Common Forms of Flocculants for Water & Wastewater
- Emulsion flocculants. Emulsion flocculants by design are a blend of water, oil and polymer that must be stored properly...
- Powder flocculants. Powder flocculants are another option when considering the use of a flocculant. Storage conditions...
- Solution flocculants. In some cases, solution (non-emulsion/non-powder)...
Full Answer
What is the purpose of the floc in water?
· Polyacrylamide is a polymer-based flocculant that is widely used in the treatment of water, ranging from waste water to drinking water. It is often used as an anionic — or negatively charged — flocculant and is popular in industry, thanks to its broad availability and relative safety when in use or in storage.
What do flocculants do in water treatment?
How Does Flocculation Work in Water Treatment Plant? First Stage: Solid Granules Suspended in Wastewater are Negatively Charged.. In Plantas piloto de tratamiento de agua ,a... Second Stage: Mixers Must be Utilized to Stir the Effluent. To guarantee that the coagulant distributes throughout the... ...
What is flocculation water treatment?
· Coagulants and flocculants, like polyacrylamide pam, are particularly useful to remove debris from wastewater, as they are efficient and cost-effective. The process of flocculation is one of the basic and most significant steps in the water treatment process.
What is flocculation in a water treatment plant?
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 …
What is the most commonly used flocculant?
The iron-based flocculants include ferric chloride, ferric sulfate, ferrous sulfate, and ferric chloride sulfate [15, 69]. Aluminum sulfate or alum (Al2(SO4)3), ferric chloride (FeCl3) and ferric sulfate (Fe(SO4)3) are the most widely used flocculants [1, 70].
What is the best flocculant?
Ferric sulfate (Fe(SO4)3)) is an iron-based salt that is one of the most widely used flocculants across different industries, along with alum and ferric chloride. It has slightly acidic properties that make it suitable for pH adjustment and is highly effective as a flocculant agent.
What do you use for flocculation?
Basically, coagulation is a process of addition of coagulant to destabilize a stabilized charged particle. Meanwhile, flocculation is a mixing technique that promotes agglomeration and assists in the settling of particles. The most common used coagulant is alum, Al2(SO4)3·14H2O.
What chemicals are added to the water to create floc?
Chemicals (coagulants) are added to the water to bring the nonsettling particles together into larger, heavier masses of solids called floc. Aluminum sulfate (alum) is the most common coagulant used for water purification. Other chemicals, such as ferric sulfate or sodium aluminate, may also be used.
What's the difference between flocculant and clarifier?
Clarifier keeps the bounded matter at the top of the pool to be grabbed by the pool filter. Meanwhile, pool floc snags the particles, assembles them, and then sinks them to the bottom of the surface. You can also leave the pool filter off overnight while the pool floc goes to work, which is one less thing to do.
What are flocculating agents?
Flocculating agents are chemical additives that cause suspended solids to form aggregates called flocs. These agents are used in water treatment, municipal and industrial waste treatment, mineral processing, and papermaking. Flocculating agents are either inorganic salts or water-soluble organic polymers.
What makes a good flocculant?
Polymers are useful as flocculants because they are robust molecules and sometimes carry charges. Because they are so large, small particles can get trapped in the curves of the polymer causing them to accumulate a mass heavy enough to prevent their retention in solution.
How do you make a floc?
And don't forget to check out the training reference section at the end of the article for some very useful links.Step 1: Tank or pond set-up. ... Step 2: Aeration. ... Step 3: Pre-seeding beneficial microbes. ... Step 4: Species selection and stocking densities. ... Step 5: Balancing carbon source input. ... Step 6: Biofloc growth.More items...•
How do you mix flocculant?
To optimize flocculant mixing system sizing, flocculant solutions are often designed to be mixed to 0.25-0.50% maximum concentration. Once dissolved, the flocculants will dilute readily with teed in water down stream of the flocculant feed pump to obtain the final target 0.1% concentration.
Why is polyelectrolyte used in water treatment?
Polyelectrolytes - the flocculation agents Polyelectrolytes are chemical flocculants used in water treatment; they act mainly in the coagulation-flocculation stage and in the conditioning/thickening of the sludge line.
Why is alum used in water treatment?
ALUMINIUM SULFATE OR ALUM IS USED AS A FLOCCULANT TO REMOVE UNWANTED COLOUR AND TURBIDITY FROM WATER SUPPLIES. IT HAS BEEN USED SINCE ANCIENT TIMES FOR THIS PURPOSE AND ITS USE TOGETHER WITH FILTRATION IS STANDARD PRACTICE IN CONVENTIONAL WATER TREATMENT PROCESSES AROUND THE WORLD.
What is ferric sulfate used for in water treatment?
