The influence of surface modification by Acid and base on adsorption of dyes and Cr ions onto activated carbons prepared from barks of Thespesia populnea

Abstract

Water is one of the utmost indispensable substances on globe. All plants and newlineanimals must have water to survive. If there was no water there would be no life on earth. newlinePeople can live several weeks without food, but only a few days without water. We newlineshould drink six to eight glasses of water each day. Water makes up 83% of our blood, newline70% of our brain and 90% of our lungs. Overall, our bodies are 70% water. About 70% newlineof the earth s surface is covered with water. Ninety-seven percentage of the water on the newlineearth is salt water. Salt water is containing salt and other minerals, humans cannot drink newlinethis water. Although the salt can be removed, it is a difficult and expensive process. Two newlinepercentage of the water on earth is glacier ice at the North and South Poles. This ice is newlinefresh water and could be melted however, it is too far away from where people live to newlinebe usable. Less than 1% of all the water on earth is fresh water that we can actually use. newlineWe use this small amount of water for drinking, transportation, heating, cooling, industry newlineand many other purposes. So the fraction amount fresh water is not enough for human newlinesurvival activities. But now a days this fraction of water also affected by various natural newlineand manmade activities. newline