Water is an inseparable component of living organisms. Water is also included into renewable natural resource, which mean its availability is unlimited in nature. As we know, water takes over around 70% of the Earth’s surface mostly in the form of oceans, including waters on land. Despite of its massive amount, water have to be used efficiently. Because, several places on Earth still experience crisis on water supply, especially during the dry season or summer.
Besides that, the massive amount of water cannot be used recklessly, especially for utilizations in human life. Only water with high quality that can be used or drink to fulfill any kind of human necessities. The quality of water is determined by the needs of the water itself. In example, the quality of water for agriculture is different to quality of water that consumed by human. However, generally the qualified water has to meet several parameters that ensure the water is safe according to the standard.
At least there are 5 main requirements to determine the quality of water is free of chemicals, has suitable pH and temperature, containing very low ammonia and nitrite, doesn’t contaminated by organic material and stable. In order to know if the waters are feasible and qualified, we have to know the quality parameters of water. And the parameters are classified into 3 categories. Here are 9 quality parameters of water and their explanations.
1. Physics Parameters
- Brightness
In the physics parameters, brightness related to photosynthesis process that found in the waters. Brightness is some light that can be passed on through the water. The higher brightness level means the translucency of the water is higher. From this parameter, we can understan how far the occurence possibility of assimilation process by living organisms, water plants, inside the water.
Brightness also can become brightness determinant that came target sparkle, light measure inside the water that caused by colloid particles and suspension of polluting material such as industrial waste, household waste, agriculture, and others.
- Temperature
Water temperature can be affected by many things such as duration of sunlight exposure, heat exchange between air and water, elevation position or geographical location, canopy by vegetation around the waters, human activities (waste disposal) and others. In the marine science, water temperature becomes an interesting factor because it’s related to the life of animals and plants inside sea.
Water temperature also affects metabolism of the water organisms, because the distribution of the organisms between sea and fresh waters is bound by water temperature. Higher water temperature will increase growth rate, but also can suppress life and even lead to the death of animals if the water temperature is too high. When the temperature is too low, fish are more vulnerable to bacteria or fungi, but the oxygen content in the water will be higher. But, the lower temperature will inhibit the respiration and heartbeat rate, so there is a possibility the fish will unconscious due to lack oh oxygen inside their bodies.
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Depth
Depth of waters can be a significant factor as the quality parameters of water. Because of the depth of water determines how much the sunlight can penetrate the water, also the availability of the oxygen. Living organisms, especially fish, usually will experience stress in the water that lack of sunlight. This also applies with the availability of oxygen in the water, more shallow the waters so more oxygen, while the oxygen is less in the deep waters.
2. Chemical Parameters
- Acidity Level
Good quality of water have to possess neutral acidity level or degree, which means the water isn’t too acid or alkali. pH is the acidity level which known based on the measurement of hydrogen ion by using pH equation =-log(H+). While for pure water, H+ ion and OH- ion is on the same level, so the water has pH 7. Most of waters on Earth have acidity level between 7 to 8.2. However, some waters have pH below 6.5 or above 9.5. The acidity level is ranging from 0 to 14. The acidity level becomes an important parameter because it affects the growth rate of waters and affects the life of living organisms inside the waters. If the waters are too acid, indeed it can kill the living organisms because the oxygen content inside the water is decreasing.
- Dissolved Oxygen (DO)
The existence of oxygen in some waters is related to temperature. Dissolved oxygen will decrease if the water temperature is too high. In sea, dissolved oxygen came from 2 sources which are oxygen that came from atmosphere and oxygen that produced by photosynthesis of phytoplankton and sea plants. All the living organisms require oxygen to breath and metabolism. It can be said that the higher dissolved oxygen in some waters, so the higher the quality of those waters. And the continuity of water organisms can be maintained. Also, if the composition of dissolved oxygen isn’t stable all the time, it will affect the mixation, photosynthesis process, respiratory in marine fish, motion of water mass and waste that enter the waters.
- Salinity
Salinity can be defined as total concentration of all dissolved ion inside the water. Those ions are potassium, sodium, chloride, magnesium, sulphate and also bicarbonate. Salinity level in some waters can be known by calculating the amount of chlorine inside a sample (chlorinity). Salinity can be measured in gram/litre, ppt (part per thousand) or permil. Therefore, water as dissolvent is one of the properties of water.
- Alkalinity
Alkalinity is the capacity of water to neutralize additional acid without have to decrease the acidity level (pH) of the water. Alkalinity can be a buffer for acidity effect. Generally, alkalinity is composed of bicarbonate anion (HCO3-), hydroxide (OH-), carbonate (CO32-) also other ions. For fish or shrimp farmers, alkalinity is very important, especially to suppress the fluctuation of water acidity level in the morning and daylight, and to determine the natural fertility rate on the waters.
3. Biological Parameters
- Plankton
Plankton is one of the organisms in waters that has very small size and moving accordingly to the water current. Plankton is classified as 2 types which are zooplankton (animal) and phytoplankton (plant). Inside the waters, the existence of plankton is crucial. That means the high amount of plankton will ensure the continuity of all the living organisms in the waters. Phytoplankton can do photosynthesis and produces dissolved oxygen inside the water. In food chain, plankton is the food source for tiny fish that live in the waters.
- Fish
Aside from its ability to live in water, fish also can be a biological parameter to determine the quality of water. If inside some waters there are less fish or nothing at all, it can be said that the waters have poor water quality. While, if there are many kinds of fish that found in some waters, the waters have good water quality. Besides that, the existence of fish can create fisheries activities of the area which can increase the economy of the area.
Those are 9 quality parameters of water and their explanations, in order to find out the quality of waters. From those parameters above, we already knew that the high quality water and can be consumed by human doesn’t have color, doesn’t have taste or smell, also free of any microorganism. Hopefully this kind of information is useful for you.