration, coagulation and flocculation, and aerobic and anaerobic treatments can significantly reduce TSS. SSI Aeration, Inc. offers high-quality wastewater treatment systems and equipment to enhance your treatment processes.

Our fine bubble disc diffusers and fine bubble plate diffusers are versatile and efficient, allowing you to remove more suspended solids from the water you treat. We also offer polytetrafluoroethylene (PTFE) aeration diffuser membranes to increase standard aeration efficiency (SAE). These quality membranes offer uniform bubble distribution, providing more oxygen for increased efficiency in aerobic treatment processes. Contact us to learn more about our water treatment equipment and how we can help you reduce TSS.