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PACKAGED DRINKING WATER.pptx
- 1. Department of foodtechnology ; IUST Awantipora
- 2. OUTLINE Packaged drinking water– definition Types Manufacturing process Quality evaluation Raw and processed water Methods of water treatment.
- 3. INTRODUCTION : Water isvery essential for mankind. Water available from untreated sources like bore wells, rivers etc. is not safe for drinking. Thus it is necessary to purify water for drinking purposes. Safe potable water is not available everywhere. Water is contaminated with impurities which cause diseases if consumed. Due to this water is processed and bottled for the use of mankind. Packaged drinking water means water from any potable water source including public drinking water supply systems which is subjected to different treatments to meet the various standards and packed. In India, access to safe drinking water is very difficult to mainly due to over-population and scarcity of clean water resources. This has resulted in high growth in demand for packaged drinking water. Though the rural population still does not use packaged water but as the literacy rate grows and awareness of safe drinking water increases, this industry will experience a huge boom. Today packaged drinking water is used in offices, restaurants, railway stations, airport, bus stands, hospitals etc. Though a large number of units have been established for the production of packaged drinking water but, due to the ever growing need, there is still a huge gap between the demand and supply of packaged drinking water
- 4. Packaged Drinking Packaged drinkingwater means water derived from surface water or underground water or sea water which may be subjected to specified treatments, namely, decantation, filtration, combination of filtrations, aeration, filtration with membrane filter, depth filter, cartridge filter, activated carbon filtration, demineralization, re-mineralization, reverse osmosis and packed after disinfecting the water to a level that shall not lead to any harmful contamination in the drinking water by means of chemical agents or physical methods to reduce the number of microorganisms to a level beyond scientifically accepted level for food safety or its suitability: Provided that sea water, before being subjected to the above treatments, shall be subjected to desalination and related processes. It shall be filled in sealed containers of various compositions, forms and capacities that is suitable for direct consumption without further treatment. In case de-mineralization is a part of the treatment process, the ingredients used shall be of food-grade quality and conform to the requirements set by Food Safety and Standards Authority of India and rules framed there under.
- 5. Types The FDA classifiespackaged bottled water according to its origin. The three major types of bottled water are : • Natural Mineral water • Spring water • Purified water • The International Bottled Water Association considers four additional categories of bottled waters (IBWA, 2000): Artisan water, sparkling water , well water , drinking water.
- 6. • MINERAL WATER: Bottled water containing not less than 250 parts per million total dissolved solids may be labeled as mineral water. Mineral water is distinguished from other types of bottled water by its constant level and relative proportions of mineral and trace elements at the point of emergence from the source. No minerals can be added to this product. Mineral water does indeed have some health benefits , since it provides minerals your body can’t create on its own. It can also help aid in digestion, and many people even like the taste of it over tap water, though that’s down to personal preference. One of the main downsides to mineral water is cost, especially when compared to tap water. Many of the minerals from this type of water can also be obtained from a healthy, varied diet.
- 7. • PURIFIED WATER:Water that has been produced by distillation, deionization, reverse osmosis or other suitable processes can be labeled as purified bottled water. Other suitable product names for bottled water treated by one of the above processes may include Distilled water or de- mineralized water and is one where the water has been subjected to a treatment that removes all its minerals and salt by the process of reverse osmosis and distillation. It is an absolutely pure form of water but it is not typically recommended for drinking. It can cause mineral deficiencies because it is devoid of all salts and most of the natural minerals in the water are gone as a result of this process. Drinking this water may cause rapid sodium, potassium, chloride, and magnesium loss.
- 8. • SPRING WATER:Bottled water derived from an underground formation from which water flows naturally to the surface of the earth. Spring water must be collected only at the spring or through a borehole tapping the underground formation finding the spring. • DRINKING WATER : r is water that is sold for human consumption in sanitary containers and contains no added sweeteners or chemical additives (other than flavours, extracts or essences). It must be calorie- free and sugar-free. Flavours, extracts or essences may be added to drinking water comprising less than one-percent-by-weight of the final product or the product will be considered a soft drink. Drinking water may be sodium-free or contain very low amounts of sodium. • WELL WATER: Bottled water from a hole bored, drilled or otherwise constructed in the ground, which taps the water of an aquifer.
