Ting-Chien Chen

Stabilization of an elevated heavy metal contaminated site

Heavy metal contamination is a common problem that is encountered at many uncontrolled sites. Immobilization is seen as a promising technology for heavy metal remediation. Here, we report a remediation case study of an elevated and multi-metal contaminated site containing Cd, Cu, Ni, Pb, and Zn. In a laboratory test, when the soil was stabilized with reagent grade stabilizers (CaHPO(4) and CaCO(3)), the toxicity characteristic leaching procedure (TCLP) extractable concentrations of Cd, Cu, Pb, and Zn were reduced by more than 87%. The greatest reduction was shown with Pb (99.8%). In the field, Ca(H(2)PO(4))(2) due to lower cost and higher solubility replaced CaHPO(4). The TCLP results of the field treatment showed that the extractable concentrations of Cd, Cu, Pb, and Zn were significantly reduced after 30 days of stabilization. The reduction ratios were 98% (Cd), 97% (Cu), 99% (Pb), and 96% (Zn). Although, the reduction ratio of Ni was only 65%, the average extractable concentration was still less than 4.0mg/l. The percent reduction can, therefore, be considered reasonable. The significant reduction of extractable metal concentrations showed that the stabilizers, a combination of Ca(H(2)PO(4))(2) and CaCO(3), successfully immobilized heavy metals on the site.

Bisphenol A occurred in Kao-Pin River and its tributaries in Taiwan

Bisphenol A (BPA), one of the endocrine-disrupting chemicals, was detected in water collected from Kao-Pin River and its tributaries. Results indicated that 59% of the water samples contained BPA. Concentrations ranged from less than the limit of detection (LOD, 0.037) to 4.23xa0μg/L. The mean concentrations were 0.16, 0.20, 1.02, 1.30, and 0.30xa0μg/L for sampling sites S1, S2, S3, S4, and S5, respectively. Concentrations were not significantly different between high and low-flow periods in sites S2, S3, and S4. In site S1, concentrations in the high-flow period were significantly greater than during the lower flow period, and in site S5, BPA concentration in the low-flow period was significantly greater than in the high-flow period. The BPA mass flow rate in site S5 was greater in the high-flow period than in the low-flow period.

Total estrogenic activity and nonylphenol concentration in the Donggang River, Taiwan

We report a survey on the occurrence and distribution of nonylphenol (NP) and 17β-estradiol equivalent quotient (EEQ) concentrations in Donggang River, Taiwan. Concentrations of NP were measured with a high-performance liquid chromatography/fluorescent system and EEQs were carried with an MVLN cell line. Concentrations of NP ranged from less than 93 to 511xa0ng/L; EEQs ranged from less than 0.16 to 8.64xa0ng-E2/L. Concentrations of NP were higher in the dry season than in the wet season, which was affected by a high flow rate. In the main watercourse, higher EEQ occurred in the wet season than in the dry season; rainfall may have flushed substances containing estrogenic activity. NP and EEQ concentrations occurred in seawater only in the dry season, especially high EEQ values, and were not detected in the wet season. The reasons are not clear at this moment. Furthermore, NP concentrations provided low contribution to the total estrogenic activity.

Tributyltin distribution and producing androgenic activity in water, sediment, and fish muscle.

This study investigated the concentrations of Tributyltin (TBT) in water, sediment, and fish muscle samples taken from Kaohsiung Harbor and Kaoping River estuary, Taiwan. TBT concentrations in water and sediment samples ranged from less than 18.5 to 34.1 ng Sn L−1 and from 2.44 to 29.7 ng Sn g−1 weight per weight (w/w), respectively. Concentrations in the TBT‐contaminated fish muscle samples ranged from 10.8 to 79.6 ng Sn g−1 w/w. The TBT concentrations in fish muscle were higher than those in water and sediment samples. The fish muscle/water TBT bioconcentration factor (BCF) ranged from 590 to 3363 L kg−1. Additionally, the water samples were assessed for androgenic activity with an MCF7‐AR1 human breast cancer cell line. The androgenic activity ranged from 0.94 to 3.1 ng‐dihydrotestosterone per litre water (ng‐DHT L−1). Higher concentrations of TBT in water and sediment samples occurred in the dry season, but the androgenic activity had higher values in the rainy season.

