Author: Tasrik

Water purification tablets

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Water purification tablets are used to make water safe by killing harmful micro-organisms in water to prevent different water borne diseases as like typhoid, cholera, dysentery and more others. Water purification tablets are used in emergency situation such as travelers, militaries, hikers, campers and emergency organizations and any person else who needs to drink water of questionable quality. It can also be used for continuous in household’s purpose. It is also called water disinfection tablets or water treatment tablets.

Normally water is contaminants by suspended particles, different Inorganic and organic elements that create turbidity and color in water, algae, bacteria, viruses and more others micro-organisms. Water purification tablets are not suitable for all type of water; it is suitable for clear water that is contaminants by bacteria, viruses and many others micro-organisms. If the water is contaminants by suspended particles or turbid then it should be need filtered throughout a cloth or other methods until the water would be clear. After the water is clear then it is suitable for Water purification tablets to make water purified.

Generally Chlorine compounds are the most common type of ingredients that is used in water purification tablets. Chlorine is an excellent disinfectant and able to rapidly destroy a lot of harmful micro-organisms. There are several ingredients that are used in water purification tablets such as Sodium Dichloroisocyanurate (NaDCC), sodium hypochlorite, bleach, iodine, Chlorine dioxide, chloramines and halazone. Sodium Dichloroisocyanurate or Troclosene Sodium ingredient is approved by USA EPA (Environmental Protection Agency) and it is more efficient than others ingredient. Chlorine compounds are a chlorine donor, when it is dissolved in water they releases free chlorine and react as a strong oxidant.

Water purification tabletsWater purification tablets dissolves within minutes and disinfects the water within 30 minutes. It is work a very wide range of water types and reduces total and fecal coliform bacteria and other micro-organisms levels to zero or low risk. It should be careful about inject over dosage. It is recommended that chlorine addition into drinking water should not cross over range between 4 and 8 ppm. Reason chlorine is a toxic gas and overdose can be harmful for human. In USA public utility water generally has 1 to 2 ppm chlorine. The chlorinated water ought to be allowed to sit for at least half an hour prior to being used for drinking purpose.

Although chlorine is an excellent disinfect but it has some drawbacks. For example if the water contain organic compounds, the chlorine may be reacts with some of them and can be form potentially harmful compounds (such as trihalomethanes, haloacetic acids). More over it has limited efficiency against protozoa (as like Giardia lamblia) that form cysts of its life cycle in water. But Iodine tablets are effective against Giardia lamblia.

Many organizations such as WHO, Unicef, Red Cross, Oxfam are used water purification tablets for their emergency aid service in different countries.

Water testing kits

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The water testing kits are used for monitoring the quality of drinking water and controlling the important operational parameters. The kit is not given high level accurate result but it given a warp idea. This kit can help us by providing the idea about what is the condition of our water or check out how the treatment working on. Although we are not get exact result but this result is very important for us. Water test kit is the best technique to test the water quality in our home. There are several type water testing kits are used such as test strip, color disc, digital titration, drop count titration etc.

The water
testing kits are used for different quality test such as bacteria, Alkalinity, Arsenic, iron, lead, pesticides, pH, hardness, nitrites/nitrates, chlorine, chloride, dissolved oxygen, silica, phosphorus etc. Water test kit provides professional lab results in your own home within a short time. No mixing or measuring required.

Water ought to be uncontaminated and free from pathogenic organisms and unsafe chemicals. Contaminants in your drinking water system can lead to the severe health troubles. Some of them are described below:Water testing kits

Bacteria: E. coli and coliform Bacteria can cause serious illness or health problems.

Lead: Contaminants through the old brass plumbing components. It is an extremely poisonous metal and responsible for serious health problems such as effects on brain development and red blood cell, neurological and kidney damage. The highest level for lead in drinking water is 0.015 mg/L.

Arsenic: It is responsible for increasing the risk of bladder, lung, or skin cancer and cardiovascular disease. The highest level for arsenic in drinking water is 0.01 mg/L.

Pesticides: Contaminants through agricultural uses and responsible for increasing cancer rates.

Nitrates/nitrites: Contaminants through the fertilizers and animal waste or septic systems. It is responsible for oxygen deficiency in the blood, developmental and cancer problems. The maximum level for nitrate in drinking water is 10.0 mg/L.

Chlorine: It is responsible for raising cancer risk, bad taste and odor.