- 9. • ARTESIAN WELLWATER : underground layer of rock or sand) in which Bottled water from a well that taps a confined aquifer (water-bearing the water level stands at some height above the top of the aquifer. Another name for bottled water. Accordingly, drinking water a is water that is sold for human consumption in sanitary containers and contains no added sweeteners or chemical additives (other than flavors, extracts or essences). It must be calorie-free and sugar-free. Flavors, extracts or essences may be added to drinking water, but they must comprise less than one-percent weight of the final product or the product will be considered a soft drink. Artesian Aquifer: Cross-section showing an aquifer tapped by artesian wells. Pressure within the aquifer forces water up the wells. The well on the right side of the diagram is a flowing artesian well that yields water without pumping. The artesian well on the left has a water level that is higher than the top of the aquifer; however, it is not a flowing artesian well
- 10. • SPARKLING WATER: Sparklingwater, also known as seltzer, soda, or tonic water, is infused with carbon dioxide to create tons of bubbles and fizziness at least as much carbonation as the water contained when it came from its natural spring. That being said, any minerals originally present in the water are often removed during processing. Sparkling water is often used as a healthy substitute for sugary sodas and other beverages, because it is lower in calories and sugar, and can be naturally flavored with healthier sweeteners and fruit flavoring. Sparkling water is also often used in cocktails and other drinks to create a fizzy sensation on your tongue.
- 11. Manufacturing process RAW MATERIALS: • Water: Raw water is generally pumped out from the ground. Municipal water supply may also be used as a source of raw water. • Chemicals: These are used in the treatment of water. Soluble salts precipitate over the membranes of Reverse Osmosis (RI)) system and render them non-functional. Thus antiscalents are used to keep the membranes from fouling. Ozone gas is used for disinfection. • Preform- It is a small plastic test tube which expands into a bottle when hot air is blown Into it. The quality of the bottle depends upon the quality of the preform. These bottles are for one time use i.e. they are not refilled. Bottles are generally made in capacities of 1 litrej 1.5 litre and 2 litre.
- 12. • Cap- Capsare used for sealing the bottles after water is filled into them. These are reusable 20 litre plastic containers. They are washed and refilled. The average life of a jar is 40 rounds i.e. they are refilled and used 40 times and then discarded for recycling. • Jar seal- Similar to the cap of a bottle, it is used to seal the 20 litre containers. Once the seal is broken, it cannot be used again on a jar. Thus, every time a jar is refilled a new seal is fitted on it. • Labels- These are of two types. The bottle labels are thin and circular which are slid onto the bottle from the top. The jar labels are stickers which are put somewhere on the body of the jar. • Miscellaneous: Cartons are brown paperboard containers in which water bottles are packed (usually 12 bottles) for transportation. Laser ink is fed into the laser printer which is used for printing batch number on the neck/bottom of the bottle. After the cartons are filled with bottles, they are packed and sealed with cellotape.
- 13. MACHINERY : Three differentmachines are involved in the process: • Preform Blowing Machine: The preform in passed through a heated chamber which makes it soft. This soft preform is then picked and put into the blowing chamber where hot air is blown into it and gives it the shape of a bottle. • Water purification system: This includes the sand and carbon filter and the R.O. system. Raw water is processed and finished water is stored in the stainless steel tank. For every 5000 litres of water produced by the R.O. system, 3500 litres of waste water is generated. This waste water is recharged back into the ground via soak pit. The R.O. system can be purchased from various sources. • Automatic Filling Machine: This machine comprises of four different sections- suction pump, filling unit, cap feeder and the conveyor belt. Empty bottles from the blowing machine are fed into a suction pump which pulls these bottles and pushes them into the filling unit. These empty bottles are washed and filled. The automatic cap feeder unit feed caps to the filling machine which are then tightened to seal the bottles. These sealed bottles are queued on the conveyor belt where labels are put and batch number is printed.
