Water Resources Research Act Program

Details for Project ID 2007AZ221B

Modification of conventional wastewater treatment processes for estrogen removal

Institute: Arizona
Year Established: 2007 Start Date: 2007-03-01 End Date: 2008-02-28
Total Federal Funds: $11,454 Total Non-Federal Funds: $28,449

Principal Investigators: David Quanrud, Robert Arnold, Martin Karpiscak

Project Summary: Meeting regional water demands without long-term reliance on groundwater mining will depend on wastewater renovation and reuse. By 2025, it will be necessary to reclaim and reuse approximately 100,000 AFY of wastewater in the Tucson Active Management Area. Acceptable uses and use-dependent treatment requirements remain to be established. That is, growth cannot be sustained without considering water resources of lower water quality. Municipal wastewater is the only resource of that kind that is present in abundance in every high-growth region including Tucson or, if magnified, the Tucson/Phoenix corridor. Observations during the last decade or so related to residual trace organics in conventionally treated wastewater suggest that advanced treatments are requisite to the kinds of reuse applications that are now being considered. Among the myriad trace organic contaminants in wastewater effluent, hormones and hormone mimics may be of greatest concern to human and environmental health. Estrogen and estrogen mimics are among the most relevant sources of concern in waters destined for reuse. Recent measurements suggest that Arizona wastewater treatment plants differ remarkably in terms of estrogen removal efficiencies (see below). It seems likely that the type and operating efficiency of biological treatment provided during wastewater treatment are strong determinants of residual estrogen levels in effluent. Understanding the basis of process-dependent differences will set the stage for process design or operation for efficient removal of estrogens and estrogen mimics. The Tucson area is in the midst of planning efforts that will lead to selection of a water plan and wastewater treatment facilities that will serve the region for decades. Wastewater reclamation and reuse will be a major part of both water supply and wastewater treatment planning. The fate of trace organics during wastewater treatment or, from another perspective, facilities design/operation for control of trace organics should be an important factor in facilities planning. The project is designed to provide data in that critical area. The project is a full-scale investigation of wastewater treatment processes that are likely to reduce significantly the activities of estrogenic and androgenic compounds in wastewater. The processes of interest are (i) membrane biological treatment and (ii) activated sludge treatment. Both will be studied under nitrifying conditions that are likely to produce biochemical transformations of aromatic trace contaminants such as those that contribute to estrogenic and androgenic activities. In Phase I, we will measure the attenuations of specific trace contaminants and estrogenic activity at the Randolph Park Wastewater Treatment Plant and the Ina Road Pollution Control Facility. During Phase II of the project, we will attempt to produce a profile of nonylphenol concentration and total estrogenic activity through the Randolph Park facility. Sampling points along the process train will be selected to establish the relative contributions of anaerobic and aerobic biochemical treatment, physical adsorption to biosolids, recycle and disinfection to overall removal of p-nonylphenol and estrogenic activity. The hydrophobic nature of most estrogenic compounds suggests that some or all will partition strongly with organic-rich solids. Thus, solid-phase extraction and measurement of estrogenic activity in the resultant extracts are critical to achievement of meaningful balances for the study parameters. It is emphasized, however, that all procedures to be used in the proposed study were previously developed or adapted for use in the University of Arizona environmental engineering laboratory.