Estrogen degradation and sorption onto colloids in a constructed wetland with different hydraulic retention times

Endocrine disrupting compounds are a global concern, owing to their interference with the endocrine system of wildlife. In particular, natural estrogens at concentrations as low as ng/L level can interrupt the endocrine system of many organisms. A constructed wetland is an effective means of removing the residual levels of estrogen. This study investigates the estrogen degradation and sorption on colloids in a constructed wetland at hydraulic retention times (HRTs) of 27.5, 45.9, and 137.5h. Three natural estrogens (i.e. estrone (E1), 17β-estradiol (E2), and estriol (E3)) are analyzed with liquid chromatography/tandem mass spectrometry. At HRT=27.5h, no degradation occurs; at HRT=45.9h, the degradation rates are 0-46.2%; and at HRT=137.5h, the degradation rates are 40-84.3%. Additionally, estrogen sorption coefficients (logKCOC values) range from 3.37 to 4.89. Average logKCOC values are 4.08±0.33, 4.04±0.34, and 4.11±0.28 for E1, E2, and E3, respectively. At different HRTs, values of logKCOC increase with an increasing HRT. Analytical results indicate that constructed wetlands can remove residual natural estrogens. With an increasing HRT, the estrogen degradation rate increases as well as the estrogen sorption on colloids.

Variation, correlation, and toxicity of phenolic endocrine-disrupting compounds in surface water.

This study investigated the variation in toxicity of phenolic endocrine-disrupting compounds (EDCs) and determined the correlation between their concentrations. All twenty-four samples acquired from a polluted river contained five phenolic EDCs. The EDC nonylphenol (NP) concentration was found to be the highest (4.26 ± 2.74 μg/L) in the river water. In addition the concentrations of nonylphenol diethoxylate, (NP2EO), octylphenol (OP), nonylphenol monoethoxylate (NP1EO), and bisphenol A (BPA) were 1.58 ± 1.37 μg/L; 2.90 ± 2.77 μg/L; 2.89 ± 2.15 μg/L; and 2.25 ± 0.96 μg/L, respectively. Concentrations of NP, NP1EO, and OP were significantly greater in the daytime than in the nighttime samples. Furthermore, concentrations of NP, NP1EO, and NP2EO showed a strong correlation due to similar parent compounds while BPA and OP did not. NP1EO had the highest risk to aquatic organisms (hazard quotient, HQ = 26.3) and BPA the lowest (HQ = 2.24).The accumulative HQ sum (hazard index, HI) was 81.3 within all the samples. The HI was 110.3 in the daytime samples. This was 97% higher than in the nighttime HI (56.3), which suggested daytime anthropogenic discharges were an important source of toxicity to aquatic organisms.

Nonylphenol concentration and estrogenic activity in Kaoping River and its tributaries, Taiwan.

This study investigated the occurrence of nonylphenol (NP) and 17beta-estradiol equivalent quotient (EEQ) concentrations in Kaoping River and two of its tributaries in Taiwan. During this study 44 water samples were collected from four sampling campaigns. Concentrations of NP in these samples ranged from 0.19 to 183.4 mug/L; EEQ ranged from less than limit of detection (1.41) to 32.2 ng-E2/L. NP concentrations in the main watercourse ranged from 0.19 to 9.21 mug/L; EEQ ranged from less than limit of detection to 2.13 ng-E2/L. These values are comparable to most rivers worldwide. The Wulo Creek tributary was polluted by animal waste discharges and the NP concentrations ranged from 0.72 to 6.8 mug/L. The EEQ ranged from 3.86 to 32.2 ng-E2/L. The Niouchou Creek tributary was polluted with domestic wastewater. Concentrations of NP ranged from 8.79 to 183.4 mug/L and EEQ ranged from 2.94 to 27.8 ng-E2/L. These data suggest that both inadequately treated livestock and human wastewater can cause high NP and EEQ concentrations.

Use of fluorescence quenching method to measure sorption constants of phenolic xenoestrogens onto humic fractions from sediment.

Humic substance (HS) in sediment can affect hydrophobic organic compound distribution, transportation, bioavailability, and toxicity. This study investigated the HS (BKHS) extracted from sediment and separated it into low molecular humic (LMHS, <1kDa) and high molecular humic substances (HMHS, 1kDa-0.45μm). Nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA) have a significant sorption capacity for HMHS and BKHS solutions. They are xenoestrogenic endocrine-disrupting compounds that are widely produced and discharged to the environment. The log KHS values of the BKHS and HMHS solutions were between 4.74-5.09Lkg-C(-1) and 4.57-5.09Lkg-C(-1), respectively. However, the three compounds were not sorbed by the LMHS solution. The average values of SUVA254 for HMHS and LMHS were 4.29 and 1.31Lm(-1)mg-C(-1) and the average values of A250-400 for HMHS and LMHS were 18.1 and 4.51nmcm(-1), respectively. The HMHS peak position in the fluorescence excitation/emission matrix at longer wavelengths corresponded to the peak position of LMHS, which indicates that the HMHS had a higher degree of humification than the LMHS. The results suggested that the KHS values dominant factor was the degree of HS humification.

