Patent no: 398235
The patent 398235 discloses a method of obtaining adsorbents from barks of trees to be used in a filtration apparatus. The method includes drying the clean pieces of barks in sunlight to remove moisture from the clean pieces of barks to obtain dried pieces of barks. Treating the dried pieces of barks with a formaldehyde to release a colour of dried pieces of barks. Heating the treated pieces of barks in a muffle furnace in an absence of air for a particular period of time to obtain adsorbents.