Why ferric chloride for drinking water treatment?
Ferric Chloride has been commercially available in the United States since the 1930's but it is only in the last 20 years that we've seen a trend of increased acceptance of Ferric Chloride for drinking water treatment. This trend is likely due to the chemical's improvements in product economics, quality and availability in the United States.
What is ferric coagulant used for?
Ferric coagulants may be used in color removal at the high pH values required for the removal of iron and manganese and in softening of water.
Is alum or ferric chloride better for your water treatment plant?
To the vast majority of water treaters, who struggle with meeting required levels for TOC and DBPs, there are likely better solutions for your plant than alum and ferric chloride.
What is ferric sulfate used for?
Ferric sulfate, aluminum sulfate, or ferric chloride, classed as aluminum or iron salts, are common coagulants for water treatment. A coagulant is a chemical that is used to remove suspended solids from drinking water. They are made up of positively charged molecules, which help to provide effective neutralization of water.
How does ferric chloride clean water?
As a flocculant, chemicals that help small particles in water clump together so they can be removed, Ferric Chloride is dissolved in solution, where it forms an aqueous brown tinted solution. The solution is used to clear water of particles.
What happens when ferric chloride is added to water?
Ferric Chloride or Iron (III) Chloride (FeCl3) is used as a flocculant in sewage treatment and drinking water production. When small quantities of ferric chloride are added to the raw water, iron(III) hydroxide precipitates and adsorbs finely divided solids and colloids.
How does ferric chloride coagulation work?
Ferric chloride (FeCl3) is the most common iron salt used to achieve coagulation. Its reactions in the coagulation process are similar to those of alum, but its relative solubility and pH range differ significantly from those of alum. Both alum and ferric chloride can be used to generate inorganic polymeric coagulants.
What is ferric acid used for?
Ferric chloride is a moderately strong Lewis acid. Ferric Chloride is used in photoengraving, photography, the manufacture of pigments and ink, the chlorination of silver and copper ores, and as a mordant in dyeing and printing textiles.
What is the use of ferric chloride in aquaculture?
Although ferric chloride application has not been evaluated for aquaculture pond treat- ment, it has a potential use in the removal of phosphorus from pond wa- ters. Ferric chloride treatment at 5 mg/L to 35 mg/L removes phosphorus from pond waters (Rowan 2001).
Does ferric chloride dissolve in water?
WaterEthanolMethanolAcetoneDiethyl etherIron(III) chloride/Soluble in
Does ferric chloride lower pH?
Iron-based coagulants, such as ferric chloride, ferric sulphate and PFS®, are not that popular in Australia and tend be more expensive than alum on an equivalent dose basis. They also consume more alkalinity than alum, and hence tend to depress pH of the dosed water much more.
What role does coagulation play in water treatment Why is it necessary to add ferric chloride?
because coagulation removes many of the particles, such as dissolved organic carbon, that make water difficult to disinfect. Because coagulation removes some of the dissolved substances, less chlorine must be added to disinfect the water.
Is ferric sulphate a coagulant?
2 Ferric Sulfate as Coagulant and the Chemical Reactions. Like alum, ferric sulfate also requires alkalinity in the water in order to form the flock particles ferric hydroxide [Fe(OH)3].
Where do you use ferric chloride?
It is used to treat sewage, industrial waste, to purify water, as an etching agent for engraving circuit boards, and in the manufacture of other chemicals. Ferric chloride, solution appears as a colorless to light brown aqueous solution that has a faint hydrochloric acid odor.
Is ferric chloride hazardous?
Harmful or fatal if swallowed. Harmful if inhaled. Eye or skin contact may cause irritation. Contact with liquid or vapor form of this chemical may cause severe injury or death.
What is ferric sludge?
Ferric chloride solutions are used as coagulants or flocculants in water treatment operations for human consumption. This treatment produces large amounts of clay-type solids formed mainly of montmorillonite with iron oxides and humic substances.