Combination of a fast cleanup procedure and a DR-CALUX® bioassay for dioxin surveillance in Taiwanese soils

Our goal was to determine dioxin levels in 800 soil samples collected from Taiwan. An in vitro DR-CALUX® assay was carried out with the help of an automated Soxhlet system and fast cleanup column. The mean dioxin level of 800 soil samples was 36.0 pg-bioanalytical equivalents (BEQs)/g dry weight (d.w.). Soil dioxin-BEQs were higher in northern Taiwan (61.8 pg-BEQ/g d.w.) than in central, southern, and eastern Taiwan (22.2, 24.9, and 7.80 pg-BEQ/g d.w., respectively). Analysis of multiple linear regression models identified four major predictors of dioxin-BEQs including soil sampling location (β = 0.097, p < 0.001), land use (β = 0.065, p < 0.001), soil brightness (β = 0.170, p < 0.001), and soil moisture (β = 0.051, p = 0.020), with adjusted R2 = 0.947 (p < 0.001) (n = 662). An univariate logistic regression analysis with the cut-off point of 33.4 pg-BEQ/g d.w. showed significant odds ratios (ORs) for soil sampling location (OR = 2.43, p < 0.001), land use (OR = 1.47, p < 0.001), and soil brightness (OR = 2.83, p = 0.009). In conclusion, four variables, including soil sampling location, land use, soil brightness, and soil moisture, may be related to soil-dioxin contamination. Soil samples collected in northern Taiwan, and especially in Bade City, soils near industrial areas, and soils with darker color may contain higher dioxin-BEQ levels.

Identification, contribution, and estrogenic activity of potential EDCs in a river receiving concentrated livestock effluent in Southern Taiwan

We assessed 22 selected endocrine-disrupting compounds (EDCs) and other emerging, potentially endocrine-active compounds with estrogenic activity from the waters of the Wuluo River, southern Taiwan. This watershed receives high amounts of livestock and untreated household wastewaters. The river is surrounded by concentrated animal feedlot operations (CAFOs). River water samples were analyzed for selected compounds by liquid chromatography-tandem mass spectrometry (LC-MS/MS), T47D-KBluc reporter gene assay, and E-screen cell proliferation in vitro bioassay. Total concentrations of ∑alkylphenolic compounds (bisphenol A, 4-nonylphenol, t-nonylphenol, octylphenol, nonylphenol mono-ethoxylate, nonylphenol di-ethoxylate) were much higher than ∑estrogens (estrone, 17 β-estradiol, estriol, 17ß-ethynylestradiol, diethylstilbestrol), ∑preservatives (methyl paraben, ethyl paraben, propyl paraben, butyl paraben), ∑UV-filters (benzophenone, methyl benzylidene camphor, benzophenone-3), ∑antimicrobials (triclocarben, triclosan, chloroxylenol), and an insect repellent (diethyltoluamide) over four seasonal sampling periods. The highest concentration was found for bisphenol A with a mean of 302u202fng/L. However, its contribution to estrogenic activity was not significant due to its relatively low estrogenic potency. Lower detection rates were found for BP, EE2, TCS, and PCMX, while DES and EP were not detected. E1 and E2 levels in raw water samples were 50% higher than the predicted no-effect concentrations (PNEC) for aquatic organisms of 6 and 2u202fng/L, respectively. The potency of estrogenic activity ranged from 11.7 to 190.1u202fng/L E2T47D-Kbluc and 6.63 to 84.5u202fng/L E2E-Screen for extracted samples. Importantly, estrone contributed 50% of the overall activity in 60% and 44% of the samples based on T47D-KBluc and MCF-7 bioassays, followed by 17 ß-estradiol, highlighting the importance of total steroid estrogen loading. This study demonstrates that the estrogenic activity of target chemicals was comparable to levels found in different countries worldwide. More intense wastewater treatment is required in areas of intensive agriculture in order to prevent adverse impacts on the ambient environment and aquatic ecosystems.