Hardness: It is responsible for lime scale, plumbing fixtures block, and higher detergent use.

pH: The pH is very important for industries such as boiler feed water. It is responsible for plumbing damage.

Alkalinity: It is caused by the presence of hydroxides, carbonates, bicarbonates, and other dissolved salts in the water. It is very important for food and beverage process or boiler water.

Iron: It is an essential element and has positive health effects for certain amount of level but negative effects for laundry and plumbing fixtures purpose.

Where to buy water testing kits
You can buy a water test kit from your neighboring residence center or online.

Reverse Osmosis water treatment system

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Reverse Osmosis definition

The movement of molecules across through a semi-permeable membrane from a higher concentration region to a lower concentration region is called reverse osmosis. This process is used successfully in water treatment. In this case semi-permeable membrane allow the water to passes through, but not allowed hardness forming metal ions and other bulk molecules such as bacteria.  The process will continue until reach the equilibrium condition.

Ion Exchange water treatment system

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Ion exchange water treatment system is one of the most common processes and it is works on the basis on ion exchange principle. It removes the scale-forming calcium and magnesium and others metal ions from hard water. To removes these ions water are passes through ion exchange column filled with synthetic resin.

Ion exchange column
There are two type ion exchange column; cation exchange column and anion exchange column. In cation exchange column selectively cations are adsorb, on the other hands in anion exchange column selectively anions are adsorbs from supplied water and release same type of ions. Depends on application only cation exchange column or both ion exchange column are used for water treatment. For boiler and demineralised water needs both ion exchange column.

Cation exchange column
The column that filled with the resins containing base exchanging radicals are called cation exchange column.  Sodium or hydrogen cation exchangers are generally used in this column. Hydrogen cation exchanger is used to remove all cations from water including sodium ion. The process of ion exchange will continue until available cations are packed. Then it should be need regeneration with suitable chemicals. The following reactions are taken place in cation exchange column.

2HR  + Ca(HCO3)2 → CaR2 + 2H2O + 2CO2

2HR  + 2NaHCO3 → 2NaR + 2H2O + 2CO2

2HR  + MgSO4 → MgR2 + H2SO4

Regeneration: MgR2 + H2SO4 → 2HR  + MgSO4

Anion exchange column
The column that filled with the resins containing acid exchanging radicals are called anion exchange column.  Here OH- ion is exchanged for the anion. The process of ion exchange will continue until available anions are packed. Then it should be need regeneration with suitable chemicals such as caustic soda. The following reactions are taken place in anion exchange column.

H2SO4  + 2R4NOH → (R4N)2SO4 + 2H2O

Regeneration: (R4N)2SO4 + NaOH  → 2R4NOH  + Na2SO4

The softening water by Ion exchange water treatment system can be used all purpose, even boiler. Because of the process removes all ions and acids from water. To produce house hold water, laundry process water it should be used sodium cation exchanger only. In this case regeneration is completed by passing a NaCl solution through the resin.

Zeolite process for water softening

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What is zeolite
Zeolite is micro-porous mineral which is used as catalyst in many industrial purposes such as water purification and air purification. The zeolites are hydrated aluminosilicates and general composition AlxSiyO2(x+y)  (without water molecules). Zeolites are two types natural and synthetic or artificial. The natural zeolite that is used for water softening is gluconites or greensand. Permutit is the synthetic zeolite that is most used in water softening and its chemical formula is Na2O, Al2O3, nSiO2, xH2O. These are used as ion exchanger and odor removal in water softener. Permutit are more porous, glassy, and have higher softening capacity than greensand.
Zeolites are characteristically soft to moderately hard, light in density, insoluble in water but can act as base exchangers in contact with water containing cations. Hence these can remove Ca2+ and Mg2+ ions from water when hard water is passes through.

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Zeolite process for water softening
Zeolite process for water softening has become a commercial success for the reason that zeolite can be easily regenerated. When Ca2+ and Mg2+ ions containing hard water is passes through a bed of sodium zeolite, the sodium ions are replace by the calcium and magnesium ions.

Na2Ze  + Ca(HCO3)2 → 2NaHCO3 + CaZe
Na2Ze  + Mg(HCO3)2 → 2NaHCO3 + MgZe
Na2Ze  + CaSO4  → Na2SO4 + CaZe
Na2Ze  + MgSO4 → Na2SO4 + MgZe

When all sodium ions are replaced by calcium and magnesium ions, the zeolite becomes inactive. Then the zeolite needs to be regenerated. Brine solutions are passing through the bed of inactivated zeolite. The following reactions are taken place and form Na2Ze.

