If water is boiled at temperatures above seventy degrees Celsius most pathogens present inside the water will probably be killed inside 30 minutes, if water is boiled above eighty five degrees Celsius most pathogens will probably be killed within a few minutes, if the temperature of the water is at boiling point the majority of the pathogens present in the water will probably be killed, even so for some pathogens like clostridium botulinum it’ll take a temperature of a hundred and eighteen degrees Celsius just before they’ll be killed. This technique, though beneficial, has its limitations as boiling water won’t remove metals or chemicals having boiling points above a hundred degrees Celsius. Portable water purifiers also employ filtration to purify water. They can remove pathogens in a range of 0.2 to 0.3 microns. These forms of water purifiers are helpful for removing most bacteria and protozoa but not viruses as they’re too little. The activated charcoal absorption employs activated carbon with a high surface location, this absorbs a terrific number of compounds and renders the water pure. The negative effects of this strategy is that it doesn’t rid the water of pathogens, this technique has to be employed in conjunction with some other strategy to ensure adequate purification of water, as it alone just isn’t sufficient. Yet another approach is chemical disinfection where chemicals can be added to untreated water to purify it. An example is iodine, adding this to untreated water is sufficient to kill essentially the most common pathogens, despite the fact that this has to be neutralized thereafter by the addition of yet another chemical e.g. vitamin c which precipitates considerably of the iodine. Ultraviolet light ensures that covalent bonds are formed on the D.N.A of pathogens and this renders them incapable of reproducing which in turn ensures that they’re far less of a hazard to the drinker. The downside of this strategy is that though it destroys the capacity of the pathogen to reproduce, they are still present within the water and this method has to be combined with other strategies for optimal outcomes. In solar water distillation, or purification utilizing a steripen opti pathogens are destroyed by the temperature and UVA radiation of the sun and thereby ensures the purity of the water.