Compare of Biochar and Vermicompost Sugarcane Bagasse Performance on Nitrate removal From Contaminated Water and Determine the Optimum Conditions for Adsorption Process

The presence of nitrate in water is one of the most important global concerns. Therefore use of cheap absorbents such as biochar and vermicompost is important as a solution environmental protection and management of crop residue. This study was conducted whit porpuse of compare of biochar and vermicompost sugarcane bagasse performance on nitrate removal from contaminated water and determines the optimum conditions for adsorption process. after providing of sugarcane bagasse biochar and vermicompost and determine of theirs characteristics, the effect of different parameter such as initial pH (2-11), dosage of adsorbent (1-10 g/L), solution temperature (10, 22 and 30 ° C), the presence of competing ions (phosphate, sulphate, carbonate and chloride) and contact time (0-180 min) was investigated on the efficiency of absorption. Then, different kinetic and isotherm models were fitted to the experimental data. The results of this study showed that the optimum pH of nitrate adsorption by sugarcane bagasse biochar and vermicompost was 4.64 and 3.78, respectively. Also optimum adsorbent dosage was obtained 2 gr/L. Among the competing anions, carbonate and chloride had the highest and the lowest impact on the reduction of nitrate removal and nitrate removal efficiency was increased as the temperature increases. According to kinetic experiment, equilibrium time for nitrate adsorption by biochar and was obtained 60 and 120 min, respectively. The higher removal of nitrate by biochar (73.7%) in compare to vermicompost (48%) was due to specific surface area, the amount of carbon and anionexchange capacity of sugarcane bagasse biochar is higher than vermicompost. The pseudo-second order adsorption kinetic model and Langmuir adsorption isotherm model showed the best fit to the experimental adsorption data.