Category: Bacteria

Iron Related Bacteria Test – Hach Test

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BART (Biological Activity Reaction Test) is one of the most common iron related bacteria test. This Hach Company kit includes 9 tests. When IRB present in the sample, then a series of reaction occurs with IRB and nutrients ingredients in the inner tube. The change to red color of the water indicates a presence of bacteria within that sample. The IRB-BARTs can detect both iron oxidizing and iron reducing bacteria.

What are Iron Related Bacteria

Iron related bacteria are microorganisms that can use iron in their metabolism. Generally they are found in surface water and soil but they can also found in well water. The Common iron related bacteria are iron oxidizing bacteria, iron reducing bacteria gallionella, sheathed iron bacteria, pseudomonads and enteric bacteria. Among them the iron oxidizing and iron reducing bacteria are most important. These bacteria are usually found in waters having relatively high concentrations of iron and manganese in the water.

Iron related bacteria
Image: wikipedia

What are the effects of iron bacteria?

Iron related bacteria usually change the color of the water to red, brown or orange or stain on fixtures.  The IRB are responsible for slim production, creating corrosion, clogging, fouling, and hygiene risk. Besides they can also create unpleasant tastes and odor which are more noticeable in the water that is not used for long time.  Normally Iron bacteria are not hazard to health but some cases they cause problems. During drilling and handling the well and groundwater may contaminant with IRB so we have to carefully handle it. It don’t create hydrogen sulfide, the “rotten egg” smell.

Method of Iron Related Bacteria Test

1. Sample collection: This IRB BART contains two tube – inner tube and outer tube. To collect the sample water, firstly open the outer tube cap and remove the inner tube from the outer tube. Then collect at least 20 ml of sample water by using the outer tube. During sample collection do not touch the inside of the tube. Moreover, the outer side of the sample source should be cleaned so that bacteria cannot enter the sample from outside.

IRB Test

2. Now open the inner tube cap and keep on a clean surface so that the cap does not contaminant. It should be remember that IRB primarily grows on the pipes. Fill the inner tube with the collected sample water up to mark which is 15 ml. The inner tube contains nutrients ball to grow IRB.

Iron Related bacteria test

3. Then close the inner tube cap tightly. Discard the unused sample in the outer tube and return the inner tube into the empty outer tube. Then screw the outer tube cap tightly. Allow the ball to float to the top with no help. After placing the sample do not shake or swirl the tube.

IRB Test

4. Label the outer IRB test tube with the date and sample name.

IRB Test

5. Place the IRB test tube away from direct sunlight and allow incubating at room temperature for eight days (if necessary). Check the BART visually for reaction daily.

Iron Related bacteria test

6. Foam or a brown slime ring around the ball and on the bottom of the sample tube will indicate the sample contains iron related bacteria. Whereas the absence of foam or brown slime will indicates the sample has no iron related bacteria.

Iron Related bacteria test

7. Estimate bacteria population: When the iron related bacteria test result is positive then come in the question, how many the bacteria in the water sample? By observing how many days brown slime is formed we can make an estimate of the bacterial population. When the bacteria population is high, then a faster reaction is occurred. We can determine the amount of bacteria by the following table. If the IRB is higher, then you can consider a fecal coliform test.

Days to reaction Approximate IRB population (cfu/ml) Aggressivity
1 540,000 Very high
2 140,000 High
3 35,000 High
4 9,000 Moderate
5 2,300 Moderate
6 500 Moderate
7 150 Moderate
8 25 Low

8. Dominant bacteria:

IRB BART

If the iron related bacteria test result is positive then we have to examine the type of dominant bacteria. With the color comparison of the IRB test tube we can determine the dominant bacteria type in the sample water. If the sample tube water is red color and cloudy then the dominant bacteria is enteric while it is black then the dominant bacteria type is pseudomonad’s and enteric.

