Behavior of Estrogens and Triclosan in Turf Grass Amended with Biosolids or Irrigated with Reclaimed Water
Abstract:Recent concerns about the fate of microconstituents in municipal biosolids and reclaimed water have led to a demand for region specific data. King County, Washington has a successful land application program for Class B biosolids. Biosolids are applied to agricultural lands and commercial forest plantations. The County is also developing a program for beneficial use of reclaimed water, targeted at golf courses, municipal parks and landscaping and truck farms. As part of an effort to demonstrate the utility and benefits associated with the use of reclaimed water and the continued safety of beneficial use of biosolids, the County has supported research at the University of Washington on the fate of two microconstituents, estrogen (including estriol (E1), 17β-estradiol (E2) and ethinylestradiol (EE2)) and the anti microbial triclosan (TCS), in reclaimed water and biosolids amended turf grass.
Turf grass used for this study was collected from the Foster Links golf course in Tukwila. Foster Links, which is slated to be one of the first customers for Class A sand filter water as part of the reclaimed water program. Squares of turf, including approximately 5 cm of soil and roots, were potted on top of sand and then assigned one of four treatments. Treatments varied by water source and fertilizer application and included one conventional fertilizer treatment, 3 reclaimed water and fertilizer treatments and a biosolids treatment. Biosolids were added at a rate equivalent to 7.3 Mt ha-1. Over the course of the study, each pot received 2.75 l of reclaimed water. The experiment was a randomized complete block design with 4 replicates and ran for 6 months. Both biosolids and reclaimed water were analyzed for the estrogens and triclosan. Quantities of water used per pot were measured. Approximately every other week, soils were watered in excess (500 ml per pot) and leachate was collected and analyzed for each of the three estrogens and triclosan. A mass balance was done at the end of the trial to calculate total addition of each form of estrogen and triclosan in both the biosolids and reclaimed water treatments. Soil and above ground plant tissue were analyzed for estrogens and soil was analyzed for triclosan.
Sample analysis was done at the King County Environmental Laboratory. Leachate samples for each treatment were combined across for each sampling period. A deuterated internal standard containing all three estrogens was added to each sample immediately prior to analysis to determine recoveries. For triclosan analysis, water samples were spiked with deuterated NP, an EDC surrogate (2,3,5,6,d4 nonylphenol), and 100 μL of [13C] TCS to determine recoveries of each compound. Samples were analyzed with a gas chromatograph mass spectrometer. Each sample run included a method blank, spike blank and laboratory duplicate. The method blank and spike blank contained a known amount of deuterated E1, E2 and EE2 carbon labeled surrogate and 13C-Triclosan. Total concentrations of each compound and total rate of addition per pot is shown below.
|Estriol (E1)||17β-estradiol (E2)||Ethinylestradiol (EE2)||Triclosan|
|Water Conc. (ug L-1)||0.068 +/− 0.049||0.019 +/− 0.0065||0.021 +/− 0.011||1.23 +/− 0.5|
|Biosolids Conc. (ug kg-1)||152+/− 2||10.6+/−0.3||4.8+/−0.3||34973 +/− 1240|
The concentrations of the three estrogens varied significantly in the reclaimed water over time. For E1, concentrations ranged from 0.01 to 0.27 μg l-1. For this study, the method detection limit (MDL) for water samples was 0.0012 μg L-1. Variation for E2 and EE2 was less pronounced, with concentrations ranging from below detection limit to 0.035 μg l-1 . The MDL for E2 and EE2 in water was 0.002 μg L-1. Triclosan concentrations in reclaimed water averaged 1.23 ± 0.5μg l-1. In the biosolids, the concentration of E1 was 152 ± 2 μg kg-1, E2 was 10.6±0.3 μg kg-1, EE2 was 4.8 ± 0.3 μg kg-1., and triclosan was 35±1.2 mg kg-1. Estrogen (E1 and E2) was detected in the leachate samples from the reclaimed water treated pots in some, but not all, of the sampling intervals, and concentrations were typically ten fold smaller than in the reclaimed water. For all sampling intervals, EE2 was not detected in the leachate samples. In the biosolids amended soils, there was no detectable movement of any of the estrogens for all sampling intervals. Spike recoveries for the leachate for the biosolids amended soils ranged from approximately 75% to 125%. Concentrations of TCS were below detection in all leachates (reclaimed water and biosolids treatments), with spike recoveries in the leachate averaging 112%.
At the end of the trial, the total concentration of each compound was measured in the soils. In the reclaimed water treatments, all estrogens and TCS were below detection limits in soils. The soil detection limit for TCS was 33μg kg-1. Estrogen was also below the detection limit for soils in the biosolids treatment (0.03 μg kg-1). No estrogens were detected in leaf tissue for any treatment. In addition, the final concentration of TCS in the top 4 cm of the soil (39 ± 13 μg kg-1) was close to the soil detection limit. In the biosolids treatments, dried and ground biosolids were added to the surface of the turf grass. Turf grass was cut several times during the study, but leaf tissue was not analyzed for any compounds until the final harvest and total plant removal of chemicals was not quantified. Thus, our results for soil concentrations of estrogens and TCS cannot be interpreted as proof of degradation of the added compounds. However, the collective data suggest minimal negative impacts of estrogen and triclosan addition via land applied reclaimed water or biosolids on soil or water quality.
Document Type: Research Article
Publication date: January 1, 2009
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