Determination of the Quality of Drinking Water
Idea / Objective
Access to good quality drinking water is becoming a part of Universal Human Rights. However, access to good quality drinking water in the right quantity and at the right time and place is still a dream to be achieved in many urban and rural areas of our country. People living in cities and municipalities do get potable water supplied by municipal authorities, but the quality of this drinking water and its availability is often a question. In large rural areas people face the burden of collecting water from various sources like rivers, ponds, lakes, springs, tube wells etc. The quality of these various water sources is often threatened from agricultural run-off and industrial wastes. The objective of this exercise is to analyze and test the quality of water used specially for drinking purposes. Further, it aims to inform the people about the importance of standard quality drinking water.
Materials / Equipment Required
- Draw a map of the area under observation.
- Carefully conduct survey of at least 50 samples in the selected study area. This will give you some insight about:
- The sources of water used for drinking, and
- Common water-related diseases affecting the local population over the last six months.
- Collect the samples of water from different sources from at least 15 points.
- Collect 15 glass bottles with stoppers (capacity – 500 ml each).
- Clean and wash them with distilled water and then dry them.
- About 500 ml of water are collected in the bottles from different sources. Fill each of the glass bottles with 15 collected water samples and label them, mentioning the source and date of collection.
Experiments and analysis of the samples
A. Physical parameters
Check for colour, odour, turbidity, suspended solids, temperature etc, as detailed in this document ‘Methodology and parameters for water testing’.
Record the results of all the samples in a tabular form.
B. Acidity or Alkalinity
With the help of pH papers, the pH of all the collected samples are determined and their values are recorded in tabular form.
C. Total solids
Water with high percentages of dissolved solids are generally of an inferior potability.
For this reason, a limit of 500 milligram of dissolved solid, per litre of water is desirable for drinking purpose.
To test the presence and amount of total solids suspended in the water, the following experiment is carried out. A beaker (100 ml) is washed with distilled water, dried and weighed. Let the weight of the empty beaker be ‘x’ grams. It is then filled with water samples and weighed again. Let the weight be now ‘y’ grams. Hence the weight of the water sample taken = (y-x) grams. The water is then slowly evaporated by heating over a low flame Bunsen burner / spirit lamp / oven. It is then cooled and is weighed again. Let the weight be ‘z’ grams. Hence weight of the solid residue in the beaker is (z-x) grams.
The total solid content in water sample in milligrams per litre can thus be calculated as:
(z-x) * 1000 * 1000
From the above data, after comparison with the standard specification from drinking water, the samples suitable / unsuitable for drinking purposes and its corresponding sources are labeled accordingly.
- Inform the general population of the nature of impurity in the identified water samples and sources and the health hazards associated with the same, if consumed. You can prepare attractive posters on this.
- To make the samples suitable for drinking, find out methods to reduce solids and colour in water. A correlation between common diseases and water used may be studied.
- Repeat the entire process after a gap of 20-25 days. For a quality project work, you will need at least three sets of data produced in a span of roughly two months. All the data should be thoroughly analyzed
Source: Harness water resources for a better future - Activity Guide for the 13th National Children's Science Congress