▎ 摘　　要

NOVELTY - Removing scale and heavy metal ion in water involves dispersing carbon nano-tubes in the mixed acid solution and then heating at 60-80 degrees C for 1-3 hours. The solution is filtered, dried at 80-120 degrees C for 8-12 hours to obtain the purified carbon nano tubes. Natural graphite is added to 98% concentrated sulfuric acid and mechanically stirred until graphite is completely dissolved followed by the addition of sodium nitrate and potassium permanganate while maintaining the mixture at 0-10 degrees C with stirring for 2.5-4 hours. The mixture is placed in water bath at 25-35 degrees C. USE - Method for removing scale and heavy metal ion in water (claimed). ADVANTAGE - The method for removing scale and heavy metal ion in water is simple and cost effective. DETAILED DESCRIPTION - Removing scale and heavy metal ion in water involves dispersing carbon nano-tubes in the mixed acid solution and then heating at 60-80 degrees C for 1-3 hours. The solution is filtered, dried at 80-120 degrees C for 8-12 hours to obtain the purified carbon nano tubes. Natural graphite is added to 98% concentrated sulfuric acid and mechanically stirred until graphite is completely dissolved followed by the addition of sodium nitrate and potassium permanganate while maintaining the mixture at 0-10 degrees C with stirring for 2.5-4 hours. The mixture is placed in water bath at 25-35 degrees C followed by adding deionized water and then heating at 90-100 degrees C with stirring for 20-40 minutes. The mixture is diluted by adding 600-1000 ml of deionized water with stirring for 5-15 minutes followed by the addition of 30% hydrogen peroxide. The obtained solution is centrifuged at a rate of 8000-10000 revolutions/minute to obtain a solid substance which is dispersed in ethanol and dried for 12-24 hours to obtain graphene oxide. The purified carbon nano tube is added to graphene oxide. The mixture is ultrasonicated for 30-60 minutes and dried in vacuum for 8-12 hours to obtain graphene oxide/carbon nanotube composite material. Deionized water is added into the water circulating system followed by the addition of heavy metal ions, calcium ion and graphene oxide/carbon nano tube composite. The temperature, magnetic field intensity of the water circulating system is adjusted and the treatment is continued for 12 hours. After every two hours, 10 ml of water sample is detected for the presence of heavy metal ions and calcium ions.