ALAR recommends Ferric Sulfate for pH adjustment, coagulation and dissolved heavy metal precipitation. Ferric Sulfate starts out as a dissolved solid, but falls out of solution and becomes a suspended solid at multiple pH levels for easy filtration.
How long does it take for flocculant to work?
8 to 16 hoursPool flocculant can clear up your cloudy pool water in 1 or 2 days. Though it works faster than pool clarifiers, it will need 8 to 16 hours to clump together the particles before you can vacuum.
Can I add clarifier and flocculant at the same time?
Do you use Clarifier in conjunction with Flocculant? Flocculant can be used after clarifier. However, using too much of any product can work against the clarifying process.
Can you use too much flocculant?
Flocculant is aluminum sulfate, which is designed to clump with the particles you're trying to remove. But if you add too much, the flocculant will start to agglomerate with itself instead of those particles. These flocculant clumps will not drop to the pool floor and can clog up your filter.
Can you shock and floc at the same time?
Answer: Shock can be added at any time. Especially since you are treating a green pool. The hot sun can tend to burn off chlorine faster, but the green pool needs to be treated and the sooner, the better. The chlorine will remain high for a few days after shocking anyway whether or not the sun is out.
What is the purpose of flocculant in wastewater treatment?
Coagulants and flocculants, like polyacrylamide pam, are particularly useful to remove debris from wastewater, as they are efficient and cost-effective . The process of flocculation is one of the basic and most significant steps in the water treatment process.
What is flocculant in water?
Flocculants are materials that help in promoting the accumulation of fine particles in water that creates a flo c, floating to the surface or settling in the bottom. This makes it easier to remove these particles from the water. Flocculants are inorganic or organic and are in multiple forms, molecular weights, charge densities, and charges.
Why are organic flocculants used?
Organic polymeric flocculants are being widely used nowadays because of their ability to promote flocculation with small dosages. Biopolymers are also popular as they are more environmentally friendly, but they require a higher dosage and have a shorter shelf-life.
How is floculation done?
Flocculation is done through a chemical procedure involving chemicals in the wastewater to enable the small particles and debris to gather and combine to form a large mass known as floc. This process is conducted in different stages to treat water:
What happens after flocculation?
Once the flocculation process is successful, the water treatment plant moves to the next stage of water treatment, depending on the purpose of the treated water. Some include additional steps to thoroughly disinfect the water. It is essential to consider various factors when considering your options for flocculant and coagulant to ensure you get the right end result.
Why is flocculation important?
Due to applications of some industries , a high amount of phosphorus is released in the wastewater that requires pretreatment of water before being released to water treatment plants. Therefore, the process of flocculation is integral to remove these impurities.
Why is high energy mixing reduced during flocculation?
Once the process of flocculation begins, the high energy mixing is reduced to avoid the flocs from separating again.
What is flocculation in water?
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.
How does flocculant work?
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.
What are the advantages of flocculants?
When used properly, the advantages of flocculants in the water treatment process are immense. With flocculants and coagulants, your water treatment facility can: 1 Reduce contamination from solid particles and colloids 2 Decrease sludge volume 3 Encourage particle settling for easy removal 4 Improve the efficiency of the water filtration process 5 Enhance the filter's performance 6 Promote increased cost-effectiveness and simplicity in water treatment
What is coagulant in water treatment?
First, water treatment facilities use coagulants to neutralize any charged particles suspended in the water. Brenntag North America is your one-stop source for information about water treatment additives throughout the water treatment industry.
What is a wastewater treatment polymer?
Wastewater treatment polymers usually come in either a dry granular form or a liquid form. The liquified polymers are known as emulsions and contain surfactants and emulsifying agents. These are roughly 1/3 equal parts and required to keep the flocculant portion in a readily available condition.
What is coagulant used for?
It’s important to note that coagulants and flocculants aren’t only used to make sediment fall out of liquid suspension. Due to their ability to neutralize and agglomerate colloids, the chemicals also support dissolved air flotation (DAF) applications. In DAF applications, microbubbles pull the solids to the top of a tank, where a skimmer removes them.
Why are polymers important in wastewater treatment?
As you can tell, polymers play an important role in wastewater treatment. Besides separating solids from liquids, they also help thicken sludge and dewater contaminated material for easier handling and disposal. Removing the water content from a waste sludge can change the waste properties from liquid to solid waste.
How does polymer dosing work?
By using a polymer dosing system, producers can inject the polymer solution directly into their settling ponds. The polymer dosing increases the sedimentation rate, provides clean water, and thickens the sludge at the pond’s bottom for easier management and disposal.
What is the role of polymers in wastewater treatment?
Polymers in Wastewater Treatment. Polymers separate solids from liquids through coagulation and flocculation. Their ability to do so is central to their critical role in wastewater treatment. Most industrial process water or wastewater includes sediment and particles with a negative electric charge.