Total coliform bacteria test – LaMotte 4-3616 Coliform Test Kit

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Total coliform bacteria test is an easy method with The LaMotte 4-3616 Coliform Test Kit. It Contains 5 disposable tubes and a water sample bag. Each of the tube contains a nutrients tablet that supports the growth of coliform bacteria, a gelling substance, and a pH indicator. If the coliform bacteria are present in the water sample then the bacteria metabolizing the nutrients in the tablet and generated gas. This gas will get stuck in the gelling substance and the gel will rise in the tube. The pH indicator will change the color of the water from red to yellow as further evidence of coliform bacterial activity. The higher the number of positive results in the supply tube, the greater the risk of serious bacterial infection. The test required a 44-48 hours to get the result.

Total coliform bacteria test

Total coliform bacteria are a collection of different types of bacteria in water, soil, human or animal waste. Most of them are harmless. Detection of these bacteria in drinking water or water sources is very important because the presence of total coliform bacteria is an indicator of possible contamination. Consequently we can easily move forward to solve the problem. If only the total coliform bacteria are present in the water and fecal coliform bacteria are absent; This indicates that the source is probably environmental (portable water).

Method of Total coliform bacteria test by LaMotte 4-3616 Coliform Test Kit

  • Sample collection: First you have to collect water sample in the supplied water sampling bag with the LaMotte 4-3616 Coliform Test Kit. Note that the bag contains a tablet rich in dechlorinating agent (2-2197), which is provided to neutralize any chlorine present in the water. Chlorine helps to suppress the growth of coliform bacteria. The outlet at the source of the sample should be cleaned and erased during sample collection and the sample collection bag should not be touched on the inside so that bacteria cannot enter the sample from outside.
LaMotte 4-3616
  • Allow the tap (cold water) to run for 2 to 3 minutes or until the line is flush. Reduce the flow of tap water at such a rate that water can be collected in the sampling bag without spraying water. Now tear off the top of the bag in the scored line and pull the tabs outwards to open the bag. Do not touch the inner surface when opening the bag.
  • Fill the bag up to 4 oz field line. Pull the wire ends to close and whirl the bag for three complete revolutions. Shake the bag to dissolve the tablet.
coliform mpn test
  • Remove all 5 tubes from the display package and open the caps. Unwhirl the bag and pull the tabs outward to open the bag. Fold the inside of a tape wire to form the spout. Carefully fill all 5 tubes up to the 10 ml line with the water sample. Replace the caps tightly. Do not mix or shake the tubes.
total coliform test

LaMotte 4-3616 Coliform Test Kit

  • Stand the carton straight and carefully place all 5 tubes in the display package. Make sure all the tubes are standing vertically. The tablet should lie flat on the bottom of each tube.
total coliform in well water
  • Store the tubes at room temperature for 44-48 hours without direct sunlight. The air temperature should be fairly constant and between 70°-85°F (21°-29°C). While the tubes can be incubated at room temperature, incubation at 44.5° C (112° F) will accelerate growth and result in a more rapid test result. Do not disturb or shake the tubes during the scheduled incubation period. If these storage conditions are not followed properly, then the total coliform bacteria test results may not be appropriate.
  • A positive result in any one of the five tubes should be considered as a potential coliform bacterial contamination. Both yellow color and gas bubbles must be present for positive test results. You should remember that yellow color without gas bubble does not indicate the presence of bacteria. If any positive results are found in two or more tubes, there is a possibility of a serious bacterial infection problem. Further steps should be taken to validate these results by a certified ad bacteriological laboratory.
LaMotte 4-3616 Coliform Test Kit

DISPOSAL
After recording the results of total coliform bacteria test dispose the inoculated tubes by treating with chlorine bleach. Dispose of the LaMotte 4-3616 Coliform Test Kit tubes and package as required by local jurisdiction. Do not reuse the tubes for the test of total coliform bacteria.

Questions & answers

Q. Is the product for a single test or 5 different tests?

Answer: The 5 vials of the kit are for a single test. You should know that a positive result can be found in any one of the five tubes. One positive result considered as a possible coliform bacterial contamination whereas two or more positive results considered as a possibility of a serious coliform bacterial contamination.

