Water Treatment Process (WTP) A to Z For Food Process

Water Treatment Process (WTP) A to Z For Food Process

Water treatment process

WHAT IS WATER?

Water may be a compound consisting of two hydrogen atoms and one oxygen. The solid phase is known as the ice and gas phase is called steam. Also Known As Di-hydrogen monoxide(H2O)

Three-dimensional molecular structure of water

SOURCE OF WATER

Community water systems obtain water from two sources: surface water and spring water. People use surface and spring water a day for a spread of purposes, including drinking, cooking, and basic hygiene, additionally to recreational, agricultural, and industrial activities

WHY IS WATER TREATED

The water is never pure and its impurities are the factors of concern in industries water treatment. The major impurities in water are summarized as follows:

OBJECTIVES

1. To reduce unexpected impurities from water

2. To produce potable water

3. To produce safe & pure water for beverage product

4. To utilize industrial purposes

MAIN QUALITY CHARACTERISTICS OF WATER

Water quality refers to the physical, chemical &biological characteristics of water for a particular use. Selected characteristics are then compared to numeric standards and guidelines to make a decision if the water is suitable for a specific use. The most common physical, chemical & biological characteristics are,

A) Alkalinity: In presence of Carbonate, Bicarbonate, Hydroxide.

B) Hardness: Containing Bicarbonates, Sulphates, and Chloride of Ca and Mg

C) Total dissolved solids: Amount of Nonvolatile substance present in water as colloidal or molecular dispersed.

D) Transparency

E) Free of a pathogenic organism

WATER TREATMENT PROCESS OF ABC PLANT

Water treatment is carried on in Three different treatment process in ABC PLANT

• Coagulation Flocculation process.
• Softener.
• RO process

SOURCES OF ABC PLANT WATER:

For industrial purposes, Water is collected from underground by two deep pumps. The collected water is taken in the first compartment of the underground reservation tank-like as the concreted pond. Then it gradually transfers the second compartment. During the transfer, heavy particles settle down.

Pre-disinfection :

Pre disinfection inhibits the growth of pathogenic microorganisms in water. Pathogens are defined as any type of microorganisms capable of producing disease. In an underground reserve tank, 0.3ppm of chlorine is used which acts as pre-disinfector.

Overall Flow Diagram of Water Treatment Process Of ABC PLANT

Coagulation Flocculation process

Carry out by,

• A chemical reaction in coagulation tank
• Filtration
• Reservation

FLOW DIAGRAM OF COAGULATION WATER TREATMENT SYSTEM

Coagulation Tank

Coagulation and flocculation:

Coagulation and flocculation are often the primary steps in water treatment. Chemicals with a charge are added to the water. The charge of chemicals neutralizes the charge of dirt and other dissolved particles within the water. This process is called coagulation. The chemicals which are used for the coagulation process called coagulants. The most coagulants are- Alum, Ferrous Sulfate, Ferric Chloride, etc. When this happens, the particles bind with the chemicals and form larger particles, called floc. This process is called flocculation.

CHEMICAL REACTION (REACTION TANK)

The chemical reaction incorporates coagulation, flocculation, and sedimentation.

For the Chemical reaction mainly used

• Lime
• Ferrous Sulphate
• Chlorine.

First lime play following reaction with impurities,

1.Ca(OH)2 + Ca(HCO3)2 = CaCO3 + CO2 + H2O

2.Ca(OH)2 + Mg(HCO3)2 = MgCO3 + CaCO3 + H2O

3.Mg CO3 + Ca(OH)2 = Mg(OH)2 + CaCO3

4.MgCl2 + Ca(OH)2 = Mg(OH)2 + CaCl2

5.MgSO4 + Ca(OH)2 = Mg(OH)2 + CaSO4

Then Ferrous sulfate react by the way

FeSO4 + Ca(HCO3)2  CaSO4 + Fe(HCO3)2 insoluble

Fe(HCO3)2  Fe(OH)2+CO2

FeSO4 + 2H2O =Fe(OH)2(not coagulant) + H2SO4

H + HCO3 =CO2 + H2O

H2O + 2Fe(OH)2 + 1/2O2 = Fe(OH)3

Also, the chlorine has effective role on coagulation, if chlorine is used.

Bleaching powder is the source of chlorine which is produced by the following reaction.

Ca(OCl)Cl + H2OCa(OH)2 + Cl2

Cl2 + H2O  HOCl + HCl

HOCl HCl + [O] Nascent oxygen

6FeSO4.7H2O + 3Cl2 = 2Fe2(SO4)3 + 2FeCl3 + 42 H2O

Fe2(SO4)3 + 3Ca(OH)2 = 3CaSO4 + Fe(OH)3

Flocculation is bridging together of the coagulated particles (floc).

