3. Screening for Water Quality

So if somebody comes and asks is the water contaminated, is water safe to drink? So your answer cannot be, your absolute final answer can be okay give me a month's time, I will analyze whether it contains all the one lakh chemicals that we know that are that exist in nature and then I will tell you in a month's time, that is not acceptable, people won’t wait for that long. So you need a quick answer.

When assessing water quality, people often need immediate answers about its safety, especially regarding contamination. Waiting for a long, detailed analysis isn't feasible; hence, quick assessments are crucial. This highlights the need for screening methods that can provide preliminary information about the water quality in a very short time, allowing for efficient decision-making.

Imagine you’re at a picnic, and someone asks if the water from the river is safe to drink. Telling them it will take a month to find out is impractical. Instead, you need to quickly assess whether it looks clear or has any unpleasant smell to give them a fast answer.

Screening, we do a preliminary analysis and we say is this good or bad? Now, this is a very, it’s a bit, it’s it’s not a very from a scientific or rational point of view, you know that the answer could be wrong, but at least you have some sense of what is happening.

Screening in water quality assessment is about performing a preliminary analysis to determine if a water sample is 'good' or 'bad'. However, it’s important to acknowledge that while this method provides quick insights, it may not always be scientifically accurate, and the screening results should not be seen as conclusive but rather preliminary.

Think about screening for a job: a quick resume review can give you an idea of a candidate’s suitability, but that doesn’t guarantee they will excel at the job. In the same way, water screening gives a snapshot of quality but requires more detailed tests for certainty.

So when we look at water quality itself, what do you look for? The first question you ask them? When somebody says please tell me if it is good water? So your question, what is your follow up question? Good for what? Drinking.

When assessing water quality, it’s essential to clarify what the water will be used for. For instance, drinking water needs to meet higher safety standards than water for washing. Thus, determining the intended use helps tailor the assessment criteria, ensuring a more relevant evaluation of the water quality.

It’s like asking if a car is good. If you intend to use it for racing, you’ll need a high-performance vehicle, but for commuting, a more economical car would suffice. Similarly, knowing the purpose of the water helps define its quality needs.

When somebody gives you a glass of water, when will you not drink the glass of water? If it is coloured, if it is turbid, if it smells, something is smelling, yeah. Then all these three are good, then you take it in your mouth, it does not taste good.

Basic screening for drinking water often involves checking for visual indicators and other sensory information. If the water is colored, turbid (cloudy), or smells bad, it's a clear sign that it may not be safe to drink. Taste is also a crucial factor; if it doesn’t taste good, it’s a red flag. These visible and sensory parameters provide immediate insights into potential contamination.

Think about tasting spoiled milk. If it looks okay but has a strange smell or taste, you know not to trust it. The same principles apply to water; before any chemical analysis, we can use our senses to evaluate its quality quickly.

Dissolved is it is in the structure of the water and I think it does not form any precipitate, it is dissolved... Suspended Solids, something is suspended, means it just floats in the water.

In water quality, it's crucial to distinguish between dissolved solids and suspended solids. Dissolved solids are substances that are completely integrated into the water and do not settle out, while suspended solids remain floating and can be filtered out. Understanding this distinction helps in assessing water quality accurately and determines the treatment methods required.

Think of sugar in water. When you dissolve sugar, it becomes part of the water and you can't see it—just like dissolved solids. Now, consider dirt in a glass of water; it doesn't dissolve and you can see and remove it—this is akin to suspended solids.

One of the water quality parameters is we call it as total dissolved solids. See the word solids is a very it is a misnomer here, it is not a it’s not an insoluble solid.

Total Dissolved Solids (TDS) and Total Suspended Solids (TSS) are two fundamental measurements in evaluating water quality. TDS refers to all dissolved substances in water, whereas TSS measures the amount of solids that are suspended. Understanding TDS and TSS helps in determining the overall quality and safety of the water for specific uses.

If you think about a smoothie, TDS is like the pure juice that you can't see but still affects the taste, while TSS is like the bits of fruit that float in the smoothie. Both play a role in determining the smoothie’s quality, just like dissolved and suspended solids do in water.

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