Natural and Artificial Mercury Decontamination - Ottawa River and Minamata Bay (Yatsushiro Sea)

1992 ◽  
Vol 26 (1-2) ◽  
pp. 217-226 ◽  
Author(s):  
A. Kudo
Keyword(s):  
Half Life ◽  
River System ◽  
Surrounding Area ◽  
Surrounding Water ◽  
Ottawa River ◽  
Natural Processes ◽  
Yatsushiro Sea ◽  
Polluted Sites ◽  
Minamata Bay ◽  
The Given

Everyday, man creates new processes and materials whose properties are not fully known and are sometimes toxic to him and the environment. One of the worst cases was in Minamata Bay, Japan where a fatal accident occurred due to mercury pollution. The accident was unique in many aspects thus forcing the establishment of a new decontamination process for polluted areas. Two mercury polluted sites, the Ottawa River, Canada and Minamata Bay (Yatsushiro Sea), Japan, have been investigated to establish a fundamental approach for decontamination with special emphasis on natural and artificial processes and their problems. Artificial decontamination on bottom sediments has primarily cleaned-up Minamata Bay and the near-by Yatsushiro Sea considerably, an acceleration of the natural processes by 31.5 years. The surrounding area will be fully cleaned-up by natural forces, following the artificial work, by 2011 AD (or 20 years from now). This means that the natural decontamination has a half-life of 9.5 years in Yatsushiro Sea. For the Ottawa River, only natural processes were applied to clean-up the river system. It took 5 years for physical components to be decontaminated (a half-life of 1.20 years) while it took a longer period for biological components. This last finding was also true for Minamata Bay. This delay may be due to the longer life span of the biota and their efficient processes of bioaccumulation from diluted surrounding water. Based on the findings herein, a combination of both artificial and natural decontamination methods is recommended in consideration with the given environmental conditions.

Predicted Restoration of the Surrounding Marine Environment after an Artificial Mercury Decontamination at Minamata Bay, Japan - Economic Values for Natural and Artificial Processes

1992 ◽  
Vol 25 (11) ◽  
pp. 141-148 ◽  
Author(s):  
A. Kudo ◽  
S. Miyahara
Keyword(s):  
Half Life ◽  
Surface Sediments ◽  
Economic Value ◽  
Inorganic Mercury ◽  
Reclaimed Land ◽  
Natural Processes ◽  
Yatsushiro Sea ◽  
Land Mass ◽  
Polluted Sites ◽  
Minamata Bay

More than 35 years ago, an accident surfaced because of human misery at Minamata Bay, Japan. By 1960, more than 100 people suffered (mortality rate was over 20%) by eating fish containing methylmercury. By 1987, 1742 people were identified with this Minamata disease. The methylmercury along with inorganic mercury was released from a nearby chemical factory into the Bay, contaminating not only fish but the entire ecosystem including the bottom sediments. The amount of mercury deposited in the sediments was considered to be 150 tons. The Japanese Government initiated, in 1984, a decontamination project vacuuming the contaminated sediments into a sealed area creating a reclaimed land mass of 582,000 m2. The movement of the mercury deposited in the Bay outward to Yatsushiro Sea, was observed during the last 16 years by sampling and analyzing the surface sediments of Yatsushiro Sea. Since 1975, the deposited mercury moved continuously outside from the Bay at an annual rate of 3.7 tons. The initiation of the artificial decontamination (over $500 million in US funds), however, changed the pattern of mercury movement and drastically reduced its contents with a half-life of 1.83 years. Since 1985, the amounts of mercury in the surface sediments of Yatsushiro Sea have been decreasing dramatically with a half-life of 9.5 years. If this present trend of decrease continues, it becomes possible to predict that the Sea would be completely restored by 2011 AD. Another interesting observation was a historical storm in 1982, which cleaned-up the surface sediments of Yatsushiro Sea with a half-life of 2.76 years. If the clean-up effect of the natural processes in Yatsushiro Sea was compared to the artificial one, its economic value was calculated to be $96 million (US funds). Any decontamination attempt for polluted sites should consider a combination of the natural and artificial decontamination processes for economic reasons.

