“A safe water supply is the backbone of a healthy economy, yet is woefully under prioritized, globally.” Almost a quarter of the world’s population is moving towards a water crisis. The pandemic is worsening the problem. In Asia, India and Pakistan are being hit hard. In India, over 50% of its population does not have access to clean drinking water. About 2 lakh people die every year because of zero access to clean water. Tens of millions of people in India are consuming excess fluoride. In West Bengal, up to 15 million people get affected due to excess arsenic. This is why lab water testing by certified companies like Arbro pharmaceuticals is crucial. What should water be tested for?

Microbial properties of water should be tested for bacteria, viruses, worms, etc., and chemical properties should be tested for minerals, metals, and chemicals, etc. Physical properties should be tested for temperature, taste, turbidity, etc.

Here is how water is tested for many purposes like drinking, irrigation, use in industry, etc.


What are the tests performed to infer microbial properties:

1. ATP test: Adenosine Triphosphate (ATP) is the energy driving molecule in any living organism. So active microorganisms in the water are tested through this process. The intensity of light produced when ATP reacts with an enzyme, named the enzyme firefly luciferase, is measured using a luminometer.
2. This is a direct indicator of the number of active microorganisms in the sample water.
3. Direct plate count method and membrane filtration method: These two methods differ in the media (VBRA Agar and mEndo Agar, respectively) used to grow bacterial colonies to test for their presence in the sample water. The colonies formed are a measure of water contamination.
4. More tests include tests for fecal coliform, viruses, worms, etc.


What are the tests performed to infer chemical properties:

Dissolved oxygen test using Winkler’s method: While dissolved oxygen is vital for plants and animals that consume the water to survive, it is also essential for aerobic aquatic organisms. So this becomes a key indicator of water quality. MnO2(IV) {Manganese peroxide solution} and NaOH {sodium hydroxide solution} are added to the sample water, and they produce a white precipitate of Mn(OH)2 {Manganese hydroxide (II)}.
This reacts with dissolved oxygen in the sample and forms a brown precipitate of MnO(OH)2 {Manganese(II) hydroxide}. This brown precipitate is dissolved in the presence of iodide ions (I-) in acid, and the released iodine (I2) will give the measure of dissolved oxygen in the water sample.


Clean Water

Other general chemical tests and their effects:

1. pH test: pH is a measure of hydrogen ions dissolved in a solution. The pH level of drinking water should be neutral, which is 7. If it is below 7, it means that the water is acidic. This acidity indicates that the water is most likely to be contaminated with industrial pollutants.
2. Test for fluoride: Excess consumption of fluoride can cause dental fluorosis, which causes stains, pits, and surface irregularities in the tooth. Prolonged consumption of fluoride can cause skeletal fluorosis, which causes stiffness and pain in joints.
3. Test for nitrates: Excess consumption of nitrate affects how the blood carries oxygen.
4. Test for arsenic: Long-term exposure to arsenic can cause skin lesions, cardiovascular disease, cancer, diabetes, etc.
5. Test for Manganese: High levels of Manganese in water tamper with memory, attention, and motor skills.
6. Test for iron: Too much iron consumption can lead to hemochromatosis, known as iron overload. This leads to damage to the heart, liver, and pancreas. Too much iron also causes the early onset of wrinkles and a metallic taste in water.
7. TDS (Total dissolved solids): TDS involves a wide range of cations, anions, metals, etc., that dissolves in water. TDS in water can cause water hardness, scale formation, staining, leach harmful metals from plumbing pipes and hardware. Too much and too low levels of TDS can have adverse effects on health. Therefore drinking water with moderate amounts of TDS is suggested.


What are the tests performed to infer physical properties:

1. Temperature test: If the water temperature is high, it cannot hold enough oxygen for the organisms in it to survive. This affects the biochemical reactions in the organisms. So a temperature measure of temperature gives an idea about the quality of water.
2. Turbidity test: It simply means how clear or see through the water is. This test measures the amount of suspended particulate matter in the water.

Just because the water is clear doesn’t mean that it is free of microorganisms and harmful chemicals. Lab water testing is one way to know that water is fit for consumption.


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