What is water soluble polymer used for?
Specific, water-soluble polymers are widely used in wastewater treatment to remove suspended solids and/or contaminants from the water. They’re used regularly in municipal, industrial, and stormwater treatment systems, but many consumers aren’t aware of their importance.
How does polymer dosing affect sedimentation?
By using a polymer dosing system, producers can inject the polymer solution directly into their settling ponds. The polymer dosing increases the sedimentation rate, provides clean water, and thickens the sludge at the pond’s bottom for easier management and disposal.
What is the purpose of coagulation and flocculation?
Coagulation and flocculation are essential components of both drinking water and wastewater treatment. They provide a reliable process for treating water turbidity (the cloudiness or haziness of a fluid typically invisible to the naked eye) which is a key test of water quality.
Why are polymers added to flocculants?
They are added as part of the flocculation process to help strengthen and increase the settling weight of the floc. Polymers can be either natural or synthetic. Natural polymers also date back to ancient times, with Sanskrit literature from around 2000 BC referencing the use of crushed nuts to clarify water.
What is the difference between flocculation and coagulation?
Coagulation and flocculation are two, separate, crucial parts of water and wastewater treatment. Coagulation destabilises the minute suspended particles by static charge neutralisation, while flocculation helps them to bind together to form much bigger morphologies, so they can be more easily separated from the liquid phase.
What destroys the process whereby tiny particles repel each other and promotes their consolidation to bigger ones that are able
The coagulation process. This destroys the process whereby tiny particles repel each other and promotes their consolidation to bigger ones that are able to stick together. The bigger the particle, the easier it is to separate from the liquid.
Why is rapid mixing important?
Rapid mixing ensures the coagulant is properly dispersed to promote particle collisions. The metal coagulant hydrolysis products formed within 0.01 to 1.0 seconds tend to be the most effective for destabilisation – this is why adjustment of pH and post-dosing of more coagulant is rarely effective after the initial coagulant addition.
What are the two types of coagulants?
Types of coagulants. Today, there are two types of coagulants that are most commonly used in water and wastewater treatment. Organic and inorganic. Inorganic coagulants include: Iron coagulants - e.g. ferric sulphate, ferrous sulphate, ferric chloride and ferric chloride sulphate. Organic coagulants include:
How long does it take for a suspended particle to settle out of the water?
This causes them to remain suspended rather than clumping together and settling out of the water. They might take days or even up to centuries to settle out! Coagulation and flocculation are two separate processes, used in succession, to overcome the forces stabilising the suspended particles. While coagulation neutralises the charges on ...
What is flocculant used for?
Used in a wide range of industries and applications, flocculants help to remove suspended solids from wastewater by aggregating contaminants into flakes or “flocs” that float to the surface of the water or settle at the bottom. They can also be used for lime softening, sludge thickening, and solids dehydration.
What is a coagulant and floculant?
What Is A Coagulant And Flocculant? Flocculants and Coagulants for Wastewater are used in every industrial water treatment process. Wastewater slurries exhibit a range of particle sizes and charge requirements. Optimum Coagulant and Flocculant treatment are used to separate solids from wastewater and requires specific dosages.
What is the difference between anionic and cationic flocculants?
Generally speaking, anionic flocculants are used to catch mineral particles while cationic flocculants can capture ...
What are the two categories of coagulants used in wastewater pretreatment?
Chemical coagulants used in industrial wastewater pretreatment fall into one of two categories: organic and inorganic coagulants.
What is source to discharge treatment?
Source-To-Discharge Treatment Solutions involved the use of high purity, high quality Flocculants and Coagulants to treat the hardest wastewater situations
What are some examples of organic coagulants?
Examples of common organic coagulants include polyamines and polyDADMACs, as well as melamine formaldehydes and tannins.
What is the mechanism that removes sludge from water?
This is referred to as the “sweep-floc” mechanism. While effective, this process adds to the overall sludge volume that needs to be removed from the water.
What are some examples of flocculants?
Examples of ChemTreat flocculants include low-, medium-, and high-molecular weight polymers.
When to use organic coagulant?
Organic coagulant is generally used when a reduction in sludge generation is desired. Furthermore, blended organic and inorganic chemicals are often more effective than either organic or inorganic chemicals alone. The correct blend can often combine the advantages of using the inorganic coagulant sweep-floc mechanism with ...
What polymers act similarly to inorganic coagulant products?
Melamine Formaldehydes and Tannins. These all-organic polymers act similarly to the inorganic coagulant products in that they not only coagulate the colloidal material in the water, but also contribute their own precipitated floc. This sweep-floc precipitate readily adsorbs organic materials such as oil and grease.
What is a coagulant in water?
Water treatment coagulants are comprised of positively charged molecules that, when added to the water and mixed, accomplish this charge neutralization. Inorganic, organic, or a combination of both coagulant types are typically used to treat water for suspended solids removal.