scholarly journals Actual inflow of riverine sediment load into Lake Baikal: main tributaries the Selenga, Upper Angara, and Barguzin Rivers (Russia)

2021 ◽  
pp. 1111-1114
Author(s):  
T.G. Potemkina ◽  
◽  
V.L. Potemkin ◽  
Keyword(s):  
Lake Baikal ◽  
Meteorological Parameters ◽  
Sediment Load ◽  
Water Discharge ◽  
Baseline Period ◽  
Integrated Analysis ◽  
Natural Processes ◽  
Precipitation Decrease ◽  
Riverine Sediment ◽  
The Given

Abstract. The sediment load delivery into Lake Baikal from its main tributaries the Selenga, Upper Angara, and Barguzin Rivers has been reduced since the mid-1970s. This is explained by climate change and socioeconomic activities. Integrated analysis of changes in hydro-meteorological parameters (water discharge, sediment load, air temperature, precipitation) and their trends over the period 1946 1975 (baseline) and 1976 2017 (warming) is performed. Changes in natural processes and human activity were negligible during the baseline period. During the warming period, the greatest reduction of the sediment load inflow against the background of temperature rise and precipitation decrease occurred in the interval between 1996 and 2017 in the Selenga River, between 1985 and 2017 in the Upper Angara River, and between 1992 and 2017 in the Barguzin River. The flux of the sediment load into these rivers was 768 103, 88 103, and 29 103 t y 1, respectively. This is 2 3 times less than the average multiyear values for all period of 1946 2017, which are usually used when characterizing sediment load runoff from these rivers. Currently the values in the given intervals correspond to the actual sediment load flux into Lake Baikal from the main tributaries.

Modelling the Pathways of Toxic Contaminants in the St. Clair-Detroit River System Using the Toxfate Model: The Fate of Perchloroethylene

1986 ◽  
Vol 21 (3) ◽  
pp. 411-421 ◽  
Author(s):  
Efraim Halfon
Keyword(s):  
Half Life ◽  
Lake Erie ◽  
River System ◽  
High Water ◽  
Water Levels ◽  
Water Soluble ◽  
Detroit River ◽  
Wind Speeds ◽  
High Volatility ◽  
Local Water

Abstract Perchloroethylene (PERC) is a heavier-than-water, soluble and volatile solvent used primarily in the dry cleaning business. Black puddles (popularly known the the “blob”), containing several contaminants inducing PERC, were reported in the St. Clair River bottom sediments downstream from Sarnia in 1984 and in 1985. The TOXFATE model is used to predict the fate of PERC and the relative importance of volatilization in relation to water transport. Simulations show that in the St. Clair-Detroit River system about 82% (78-87%). under a variety of temperature and wind conditions) of the PERC loading is volatilized, about 17% (12-21%) of loading enters Lake Erie (more in winter, less in summer) and only about 1% remains in the system. The residence half life of PERC being transported in the water from Sarnia to Lake Erie is 350-400 hours and the half life of PERC being volatilized is 80-85 hours. A sensitivity analysis shows the importance of knowing the daily loadings to compute, in real time, local water concentrations following a PERC spill. The high water levels in the St. Clair River system do not influence the fate of PERC. Given the high volatility of PERC low temperatures and wind speeds do not reduce significantly the rate of removal of PERC from the system through volatilize nation.

Methane Diffusion in a Porous Environment

2014 ◽  
Vol 353 ◽  
pp. 50-55 ◽  
Author(s):  
Pavel Staša ◽  
Vladimír Kohut ◽  
Oldřich Kodym ◽  
Zora Jančíková
Keyword(s):  
Fluid Dynamics ◽  
Geometric Model ◽  
Water Layer ◽  
Mining Activities ◽  
Natural Processes ◽  
First Case ◽  
Flow Through ◽  
Methane Diffusion ◽  
The Given ◽  
Methane Flow

The paper deals with modeling and simulation of methane flow through the porous environment using the CFD (Computational Fluid Dynamics) software Fluent. We compare three situations, which can occur in areas, where mining activities were closed few years ago, in this article. First case is modeling of methane flow through the rocks. Second event is situation where the thin water layer is situated at the surface. The last one is occurrence of groundwater. The article responds to the need for knowledge of natural processes in the given area and it follows our previous papers [1], [2]. Software Gambit was used for creating a geometric model of the working area, for modeling the flow of gas it was used CFD software, Fluent from ANSYS, Inc..

