Daily Archives: May 23, 2020

Yellow Sand Wasps

Mention of a wasp is enough to make you fear. They deliver painful stings. One of the species of wasps is Sand Wasps or Bembix. They nest in the ground preferably in the sand. These live in urban areas, forests and woodlands.

Adult sand wasps feed on nectar but most hunt for flies to feed to their larvae in the nest. They are excellent hunters, capturing flies on the wing, paralysing them with venom in mid-air and carrying them back to the waiting larvae. Sand wasps can deliver painful stings only when they are disturbed.

I spotted these wasps many times in a forest area near me. One of them was furiously digging a nest in the sand. It was doing it very deftly. As the sand piled up at the mouth of the hole, it comes out to clear it so that further digging is continued.

Wasp digging the hole
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RO Water Purification Systems

Potable Water in many places contains undesirable impurities like suspended solids and harmful organisms like bacteria and viruses. On the other hand, its chemical composition depends upon its source.

RO water purification systems claim to do remove the suspended impurities. This is done using sand filters also called the pre filters, and killing the harmful organisms by UV light. Next these bring down the total dissolved salts TDS to desirable levels if the water under treatment has excess TDS. Why TDS ? Why not adjust the concentration of individual ions present to the desirable levels?

This they can’t do. These systems only can subtract something from the water composition not make up for the ions concentration which are deficient. As everyone knows, many salts which are essential as micronutrients for our bodies. These are also removed along with the harmful salts. The natural water’s chemical composition is different at different places. Some salts may be present in higher concentration levels. And some desired salts may be in deficit. The ideal drinking water should contain the salts in recommended limits, with no suspended impurities and no bacteria and virus.

But the ionic part is problematic. The RO systems work on bringing down the total dissolved salts (TDS) instead of individual ions. The resultant water has desired TDS but not the desired quantity of individual ions. The systems are not intelligent enough to adjust the concentrations of deficient ions to desired level by addition from outside. Cost will be prohibitively high for all these capabilities.

In conclusion we can say RO systems are as far as the removal of suspended impurities and killing of bacteria and viruses. But on the ionic composition front these are of not much use.

It becomes necessary to compensate this loss, by elevating the intake of these salts through food and other means.