Do you know that the water which we use for different purposes be it domestic, agriculture, business or the glass of water that you might be sipping while going through these lines could be of inappropriate quality.
According to the World Bank Report of 2019, the deteriorating quality of water worldwide is slashing the economic potential of heavily polluted areas. It also warns the invisible crisis of water quality is threatening human and environmental wellbeing.
Albert Szent Gyorgyi a Hungarian biochemist who won the Nobel Peace Prize in Physiology or Medicine has appositely said, “Water is life’s matter and matrix, mother and medium. There is no life without water”. Water is crucial for all the activities. However, it is a matter of concern that the quality of water is deteriorating due to a plethora of factors.
Water quality is not entirely dependent on human activities , other simmering factors like weather and meteorology floods due to climate change can increase the water pollution as the pollution from farms, residential lawns, overfilled sewage systems, trash , animal waste, nitrogen phosphorous mixes in water ways which increases the risk of contamination and higher cost of water treatment. There is a notion that water quality is getting severely affected by climate change.
Chemical Water Quality Parameter
Several parameter helps to determine water quality
1. Chloride ion:
The concentration of chloride ion is quite low in natural water system. It increases in contaminated water. Moreover high concentration of chloride ion makes the water salty and corrodes pipelines of water.
The decomposition of organic matter like protein, amino acid increases the concentration of Ammonia in water . Besides it also increases with the use of chloramine in water disinfection process. Concentration of NH3 in ground water system is usually 3mg/ltr. If its concentration is greater than 50mg/ltr, it gives characteristic taste and odor.
- It is very unstable intermediate formed during conversionof NH2 into nitrate.
- In aerobic condition nitrite is oxidized into nitrate whereas in anaerobic condition, nitrite is reduced to ammonia.
- If concentration of nitrite is greater in drinking water, it brings serious health hazard to the consumers.
- Disease caused by high concentration of nitrite in infants is called Blue baby syndrome, which is characterized by blue coloration of skin
- Level of nitrite in drinking water should not exceed 3mg/ltr.
- **Note; blue baby syndrome: hemoglobin has greater affinity for nitrite than oxygen. Therefore, if level of nitrite is high in blood due to consumption of contaminated water then it inhibit formation of oxyhemoglobin, instead it form nitrosomyoglobin. This prevent transport of Oxygen to tissue giving characteristic blue color. In infants nitrite poisoning occurs even due to high concentration of nitrate in drinking water because stomach of infant is less acidic. In this situation nitrate is reduced by intestinal bacteria into nitrite causing blue baby syndrome.
- It is most stable oxidized form of nitrogen. In water nitrate comes from organic matter decomposition and from atmospheric nitrogen fixation.
- Like nitrite Nitrate should not exceed 3mg/ltr in drinking water. It is because nitrate can be reduced into nitrite in gut of infants and causes nitrite poisoning.
- Nitrate is very important in natural water system like lake and pond because high concentration of nitrate facilitates heavy growth of aquatic plants causing eutrophication.
- In water phosphate is present in the form of H2PO4-, polyphosphate and as organic phosphate.
- Phosphate in water sources comes from agricultural wastes, sewage and from industrial effluent.
- Phosphate is not toxic to human being but it is important chemical in natural water system like pond because its high concentration facilitates eutrophication.
- Hardness of water is merely due to salt of calcium and magnesium.
- Temporary hardness is due to carbonate and bicarbonate of calcium and magnesium while permanent hardness is due to chloride and sulfate of calcium and magnesium.
- Water is classified as 9on the basis of concentration of calcium carbonate)
- Soft water:<5omg/ltr
- Moderately hard water: 50-150 mg/ltr
- Hard water: 150-300 mg/ltr
- Very hard water:>300 mg/dl
- Hard water is not suitable for industrial use. But hard water is usually beneficial for drinking purposes. However hardness caused by MgSO4 give some serious health effects. So, concentration of Mg++ should not exceeds 50 mg/lt in drinking water.
- Biological oxygen demand (BOD):
- Biological oxygen demand represents amount of oxygen required by living organism (microorganism) for oxidation of biodegradable organic matters present in water under aerobic condition.
- BOD is a direct measurement of quality of oxygen needed for biodegradation of organic matter and indirect measurement of quantity of biodegradable organic matter in water.