CaZe + 2NaCl → Na2Ze + CaCl2
MgZe + 2NaCl → Na2Ze + MgCl2

The softening water by this process is used for laundry process and cannot be used for boiler purpose. Because this water softening system contains NaHCO3 in the water; when this water is heated, it produces CO2 which is corrosive for boilerplates.
zeolite water softening process
1 Pound – Clinoptilolite Zeolite Powder

Lime soda process

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Lime soda process is one of the water softener systems. In this system calcium hydroxide and soda ash are used as reagents. By this process soluble magnesium and calcium salts are removed as calcium carbonate and magnesium hydroxide precipitated. After removal of this precipitated, we obtain soft water. Both temporary water hardness and permanent water hardness are removed by this lime softening water softener systems. Before water treatment calculate the amount of temporary and permanent water hardness, and then estimate the amount of lime and soda ash and added control with careful. In case of temporary water hardness the following reactions are take places:

Ca(HCO3)2 + Ca(OH)2 → 2CaCO3 + 2H2O

Mg(HCO3)2 + Ca(OH)2 → 2CaCO3 + MgCO3 + 2H2O

MgCO3 + Ca(OH)2 → Mg(OH)2 + CaCO3

In case of permanent water hardness the following reactions are take places:

CaSO4 + Na2CO3→ CaCO3 + Na2SO4

MgSO4 + Na2CO3→ MgCO3 + Na2SO4

MgCO3 + Ca(OH)2 → Mg(OH)2 + CaCO3

There are two type lime-soda process; cold lime soda process and hot lime soda process.

Cold lime soda process
In the cold lime soda process the reactions take place at normal temperature. The raw water is passed into a tank with a static continuous flow, at the same time a calculated amount of chemical mixture of lime and soda ash are also added a static continuous flow and then thoroughly mixed with a stirrer in this mixture tank. Afterward this water is allowed to settle. When the settlement becomes complete the water is passed by continuous up-flow process into another tank which is called filter bed. Then we get soften water.
The cold lime soda process is not suitable for all purposes. It is limited for those purposes where partially softened water needed because this process fails to precipitate completely all the hardness forming salts. The cold lime soda process is used for municipal water and cooling water softener systems. The reason in case of municipal purpose, it is not necessary to remove all water hardness forming ions. Same way cooling water should be free from temporary water hardness. In this process it is possible to remove magnesium water hardness nearly completely but calcium hardness may be remains more than 40ppm.

Hot lime soda process
In the hot lime soda process the reactions take place at higher temperature near about boiling point of water. The chemical mixing process is same as the cold lime soda process, but steam is applied in mixture tank. As a result precipitation becomes almost complete very quickly. This process is more effective than cold lime soda process. The hot lime soda process water softener systems are exclusively used for boiler purpose. In this process it is possible to remove magnesium water hardness completely and calcium hardness may be remains very low. Moreover dissolved corrosive gases also removed by this hot lime soda process.

Hard water vs soft water

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Hard water and soft water are defining depending on water contaminants with some metals ions such as calcium, magnesium. Hard water is not good for all position; same way soft water also not suitable for all applications.

Generally hard water contains greater quantity of calcium and magnesium ions. On the other hand soft water contains little amount or no ions of some metals such as calcium, magnesium. We get soft water naturally such as rain water or conditioning the hard water.

Water for drinking purpose
Hard water is good for health than soft water. In health point of view hard water effects are neutral; some cases are beneficial because it is rich in minerals. Moreover it decreases the solubility of potentially poisonous metal ions as like copper and lead. On the other hand soft water rich in sodium ions, this is not safe to drink. It is health risk such as diabetes or high blood pressure. A study shows that less heart disease in hard water areas than in soft water areas.

Water for domestic cleaning
For domestic cleaning soft water is essential. Hard water is not suitable for this purpose because in hot water heater, steam iron, kettles, coffee makers etc it forms limescale. This water also creates spots on dishes and glassware. Moreover extra soap or detergents are consumed in this case. In addition hard water leaves iron or soap deposits in bathtubs, sinks and basins. On the other hand soft water save soap or detergents and all other hard water effects are not found in case of domestic cleaning.