Q. Can I use the kit to test for fecal coliform?

Answer: No, It only tests if coliform is present or absence in the water sample.

Q. Can it count how many total coliform are present ?

Answer: No, it does not count how many total coliform are present in the water sample. We can just idea if the sample water has serious or low coliform bacterial contamination. The higher the number of positive results in the supply tube, the greater the risk of serious bacterial infection.

Q. Is the LaMotte 4-3616 suitable for testing pool water?

Answer: Yes, you can use The LaMotte 4-3616 Coliform Test Kit for testing pool water. It can only show the presence or absence of coliform but does not shows how many total coliform are present in the supplied water.

Disinfection and sterilization of water

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Sterilization of water is the process that kills, eliminates or deactivates the all form of microorganisms in the water. It is the critical stage for safe potable water. This method must achieve all most 100% deactivation so that prevents the spread of water-borne diseases. On the other hand disinfection means the process that are removing or reducing harmful microorganisms. There are different methods of sterilization. We can divide them into two methods; chemical methods and physical method.

Chemical methods of sterilization

There are various chemicals are used to the sterilization process. The consumption of these chemical can be reduced by installing a filtration system before this stage. Some of the chemical sterilization methods are described here:-

Ozone sterilization of water

Ozone is a highly effective sterilization chemical for water. It has strong oxidizing properties. It can kills wide range of pathogens microorganisms by oxidizing method. Ozone is more powerful disinfectant than chlorine or chlorine dioxide. Moreover it has effective inactivation activities on giardia or cryptosporidium which is not possible by some others chemicals. This method does not affected by pH. After complete the oxidation process, the excess ozone will breaks into oxygen. So it does not create bad taste or odor’s to the water and leaves no solid residue. On the contrary, it added dissolved oxygen into the water which enhances the water’s taste. The disadvantages of ozone are that it is costly, toxic, unstable and must be produced on mill site. It can create irritation on nose even in low concentrations.

Hydrogen peroxide sterilization

Hydrogen peroxide is another ideal sterilizer like ozone. It is a strong oxidant. It destroys microorganisms without leaving any solid particle to the water. The disadvantage of the hydrogen peroxide is that it is unstable, costly and toxic at high concentrations. The vapor of it can affect the eyes and respiratory system. Some metallic peroxide like Na2O2 has better stability and effectiveness than hydrogen peroxide. Na2O2 produces hydrogen peroxide by the reaction with dissolve carbon dioxide. It also produces sodium carbonate which can able to soften the hard water. You can also apply calcium hydrogen and magnesium hydrogen. Some processes use both hydrogen peroxide and ozone commonly to accelerate the ozone decomposition rate which increases the oxidation rate.

Na2O2 + CO2 + H2O → Na2CO3 + H2O2
Na2CO3 + CaSO4 → Na2SO4 + CaCO3

Chlorination sterilization

Chlorination is the most common and cheapest system for sterilization of water. Chlorine input into the water as chlorine gas, sodium hypochlorite or calcium hypochlorite, chlorine dioxide. When inject it forms several chemicals like hypochlorous acid.

Chlorine sterilization

Chlorine is the most widely used disinfectant in municipal water and wastewater treatment. It can destroy pathogens and control nuisance microorganisms. It can also remove iron, manganese, ammonia nitrogen. Chlorine is a toxic gas so need safety facilities. It acts as a quick oxidizing agent. pH can affects on its activities so needs to control the pH. Chlorine reacts with water and form hypochlorous acid which is further break into nascent oxygen. Both of them are powerful germicide.
Cl2 + H2O → HOCl + HCl ; HOCl → HCl + [O]

Calcium and sodium hypochlorite

Sodium hypochlorite is the one of the most commonly used sterilization chemicals. It is easier and safer to use compared with chlorine gas but more expensive. It is chemically unstable which can convert into sodium chlorate. At higher pH the hypochlorite is corrosive which can attack metal pipe. Calcium hypochlorite can be found as powder, granular, liquid and solid form.
Sterilization of water

