Monitoring Estrogen Compounds in Wastewater Recycling Systems Deborah M. Kvanli & Sreelatha Marisetty & Todd A. Anderson & W. Andrew Jackson & Audra N. Morse Received: 15 May 2007 / Accepted: 13 August 2007 / Published online: 21 November 2007 # Springer Science + Business Media B.V. 2007 Abstract The presence of pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) in treated wastewater is gaining attention due to their potential environ- mental impact. An analytical method was developed to quantify estrogen compounds in samples from a concentrated wastewater matrix typical of water recycling systems used in space. The method employed conventional HPLC with UV detection. Solid phase extraction (SPE) was used to isolate the compounds of interest from wastewater. Spike- recovery tests in clean and wastewater matrices were used to test the extraction process. The results of these experiments suggest that deconjugation is the most predominant reaction occurring in the systems, as effluent concentrations of free estrogens typically exceeded influent concentrations. Despite the long retention times of the system or the near infinite solids retention time, free estrogens were not removed from graywater representative of space waste streams. For a closed-loop wastewater treatment system, these compounds may accumulate to levels requiring other removal mechanisms (i.e., reverse osmosis). Keywords Estradiol . Estrone . 17β-estradiol . 17α-ethynylestradiol . Graywater . Water reuse 1 Introduction Micropollutants are compounds present in μg/l (ppb) quantities in environmental or waste samples. The term is currently applied to pharmaceuticals (antibiotics, endocrine-disrupting compounds (EDCs), etc.) and other personal care products (PCPs) that may have environmental consequences. Although some PPCPs have been identified in the environment for several decades, the fate and persistence of these compounds are not well understood. PPCPs are of interest due to their wide occurrence in the aquatic environment and potential hazard to aquatic organisms. The release of these chemicals into the environment is primarily attributed to their incomplete removal by waste treatment systems (Gomes et al. 2005). For example, EDCs such as natural and synthetic estrogens are of potential concern because of their endocrine activity at low concentrations. A majority of these estrogens are excreted in urine as conjugates, which are biologically inactive (Belfroid et al. 1999; Water Air Soil Pollut (2008) 188:31–40 DOI 10.1007/s11270-007-9498-6 DO09498; No of Pages D. M. Kvanli : T. A. Anderson Department of Environmental Toxicology, Texas Tech University, Lubbock, TX 79409, USA S. Marisetty : W. A. Jackson : A. N. Morse (*) Department of Civil and Environmental Engineering, Texas Tech University, Box 41023, Lubbock, TX 79409-1023, USA e-mail: audra.n.morse@ttu.edu