Distribution, hydrologic transport, and cycling of total mercury and methyl mercury in a contaminated river-reservoir-wetland system (Sudbury River, eastern Massachusetts)

2000 ◽  
Vol 57 (5) ◽  
pp. 1080-1091 ◽  
Author(s):  
Marcus C Waldron ◽  
John A Colman ◽  
Robert F Breault
Keyword(s):  
Point Source ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Riparian Wetlands ◽  
Riparian Wetland ◽  
Net Production ◽  
Stream Discharge ◽  
River Reservoir ◽  
Flow Through ◽  
Eastern Massachusetts

Riparian wetlands contaminated with Hg from an industrial point source were found to be important sites of production and release of methyl mercury (MeHg) in a 40-km reach of the Sudbury River in eastern Massachusetts. Stream discharge and concentration measurements were used to calculate annual mean loads for total Hg (ΣHg) and MeHg in contaminated river reaches, a reservoir, and a riparian wetland downstream from the industrial source. Budgets based on these loads indicate that the annual mean ΣHg load increased sixfold in a reach receiving flow from the point source, but the annual mean MeHg load did not increase. About 23% of the ΣHg load was removed by sedimentation during flow through the reservoir. Net production of MeHg in the reservoir was similar to that reported elsewhere for lakes receiving Hg from atmospheric deposition only. ΣHg concentrations and loads increased significantly as the river passed through the riparian wetland reach. On the basis of flooded wetland area, net production of MeHg was 15 times greater in the wetland reach than in wetland-associated drainages described in other studies.

Retention and Removal Efficiency of Riparian Wetlands on Non-Point Source Pollutants

2012 ◽  
Vol 260-261 ◽  
pp. 841-845 ◽  
Author(s):  
Jin Xu ◽  
Li Gang Xu ◽  
Lei Dong
Keyword(s):  
Point Source ◽  
Removal Efficiency ◽  
Cost Effective ◽  
Terrestrial Ecosystems ◽  
Buffer Zone ◽  
Lake Basin ◽  
Riparian Wetlands ◽  
Nitrogen And Phosphorus ◽  
Riparian Wetland ◽  
Material Cycling

Riparian wetlands is a very important buffer and transition zone between terrestrial ecosystems and aquatic ecosystems in the lake basin system. Its edge effects played a crucial ecological role in energy flow and material cycling. Riparian wetlands have been widely used as the treatment of wastewaters, pollution control and environmental enhancement have been gainning increasing interest and application. In this paper, a typical riparian wetland was selected as case study for retention and removal efficiency on non-point source pollutants. The experimental results showed that there was certain removal efficiency for nitrogen and phosphorus. But slight effectiveness improvements took place after wetlands have been operated for a few years. So their restoration should be implemented also with the objectives of increasing the purification efficiency of pollutants. Results in this study were helpful in providing the basis for theoretical basis of designing cost-effective lakeside buffer zone and in revealing the removal mechanism of nitrogen and phosphorus in reparian wetlands.

Importance of Wetlands as Sources of Methyl Mercury to Boreal Forest Ecosystems

1994 ◽  
Vol 51 (5) ◽  
pp. 1065-1076 ◽  
Author(s):  
Vincent L. St. Louis ◽  
John W. M. Rudd ◽  
Carol A. Kelly ◽  
Ken G. Beaty ◽  
Nicholas S. Bloom ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Forest Ecosystems ◽  
Runoff Water ◽  
Riparian Wetland ◽  
Mercury In Fish ◽  
High Concentrations ◽  
Mercury Production ◽  
Upland Catchments

Wetlands were found to be important sources of methyl mercury to the boreal forest ecosystem. Yields of methyl mercury were about 26–79 times higher from wetland portions of catchments (1.84–5.55 mg∙ha−1∙yr−1) than from purely upland areas (0.07 mg∙ha−1∙yr−1). Mass-balance estimates using methyl mercury inputs in wet deposition and outputs in runoff water indicated that purely upland catchments and lakes were sites of methyl mercury retention or demethylation, while catchments with wetland areas were sites of net methyl mercury production. These observations may explain the high concentrations of mercury in fish taken from lakes that are high in colour because they receive water from wetlands. There was no relationship between the concentration of total mercury and the concentration of methyl mercury in runoff water. Total mercury yields were low from a wetland-dominated catchment, higher from a combination upland/riparian wetland catchment, and highest from a purely upland catchment. The opposite was true for methyl mercury yields from these same catchments. This indicates that environmental factors other than total mercury concentration are controlling the production and loss of methyl mercury from catchments.

scholarly journals Determination of methyl mercury and total mercury in sediment samples collected from canals in HoChiMinh city