When people are bathing with soap in hard water, a sticky film formed on the skin. Soil, dirt and bacteria can be trapped in pores beneath the soap scum; this is the possible skin infection.

Water for plumbing system
Domestic or industrial plumbing system is affected by hard water. It buildup limescale in shower head, taps, inner side of pipe, hot water tanks, washing machines, boilers, cooling tower and other industrial equipment. It reduces the life of plumbing system; even clog it. Hence increase plumbing system repairing cost. On the other hand these effects are not found in case of soft water.

Water for industry
In industrial purpose the uses of soft water is significant. Soft water is used for heat transfer, cooling tower, boiler, manufacture of beverages, sugar syrup, gelatin, juice etc in many industries. In contrast hard water is not suitable for industry; it buildup limescale in boiler, cooling tower, hot water tank etc. as a result decrease the life of tank or boiler and need more energy. Water hardness significantly effects on textile dyeing, washing and finishing section.

Soft Water

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What is soft water
Soft water means when the water is free from the ions of chloride, sulfate and bicarbonate of calcium and magnesium salt or presence little amount of these ions; in particular total water hardness less than 150 mg/l calcium carbonate. Also free from some other metals for example iron, zinc, manganese, aluminum, strontium etc. We can also be define soft water depends on foam creation with soap or detergent. Soft water can easily create foam with soap and detergents. The source of soft water mainly rain water; other sources are water that comes from granite or sandstone. Soft water can be classified into two group depends upon total hardness. When total water hardness less than 75 mg/l calcium carbonate; it is called very soft water. If total water hardness is between 75-150 mg/l calcium carbonate; it is called soft water.

Soft water has a tendency to be somewhat acidic. For example:

Water + carbon di-oxide + calcium carbonate = calcium bicarbonate

H2O (l) + CO2 (g) + CaCO3 (s) → Ca(HCO3)2 (aq)

Very Soft water can dissolve metals with which it comes into contact with at static condition or during flow time.  Lead, copper, iron etc are susceptible to attack from this type of water. In this way Lead and copper may lead to poisoning the water, which is at risk for health.  This is one of the main reasons in plumbing installations Lead and copper are no longer used.

soft water

Is soft water safe to drink
There are many reasons soft water is not good for drinking. But conditioning water is good for health. The soft water that contains high sodium ions is not safe to drink. It is health risk such as diabetes or high blood pressure. Sodium should not more than 2300 mg, it is better contains 1500 mg per day. If somebody takes soft water regularly, he/she should be need take vitamin that includes calcium. A study proves that not as much of heart disease in hard water areas than in soft water areas.

Benefits of soft water
Soft water is benefits for washing one’s body and hair because it does not create dryness. Moreover there are no sticky films formed on the skin. People escape from skin disease like Eczema. No limescale can form in kettles, coffee makers, faucets, hot water heaters, steam irons etc in whole household, Increase plumbing system life. It is also reduce cost in laundry purpose.
In industrial purpose the uses of soft water is significant. Soft water is used for heat transfer, cooling tower, boiler, manufacture of beverages, sugar syrup, gelatin, juice etc in many industries.

Coliform Bacteria in water

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What is coliform bacteria
Coliform bacteria are single-celled organisms that are present in the environment such as rivers, lakes and streams and as well as all warm-blooded animals like human. The structure of them is rod-shaped, gram-negative and non-spore forming bacteria. Coliform bacteria can be explained in this way that; it can ferment lactose into acid and gas at 35–37°C. The majority of the coliform bacteria are harmless and certain are harmful. But it is important that it represent the disease-causing organism such as viruses and protozoans might be present in the water. Since both of the organisms come from same sources. Moreover it does not always indicate that pathogenic microorganisms are also present in the water because coliform bacteria can stay alive in tropical condition. However, it indicates that other microorganisms must be checked. The colifoarm bacteria can be classified into three groups or subgroups for example total coliform, fecal coliform and E. coli.

coliform-bacteria

Total coliform Bacteria
The total coliform bacteria are a collection of large number of different types of bacteria in water or soil. Total coliform bacteria are used as the indicator for the source of water so that resolve the problem. If only the total coliform bacteria are present in water and fecal coliform bacteria are absent; it indicates that the source is probably environmental (portable water).

