Kinetics and Isotherm of Nitrate Sorption from Aqueous Solution Using Biochar

Nitrate contamination of water resources is becoming a serious environmental problem worldwide. Application of natural materials to remove nitrate can be considered as the most valuable solution. This study aims to investigate the use of date palm fiber in the production of adsorbent material. Palm fibers were burned at temperatures of 450, 600 and 750 °C in a limited supply of oxygen condition. The produced biochar at temperature of 600 °C was chosen due to its high ability in removal of the nitrate from aqueous solution. Biochar made from these fibers washed with hydrochloric acid 0.5 N and then with distilled water to increase performance. The FTIR method was used to investigate groups of the adsorbent. Additional studies were performed to measure the effects of pH, adsorbent dose, time and temperature on nitrate sorption. The optimal conditions for removal of nitrate were found to be: 0.5 g of adsorbent in 20 ml solution, temperature of 10 °C, 30 min and neutral pH. Under these conditions, the nitrate removal efficiency was over 96 . The adsorption data were explained using the Langmuir and Temkin adsorption isotherms. Kinetic studies showed that the pseudo-second order was the best fitted model to the sorption data.