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Relationship between ²¹⁰Pbₑₓ activity and sedimentary organic carbon in sediments of 3 Chinese lakes Full text
2011
Xu, Libin | Wu, Fengchang | Wan, Guojiang | Liao, Haiqing | Zhao, Xiaoli | Xing, Baoshan
This report demonstrates that organic matter was an important factor in lake sediment ²¹⁰Pbₑₓ dating. Sediment cores from lakes in central and western China with different-trophic levels were collected, and the ²¹⁰Pbₑₓ activity and total organic carbon (TOC) were measured. The Rock-Eval pyrolysis technique was used to deconvolute TOC into free hydrocarbons (S1), thermally less-stable macromolecular organic matter (S2a), kerogen (S2b), and residual carbon (RC). The results show significant correlations between TOC and ²¹⁰Pbₑₓ, particularly between S2a and ²¹⁰Pbₑₓ, in all the sediment cores. This indicated that the algal-derived organic component S2a may play the most important role in controlling the distribution of ²¹⁰Pbₑₓ. Scavenging by algal-derived organic matter may be the main mechanism. As chronology is the key to the understanding of pollution reconstruction and early diagenesis in sediments, more attention should be paid to the influence of organic matter on ²¹⁰Pbₑₓ.
Show more [+] Less [-]Assessing the diurnal variability of pharmaceutical and personal care products in a full-scale activated sludge plant Full text
2011
Salgado, R. | Marques, R. | Noronha, J.P. | Mexia, J.T. | Carvalho, G. | Oehmen, A. | Reis, M.A.M.
An intensive sampling campaign has been carried out in a municipal wastewater treatment plant (WWTP) to assess the dynamics of the influent pharmaceutical active compounds (PhAC) and musks. The mass loadings of these compounds in wastewater influents displayed contrasting diurnal variations depending on the compound. The musks and some groups of PhACs tended to follow a similar diurnal trend as compared to macropollutants, while the majority of PhACs followed either the opposite trend or no repeatable trend. The total musk loading to the WWTP was 0.74±0.25gd⁻¹, whereas the total PhAC mass loading was 84.7±63.8gd⁻¹. Unlike the PhACs, the musks displayed a high repeatability from one sampling day to the next. The range of PhAC loadings in the influent to WWTPs can vary several orders of magnitude from one day or week to the next, representing a challenge in obtaining data for steady-state modelling purposes.
Show more [+] Less [-]Mobile passive samplers: Concept for a novel mode of exposure Full text
2011
Allan, Ian J. | Nilsson, Hans C. | Tjensvoll, Ingrid | Bradshaw, Clare | Næs, Kristoffer
Integrative passive sampling with devices such as semipermeable membrane devices generally relies on rigs for month-long static exposures in water. We evaluate here whether mobile exposures of passive samplers can provide reliable estimates of dissolved contaminant concentrations. Mobile exposures were obtained by towing samplers fastened to the end of a benthic trawl net. Significant and reproducible absorption of polycyclic aromatic hydrocarbons during 5 h-long deployments was made possible by high sampling rates resulting from high water turbulences during towing at 1.2–1.5 knots. Sampling rates (72–215 L d⁻¹) estimated from the dissipation of performance reference compounds were supported by in situ calibration with samplers exposed for a 30 days in the vicinity of the test site. Higher fluoranthene and pyrene absorption in samplers exposed to the trawling-induced sediment plume could be attributed to desorption from re-suspended sediments. This mode of exposure has the potential to be used in monitoring programmes.
Show more [+] Less [-]The effect of mercury on trees and their mycorrhizal fungi Full text
2011
Jean-Philippe, Sharon R. | Franklin, Jennifer A. | Buckley, David S. | Hughes, Karen
The Oak Ridge Reservation, established in 1942, was the designated site for the construction of the atomic bomb. During a 20-year period from 1944 to 1963 radioactive and toxic chemical pollutants, especially mercury compounds were released into the surrounding waterways. Tree diversity and mycorrhizal presence and abundance were analyzed in the mercury-contaminated floodplains of East Fork Poplar Creek Oak Ridge (EFPC) (Tennessee). A subsequent greenhouse study was conducted to assess the phytotoxic effects of different mercuric solutions on Platanus occidentalis (American Sycamore), inoculated with soils from EFPC. Total soil mercury in the field had no effect on tree diversity. Organic species of mercury proved to be more toxic than inorganic species of mercury and soil inoculants from EFPC had no protective effects against Hg toxicity in our greenhouse study. Comparison of the effects of mercury contamination in our field and greenhouse studies was difficult due to uncontrolled factors.
Show more [+] Less [-]Uranium bioaccumulation and biological disorders induced in zebrafish (Danio rerio) after a depleted uranium waterborne exposure Full text
2011
Barillet, Sabrina | Adam-Guillermin, Christelle | Palluel, Olivier | Porcher, Jean-Marc | Devaux, Alain
Because of its toxicity and its ubiquity within aquatic compartments, uranium (U) represents a significant hazard to aquatic species such as fish. In a previous study, we investigated some biological responses in zebrafish either exposed to depleted or to enriched U (i.e., to different radiological activities). However, results required further experiments to better understand biological responses. Moreover, we failed to clearly demonstrate a significant relationship between biological effects and U radiological activity. We therefore chose to herein examine U bioaccumulation and induced effects in zebrafish according to a chemical dose–response approach. Results showed that U is highly bioconcentrated in fish, according to a time- and concentration-dependent model. Additionally, hepatic antioxidant defenses, red blood cells DNA integrity and brain acetylcholinesterase activity were found to be significantly altered. Generally, the higher the U concentration, the sooner and/or the greater the effect, suggesting a close relationship between accumulation and effect.