A Case History; Minamata Mercury Pollution in Japan – From Loss of Human Lives to Decontamination

1991 ◽  
Vol 23 (1-3) ◽  
pp. 283-290 ◽  
Author(s):  
Akira Kudo ◽  
Shojiro Miyahara
Keyword(s):  
Mercury Concentration ◽  
Industrial Wastewater ◽  
Total Mercury ◽  
Surface Sediments ◽  
Sea Water ◽  
Human Beings ◽  
Organic Mercury ◽  
Yatsushiro Sea ◽  
History Of ◽  
Minamata Bay

At Minamata Bay in Japan, more than 100 people lost their lives and many thousands more were permanently paralyzed from eating mercury contaminated fish. In the long history of water pollution, this was the first known case where the natural bioaccumulation (in fish) of a toxicant from an industrial wastewater killed a large number of human beings. The mercury, discharged from a factory, was deposited on the bottom of the Bay and has remained there since the 1950's. The fate of the mercury was traced by measuring 268 mercury concentrations in the surface sediments at Yatsushiro Sea (outside of the Bay) during the last 14 years. Twenty-four sampling stations were established to collect samples at the same location every year. Samples were analyzed for total mercury concentrations. The concentrations of mercury in the surface sediments at the Sea were not alarming. Only 33 samples exceeded a mercury concentration of 1 ppm. The dispersion of the mercury from the Bay, however, was clearly documented with the data. On average, 3.7 tons of the mercury was transported outside from the Bay every year. A decontamination project started in 1984 dramatically decreased the flow of mercury from the Bay to the Sea. A historic rainfall in 1982 also ‘purified' the surface sediments. Organic mercury concentration in the sea water was 5.1 ng/l while total mercury was 120 ng/l at the center of the Bay in 1985.

History of mercury migration from Minamata Bay to the Yatsushiro Sea

2000 ◽  
Vol 42 (7-8) ◽  
pp. 177-184 ◽  
Author(s):  
A. Kudo ◽  
Y. Fujikawa ◽  
M. Mitui ◽  
M. Sugahara ◽  
G. Tao ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Sediment Cores ◽  
Time Lag ◽  
Mercury Pollution ◽  
Yatsushiro Sea ◽  
History Of ◽  
Sediment Particles ◽  
Minamata Bay

Mercury concentrations were measured in sediment cores collected from the Yatsushiro Sea to clarify physical transport of mercury from Minamata, the site of major methylmercury pollution in Japan, to the surrounding sea. The results suggested that the mercury pollution in the Yatsushiro Sea sediment was caused by a slow migration of mercury-bearing sediment particles from Minamata Bay. The deposition rate of mercury observed at the Yatsushiro Sea was correlated with cumulative loss of mercury from an acetaldehyde facility in Chisso Minamata, with a certain time-lag.

scholarly journals Impact of Reclamation Project on Mercury-Contaminated Sediment Transport from Minamata Bay into the Yatsushiro Sea

2016 ◽  
Vol 72 (2) ◽  
pp. I_1285-I_1290 ◽  
Author(s):  
Edistri Nur FATHYA ◽  
Shinichiro YANO ◽  
Akito MATSUYAMA ◽  
Akihide TADA ◽  
Herawaty RIOGILANG
Keyword(s):  
Sediment Transport ◽  
Contaminated Sediment ◽  
Yatsushiro Sea ◽  
Reclamation Project ◽  
Minamata Bay

scholarly journals Acoustic Equipment and ROV Investigations of Mercury Diffusion in Minamata Bay, Yatsushiro Sea, Japan

2013 ◽  
Vol 18 ◽  
pp. 174-181
Author(s):  
Kazumi Akimoto ◽  
Kiyoshi Takikawa ◽  
Koichi Yakita ◽  
Takaomi Hokamura ◽  
Yukihide Shimasaki ◽  
...  
Keyword(s):  
Yatsushiro Sea ◽  
Minamata Bay
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