Denitrification of drinking water using saccharum spontaneum L. as a natural organic solid substrate

Abstract

There is a global concern regarding the increasing pollution of naturalwater bodies by nitrate as a resultof anthropogenic activities. To address this situation, natural organic solid substrates (NOSS) have beeninvestigated as carbon sources in denitrification. Despite advances in this field, a lack of knowledgeabout the kinetics involved in the denitrification processes using NOSS still exists. For this reason, wehave studied denitrification using Saccharum spontaneum L. (S. spontaneum) as NOSS to betterunderstand these kinetic processes. This paper presents experimental results obtained for the releaseof organic carbon from S. spontaneum, and for its use by denitrifying bacteria. Laboratory tests weredeveloped under anoxic conditions in batch reactors. Our results showed that the kinetics of release oforganic carbon from the S. spontaneum was first order (0.08 d1). Furthermore, the maximum rate ofutilization of substrate (5.61 mg N-NO3 mgVSS1 day1) and the denitrification rate (327 mg N-NO3L1d1) were high (VSS ¼ volatile suspended solids). We demonstrated that it is possible to obtain highyields of denitrification using organic carbon released from S. spontaneum. This study improves theknowledge on the use of NOSS, as alternative sources of carbon for denitrification.