- 14. Three different processes are carriedout simultaneously within a plant. Pre-form Heating chamber Hot air blowing MANUFACTURING PROCESS : 1.The pre-form is passed into a heating chamber to soften it. Hot air is then blown into it to expand it into a 1 litre bottle
- 15. Transported Packing Visual examination Filling Finished waterstorage Ozonization Reverse osmosis High pressure pump Sand & Carbon filter Raw water feed pump dosing system Raw water storage tank Raw water
- 16. 2.Raw water iscollected in the storage tanks. The water is then fed into the dosing system where anti-scalant is used for softening of water. From the dosing system, water goes into the sand and carbon filter where impurities are removed from the water. Carbon filter removes the organic impurities. Water then goes into the reverse osmosis (R.O.) system which removes 90-95% of dissolved solids. The finished water is collected into a stainless steel storage tank. The tank is provided with a manhole for cleaning purposes. This tank is used for ozonation. Ozone gas is passed for disinfection. Water from this tank is used in filling machines to fill the bottles. Empty bottles are fed from one end of the machine. The automatic filling machine washes the empty bottles, fills them with water and seals them with the cap. These bottles are then examined against light to check any defect/leakage. Labels are attached to the bottles as they pass on the conveyor belt. As the bottles move on the conveyor belt, a laser printer prints the batch number on every bottle. The conveyor belt passes through a heated chamber which causes the thin plastic label to shrink and stick to the bottle. Once the bottle reaches the end of the belt, it is picked up and packed in cartons. The cartons are then taped and are ready to be sold.
- 17. Empty jar WashingFilling Visual examinat ion Seal Transported 3.A separate jar filling section deals with the 20 litre jars. Finished water from the stainless steel tank is used here. The empty jars are washed from the inside and outside. They are filled with water and the examined for any leakage. A seal is put on the mouth of the jar and the jar is ready for transport.
- 18. Pre-form Few pre-formsbecome defective when hot air is not blown properly Pre-form Blowing machine Pre-form expands into bottle like this
- 19. Automatic Filling MachineWashing of bottles Filling & Capping Filled bottles on ConveyorBelt Bottle Labels Workers attaching labels Caps Bottle stuck in the machine Leaked/Defective Bottles
- 20. Heat Chamber toshrink label Batch Number on bottle neck Laser Printer Assembling raw cartons with tapes Bottles being packed Final Stock Empty jars Jar Filling Sealed jars ready for transport
- 21. Quality Evaluation : SafeWater/ Wholesome Water Chemically safe Aesthetically acceptable Radioactive elements absent Organic Substances absent Free from bacteria
- 22. Parameters of wateranalysis
- 23. Physical and ChemicalAnalysis of Water : Constituents responsible for rendering water unfit for use includes clay, silt, humus, and color (aesthetically not acceptable and palatability decreases); pH (health-related problems); hardness (affect mucous membrane), TDS, Ca, Mg, and SO4 (gastrointestinal irritation); fluoride (dental and skeletal fluorosis); nitrate, Ca, Mg, and Cl (methemoglobinemia and encrustation in water supply). Procedure: The physical measurement of water includes pH, specific gravity, specific conductance, acidity, alkalinity, hardness of water, nitrogen in water, total solids, and turbidity of water. (a) pH: The pH is measured accurately using digital pH meter. The pH of pure water is between 4 and 9.
- 24. (b) Specific gravity:Specific gravity bottle is used for the determination. 1. Firstly, the bottle is filled up to the rim in a way so that when cap is placed excess fluid is removed. This does not allow air bubble entrapment. Note the weight. 2. Repeat the step with water to be tested and record the weight again. Apply the formula : Specific gravity of water from unknown source = weight of sample / (weight of standard )×( specific gravity of water) The specific gravity may increase in case of contaminated water due to high ionic content
- 25. c) Specific conductance: Thespecific conductance is measured accurately using digital conductivity meter. The conductance may increase in case of contaminated water due to high ionic content. (d) Acidity: It is measured titrimetrically using 0.1 N NaOH solution as titrant and phenolphthalein as indicator. Briefly, take 10 ml of sample water in conical flask. Add phenolphthalein and perform titration until pink color persists. Calculate the amount of NaOH used and compare it with standard water.