What is the mechanism of coagulant in water?
Once added to water, inorganic coagulant chemicals react with the alkalinity and hydrate to form metal (aluminum or iron) hydroxide precipitates, which act as a sweep-floc mechanism . This mechanism can be compared to snowfall on dirty air. As the snow falls, it adsorbs particulates in the air, which coprecipitate, thus cleaning the air. In water treatment, the metal hydroxide sweep-floc acts on water the way a snowfall acts on air. Many difficult-to-treat colloidal suspensions can be effectively treated using inorganic coagulants.
What is the most widely used class of organic coagulation chemicals?
Polyamine and PolyDADMAC. These are the most widely used classes of organic coagulation chemicals. They function by charge neutralization alone, so there is no advantage to the sweep-floc mechanism. Polyamines will generally treat higher turbidity raw water (approximately >20 NTU) effectively.
Is sludge hazardous to water?
For influent or raw water applications where the sludge is generally non-hazardous, the penalty for creating more sludge with higher water content is small. For wastewater applications with hazardous sludge, the economic penalty can be significant.
What are some examples of flocculants?
Examples of ClearWater flocculants include low-, medium-, and high-molecular weight polymers.
What is a coagulant in water treatment?
Water treatment coagulants are comprised of positively charged molecules that, when added to the water and mixed, accomplish this charge neutralization. Inorganic coagulants, organic coagulants, or a combination of both are typically used to treat water for suspended solids removal.
What happens when you add a coagulant to water?
When an inorganic coagulant is added to water containing a colloidal suspension, the cationic metal ion from the coagulant neutralizes the negatively charged electric double layer of the colloid. Much the same occurs with an organic coagulant, except the positive charge most commonly comes from an amine (NH 4+) group attached to the coagulant molecule. ClearWater has both NSF-approved and GRAS-applicable coagulation products. Examples of ClearWater coagulants include aluminum salts, iron salts, and polyelectrolytes.
What is the mechanism of coagulant in water?
Once added to water, the inorganic coagulants react with the alkalinity and hydrate to form metal (aluminum or iron) hydroxide precipitates, which act as a sweep-floc mechanism . This mechanism can be compared to snowfall on dirty air. As the snow falls, it adsorbs particulates in the air, which coprecipitate, thus cleaning the air. In water treatment, the metal hydroxide sweep-floc acts on water the way a snowfall acts on air. Many difficult-to-treat colloidal suspensions can be effectively treated using inorganic coagulants.
Is ferric chloride a coagulant?
Ferric chloride is generally the least expensive inorganic coagulant, because it is generated as a waste material from steel-making operations (waste “pickle liquor”). However, it is by far the most corrosive and hazardous inorganic coagulant, and its use is limited to facilities equipped to handle it safely.
Is coagulant effective in water?
Inorganic coagulants are both cost-effective and applicable for a broad variety of water and wastewater. Inorganic coagulants are particularly effective on raw water with low turbidity (total suspended solids concentration) and will often treat this type of water when organic coagulants cannot.
Why do flocculants work?
These two basic concepts are the reasons that flocculants work. When the particles come together, they get heavier. When they get heavier, the water molecules cannot push them around as easily as they used to, and gravity pulls them to the bottom of the water container. The result is water with less dirt in it!
Why do flocculants accumulate mass?
Because they are so large, small particles can get trapped in the curves of the polymer causing them to accumulate a mass heavy enough to prevent their retention in solution. Many other flocculants are currently used in water treatment today and even more are being studied by engineers and researchers around the world.
How do engineers help solve the problem of water pollution?
Engineers help solve this problem by using flocculants to clean water before and after it is used in households around the world. Several different flocculants are currently used to clean water, and engineers continue to design more effective and less expensive ways to remove particles from water.
Why do colloids settle out of water?
Another reason that colloids take a long time to settle out of water is surface charges. Surface charges can form on a particle in several ways.
What is the measurement of the cloudiness of water?
In this lesson, we focus on the removal of solids. Turbidity —To measure water cleanliness prior to consumption, we use the concept of turbidity. Derived from the word turbid, turbidity is a measurement of the "cloudiness" of water. It essentially tells us the amount of solids in the water.
What are the contaminant types in water?
Several contaminant types are found in water including chemicals (such as salts and sugars), microorganisms (such as bacteria and algae), and solids (such as clay and sand). Most of these contaminants are removed in the water treatment cycle. In this lesson, we focus on the removal of solids.
Does flocculant affect the volume of solution?
The volume of solution and flocculant can also affect flocculation. Chances are, if a large amount of water is being cleaned, a larger amount of flocculant is needed. The most effective dose may also change depending on the flocculant type, which is often dictated by the available charges or size of the flocculant.
