Study on Adsorption of Cd2+ by Modified Bamboo Charcoal

Modified bamboo charcoal was made by immersion with Nitric acid and heating at high temperatures. This paper compared the adsorption properties before and after modified bamboo charcoal which were used to treat the Cd2+ solution. The influencing factors such as solution pH, adsorption time, charcoal dosage, initial Cd2+ concentration, temperature were investigated. The results show that modified bamboo charcoal made by immersion with Nitric acid and heating at high temperatures improves the adsorption efficiency. The equilibrium of adsorption capacity is 6.65mg/g. Adding 15 g modified bamboo charcoal in every 1L Cd2+ solution, the removing rate of Cd2+ is above 99% after adsorbed 60min under pH from 4 to 8. The adsorption Cd2+ process with modified bamboo charcoal accords with similar secondary dynamic model. Langmuir isotherm equation is more suitable than the Freundlich equation to describe the adsorption Cd2+ process with modified bamboo charcoal. The adsorption Cd2+ process is exothermic and physical adsorption.