- 26. (e) Alkalinity: Itis measured in the same way as acidity except 0.1 N HCl is used as titrant and methyl red/methyl orange as indicator. Procedure : 1. Select the titrant. 2. Select the normality. 3. Adjust the speed of the drops from the burette. 4. Select the titrate and choose a definite volume of the water sample. 5. Select the indicator, phenolphthalein, to get a pink color. 6. Stop titration when the solution becomes colorless, and calculate phenolphthalein alkalinity (PA) as CaCO3 (mg/L) using the equation . Let A be the volume of titrant (mL) used in the titration (V1). 7. Add methyl orange to the same flask and continue titration till the color changes from yellow to orange. The total volume of titrant corresponds to total alkalinity (TA) as CaCO3 (mg/L). Let B be the total volume of titrant (mL) consumed with both the indicators (V2) 8. Volume of HCl corresponding to phenolphthalein end point (A) = ..................mL. Normality of acid = ..................N. Volume of the water sample = ..................mL. Normality of water corresponding to phenolphthalein end point = ..................ppm. Volume of HCl corresponding to methyl orange end point (B) = ..................mL. Normality of acid =..................N. Volume of the water sample =..................mL. Normality of water corresponding to methyl orange end point =..................ppm Results: Alkalinity is due to............ =..............ppm
- 27. (f) Hardness ofwater 1. Select the titrant. 2. Adjust the speed of the drops from the burette. 3. Adjust the molarity of titrant. 4. Select a definite volume of water sample. 5. Choose the indicator and start the titration. 6. When color changes from wine red to blue, click the “stop” button and note the volume of EDTA used. 7. Then calculate the hardness of water sample in ppm using the equation as follows Total hardness as CaCO3 (ppm) = Volume of EDTA × .01 × molarity of EDTA × 10*6 /Volume of the sample Volume of EDTA used = ..................mL. Molarity of EDTA = ..................M. Volume of the water sample = ..................mL. Therefore the total hardness of the sample is =.................ppm. Result: Total hardness of the water sample ¼ ..................pp
- 28. (g) Total dissolvedsolids: It is the portion of solids which pass through the 2.0 μm pore size filter or smaller. The determination involves two basic methods: Evaporation at 180 ± 2 °C, at this temperature all the mechanically occluded water is lost. Conductivity determination using digital conductivity meter. (h) Turbidity of water Turbidity in water is caused by suspended matter such as clay, silt, finely divided organic and inorganic matter, soluble colored organic compounds, plankton, and other microscopic organisms. Turbidity is an expression of the optical property that causes light to be scattered and absorbed. Turbidity measurement by nephelometer is written in terms of nephelometric turbidity units (NTU). Formazin polymer is used as the reference turbidity standard suspension. Principle: Nephelometric method of turbidity measurement is based on a comparison of the intensity of light scattered by the sample under defined conditions with the intensity of light scattered by a standard reference suspension under the same conditions. The higher the intensity of scattered light, the higher the turbidity Precautions: (a) Meter is designed to prohibit stray light reaching to detector. (b) Short warm period is necessary to make the instrument free from significant drift. (c) Clear colorless glass tube is used for sample
- 29. (i) Determination ofchemical oxygen demand (COD) of water sample 1. Select the water sample. 2. To reflux the contents in the RB flask, click the “switch on mantle” button. 3. Click “start titration” to titrate the contents. 4. Select the normality of ferrous ammonium sulfate (FAS). 5. Start titration and note the volume of titrant consumed when color changes from bluish green to wine red. (Let the volume of titrant be V2 mL.) 6. Repeat the same with the blank (let the volume of the titrant be V1 mL). 7. COD calculated using the equation Volume of FAS used = (V1–V2) = ..................mL. Normality of FAS ..................N. Volume of the water sample = ..................mL. Therefore COD of the water sample =..............ppm. Result: COD of water sample ¼ ....................ppm. Precautions: 1. Always wear lab coat and gloves in the lab. 2. Clean all the apparatus with chromic acid and distilled water and ensure that all the glasswares are free from water droplets while performing the experiment.
- 30. Bacteriological Analysis ofWater : Determination of the type of bacteria in water is more important than detecting its number. The three main contaminants mostly contributed by intestinal discharge are E. coli, Streptococcus faecalis, and Clostridium spp. E. coli being excreted in largest amount (200–400 billion per day) is of prime concern. The closely related forms are called as “coliforms.” The main method used for determination is called as “multiple tube fermentation test.” Coliforms are aerobic or facultative anaerobic, gram-negative, rod-shaped, non-endospore-forming bacteria. It can ferment lactose in medium to produce acid and gas just in 24 h at 37 °C. The test is performed in three stages in sequence: presumptive, confirmed, and completed
- 31. Bacteriological analysis ofwater is performed to check the number of bacteria the water is contaminated with or simply it is a basic test for knowing about the water quality. The complete analysis consists of series of test to identify the bacteria. It mainly consists of three test presumptive test, confirmed test and completed test. So, the basic objective of this test is identification of various bacteria present in a water sample. REQUIREMENTS Apparatus: Durham tubes containing lactose broth triple strength with Bromo thymol blue-3 no’s Durham tubes containing lactose broth regular strength with Bromo thymol blue-6 no’s Collection bottles with sterile water Sterile pipette – 10 ml and 1 ml PROCEDURE: Presumptive test Take 50 ml of the water sample and shake it well. Then transfer 10 ml of this sample to each of the triple strength lactose tubes. After mixing well, transfer 1 ml of this sample to regular strength lactose tube. Then place it in incubator at 37 C for 24 hours. Confirmed test Examine the tubes from presumptive test for acid/gas production. If no gas is produced then it is negative presumptive test. If any gas/acid is produced compare it with MPN (most probable number).Tubes showing more than 10% gas is taken for completed test. Take one loopful of this positive presumptive test sample and streak it on EMB plate. Then incubate this at 37°C for 24 hrs. For better result, the positive presumptive ones can be collected and one ml of each can be inoculated to Brilliant Green lactose bile Broth (BGLB) tube, after incubating at 45°C for 24 hrs; then the tubes containing both gas and turbidity were to be considered positive for faecal coilforms.