DOSING STATUS FOR TREATMENT

1. LIME: 3200 ml/ min (basis of 20000 ltr/hr flow)
2. FeSO4.7H2O: 1400 ml/min(basis of 20000 ltr/hr flow)
3. Bleaching powder: 1300 ml/min(basis of 20000 ltr/hr)

Sedimentation:

During sedimentation, floc settles to the bottom of the tank due to its weight. This settling process is called sedimentation.

After a certain time(each every 24 hr interval)

settled floc (sludge) drained by drain valve to maintain a specific % sludge (max20%) in bottom water.

Filtration

Filtration is defined as the passage of a fluid through a porous medium to remove matter held in suspensions. In water purification, the unwanted matter to be removed includes suspended silts, parasites, clay, organic matter, colloids and microorganisms including bacteria n viruses.

The most common filtration process employs are,

• Sand filter
• Activated carbon filter
• Micron filter.

Sand filter:

The clear water on top will of reaction tank pass through the buffer tank to control flow and then it passes through the sand filter. In a sand filter, suspended silts, parasites, residual floc, etc are removed. In a certain time, the filter is backwash n right wash to improve its activities

Activated Carbon Filter:

After sand filter water reserve in reserve tank. Then the water passes through the carbon tank where carbon absorbed residual chlorine(mainly). Also, color, odor, and organic matter if presence.

After a certain time, every 24 hr interval the carbon filter is backwash and right wash to recover carbon activities.

Also, steam treatment at 85°C, is compulsory after every week for,

• To improve carbon activities.
• To reduce microbial growth.

Microfiltration:

For treated water passes through 5.0 µm and 1.0 µm filter to remove particles getter then 5.0 n1.0 µm including bacteria and some virus.

For drinking water 0.2 µm filter also used to remove all microorganisms and particles getter then 0.2 µm.

In a certain (every week)interval the microfilters are sink in 5-10%citric acid solution about 3 hrs for clean the filter to improve filtration activities.

Reservation

After filtration, the water passes through the pipeline and reserve in two tanks. Each tank 70000 Lt capacity. From reserve tank water distribute different production units.

Comparative data of treated water & source water

Basic Information of Treated water

• 4 water treatment line is available of ABC PLANT.
• Production capacity 15000 ltr/hr each treatment line.
• The treatment process completed about 3.5 hrs.
• Treated water mainly used for beverage production purposes.

ALKALINITY

Alkalinity is the quantitative capacity of bases in an aqueous solution that can be converted to uncharged species or neutralized by a strong acid. The alkalinity is adequate to the stoichiometric sum of the bases in solution.

TYPES OF ALKALINITY

• Total Alkalinity(M-Alkalinity)The total number of bases that can neutralize by an acid.
• Carbonate Alkalinity (P-Alkalinity) Only carbonate n hydroxide alkalinity.

Alkalinity test

Step 1: Phenolphthalein Alkalinity

For solutions at pH 8.3, bicarbonate is that the predominant carbonate species:

CO32- + H+ → HCO3-

Water that features a pH >8.3 is claimed to possess “phenolphthalein alkalinity,” which is alkalinity due primarily to the presence of carbonate or hydroxide ions.

Step 2: Total Alkalinity

Total alkalinity is that the final endpoint for the alkalinity titration. At pH 4.5, all carbonate and bicarbonate ions are converted to acid (H2CO3):

HCO3- + H+ → H2CO3

This endpoint for the titration is often identified employing a Bromcresol Green-Methyl Red indicator. The indicator changes from green to pink at pH 4.5. Below pH 4.5, the water is a smaller amount ready to neutralize the vitriol and there's an immediate relationship between the amount of vitriol added to the sample and therefore the change within the pH of the sample

Alkalinity:

The alkalinity of water is due to the presence of carbonate, bicarbonate and hydroxide ions. This parameter is determined by Titometric Method.

Principle: Alkalinity is determined by titration with 0.02N H2SO4 using methyl orange and phenolphthalein as indicators.

Reactions: 2 CaCO3+H2SO4  CaSO4+ Ca(HCO3)2

Ca(HCO3)2+ H2SO4 CaSO4+2CO2+2H2O

Ca(OH)2+H2SO4CaSO4+2H2O

Reagents: (i) O.02N H2SO4

(ii) 0.1N Na2S2O3 Solution.

(iii) Phenolphthalein indicator solution.

