Abstract
Endocrine disrupting chemicals and pharmaceuticals represent two classes of emerging contaminants that are ubiquitously present in municipal wastewater effluents. Some of these contaminants have been shown to impact aquatic organisms at trace concentrations (i.e., ng/L). Moreover, the public has expressed human health concerns regarding the presence of emerging contaminants in water reuse projects. The primary objective of this investigation was to determine the efficacy of various membranes and activated carbons for the removal of endocrine disruptors, pharmaceuticals, and personal care products. A suite of structurally diverse target compounds was selected for evaluation based largely upon occurrence and molecular structure. Several membrane types and applications were evaluated at pilot- and/or full-scale, including: microfiltration, ultrafiltration, nanofiltration, reverse osmosis, electrodialysis reversal, membrane bioreactors, and combinations of membranes in series. Granular activated carbon was evaluated at bench-scale using rapid small scale column tests and at two full-scale utilities. Microfiltration and ultrafiltration were found to reject very few target compounds; however, some loss of steroidal type compounds was observed. Nanofiltration and reverse osmosis were capable of significant rejection of nearly all target compounds, though compounds were detectable at trace levels in permeates. Granular activated carbon was highly effective at removing all target chemicals. However, break-through curves clearly demonstrated that compounds with greater hydrophilicity breach activated carbon faster than hydrophobic compounds. In full-scale applications, the impact of regeneration was observed as activated carbon filters that received regular regeneration had minimal breakthrough of organic contaminants, while non-regenerated filters displayed no removal of target compounds. Findings confirm that membrane and carbon processes are capable of greatly reducing the concentrations of emerging contaminants; however, several compounds are detectable in membrane permeate and carbon effluent.
| Original language | English |
|---|---|
| Pages (from-to) | 156-181 |
| Number of pages | 26 |
| Journal | Desalination |
| Volume | 202 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - 5 Jan 2007 |
Bibliographical note
Funding Information:The authors would like to acknowledge the Water Quality Research and Development Division of the Southern Nevada Water Authority, particularly Brett Vanderford, Rebecca Trenholm, Janie Holady, Hongxia Lei, Linda Parker, Dave Rexing, and Ron Zegers. We would also like to thank the American Water Works Association Research Foundation for their generous support through AwwaRF project 2758 and for the relentless assistance from our project manager, Kim Linton. The bench-scale activated carbon RSSCT experiments, conducted at Penn State, were funded via an NSF-GOALI grant; while the analytical work for these was conducted at the Southern Nevada Water Authority under AwwaRF project 2758. The authors would also like to thank Dr. Paul Westhoff from Arizona State University who conducted the bench-scale PAC experiments and assisted in general on this project. We would like to also acknowledge Dr. Erin Snyder of Intertox, Inc., for her careful and thoughtful review of this manuscript. Montgomery Watson Harza designed and operated all membrane pilot skids with the exception of the saline groundwater RO pilot, which was operated by Black and Veatch (with special thanks to Rick Bond, Vasu Veerapaneni, and Willard Pack). The PAC pilot work was conducted at Louisville Water Company under the direction of Mark Campbell and Dr. Rengao Song. We would also like to thank Greg Oelker, Uzi Daniel, and Rich Nagel of West Basin Municipal Water District and Mike Wehner, JoAnn Daugherty, and Steve Fitzsimmons or Orange County Water District for their contributions and assistance to full-scale membrane testing. The authors also thank Jeff Vogt and Jack DeMarco of the Greater Cincinnati Water Works for their kind assistance in the testing of full-scale GAC. The team wishes to acknowledge Bill Pearce and Larry Wasserman from the City of San Diego and Larry Webb of the City of Rio Rancho for use of their staff and facilities in the performance of MBR/RO pilot systems.
Keywords
- Activated carbon
- Emerging contaminant
- Endocrine disruptor
- GAC
- Membrane
- Pharmaceutical
- Reuse
- Reverse osmosis
- Treatment