- 32. Completed test : Thistest is for confirmation of coliform bacteria. The plates are observed for well formed coliform colonies, by seeing any colonies of blue black with metallic green sheen on the plates. Then these colonies are inoculated in NA slant and lactose fermentation tube and incubated at 37°C. Then the colonies from lactose broth are checked for gas production and colonies from NA slant is taken for gram staining. CONCLUSION These three steps give a complete detail about the number of different bacteria present in water sample • Recommended who standard limits for Drinking Water
- 33. It is waterthat is taken directly from its source without treatment. It contains one or more of the following significant contaminants in the form of dissolved ions, particles and living organisms: Humic acid and other complex acids resulting from plant decay Minerals, which make water hard Particles of clay and silt Microorganisms such as bacteria, viruses, protozoa and their cysts Dissolved air molecules, especially oxygen Salt, which makes water brackish Industrial or municipal waste Raw water is purified for a variety of purposes, meeting the requirements of medical/pharmacological, and chemical/industrial applications. Purification methods include: Physical processes like filtration, sedimentation and distillation Biological processes like slow sand filters or biologically active carbon. Chemical processes like flocculation and chlorination Electromagnetic radiation such as ultraviolet light. For steam generation, suspended solids are eliminated by settling or filtration. Scale-forming hardness is reduced by chemical treatment to make insoluble precipitates that are removable by filtration, or soluble compounds that do not form scale. Complete purification is obtained by de-mineralizing treatments or evaporation. Industrial raw water purification is employed to optimize most water-based industrial processes like heating/cooling/processing, and cleaning/rinsing. The ultimate goal is to reduce operating costs and risks. Improper water treatment can cause serious damage to the process and the final results. Surfaces of pipes and vessels can be affected by corrosion and steam boilers can scale or corrode. Raw water :
- 34. It is thename given for water which is not considered drinkable (not drinking water) and is basically used in relation to industrial plants, industrial processes and production facilities. Process water was originally subjected to a substantial water treatment, like for instance; multimedia filters, softeners, reverse osmosis, etc. Process Water in the industrial water treatment process. Most probably each and every product being manufactured uses industrial water treatment during some if not all stages of the production procedure. Industrial water treatment main purpose is to facilitate the manufacturing process, reduce cost and help support production for certain products of which water is an essential element in its composition; i.e: beverages processing, detergents, paper, chemical processing, etc. The use of process water can be in many forms such as;  fabrication, dilution, sanitation or incorporation of process water into a product. It should typically have conductivity 0.1 to 50 Microsiemens per Centimeter µS/cm, with almost zero hardness to prevent scaling. Carbon dioxide (CO2) and Oxides (Oxygen) cause corrosion. Water requirements Process water
- 35. METHODS OF WATERTREATMENT Water treatment means the cleansing of water through various phases to be available for end-use by the people. The treated water is then used for various purposes like irrigation, industrial water supply, drinking, river flow maintenance, or any other such uses. The treatment of water removes harmful contaminants and compounds or the concentration of these is reduced for public use. This treatment is mandatory to promote human health and its uses for drinking and irrigation. The water contaminated with feces of humans and animals pose a great threat to the public because of the presence of microbial elements in them that cause various diseases. Feces are the main source of viruses, pathogenic bacteria, protozoa, and helminthes. The destruction or removal of such substances from the water is essential for it to be used by humans. Reactive chemical agents like suspended solids are used in the process of purification of water. These agents help in removing bacteria, viruses, algae, fungi, iron, and manganese. Water is naturally a pure substance containing hydrogen and oxygen. However, the distribution and supply of water come in contact with various organic minerals, man made pollutants, and chemicals. This makes water unfavorable for drinking purposes as it contains deadly viruses, bacteria, and other dangerous agents.