Procedure:

Pipette out 100ml of water into a 250ml conical flask. 3-4 drops of Thiosulphate solution is added. No color is produced. 4-5 drops of Phenolphthalein is added in solution. As a result, Pink color appears. Then the solution is titrated with 0.02N H2SO4 solution until colorless and the pipette reading is recorded. Again 3-4 drops of mixed indicator (Methyl orange + bromocresol green) are added in solution and green color appears. Then the solution is titrated with 0.02N H2SO4 solution until colorless and the pipette reading is recorded.

• P-alkalinity = volume of H2SO4 X 10 (Upto pink color disappeared)
• M-alkalinity = total volume of H2SO4 X 10 (Upto pink color appeared)
• The alkalinity of water is maintained by (2P-M) formula. It is the main purpose to produce quality water products.The Standard value of 2P-M = +2  +7.
• If the value of alkalinity exceeds the required range, then the quality of water is worst, which is undesirable for our consumption.

Hardness test

Hardness is one of the main parameters of water. This parameter is determined by Titometric Method.

Principle: Hardness is determined by titration with 0.01M EDTA using hard indicators.

Reagents:

• 0.01MEDTA solution
•  Ammonium buffer solution
•  Hard indicator

Procedure:

Pipette out 100ml of water into a 250ml conical flask. 2-3 ml ammonium buffer added to neutralize the sample then 4-5 drops of a hard indicator is added in solution. As a result, the brownish color appears. Then the solution is titrated with 0.01 M EDTA solution until the greenish color is appearance and the pipette reading is recorded.

The burette riding multiplies with 10 and this is the hardness value.

Chlorine test

During the treatment process chlorine test is a very important factor.

Principle:

OT(Ortho toluidine)solution added with chlorinated water and matching the color with a standard chlorine solution to identify chlorine value.

Procedure:

5ml water sample takes place in a sample test tube then add 1 ml OT solution and shake well. Then the solution match with different standard chlorine solution in which standard chlorine solution color matching with the sample color this value is the chlorine value.

Softener

Softener contains a resin which is one kind of polymeric substances having free cation and anionic radical. water is passing through the softener then dissolving cation and anion of water are exchange with the free radicals of resin and water becomes soft. A brine solution is added to the regeneration of the activity of used resin. It is mention that water act as a mobile phase and resin act as a stationary phase.

Resin

The carriers of the exchangeable cations and anions are called resin. Resin is a copolymer which contains exchangeable cations and anions.

There are three types of Resin

1. Cation exchangeable resin
2. Anion exchangeable Resin
3. Mixed Resin(Which exchange both ions)

Flow diagram of Softener process

Process description

• Raw water from the underground reservation is used as a source of soft water.
• From the reservation tank, raw water passes through the carbon tank where carbon absorbed chlorine(mainly). Also, color, odor, and organic matter if presence.
• Then water is passing through the resin column where dissolving cation and anion of water are exchanged with the free radicals of resin and water becomes soft.
• After the treatment of water with resin, the soft water is collected in the underground reserve tank to utilize for different purposes. The hardness of soft water is below 5ppm.

Basic Information of Softener

1. Five soft water lines available.
2. Line 4/5 production capacity 30000 ltr/hr each line.
3. Line 1/2/3 production capacity 20000 ltr/hr each line.
4. Soft water max hardness 5 ppm.
5. Soft water mainly uses for CIP purposes, Boiler water, etc.
6. Soft water use as a source of RO water.

Reverse Osmosis

Reverse Osmosis, commonly mentioned as RO, maybe a process where you dematerialize or deionizer water by pushing it struggling through a semi-permeable Reverse Osmosis Membrane

Reverse osmosis Technique

Osmosis

Osmosis may be a present phenomenon and one among the foremost important processes in nature. It is a process where weaker saline will tend to migrate to robust saline.

RO Process of ABC PLANT

Process carry out,

• Multimedia sand filter
• Activated carbon filter
• Tick nil filter
• RO filter
• Reserve

Flow diagram of RO Process

Process description:

Soft water use as a source of RO water. Then the water passes through the multimedia sand filter. After sand filter water also pass through the activated carbon filter. After carbonation then the water passes through 5µm trickling filter. Then water reserve in a reserve tank. After reservation water again pass through 5µm tickling filter where getter then 5µm particles are filtered. After Tickling filter water pass the RO membrane where getter then 0.001µm particles are filtered.

Basic Information of RO water

The main source of soft water.

Production capacity 30000 ltr./hr, where 24000 ltr. pure water n 6000 ltr. wastage water.

One RO water line where three RO membrane available.

RO membrane size 0.001 µm.

Hardness 0 .0 ppm.

Mainly use in sophisticated machinery such as Ciller, Aseptic filler, SIPA plant, CO2 plant, etc.