- When biodegradable organic matter is added in water. Microorganism utilizes dissolved oxygen to oxidize organic matter. If the rate of consumption of oxygen during biodegradation is greater than solubilization of atmospheric Oxygen into water, level of dissolved oxygen gradually decreases.
- If organic matter content is very high, complete loss of dissolved oxygen occurs. This creates anaerobic environment in water. In this case aerobic aquatic organism cannot survive.
- Furthermore, if dissolved oxygen is absent then organic matter starts to decompose anaerobically that creates taste and odor problem.
- High value of BOD is an indicator of water pollution.
What are different types of water testing?
There are a wide range of water quality tests used to help determine how safe, or even drinkable, water is to be used in a household setting or otherwise that water test labs perform.
These different types of tests help determine if specific materials of contaminants have infected a body of water, and help inform how it needs to be further treated. Here are just a few types of water testing methods.
There are a range of potential bacterial contaminants that can plague water. One of the most common and most looked for is E. coli bacteria, which comes from fecal matter exposure and can result in serious health issues when consumed. Bacteria testing is essential in determining how safe water is to drink or expose to your skin.
The list of mineral testing available could be a thesis paper, for how many there are. A few common and important mineral tests include chlorine and chloride, nitrate and nitrite, lead, copper, iron, zinc, potassium, and sodium.
This wide range of mineral testing is essential and relevant in determining water quality, as different regions or areas of terrain may have more of a buildup of certain types of minerals, which informs what kind of mineral treatments the water actually needs in order to be purified.
What is pH? If middle school science class feels like an age and a day behind you, here’s a quick reminder. pH is a measure of the concentration of hydrogen ions in a solution.
The more of these hydrogen ions there are in a solution, the more acidic that water is. Acidity effects taste of water, but it can also affect how health water is to consume. Drinking water that’s not neutral enough in acidity can make people sick!
Other Types of Testing
There are some basic water tests that don’t have anything to do with chemical testing: conductivity, odor, sediment, and turbidity. Not relevant in all situations, these tests create a measure of the more physical traits of a water sample.
Is it clear, or clouded with sand and silt? Does it smell swampy, or fresh? How well does it convey electricity—and what does that say about the mineral content?
What is the most important water quality test?
Quality of drinking water indicates water acceptability for human consumption. Water quality depends on water composition influenced by natural process and human activities.
Water quality is characterized on the basis of water parameters (physical, chemical, and microbiological), and human health is at risk if values exceed acceptable limits [1–3]. Various agencies such as the World Health Organization (WHO) and Centers for Disease Control (CDC) set exposure standards or safe limits of chemical contaminants in drinking water.
A common perception about water is that clean water is good-quality water indicating knowledge gap about the presence of these substances in water. Ensuring availability and sustainable management of good-quality water is set as one of the Sustainable Development Goals (SDGs) and is a challenge for policy makers and Water, Sanitation and Hygiene (WASH) practitioners, particularly in the face of changing climatic conditions, increasing populations, poverty, and the negative effects of human development.
Water quality tests will give information about the health of the waterway. By testing water over a period of time, the changes in the quality of the water can be seen. Parameters that may be tested include temperature, pH, turbidity, salinity, nitrates and phosphates.
Drinking water can come from different sources depending on where we live in the world. Three sources that are used to collect drinking water are:
Water is in continuous movement on, above, and below the surface of the earth. As water is recycled through the earth, it picks up many things along its path. Water quality will vary from place to place, with the seasons, and with the various kinds of rock and soil it moves through.
For the most part, it is largely natural processes that affect water quality. For instance, water moving through underground rocks and soils may pick up natural contaminants, even with no human activity or pollution in the area.
In addition to nature’s influence, water is also polluted by human activities, such as open defecation, dumping garbage, poor agricultural practices, and chemical spills at industrial sites (see also water source protection).
Even though water may be clear, it does not necessarily mean that it is safe for us to drink. It is important for us to judge the safety of water by taking the following three qualities into consideration (see also pathogens and contaminants):
- Microbiological – bacteria, viruses, protozoa, and worms
- Chemical – minerals, metals and chemicals
- Physical – temperature, colour, smell, taste and turbidity
Safe drinking water should have the following microbiological, chemical and physical qualities:
- Free of pathogens
- Low in concentrations of toxic chemicals
- Tasteless and colourless (for aesthetic purposes)
When considering drinking water quality, microbiological contamination is the main concern in most cases since it is responsible for the majority of illnesses and deaths related to drinking unsafe water. Learn more about water purification.