Coagulants and Flocculants for Liquid Solids Separation

Yielding excellent results for our customers

The Brennfloc coagulants and flocculants product line for liquid solids separation yields excellent technical and economical results for our customers. Brennfloc products are effective in a variety of applications, including: water clarification, solids settling, oil in water emulsion breaking, metals precipitation, filtration, and sludge processing.

In this article you will learn:

Variety of applications for coagulants and flocculants

Brennfloc organic and inorganic coagulants neutralize the anionic charges that surround suspended colloidal particles. These anionic charges cause these fine colloidal particles to repel each other preventing coagulation. By neutralizing charges, these fine particles can collide increasing their size and creating a “pin floc”. Charge neutralization is the first step in water clarification.

In addition, Brennfloc inorganic coagulants neutralize the anionic charges surrounding colloidal suspended particles and produce a metal precipitant. This metal precipitant can aid with settling and clarification.

Brennfloc flocculants improve clarification by gathering the fine coagulated particles (or pin floc), increasing floc size, and increasing these particles’ settling or rise rates. Flocculation is the second step in clarification and can greatly improve the plant operation by speeding up separation and clarity. Terms such as "floc building" or "floc bridging" describe the flocculation step.

Like fine suspended colloidal particles in water, oil can also be suspended, which is known as an oil in water emulsion. Much like the fine particles having negative charges which cause repulsion, these fine oil particles also tend to display the same tendencies. Oil in water emulsions can have surfactants and fine particles which will stabilize the emulsion and hinder separation. Brennfloc coagulants are effective in treating oil in water emulsions by charge neutralization and breaking surfactant bonds.

Water can become contaminated with many dissolved materials such as lead, zinc, copper to name a few. Brennfloc metals precipitants effectively and safely precipitate these contaminates allowing for removal by traditional clarification methods.

Filtration can be used alone to remove particles or as a final polishing step in clarification. Using Brennfloc products enhances filtration efficiency by increasing floc size, improving capture, and extending filter run times.

When solids are removed from water, a sludge is produced. This sludge can contain large amounts of water which can affect disposal, reuse, or reclamation. Brennfloc flocculants improve sludge thickening and sludge dewatering.

Markets and applications using water treatment products

Brennfloc products can be used in numerous industrial and municipal water and wastewater applications.

Markets served

Brennfloc product applications

Learn more about Brennfloc products


Water treatment is an essential tool in protecting public and environmental health. Water needs to be properly treated, both before human use and after, when it is being returned to the source. This process helps ensure product quality and safety for people and proper balance for local ecosystems.

One of the most important steps in water treatment is coagulation. This process helps separate water from other particles suspended within it, including oils, metals, and solids, so that they can be disposed of properly. The challenge is getting the suspended particles to group together into flocs large enough to capture and remove.

To make coagulation possible, water treatment professionals rely on coagulants, or substances that cause particles to clump together via chemical reaction when added to the water. Coagulants find use during water pretreatment and wastewater treatment in various industries, including the food and beverage industry, mining, oil refining, and manufacturing.

The type of coagulant you choose for your application will depend on what solids you are removing from the water and what environmental and health regulations you must follow.

Inorganic coagulants are commonly used due to their low cost and ability to treat water with low turbidity. However, inorganic coagulants are required in higher doses to treat water. They also produce more sludge that must be removed after treatment and affect pH levels in the treated water.

Organic coagulants, by comparison, require smaller dosages, produce less sludge, and have reduced impact on pH levels, though they are most effective for separating liquids from solids and removing oil.

Coagulants are a category of products used to reduce water turbidity — in other words, to clarify water. They add cationic charges to neutralize the negative charges surrounding soluble particles, rendering them insoluble.

Different coagulants have been used to clarify water for many years. Today, we divide coagulants into two main categories: organic and inorganic. Each type has properties suited to different applications.

Both inorganic and organic coagulants have their uses in water treatment. Some common coagulants in these categories include:

  • Aluminum salts: This category includes common inorganic coagulants such as
    aluminum chlorohydrate and aluminum sulfate, which are easy to handle and use during
    the treatment process.
  • Iron salts: Iron-based inorganic coagulants such as ferric sulfate, ferric chloride, and
    ferrous sulfate are effective coagulants but usually require added alkalinity.
  • Bio-polymers: Bio-polymers such as Brennfloc work in a range of pH levels and provide
    a more environmentally friendly alternative to some inorganic coagulants. This type of
    coagulant excels in separating oil from water.