What is ferric chloride?
Ferric chloride is a configuration of iron that can be used for treating drinking water in the water treatment process. Ferric chloride can purify water of many different PH balances and can help remove any discoloration present in the water. Ferric chloride can also work to purify drinking water at a lower dose than comparable sulfate-based ...
What happens if you store ferric chloride?
If stored improperly, ferric chloride can cause a reaction known as defoliation, the process of leaf removal, to any plant matter within range. To help prevent this unfortunate side-effect, it is highly recommended that you purchase tank lids that are fume-tight.
Does ferric chloride purify water?
Ferric chloride can also work to purify drinking water at a lower dose than comparable sulfate-based coagulants. Interestingly, when used to purify drinking water, ferric chloride produces a by-product substance that has a very high iron content.
Can you use fibreglass in ferric chloride tanks?
Though fibreglass can be a potentially effective storage solution for your ferric chloride storage tanks needs, it is always important to take the proper precautions and use the correct protective measures when working with, or around, a chemical like ferric chloride. When looking for ferric sulfate storage tanks, consider Belding Tank.
Is ferric chloride safe to drink?
Ultimately, ferric chloride can be an effective and low-cost option for purifying drinking water. However, it is important to store ferric chloride securely and safely. Ferric chloride is what is known as a high fuming chemical.
What is the best way to store ferric chloride?
For safe storage, we recommend a high-density crosslinked polyethylene tank. Ferric chloride is also a high fuming chemical. These fumes can potentially defoliate surrounding trees and plants. When storing Ferric Chloride in a chemical storage tank, a fume-tight manway lid cover prevents fumes from escaping the tank.
What is flocculant in water?
A flocculant is a substance that promotes the clumping of particles so that they may be removed from water. Flocculants are essential in proper water treatment. One particularly popular flocculant is Ferric Chloride.
Is ferric chloride a pure iron?
As one of the purest and most concentrated forms of iron commercially available for water treatment, Ferric Chloride has a unique distinction. In order to produce Ferric Chloride, Ferrous Chloride must be used. It is the oxidation of Ferrous Chloride with Chlorine that creates this new compound.
Is ferric chloride a coagulant?
Ferric Chloride offers versatility in the water treatment industry, by working as a flocculant and coagulant, as well as a reactant. It promotes faster sedimentation in general and specifically, better sedimentation in cold water, making it an ideal choice for the industry.
What is a Coagulant for Water Treatment?
Ferric sulfate, aluminum sulfate, or ferric chloride, classed as aluminum or iron salts, are common coagulants for water treatment.
How Does Coagulation Treatment Work?
Coagulation treatment is usually carried out before sedimentation and filtration. During the process, a coagulant is added to water, and its positive charge neutralizes the negative charge of suspended contaminants.
What Is Removed During Coagulation?
Coagulation is most effective at removing suspended solids and natural organic matter like gravel, sand, algae, clay, iron, protozoa, and even bacteria. Many of these contaminants can give water an unpleasant taste when present in large quantities, and can also give water a brown or orange color.
What Are the Most Common Types of Coagulants?
The most commonly used chemical for coagulation is aluminum sulfate. Ferric sulfate, ferric chloride, or sodium aluminate are also popular types of coagulants.
How to Choose a Coagulant for Water Treatment
The type of coagulant used by your local water treatment facility will usually depend on availability and affordability. With aluminium sulfate being available, affordable and highly effective, it is the preferred choice for public water treatment around the world.
About the author
Brian Campbell is the founder of WaterFilterGuru.com, where he blogs about all things water quality. His passion for helping people get access to clean, safe water flows through the expert industry coverage he provides. Follow him on twitter @WF_Guru or contact him by email [email protected]
What is ferric chloride?
In the laboratory, ferric chloride is commonly used as a Lewis acid for catalyzing reactions, such as Friedel-Crafts reaction of aromatics and chlorination of aromatic compounds. Ferric chloride, also called iron chloride, is a chemical compound with a chemical formula of FeCl3. It has a relatively low melting point, ...
