Water Quality: Categories, Importance, Assessment microbiologystudy

The physical, chemical, and biological properties of water as regards set standards are called water quality. Water quality is usually used to set the standards through references obtained through the water treatment process.

The standards were used to monitor and assess the water quality of different sources like surface water, groundwater, and etc. Water quality assessment is the process of evaluating of physical, chemical, and biological properties of the water concerning natural and anthropogenic consequences and prospective applications. The quality of water helps to identify the productive health of ecosystems, human safety with water uses, and the range of water pollution. The water quality also helps to identify the uses of water for domestic, drinking, aquatic, irrigation, and industrial purposes which play a major role in considering the water supply options.

Categories of Water Quality

There are four categories of water quality.

1. Potable water: Acceptable to drink, tastes good, and appropriate for domestic use. 
2. Palatable water: Aesthetically pleasant, examines the occurrence of pollutants that are not hazardous to human health. 
3. Contaminated (Polluted) water: Not suitable for drinking or domestic use which carries unwanted physico-chemical contaminants in water. 
4. Infected water: Contaminated through pathogenic microbes.

Importance of Water Quality

• The high dependency on freshwater throughout the world which accounts for a small portion and covers barely 2.5 % out of water availability of approx. 70% of the Earth.
• However, only about 1.2 % of freshwater is available with the rest 2.5 % trapped in glaciers and ice caps (68.7 %) and groundwater (30.1 %). 
• The preservation of freshwater is vital to safeguarding human health and aquatic ecosystems, which provide us with various benefits such as drinking water, food, and recreational opportunities. 
• In the recent condition of increasing per capita water demand and freshwater availability, water quality assessment and monitoring can be utilized for water supply which is crucial for societal, economic, and conservation purposes.
• The site-specific water quality can be utilized to evaluate the origins and fates of harmful chemicals and contaminants which are mostly influenced by ecology, geology, and human-induced activities.
• The determination of the origin of contamination helps to minimize the potential health impacts and formulate the proper management techniques. 

Indicators of Water Quality Analysis

There were various parameters which are used to analyze the physical, chemical, and microbiological properties of the water which are disseminated below. 

a. Physical parameters

The physical parameters of water include water temperature (Temp), electrical conductivity (EC), total suspended solids (TSS), total dissolved solid (TDS), turbidity, odor of water, color of water, water clarity, and taste of water.  

b. Chemical parameters

The chemical parameters include total hardness (TH), calcium hardness (CaH), magnesium hardness (MgH), chloride (Cl), chlorine residual, alkalinity, acidity, free CO₂, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demands (COD), toxic organic substances, and radioactive substances.

Here, the chemical parameters are further categorized as follows:

1. Cations

The cations of water include calcium ions (Ca²⁺), magnesium ions (Mg²⁺), sodium (Na⁺), potassium (K⁺), and ammonium ions (NH₄⁺). 

2. Anions 

The anions of water include bicarbonate (HCO₃^–), carbonate (CO₃^–), chloride (Cl^–), sulphate (SO₄^2-), nitrate (NO₃^–), and fluoride (F^–). 

3. Heavy metals 

The heavy metals in the water include iron (Fe), arsenic (As), zinc (Zn), aluminum (Al), manganese (Mn), cadmium (Cd), lead (Pb), copper (Cu), and nickel (Ni). 

c. Biological parameters

1. Microbiological parameters

The biological parameters include bacteria (fecal coliform, Escherichia coli, Citrobacter species, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Vibrio cholerae), algae, viruses, and protozoa.

2. Benthic macroinvertebrates 

The benthic macroinvertebrates were also biological indicators of surface water quality which includes insects like Ephemeroptera (mayfly), Plecoptera (stonefly), and Trichoptera (caddisfly) (EPT).

Five core parameters of ambient water quality

Sustainable Development Goals (SDG 6.3.2) examine the percentage of bodies of water with high ambient water quality with national water quality requirements. This could be determined by evaluating five different parameters DO (surface water), EC (surface and groundwater), Nitrogen (N)/NO₃^– (surface and groundwater), phosphorus (surface water), pH (surface and groundwater) which provide insights on the most common stressors on water quality globally.

Freshwater pollution throughout the world

The water quality is altered by natural occurrences; however, anthropogenic activity causes a significant impact on the majority of oceans, lakes, and rivers. Since there are significant data gaps, in water quality, both regionally and temporally, it is extremely difficult to estimate the precise quantity of contaminated freshwater and water bodies worldwide. It required immediate action to understand the impact on water quality and deal with the issues it raises throughout the world.

Conclusion

Thus, the assessment of water quality parameters before consumption for drinking and any other purposes helps to reduce the public health impacts and provide the strategic management way in public water supply, industrial, and aquaculture uses. 

References

1. FAQs on water quality. (2024). UNEP – UN Environment Programme. https://www.unep.org/explore-topics/water/what-we-do/world-water-quality-alliance-wwqa-partnership-effort/faqs-water
2. Omer, N. H. (2020). Water quality parameters. In IntechOpen eBooks. https://doi.org/10.5772/intechopen.89657
3. World Water Quality Alliance (WWQA) – a partnership effort. (2024). UNEP – UN Environment Programme. https://www.unep.org/explore-topics/water/what-we-do/improving-and-assessing-world-water-quality-partnership-effort
4. Adelagun, R. O. A., Etim, E. E., & Godwin, O. E. (2021). Application of Water Quality Index for the Assessment of Water from Different Sources in Nigeria. In IntechOpen eBooks. https://doi.org/10.5772/intechopen.98696
5. UNEP. (2024). Indicator 6.3.2 “Proportion of bodies of water with good ambient water quality”. Acessed date: September 24, 2024 From https://www.sdg6monitoring.org/indicator-632/.
6. Wikipedia contributors. (2024, September 15). Water quality. Wikipedia. https://en.wikipedia.org/wiki/Water_quality