Show more [+] Less [-]Assessing the recovery potential of alpine moss–sedge heath: Reciprocal transplants along a nitrogen deposition gradient Full text
2011
Armitage, Heather F. | Britton, Andrea J. | Woodin, Sarah J. | Wal, René van der
The potential of alpine moss–sedge heath to recover from elevated nitrogen (N) deposition was assessed by transplanting Racomitrium lanuginosum shoots and vegetation turfs between 10 elevated N deposition sites (8.2–32.9 kg ha⁻¹ yr⁻¹) and a low N deposition site, Ben Wyvis (7.2 kg ha⁻¹ yr⁻¹). After two years, tissue N of Racomitrium shoots transplanted from higher N sites to Ben Wyvis only partially equilibrated to reduced N deposition whereas reciprocal transplants almost matched the tissue N of indigenous moss. Unexpectedly, moss shoot growth was stimulated at higher N deposition sites. However, moss depth and biomass increased in turfs transplanted to Ben Wyvis, apparently due to slower shoot turnover (suggested to result partly from decreased tissue C:N slowing decomposition), whilst abundance of vascular species declined. Racomitrium heath has the potential to recover from the impacts of N deposition; however, this is constrained by the persistence of enhanced moss tissue N contents.
Show more [+] Less [-]A rapid and high-throughput quantum dots bioassay for monitoring of perfluorooctane sulfonate in environmental water samples Full text
2011
Zhang, Jiong | Wan, Yanjian | Li, Yuanyuan | Zhang, Qiongfang | Xu, Shunqing | Zhu, Huijun | Shu, Baihua
Currently HPLC/MS is the state of the art tool for environmental/drinking water perfluorooctane sulfonate (PFOS) monitoring. PFOS can bind to peroxisomal proliferator-activated receptor-alpha (PPARα), which forms heterodimers with retinoid X receptors (RXRs) and binds to PPAR response elements. In this bioassay free PFOS in water samples competes with immobilized PFOS in ELISA plates for a given amount of PPARα–RXRα. It can be determined indirectly by immobilizing PPARα–RXRα–PFOS complex to another plate coated with PPARα antibody and subsequent measuring the level of PPARα–RXRα by using biotin-modified PPARα–RXRα probes–quantum dots–streptavidin detection system. The rapid and high-throughput bioassay demonstrated a detection limit of 2.5 ng L⁻¹ with linear range between 2.5 ng L⁻¹ and 75 ng L⁻¹. Detection results of environmental water samples were highly consistent between the bioassay and HPLC/MS.
Show more [+] Less [-]Urban nonpoint source pollution buildup and washoff models for simulating storm runoff quality in the Los Angeles County Full text
2011
Wang, Long | Wei, Jiahua | Huang, Yuefei | Wang, Guangqian | Maqsood, Imran
Many urban nonpoint source pollution models utilize pollutant buildup and washoff functions to simulate storm runoff quality of urban catchments. In this paper, two urban pollutant washoff load models are derived using pollutant buildup and washoff functions. The first model assumes that there is no residual pollutant after a storm event while the second one assumes that there is always residual pollutant after each storm event. The developed models are calibrated and verified with observed data from an urban catchment in the Los Angeles County. The application results show that the developed model with consideration of residual pollutant is more capable of simulating nonpoint source pollution from urban storm runoff than that without consideration of residual pollutant. For the study area, residual pollutant should be considered in pollutant buildup and washoff functions for simulating urban nonpoint source pollution when the total runoff volume is less than 30mm.
Show more [+] Less [-]Partitioning behaviour of perfluorinated alkyl contaminants between water, sediment and fish in the Orge River (nearby Paris, France) Full text
2011
Labadie, Pierre | Chevreuil, Marc
This paper reports on the partitioning behaviour of 15 perfluorinated compounds (PFCs), including C₄–C₁₀ sulfonates and C₅–C₁₄ carboxylic acids, between water, sediment and fish (European chub, Leuciscus cephalus) in the Orge River (nearby Paris). Total PFC levels were 73.0±3.0ngL⁻¹ in water and 8.4±0.5ngg⁻¹ in sediment. They were in the range 43.1–4997.2ngg⁻¹ in fish, in which PFC tissue distribution followed the order plasma>liver>gills>gonads>muscle. Sediment–water distribution coefficients (logKd) and bioaccumulation factors (logBAF) were in the range 0.8–4.3 and 0.9–6.7, respectively. Both distribution coefficients positively correlated with perfluoroalkyl chain length. Field-based biota–sediment accumulation factors (BSAFs) are also reported, for the first time for PFCs other than perfluorooctane sulfonate. logBSAF ranged between −1.3 and 1.5 and was negatively correlated with the perfluoroalkyl chain length in the case of carboxylic acids.
Show more [+] Less [-]Characteristics of the event mean concentration (EMC) from rainfall runoff on an urban highway Full text
2011
Lee, Ju Young | Kim, Hyoungjun | Kim, Youngjin | Han, M. Y.
The purpose of this study was to investigate the characterization of the event mean concentration (EMC) of runoff during heavy precipitation events on highways. Highway runoff quality data were collected from the 7th highway, in South Korea during 2007–2009. The samples were analyzed for runoff quantity and quality parameters such as CODcᵣ, TSS, TPHs, TKN, NO₃, TP, PO₄ and six heavy metals, e.g., As, Cu, Cd, Ni, Pb and Zn. Analysis of resulting hydrographs and pollutant graphs indicates that the peak of the pollutant concentrations in runoff occurs 20 min after the first rainfall runoff occurrence. The first flush effect depends on the preceding dry period and the rainfall intensity. The results of this study can be used as a reference for water quality management of urban highways.
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