|Sikora, Lawrence - Compost Utilization And Systems|
|Casey, Francis - North Dakota State University|
Submitted to: Ecological Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2017
Publication Date: 2/1/2018
Publication URL: http://handle.nal.usda.gov/10113/5863781
Citation: Hakk, H., Sikora, L.S., Casey, F.X. 2018. Fate of estrone in laboratory-scale constructed wetlands. Ecological Engineering. 111:60-68. https://doi.org/10.1016/j.ecoleng.2017.11.005.
Interpretive Summary: Estrone is a steroid hormone eliminated by animals in urine and feces. As good stewards of surface waters livestock producers are interested in ensuring that very low levels of estrone are released into the environment after waste water treatment. Constructed wetlands are an environmentally friendly approach to cleaning wastewaters. To test the effectiveness of constructed wetlands at removing estrone, a laboratory scale wetland was built and estrone fate and transport was measured as swine lagoon waste passed through the system. Estrone was efficiently removed from the waste water by binding to vegetation and sediment, and by metabolism. Our findings demonstrated that estrone levels can be greatly reduced in animal waste waters by passage through a properly constructed wetland system.
Technical Abstract: A horizontal, subsurface, laboratory-scale constructed wetland (CW) consisting of four cells in series was used to determine the attenuation of the steroid hormone estrone (E1) present in animal wastewater. Liquid swine manure diluted 1:80 with farm pond water and dosed with [14C]E1 flowed through the series of cells containing floating vegetation (duckweed, family Lemnaceae) and a sand:gravel sediment layer. The aqueous layer within each cell was sampled across time, and at 168 h duckweed and sediment were sampled for E1 and/or its metabolites. Control and Blank systems consisted of single cells with no vegetation or no vegetation/sediment, respectively. Only 5% of the dose was detected in the effluent at 168 h. With the use of mass spectrometry and thin layer chromatography, it was determined that E1 was metabolized into estriol (E3) and to polar metabolites. The largest compartment for [14C] was duckweed (42.1% of administered dose) at 168 h followed by sediment (17.3%) and the liquid layer (15.1% of the dose). Most of the vegetative removal of E1 occurred in the first cell, and thereafter, sediment:liquid layer interactions governed E1 movement suggesting particle-bound transport on either colloids or dissolved organic matter. Horizontal, subsurface flow CW were able to remove approximately 95% of the influent E1, and demonstrated the importance of vegetative matter in removal of this potent steroid hormone.