2016 ◽  
Vol 19 (4) ◽  
pp. 123-136
Author(s):  
Hien Thai Hoang ◽  
Dong Van Nguyen
Keyword(s):  
Reference Material ◽  
Analytical Method ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Inorganic Mercury ◽  
Absorption Spectrometry ◽  
Internal Reference ◽  
Atomic Fluorescence ◽  
Sediment Samples ◽  
Cold Vapour

In this study, the analysis of methyl mercury (MeHg) and total mercury (T-Hg) was studied using gas chromatographic separation/atomic fluorescence spectrometric detection and cold vapour atomic absorption spectrometry respectively. MeHg was extracted from sediment matrix using HNO3/KCl/CuSO4 into dichloromethane followed ethylation with NaB(C2H5)4 in hexane. Total mercury was digested using three different procedures: EPA 245.1, AOAC 971.21 and our proposed one. The reliability of the analytical method for MeHg was evaluated by the use of the certified reference material ERM CC-580. In addition, the analytical method for total merury was evaluated using a fresh water sediment as an internal reference material, spiked with inorganic mercury, methyl mercury and phenyl mercury. The method detection limits for MeHg and total mercury were 0.08 and 0.15 ng/g (as Hg), respectively. The established analytical methods were applied to analyse MeHg and total mercury in sediment samples collected from canals and rivers in Hochiminh City. The concentrations of methyl mercury and total mercury in sediment samples were 0.08–2.87 ng/g và 14 – 623 ng/g (as Hg, dw). [MeHg]/Σ[Hg] respectirely were in a range of 0.1–2.3 %, which was in good agreement with the published ratios in sediment samples. A good correlation between the concentration of MeHg with total mercury and total organic carbon contents in the studied sediment samples was found.

Distribution of mercury and methylmercury in the sediments of a lowland river system

2005 ◽  
Vol 461 (2057) ◽  
pp. 1335-1355 ◽  
Author(s):  
Jason W Birkett ◽  
John N Lester
Keyword(s):  
Point Source ◽  
Total Mercury ◽  
Sewage Treatment ◽  
River System ◽  
Initial Increase ◽  
Surficial Sediments ◽  
Spatial Trends ◽  
The Mean ◽  
Temporal And Spatial ◽  
Temporal And Spatial Trends

Concentrations of total mercury (T-Hg) and methylmercury (MeHg) were determined in surficial sediments from the River Yare, Norfolk, UK over the period 1986–1998, to assess the temporal and spatial trends of contamination arising from a historical point source discharge. The results demonstrate that the spatial distribution pattern follows that of a distinct pollution plume in the sediments with an initial increase 2–3 km downstream from the point source discharge at Whitlingham sewage treatment works (STW) outfall. Temporally, this pollution plume remains evident, although there has been an overall decline in the mean T-Hg concentrations from 5.4 in 1986 to 1.8 mg kg −1 in 1998. The major factor for this improvement has been the reduction in discharge of metals from the STW, together with burial by a fresh overlay of uncontaminated sediments. MeHg concentrations also exhibited a dispersed pollution plume. Mean concentrations of MeHg fluctuated during the study period between 3.3 and 8.5 μg kg −1 . There has been no concomitant decline in MeHg concentrations over this period. MeHg was found to constitute less than 1% of T-Hg concentrations in the sediments. The weak correlations observed between T-Hg and MeHg concentrations indicate external environmental factors have a significant influence on determining MeHg concentrations in the sedimentary compartment.

A Comparison of Mercury Contamination in Mussel and Ammocoete Filter Feeders

2010 ◽  
Vol 1 (2) ◽  
pp. 142-145 ◽  
Author(s):  
Jamie B. Bettaso ◽  
Damon H. Goodman
Keyword(s):  
Methyl Mercury ◽  
Total Mercury ◽  
Mercury Contamination ◽  
Teleost Fishes ◽  
Trinity River ◽  
Longitudinal Gradients ◽  
History Of ◽  
Filter Feeders ◽  
The Trinity ◽  
Mercury Mining

Abstract The Trinity River, California, has an extensive history of gold and mercury mining, and recent studies demonstrated uptake of legacy mercury contamination by teleost fishes. We investigated mercury concentrations of larval lampreys (ammocoetes; Entosphenus spp.) and western pearlshell mussels (Margaritifera falcata) in the Trinity River to determine whether these two long-lived and sedentary filter feeders show site-specific differences in uptake of this contaminant. We analyzed ammocoetes from four sites in the Trinity River and one reference site in the Mad River for total mercury and mussels from three of the Trinity River sites for total and methyl mercury. We identified longitudinal gradients in ammocoete total mercury levels and methyl mercury in mussels. We found a 70% increase in total mercury in ammocoetes between two of the sample sites, suggesting a potential point source of contamination. Ammocoetes contained levels of mercury 12 to 25 times those of mussels from the same site. Our data indicate that ammocoetes may be a preferred organism to sample for mercury contamination and ecological effects compared with mussels in the Trinity River.

