THE POSSIBILITY OF AN IN-SITU DENITRIFICATION USING ORGANIC POLYMER GEL AS AN ELECTRON DONOR

Abstract

 Nitrate contamination of groundwater has been recognized as an important public health issue. In this study, hydroxypropylcellulose (HPC) gel was used as an external electron donor in the in-situ biological denitrification process. In the continuous experiments using the bench-scale model aquifer, total nitrogen (TN) concentration in the groundwater was decreased along the flow direction. Although the denitirification efficiency in the model aquifer was low at around 15%, the problems such as clogging of the sand stratum and generation of nasty smell gas were not recognized through the experiment. From the results of the gene analysis, it was considered that the decrease in TN concentration in the model aquifer was due to reduction of nitrate to molecular nitrogen by denitrifying bacteria. These results showed that HPC gel could be utilized as the external electron donor in the in-situ denitrification.