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Liu J.,San Jose Creek Water Quality Control Laboratory | Carr S.A.,San Jose Creek Water Quality Control Laboratory
Water Environment Research | Year: 2013

The adsorption capacities of 17β-estradiol (E2) onto two Y type zeolites (CBV-100 and CBV-901), a ZSM zeolite (CBV-28014), and a silicalite zeolite (HISIV-3000) in water were investigated. The CBV-901 extrudate, which has a lower ratio of silicon dioxide/aluminum oxide (SiO2/Al 2O3) than CBV-28014 and less surface area than CBV-100, had the highest adsorption affinity for 17β-estradiol. At an equilibrium concentration of 0.09 mg/L, the adsorption capacity of E2 by CBV-901 extrudate was 8.24 mg/g, whereas the E2 adsorption capacities of CBV- 28014, HISIV-3000, CBV-100 were all < 0.05 mg/g. CBV-901 had adsorption affinities for other estrogens such as estrone (E1) and estriol (E3). In a mixture of E1, E2, and E3, CBV-901 extrudate showed a greater affinity for E1 and E2 than for E3. The CBV-901 extrudate was also studied for the adsorption of E1, E2, EE2 (17β-ethynylestradiol), progesterone, 4-nonylphenol, and 4-tert-octylphenol in a spiked effluent. Results showed a promising prospect of CBV-901 for the removal of estrogenic compounds in aqueous solutions.


Carr S.A.,San Jose Creek Water Quality Control Laboratory | Liu J.,San Jose Creek Water Quality Control Laboratory | Tesoro A.G.,San Jose Creek Water Quality Control Laboratory
Water Research | Year: 2016

Municipal wastewater treatment plants (WWTPs) are frequently suspected as significant point sources or conduits of microplastics to the environment. To directly investigate these suspicions, effluent discharges from seven tertiary plants and one secondary plant in Southern California were studied. The study also looked at influent loads, particle size/type, conveyance, and removal at these wastewater treatment facilities. Over 0.189 million liters of effluent at each of the seven tertiary plants were filtered using an assembled stack of sieves with mesh sizes between 400 and 45 μm. Additionally, the surface of 28.4 million liters of final effluent at three tertiary plants was skimmed using a 125 μm filtering assembly. The results suggest that tertiary effluent is not a significant source of microplastics and that these plastic pollutants are effectively removed during the skimming and settling treatment processes. However, at a downstream secondary plant, an average of one micro-particle in every 1.14 thousand liters of final effluent was counted. The majority of microplastics identified in this study had a profile (color, shape, and size) similar to the blue polyethylene particles present in toothpaste formulations. Existing treatment processes were determined to be very effective for removal of microplastic contaminants entering typical municipal WWTPs. © 2016 Elsevier Ltd.


PubMed | San Jose Creek Water Quality Control Laboratory
Type: | Journal: Water research | Year: 2016

Municipal wastewater treatment plants (WWTPs) are frequently suspected as significant point sources or conduits of microplastics to the environment. To directly investigate these suspicions, effluent discharges from seven tertiary plants and one secondary plant in Southern California were studied. The study also looked at influent loads, particle size/type, conveyance, and removal at these wastewater treatment facilities. Over 0.189 million liters of effluent at each of the seven tertiary plants were filtered using an assembled stack of sieves with mesh sizes between 400 and 45m. Additionally, the surface of 28.4 million liters of final effluent at three tertiary plants was skimmed using a 125m filtering assembly. The results suggest that tertiary effluent is not a significant source of microplastics and that these plastic pollutants are effectively removed during the skimming and settling treatment processes. However, at a downstream secondary plant, an average of one micro-particle in every 1.14 thousand liters of final effluent was counted. The majority of microplastics identified in this study had a profile (color, shape, and size) similar to the blue polyethylene particles present in toothpaste formulations. Existing treatment processes were determined to be very effective for removal of microplastic contaminants entering typical municipal WWTPs.


PubMed | San Jose Creek Water Quality Control Laboratory
Type: Journal Article | Journal: Environmental toxicology and pharmacology | Year: 2011

Ozonation and chlorination of 17-estradiol (E2), 17-ethynylestradiol (EE2), bisphenol A (BPA), and nonylphenol (NP) were performed to evaluate the estrogenic activity of the by-products of these endocrine disrupting chemicals (EDCs). After 15min oxidation, samples were extracted using solid phase extraction (SPE) cartridges, and tested in vitro to measure the estrogenic activities of the oxidized products. MCF-7 cell proliferation assay showed that chlorinated BPA solution displayed slightly stronger estrogenicity than BPA, while chlorinated NP retained about one-tenth of its bioactivity. The estrogenic mono-, di-, tri-, and tetra-ClBPAs and di-ClNP were screened out from the corresponding chlorinated products by a combined application of estrogen receptor (ER) binding with ultrafiltration and identified by high performance liquid chromatography coupled with mass spectrometry (LC/MS). Ozonation of the above four estrogens and chlorination of E2 and EE2 significantly decreased their estrogenic activities under the applied conditions.

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