Rapid Semimicro Method for the Determination of Methyl Mercury in Fish Tissue

1972 ◽  
Vol 55 (3) ◽  
pp. 583-589 ◽  
Author(s):  
J F Uthe ◽  
J Solomon ◽  
B Grift
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Aqueous Ethanol ◽  
Fish Tissue ◽  
Mercuric Iodide ◽  
Mercury In Fish ◽  
Layer Chromatography

Abstract A fast semimicro method for the determination of methyl mercury in fish tissue is described. The procedure involves extracting the methyl mercury into toluene as methyl mercuric bromide, partitioning the bromide into aqueous ethanol as a thiosulfate complex, and re-extracting into benzene as methyl mercuric iodide. Methyl mercury is quantitated with gas chromatography. The method is sensitive to 0.01 ppm. Recoveries of added methyl mercury were 99% and the presence of methyl mercury in the final extract was shown by thin layer chromatography and gas chromatography of the thin layer spot. A variety of mercurial compounds do not interfere in the analyses. The amounts of both methyl and total mercury found in a variety of tissues of aquatic animals are compared. The presence of a demethylase in seal is suggested by the findings of high levels of nonmethyl mercury. Additional cleanup by column chromatography on Florisil was necessary with certain samples. The gas chromatographic columns were kept operational by the intermittent injection of 3M potassium iodide. Due to column bleed and resulting detector contamination, the use of the easily cleaned concentric tube electron capture detector is recommended.

scholarly journals Dam Effects on Downstream Riparian Wetlands: The Nenjiang River, Northeast China

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2038 ◽  
Author(s):  
Yuexin Zheng ◽  
Guangxin Zhang ◽  
Yanfeng Wu ◽  
Y. Jun Xu ◽  
Changlei Dai
Keyword(s):  
Northeast China ◽  
Quantitative Relationship ◽  
Flood Frequency ◽  
Stepwise Multiple Regression ◽  
Distribution Data ◽  
Dam Construction ◽  
Riparian Wetlands ◽  
Transport Channel ◽  
Riparian Wetland ◽  
The Impact

Many studies have found that damming a river can change downstream hydrology, sediment transport, channel morphology, and fish habitat. However, little is known about river dam effects on downstream riparian wetland dynamics and their quantitative relationship with hydrological alterations. In this study, hydrological time series and wetland distribution data spanning nearly 40 years (1978–2016) before and after the construction of a large dam in 2005 across the Nenjiang River in Northeast China were used to reveal the impact of dam on the downstream discharge regime and wetland degradation. Hydro-statistical and stepwise multiple regression analyses were performed to quantify the relationship of riparian wetland area with a metrics of 33 hydrological indicators. Dam construction caused decline in peak discharge, flood frequency, and magnitude. Moreover, 150 km riparian wetlands along the downstream of the dam was largely reduced. The count and duration of high flow pulses, 1-day maximum, and date of maximum discharge changed significantly after the dam construction. The hydrological changes have made a significant contribution to the 44% reduction in riparian wetlands following the dam construction. Our results indicated that hydrological alterations caused by dam regulation led to the area reduction of downstream riparian wetlands. The findings provide relevant information for developing best dam operation practices to protect and restore downstream wetland ecosystems.

Total Mercury, Inorganic Mercury and Methyl Mercury Determination in Red Wine

2011 ◽  
Vol 5 (3) ◽  
pp. 505-511 ◽  
Author(s):  
Valderi Luiz Dressler ◽  
Clarissa Marques Moreira Santos ◽  
Fabiane Goldschmidt Antes ◽  
Fabrina Regia Stum Bentlin ◽  
Dirce Pozebon ◽  
...  
Keyword(s):  
Methyl Mercury ◽  
Total Mercury ◽  
Red Wine ◽  
Inorganic Mercury ◽  
Mercury Determination

Importance of the Forest Canopy to Fluxes of Methyl Mercury and Total Mercury to Boreal Ecosystems

2001 ◽  
Vol 35 (15) ◽  
pp. 3089-3098 ◽  
Author(s):  
Vincent L. St. Louis ◽  
John W. M. Rudd ◽  
Carol A. Kelly ◽  
Britt D. Hall ◽  
Kristofer R. Rolfhus ◽  
...  
Keyword(s):  
Methyl Mercury ◽  
Forest Canopy ◽  
Total Mercury ◽  
Boreal Ecosystems
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