- 36. 1. Screening Screens areused to protect treatment plant units to help in the efficiency of operations. Screens remove large floating or suspended solids in the process of inflow. Materials like leaves, paper, twigs, and other debris are removed so as to avoid equipment or plant damage. There are two types of screens. Coarse screens: These are large and heavy screens used to minimize large materials like fish and logs from entering the water treatment plant. They help in the proper functioning of the mechanical equipment. Fine screens: These are used to avoid blockage in the pipes at the treatment plant. Solids that are caught in the pipes are removed by jet water and are taken for disposal. 2. Aeration Aeration takes place after the screening process. Water becomes aerated after it has been exposed in order to take in oxygen from the air. Harmful soluble gases like CO2, hydrogen sulfide are expelled by aeration.
- 37. 3.Chemical Addition : Chemicaladdition is the process in which a chemical is added that reacts along with the natural alkalinity to form an insoluble precipitate. The chemicals help make the suspended particles floating in the water clump together to form a gelatinous particle called a floc, which is usually larger and heavier than a single particulate. There is a variety of different chemicals that can be used in this process. These chemicals are called coagulants. Probably the most popular chemical used is aluminum sulfate or alum. A few other coagulants are ferrous sulfate, sodium aluminate, ferric chloride, and manufactured chemicals, which are compounds called polymers. The polymers are classified as cationic polymers, anionic polymers, and nonionic polymers. No matter which coagulant or combination of coagulants are used, they must be mixed extremely well with the water to form a heavier floc. 4.Coagulation and Flocculation: Coagulation and flocculation is where chemicals with a positive charge are added to the water. These chemicals neutralize the negative charge of dirt and other dissolved particles in the water. Particles bind with these chemicals, forming floc, similar to the process in the chemical addition step. The treatment unit where coagulation and flocculation are performed is called the “flocculator.”
- 38. 5.Sedimentation and Clarification: After the flocculation process is complete, the water will then head over to the center of the clarifier or sedimentation basin for sedimentation and clarification. The water will make its way from the center of the clarifier to the saw tooth weir at the perimeter of the unit. The large floc of particles are allowed to settle out to the bottom of the clarifier. A rake is continuously traveling across the bottom of the clarifier to scrape the floc to the middle of the unit. To pull the settled sludge out of the clarifier and send it into a sedimentation or disposal pond, pumps are used. With this process, the majority of suspended material can be removed prior to clarification. This avoids overloading the filters and allowing more water to be filtered before the filters are required to be backwashed. 6. Filtration During the filtration process, clarified water enters the filters from above then is collected in a drain system at the bottom of the filter unit. Filters are made up different materials or media, such as sand or gravel. Granular activated carbon is becoming the media of choice in many conventional plants because it provides mechanical filtration of particulate matter and it removes organic compounds which are often associated with taste and odor problems.
- 39. 7. Disinfection After thefiltration process, the water is clear and as clean as it can get but there may still be bacteria and viruses present. To destroy the viruses and bacteria, the disinfection process begins. In the United States, chlorination is commonly used for disinfection. Chlorine gas, chlorine dioxide, and hypochlorite are just a few of the different forms that chlorine comes in. Chlorine is added to the water in an amount that will ensure all microorganisms are destroyed. Chlorine levels are continuously and very carefully monitored by the water plants because enough chlorine must be added to ensure the water is disinfected but also to avoid excess that can cause taste and odor problems when delivered to the customer 8.Oxidation Inorganic contaminants like iron, manganese are removed by the process of chemical oxidation and it further aids in the removal of coagulated particles to destroy odor-causing and taste compounds. It is often used before coagulation, adsorption, and sedimentation for efficient removal of particulates, inorganics, taste, or odor. Oxidants are injected in the form of liquid or gas.
- 40. 9.Adsorption The adsorption processremoves both organic and inorganic contaminants from water. Adsorption forms on the surface by the accumulation of a solid called adsorbents. They include stationary media like metal oxide, ion exchange, and activated carbon. Flocculation forms floc that can adsorb both inorganic and organic carbon like arsenic. Activated carbon helps in removing hundreds of organic contaminants. 10. Fluoridation Fluoridation is used mainly in communities as it treats water supplies to bring a balance in the concentrated free fluoride ions. This is done till an optimal level is reached which helps avoid dental cavities.
- 41.