Monochloramine

Monochloramine is another form of chlorination. When chlorine and ammonia included into the water then it forms monochloramine which can react under well controlled conditions. It is poor sterilization chemical compared with chlorine but last long and protect from bacteria for long time.
NH3 + Cl2 → NH4Cl + NH2Cl
Chloramines hydrolysis in water and give HOCl
Chlorination sterilization of water

Chlorine dioxide

Chlorine dioxide is a powerful disinfectant compared with chlorine but more expensive. It must be produced nearby consuming plant site. It is not more used chemical for sterilization of water due to unstable and costly.

Aeration

Aeration can improves water taste and remove iron, Mn, carbon dioxide, H2S, volatile substances and bad odor. There are two type of aeration, natural and artificial. Natural aeration occurs in river, steam. To create artificial aeration several designs like spray is used. During aeration the water absorbs air. So increases the amount of oxygen into the water. This oxygen causes oxidation of the substances which are responsible for forming odor.

Silver ion method

The disinfect effect of copper and silver ions has been known for long time.

The chemical sterilization methods are precipitation method (With alum, lime, soda ash), Potassium permanganate process, Sodium hydrogen sulphate etc.

Physical sterilization methods

Boiling the water

Boiling is one of the oldest and most commonly used water sterilization techniques. If the water is boiled for about 20-30 minutes then it destroy all type of harmful bacteria and algae. They also remove dissolved gases from the water and improve the water taste. This method is only suitable for normal households but not suitable for industrial and large scale purposes.


UV sterilization

Ultra-violet light has a powerful germicidal action on water. It is one of the latest methods for sterilization of water. When ultraviolet radiation is passing through the water then it is absorbed by the cells and damages the DNA of the microorganisms. Hence they are not enable to grow or reproduce. This physical sterilization method can be applied for groundwater and households water but not suitable for large scale. It does not create solid content in water. The water should be free from suspended particles otherwise it may interfere to come in UV rays contract with microorganisms. The system is costly.

Niagara bottled water company has recalled its 14 bands bottled spring water

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Niagara Bottling, a family owned bottled Water Company in USA is a voluntary recall covering 14 brands of its water because of possible contaminant E. coli bacteria. The possible affected date is from June 10 to June 18 of this year. The affected bands are Niagara Spring Water, Acadia Spring Water, Acme Spring Water, Big Y Spring Water, Nature’s Place Spring Water, Pricerite Spring Water, Superchill Spring Water, Best Yet Spring Water, 7-11 Spring Water, Morning Fresh Spring Water, Shoprite Spring Water, Shaws Spring Water, Western Beef Blue Spring Water and Wegman’s Spring Water.

Throughout the 8 days, this effected bottled spring water was shipped to over 15 states including Pennsylvania, Connecticut, Maine, Delaware, District of Columbia, Virginia, West Virginia, Maryland, Massachusetts, Rhode Island, Vermont, New York, New Hampshire, New Jersey, and North Carolina.

These brands of bottled water are produced in two Pennsylvania manufacturing plants at Hamburg, Berks County and Upper Macungie, Lehigh County of the company. The company said that one of its spring bottled water sources was contaminated by traces amount of E. coli bacteria. Still, there are no reports of any illness linked to the above mentioned bottled Water. The voluntary removal effort is being implemented in collaboration with State and Federal Agencies. The Niagara bottled water company always tries to maintaining the maximum probable standards for product quality.

The Niagara bottled water company alerts this promptly due to the company’s good well and health concern of the people. The people who are lived of these 15 states and bottled water drinker, should to be check the manufacturing date of these 14 bands. If the product date between June 10 and June 18, 2015 and manufactured at Pennsylvania facilities than it must be avoid drinking. The bottled water that is produced outside of Pennsylvania or outside the June 10-18th, 2015 timeframe is completely safe to drink.

If anyone needs further information about this they can call at (888) 943-4894 to know more.

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.