Nitrate reduction using zero-valent iron and effect of corrosion inhibitor on reduction

---------------------------------------------------------------------***--------------------------------------------------------------------Abstract The objective of this work is to study reduction of nitrate concentration using zero-valent iron (ZVI) which has its application in permeable reactive barriers (PRBs). Also, to find out effect of concrete penetrating corrosion inhibiting admixture (CPCIA) EPCO-KP 200 on performance of ZVI in nitrate reduction. Experiments were carried out for a period of 60 days to find out optimum percentage of EPCO-KP 200 by measuring parameters like pH, conductivity, sulphate content and iron content of the solutions containing steel bars and different percentages of EPCO-KP 200. Best results were found with 1.6% and this percentage was chosen to carry out further batch experiments for nitrate reduction. Batch experiments were carried out to study nitrate reduction using synthetically prepared nitrate solution of 30mg/l and different dosages of ZVI. Best results were obtained with 0.5gm as it gave higher reduction in same time interval compared to 1gm and 0.25gm. Also, performance of corrosion inhibitor was found to be effective to increase the life span of ZVI as nitrate reduction with EPCO-KP 200 in presence of 0.5gm ZVI was found to be slow compared to reduction without EPCO-KP 200.