Nutrient reduction design for sustainable municipal wastewater treat.

摘要

Wastewater treatment plants (WWTPs) were designed for the removal of pollutants during management of reclaimed water to protect and prevent impairment of water resources. Pollutants not eliminated from WWTP discharges could possibly cause damage to receiving streams and sources of drinking water.;Eutrophication has degraded water quality, with the primary factors established as nitrogen and phosphorus contamination in discharges to receiving streams from point and nonpoint sources. The United States Environmental Protection Agency (U.S. EPA), through regulations established under the Clean Water Act (CWA), has been compelled to determine nitrogen and phosphorus limits for inclusion in National Pollutant Discharge Elimination System (NPDES) permits. In anticipation of enforced limits, a study was conducted to determine requirements for and variables contributing to the removal of nitrogen and phosphorus at the Paragould Light, Water and Cable (PLWC) WWTP located in Paragould, Arkansas. Examination incorporated operational strategies, seasonal variations, sample type, nitrogen and phosphorus concentrations in the PLWC WWTP processes and collection system samples, and incorporation of outreach and educational activities to empower consumers of their role in the protection of water resources.;For the period of this study, primary factors positively influencing the removal of nitrogen include pH, temperature, and dissolved oxygen (DO), while variables attributed to phosphorus removal included MLSS age and pH. Based data collected during this research, the Paragould WWTP is capable of removing nitrogen and phosphorus, but not sufficiently to meet potential NPDES limits. Operational management strategy considerations for further removal of nitrogen and phosphorus from effluent at the PLWC WWTP include carbon supplementation, installation of variable frequency drives (VFDs) for controlling DO, implementation of biological nutrient removal technology, addition of precipitants, and utilization of filters.;A proactive approach for PLWC in reducing nitrogen and phosphorus from wastewater discharges is expected to involve public education and outreach to emphasize the customer's role to influence water quality. Providing the public with information regarding WWTP management, ecosystem values, and their role in nitrogen and phosphorus reduction would possibly promote stewardship toward the sustainability of water resources.