Organic coagulants neutralize the negative charge in water allowing particles to come together and grow larger.

There are 3 different types of organic coagulants:

  • EPI Polyamine: refers to epichlorohydrin/alkylamine compounds
  • DADMAC: refers to diallyldimethyl ammoniumchloride compounds
  • Natural-Based: natural based organic coagulants are created from
    plants and other natural ingredients

Brennfloc organic coagulants treat a wide range of applications, giving the flexibility to design a cost effective, tailor-made program for your needs and discharge requirements.

Products are available in wide range of various chemistries, molecular weights, charges and activities, which allows you to zero in on the right product for the application.

Inorganic coagulants neutralize the negative charges in water but also precipitate to create a metal hydroxide. Brennfloc inorganic coagulants of aluminum and iron salts cover a wide range of applications. Inorganic coagulants are effective as coagulants for suspended particles.

Aluminum salts:

  • Aluminum Chlorohydrate (ACH)
  • Aluminum Sulfate (Alum)
  • Poly-Aluminum Chloride (PAC)
  • Sodium Aluminate
Iron salts:
  • Ferric Chloride
  • Ferric Sulfate
  • Ferrous Chloride
  • Ferrous Sulfate

Blending organic and inorganic coagulants can produce an effective solution compared to using either type of coagulant on its own. When jar testing indicates a dual treatment program, Brennfloc coagulant blends combine the treatment benefits of organic and inorganic coagulants, which yields superior performance.

Our Brennfloc coagulant blends are available in a wide range of chemistries and ratios using various combinations of organic and inorganic coagulants.


Flocculants are commonly used with coagulants and are a substance that helps the clumping of fine particles into a "floc", especially in the treatment of wastewater .

Flocculation is the process in which colloids — low-diameter particles that affect water's color or turbidity — are suspended in the form of loosely clumped particles called flocs. It can occur either spontaneously or by adding a flocculant — a water treatment chemical that aggregates the particles. Once these particles join together, they make it easier for the physical filtration process to remove them. First, water treatment facilities use coagulants to neutralize any charged particles suspended in the water.

When used properly, the advantages of flocculants in the water treatment process are immense. With flocculants and coagulants, your water treatment facility can reduce contamination from solid particles and colloids, decrease sludge volume, encourage particle settling for easy removal, improve the efficiency of the water filtration process, enhance the filter's performance, and romote increased cost-effectiveness and simplicity in water treatment

Brenntag Water Treatment offers an extensive range of anionic, nonionic, and cationic flocculants.

  • Anionic
  • Nonionic
  • Cationic

Liquid emulsions and dry powder flocculants are available in a full range of molecular weights and charge densities.

Branched or structured polymers deliver exceptional performance when used on centrifuge dewatering applications. The violent actions within a centrifuge expose substantially more charge sites which in turn produces a dryer more stable sludge cak.


Brennfloc ‘KB-series' natural Coagulants

Wastewater is an unavoidable by-product of modern industry, and Brennfloc provides an essential solution. Our portfolio of industrial, plant-based natural coagulants, natural flocculants and reverse emulsion breakers provide you an environmentally friendly, sustainable solution at an exceptionally low use cost.

  • Biobased: Brennfloc natural coagulants are derived from all-natural, plant-based materials making them sustainable, carbon neutral and always renewable.
  • Superior Performance: Compared to Brennfloc natural coagulants, traditional synthetic polymers, like aPam, or inorganic metal salts, like Alum, require more product while treating water less effectively.
  • Green for less: Our products are effective at lower treatment dosages, allowing you to decrease your product use and lower your overall use cost.​

Read more about the Flocculation process in the Wastewater Jar Testing Guide

Detail of Filtering System in Reverse Osmosis Water Purification Plant

Metals precipitants

As wastewater metals discharge limits become increasingly strict, there is a growing need for effective but also safe environmentally friendly precipitants.

  • Hydroxide Precipitation: although effective, cannot meet the new lower
    metals discharge limits required by many industries
  • Sulfide Precipitation: also effective but can have toxicity issues

The Brennfloc metals precipitants are effective in meeting these low discharge requirements, safe to use, and environmentally friendly.

Brennfloc metals precipitants are effective in treating: antimony, beryllium, cadmium, copper, lead, nickel, silver, tin, trivalent chrome, and zinc.

Read our guide to removing heavy metals from water