An integrated electrochemical-adsorption system for removal of nitrate from water

The purpose of this study was to investigate the performance of cotton seed fodder and amine grafted (AG) cotton seed fodder as an adsorbent to remove nitrate from water. In this study, the feasibility of an integrated EC-adsorption system to treat nitrate was explored. In the integrated EC-adsorption system, AG cotton seed fodder was kept in a stainless-steel box, which worked as an anode and Cu plate was used as cathode. The effect of time, adsorbent dose, pH, voltage and electrode distance on nitrate removal was examined. In integrated system, nitrate removal of 59.65 +/- 1.9 % was achieved at 180 min, using 2 g of adsorbent, maintaining pH 7, voltage 30 V and 1 cm electrode distance. The influence of other ions (SO42- and PO43-) on nitrate removal was also examined in integrated system. The nitrate removal efficiency of integrated system was found to be reduced in the presence of SO42- in the solution. Also, a small decrease in nitrate removal was observed with PO43- in integrated system. Using Ammonia mass balance, it was found that when adsorption process was employed within the EC system, the ammonia production due to nitrate reduction has been reduced. The nitrate removal by integrated system was almost equal to nitrate removal in EC and nitrate removal in adsorption processes.