Table of Contents
Is polymer a coagulant or flocculant?
Depending on the charge and chemical composition of your wastewater, flocculants can either be used on their own or in combination with coagulants. Flocculants differ from coagulants in that they are often polymers, whereas coagulants are typically salts.
Is polymer a flocculant?
Polymer flocculants are water-soluble polymers which can form flocs from individual small particles in a suspension by adsorbing on particles and causing destabilization through bridging or charge neutralization. Polymer flocculants promote the separation of particles from water to clean water.
What is the difference between polymer and coagulant?
Polymers are effective over a wider pH range than inorganic coagulants. They can be applied at lower doses, and do not consume alkalinity. They produce smaller volumes of more concentrated, rapidly settling floc.
What is an example of a coagulant?
Examples of primary coagulants are metallic salts, such as aluminum sulfate (referred to as alum), ferric sulfate, and ferric chloride. Cationic polymers may also be used as primary coagulants. 2. Chemicals commonly used for primary coagulants include aluminum or iron salts and organic polymers.
Is alum a coagulant or flocculant?
To accomplish this, the water is treated with aluminum sulfate, commonly called alum, which serves as a flocculant. Raw water often holds tiny suspended particles that are very difficult for a filter to catch. Alum causes them to clump together so that they can settle out of the water or be easily trapped by a filter.
What are the two categories of polymers?
Polymers fall into two categories: thermosetting plastic or thermoset. thermoforming plastic or thermoplastic.
How does cationic flocculant work?
Cationic cellulose-based flocculants, hold positively charged groups, which are fundamental for the neutralization of negatively charged suspended dye molecules. Also, due to the relatively long chains of the polymers with medium charge densities, bridging between the particles will be a complementary mechanism.
Is gypsum a flocculant?
Gypsum can coagulate or bridge clay particles, which accelerates settling. Flocculants should be used to prevent damage to sensitive water resources such as ponds, lakes and trout streams or whenever turbidity control is required. The best thing to do is a jar or bucket test using slightly varying rates of gypsum.
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.
What two chemicals are commonly used as water coagulants?
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.
Why alum is commonly used coagulant?
To induce coagulation, a coagulant (typically a metallic salt) with the opposite charge is added to the water to overcome the repulsive charge and “destabilize” the suspension. For example, the colloidal particles are negatively charged and alum is added as a coagulant to create positively charged ions.
Why is polymer used in water treatment?
Polymer products help aid in this process, because many of them can be used to coagulate particles, thus making it easier to separate them out. In coagulation, polymers can be used to cause particles to join together in large chains (called floc) making them “come out” or begin to “settle out” of the water.
Is na2so4 a coagulant?
Sodium sulfate is a well-known coagulant for PVA, and it is used in the coagulation bath of PVA before wet spinning of vinylon fibers.
What is the most used coagulant?
Chemical Coagulants Used In Water Treatment Aluminum Sulfate (Alum) – One of the most commonly used water treatment chemicals in the world. Aluminum Chloride – A second choice to Alum as it is more expensive, hazardous and corrosive. Polyaluminum Chloride (PAC) & Aluminum Chlorohydrate (ACH).
What is the function of coagulant?
What are coagulants used for? In water treatment, coagulants are used to remove a wide variety of hazardous materials from water, ranging from organic matter and pathogens, to inorganics and toxic materials, like arsenic, chemical phosphorous and fluoride.
What are the side effects of alum?
If experienced, these tend to have a Severe expression i fluid accumulation around the eye. throat swelling. a feeling of throat tightness. a skin ulcer. hives. a shallow ulcer on the skin. fainting. puffy face from water retention.
Does alum increase pH?
Ionic species present in alum solutions are highly dependent on the degree of reaction with hydroxyl ions. It is tempting to say that “the composition is pH-dependent.” However, in the vicinity of pH=4.3 the composition of alum solutions changes a great deal with very little change in pH.
How does alum work as a flocculant?
Alum, is a short term for aluminum sulfate, it works as a flocculant in your commercial pool, meaning that it attracts and traps suspended particles in the water and then sinks them to the bottom of the pool so that these particles can be vacuumed to waste.
What are 4 types of polymers?
Synthetic polymers are human-made polymers. They can be classified into four main categories: thermoplastics, thermosets, elastomers, and synthetic fibers. They are commonly found in a variety of consumer products.
What are 2 natural polymers?
Natural polymers occur in nature and can be extracted. They are often water-based. Examples of naturally occurring polymers are silk, wool, DNA, cellulose and proteins.
What are the 3 main types of polymers?
There are 3 principal classes of polymers – thermoplastics, thermosets, and elastomers. Differentiation between these classes is best defined by their behaviour under applied heat. Thermoplastic polymers can be either amorphous or crystalline. They behave in a relatively ductile manner but often have low strength.
Does flocculant lower pH?
Balance the pH level to about 7.0 Because flocculants can affect the pH level, you’ll want to start out with it at about 7.0 so you can make sure your sanitizer keeps working at maximum efficiency.
What is the process of flocculation?
Flocculation is a process by which a chemical coagulant added to the water acts to facilitate bonding between particles, creating larger aggregates which are easier to separate. The method is widely used in water treatment plants and can also be applied to sample processing for monitoring applications.
What is flocculant and coagulant?
Coagulation and flocculation are two separate processes, used in succession, to overcome the forces stabilising the suspended particles. While coagulation neutralises the charges on the particles, flocculation enables them to bind together, making them bigger, so that they can be more easily separated from the liquid.
