CONVERTING CONVENTIONAL FILTERS FOR DENITRIFICATION AT THE NEUSE RIVER WASTEWATER TREATMENT PLANT

摘要

The City of Raleigh's Neuse River Wastewater Treatment Plant is a 60 mgd advanced treatmentrnfacility that consistently meets stringent NPDES permit limits. In response to water qualityrnproblems in the summer of 1995 in the Lower Neuse River, the City of Raleigh and Hazen andrnSawyer conducted a denitrification filter pilot study at the plant in 1996 and 1997 using one ofrnthe existing effluent filters as a denitrification filter by adding methanol to the filter influent.rnThe results of the pilot study indicated that reduction of total nitrogen is possible by addingrnmethanol to an existing dual media effluent filter.rnDue to the positive results achieved in the pilot study, the City of Raleigh proceeded withrnmodifications to their existing effluent filters to provide denitrification. Construction wasrncompleted in late 2000. The project cost approximately $4 million and included replacing dualrnmedia with monomedia, increasing media depth from 2.5 feet to 4 feet, and reprogramming thernfilter PLCs to automatically perform nitrogen release cycles. The filter upgrade at the NeusernRiver WWTP has resulted in reduced total nitrogen in the plant’s effluent.