What percentage of ferric chloride is sold in municipal bids?
This is one of the few water treatment chemicals that can sequester odors. In the U.S., more than 80 percent of all ferric chloride is sold in municipal bids, with 65 percent sold for municipal wastewater applications, and 18 percent for potable water treatment applications. ADVERTISEMENT.
What are coagulants in water treatment?
Water Treatment Coagulants. Coagulant water treatment chemicals come in two main types –. primary water treatment coagulants and coagulant aids. Primary coagulants neutralize the electrical charges of particles in the water which causes the particles to clump together. Chemically, coagulant water treatment chemicals are either metallic salts ...
What pH is needed for coagulation of turbid water?
This lowering of natural alkalinity is desirable in most cases as the pH range for coagulation of turbid waters being 5.7 – 8.0. The alkali required for corrosion prevention, therefore, would be added to the filtered water, the required dose being influenced but not governed by the alum dose.
What is the purpose of coagulant in a coagulation process?
Coagulant aids when added increase the density to slow-settling flocs and toughness to the flocs so that they will not break up during the mixing and settling processes . Primary coagulants are always used in the coagulation/ flocculation process.
What is a coagulant aid?
Coagulant aid is an inorganic material, when used along with main coagulant, improves or accelerates the process of coagulation and flocculation by producing quick forming, dense and rapid-settling flocs. Coagulant aids when added increase the density to slow-settling flocs and toughness to the flocs so that they will not break up during the mixing and settling processes. Primary coagulants are always used in the coagulation/ flocculation process. Coagulant aids, are generally used to reduce flocculation time and when the raw water turbidity is very low. The particles of coagulant aids may become negatively charged making them subject to attraction by positively charged aluminium ions. It is especially useful for clear water with very low turbidity that does not coagulate well with usual processes. Nearly all coagulant aids are very expensive, so care must be taken to use the proper amount of these chemicals. In many cases, coagulant aids are not required during the normal operation of the water treatment plant, but are used during emergency water treatment of water which has not been adequately treated in the flocculation and sedimentation basin. Common coagulant aids are
How does coagulation affect water?
Coagulation will be affected by changes in the water’s pH, salt content, alkalinity, turbidity, and temperature. Within the plant, mixing effects and coagulant effects will influence the coagulation/ flocculation process.
What is the most commonly used coagulant?
Alum. One of the earliest, and still the most extensively used coagulant, is aluminum sulfate (Al/S04)3 ·14 HP), also known as alum. Alum is acidic with light tan to grey in color and available in blocks, lumps and powder with a density of 1000 -1100 kg/ m3 and specific gravity of 1.25 to 1.36.
What is ferrous sulphate?
Ferrous sulphate, ordinarily known as copperas, is granular acid compound and green to brownish yellow color available in granules, crystals and lumps. This is fed usually in solution form with strength of 4 to 8 %.
Is Fe II a reducing agent?
However, if your treated effluent contains residual excess oxidizer or Cr (VI), Fe (II) may be advantageous as a reducing agent. Also, Fe (III) compounds are more expensive than Fe (II), and their solutions are less easily pumped due to lower solubilities.
Does Fe sulfate increase TDS?
2) Yes, either Fe sulfate will increase the TDS, as the Fe precipitates as hydroxide, leaving sulfate ion in solution. Soluble sulfate can be lowered to ~2000 ppm with lime, but this may be too high for effluent limits, e.g., for reuse in irrigation.
Is ferric sulfate a coagulant?
1) Ferric sulfate is superior as a coagulant, especially for co-precipitating other metals as hydroxides . "Not only do the Fe (III) cations as the positively charged basic salt ions neutralize the negative charge on finely dispersed precipitates, they also (in slight excess) act as flocculating agents. In consequence, readily sedimentable and ...
