Onsite Remediation of Pharmaceuticals and Personal Care Products in Domestic Wastewater using Alternative Systems Including Constructed Wetlands
Pharmaceuticals, personal care products (PPCPs) and other trace organic contaminants (TOrCs) encompass a diverse group of chemicals that are not currently monitored or regulated in US drinking water or wastewater. Researchers have found low levels of TOrCs in aquatic and terrestrial environments all over the globe, and observed negative effects on impacted biota. The primary source of TOrCs in the environment is domestic wastewater discharges. Centralized wastewater treatment plants present greater risks on a global scale, but on a local scale, onsite treatment systems may have more potent impacts on resources that are invaluable to residents, including groundwater, surface waters, and soils.
The objective of this thesis is to identify and characterize promising treatment technologies for onsite TOrC remediation. Receptors who could be impacted by TOrC discharges are assessed, and applications that may require alternative treatment are identified. The best treatment technologies are recognized as those that protect sensitive environmental receptors, provide permanent removal pathways for as many TOrCs as possible, and are not prohibitively expensive to install or maintain. Findings from a pilot study show increased removal of conventional pollutants and TOrCs in an aerobic treatment unit (ATU), two types of biofilter, and a hybrid constructed wetland, all relative to septic tank effluent. The constructed wetland achieved the highest nutrient removals with TN concentrations below 10 mg/L throughout the study. A system with an ATU and peat biofilters achieved the highest removals of persistent pharmaceuticals carbamazepine and lamotrigine (>85% and >95%, respectively).