Denitrification of Groundwater Using Biodegradable Plastic Poly-β-Hydroxybutyrate

Abstract

The addition of a hydrogen donor is essential for heterotrophic biological denitrification treatment. Experiments were conducted on the denitrification treatment of groundwater using biodegradable plastic poly-β-hydroxybutyrate (PHB) . Batch denitrification tests using denitrifying activated sludge and continuous treatment using a soil column were carried out. Results showed that denitrifying activity improved with time and that the surface of PHB pellets changed unevenly in the batch tests. The soil column with PHB could remove influent NO₃-N completely, but the soil column without PHB could not remove influent NO₃-N at all. Effluent TOC concentrations from the soil column, in which 342g of PHB pellets were buried, were high (max: 38mg-TOC/l), but effluent TOC concentrations from soil columns in which 171 and 86 of g-PHB pellets were low.