Fecal coliform bacteria
Fecal coliform bacteria are a sub-group of total coliform bacteria that are contamination by warm-blooded animals. If fecal coliform bacteria are present, it indicates that the contamination occur recently. It is larger threatened for human. Moreover it can reduce dissolved oxygen of water which is undesirable for aquatic life. Fecal coliform bacteria test is one of the important water quality tests in many development countries as like USA.

E. coli bacteria
E. coli bacteria are a sub-group of the fecal coliform bacteria that are found in large amount in the intestines of people and warm-blooded animals. Although most of E. coli (Escherichia coli) bacteria are safe but some of them can cause disease; particularly the strain 0157:H7.  If these bacteria are present in water, it indicates recent fecal contamination. It means there is a potential health problem creating pathogens are present. This organism can create some disease for example meningitis, dysentery, typhoid, urinary tract, septicemia, hepatitis and intestinal infections.

How can destroy coliform bacteria
Coliform bacteria are used to study, how the contamination obtained into the water so that eliminate any probable sources. Coliform bacteria can destroy by boiling or treating contamination water including harmful 0157:H7 E. coli bacteria.

Bacteria in water

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Physiologically and morphologically heterogeneous bacteria can create nuisances in water systems. The bacteria are included in this group are slime bacteria, iron bacteria, sulfur bacteria and sulfate bacteria. Bacteria in water systems create taste, order, and produce color in water. Moreover it increases tuberculation, turbidity and decrease in carrying capacity of pipes.

Inorganic and organic substances are the source of food for the bacteria in water. Though the organic materials are small amount in supply water but some bacteria in water are able to collect their food from continuous flow of water. Other parameters that can influence their production and development are temperature, pH and oxygen.

Slime forming bacteria in water

Many industries such as food processing plants, laundries, paper and textile mills are greatly affected by the huge amount of slime. No particular groups of bacteria in water are responsible for slime production. Many bacteria have the general property of this. Bacteria in water growth normally are submerged surfaces and they are attached by mucilaginous material. After such type of film creation the accumulation are increased by production and adsorption of suspended and colloidal materials.

Inorganic compounds are the main source of food for the slime producing bacteria such as ammonia is the source of energy for the nitrifying bacteria’s growths.

Reduce iron compound and reduced sulfur compounds for example sulfur, sulfides, sulfites and thiosulfates also responsible for slime formation.

Iron bacteria in water

Iron bacteria are tiny living organisms and oxidizing agent. They are naturally found in sallow groundwater, soil, and surfaces water. They are mostly responsible for nuisance in water systems. These bacteria in water are enormous slim producers. Moreover they are guilty for many water disasters. It creates the water reddish, yellow or orange color, unpleasant test and bad odor.

Sulfur bacteria in water

There are two types of sulfur bacteria in water systems; sulfur oxidizing and reducing bacteria. But sulfur reducing bacteria are common in water. Sulfur oxidizing bacteria convert sulfide into sulfate and create a dark slime. The sulfur bacteria in water receiving their energy from the oxidation of reduced sulfur compounds. Sulfur reducing bacteria are found in oxygen deficient environments such as ground water, water softener, water filter, hot water heater and plumbing systems. They create hydrogen sulfide gas in water systems; which is corrosive for water pipe lines. Overall the sulfur bacteria in water create black slimes, bad taste, odor and responsible for corrosion of iron pipes.

Sulfate reducing bacteria in water

The sulfate reducing bacteria in water causing the reduction of sulfates they are heterotrophic and anaerobic. Sulfate reduction can happen in the lack of organic matter, if a hydrogen source is present. This type of sulfate reduction can be considered as autotrophic.

In potable water systems the reduction of sulfate is limited significance as the low amount of organic matter is presence in water supplies. In this case autotrophic reduction of sulfates may be larger significance as hydrogen can be derived from metal surface. Sulfate reducing organisms can supply as depolarizing agents under anaerobic conditions. It increases the rate of corrosion of the metal, creating bad tastes and odors.

Whole house effect by the bacteria in water

The following whole house effect can be observed by the bacteria in water:

      A large amount of slime cab be damaging the plumbing systems of the whole house. Even the slime clogged the pipe lines.
      Slime deposits can form in water softener, water filter, hot water heater, toilet tanks etc.
      Can be developed unpleasant taste and odor.
      Hydrogen sulfide can discolor copper, silverware and porcelain.