Basic Study on the Remediation Technology
of Mercury Compound-Contaminated Soil
by Low-Temperature Thermal Treatment
A. MATSUYAMA, H. IWASAKI, K. HIGAKI, H. YABUTA, T. SANa, and H. AKAGI
1
Introduction
Japan has a long history of mercury contamination, the most tragic example
being the organic mercury poisoning of Minamata Bay, and the subsequent
outbreak of Minamata disease, which killed so many people. Today in Japan
there are many cases of mercury contamination of soils in the vicinity of
agricultural and industrial chemical plants etc. In other parts of the world,
mercury contamination problems, such as those caused by the smelting of gold
in the Amazon basin and other tropical regions, have become a worldwide
concern.
In Japan, mercury-contaminated soils have generally been treated with sodium
sulfide (Na2S) or cement, which makes the mercury insoluble. One of the
problems with this approach, however, is that the contaminant, mercury,
remains in the soil after the treatment is completed, which limits the use of the
soil. In the United States and Europe it is still common to treat mercurycontaminated soils with the method used in Japan, which is to make the mercury
insoluble and stable. In recent years, however, other methods have been
proposed. One is the soil-washing method, which involves washing mercurycontaminated soil with chelating agents or acids to remove the mercury. Another
is the soil-heating method, which involves heating mercury contaminated soil to
moderate to high temperatures (600-900 °C) to steam and remove the mercury
(Larry and Jose 1990). These methods, however, present the following problems.
1. Treatment is expensive and thorough safety measures for workers must be
implemented.
2. Heating of soil to such high temperatures may have the disadvantage of
inducing a substantial change in the soil characteristics. Given these problems,
a new soil treatment method is required to ensure the safe treatment of
contaminated soils. Based on this understanding, we studied another method
for removing mercury from contaminated soil in our laboratory.
The results of heating tests on minerals containing mercury indicate that
mercury compounds tend to be unstable, and, even if in a stable form such as
mercuric sulfide, start to evaporate when heated at a low temperature of 200210 0c. The results particularly tend to occur in such as minerals as granite
(Hamaguchi et al. 1976).
Environmental Science
Mercury Contaminated Siles (ed. by R. Ebinghaus el al.)
(0 Springer-Verlag Berlin Heidelberg 1999
of Mercury Compound-Contaminated Soil
by Low-Temperature Thermal Treatment
A. MATSUYAMA, H. IWASAKI, K. HIGAKI, H. YABUTA, T. SANa, and H. AKAGI
1
Introduction
Japan has a long history of mercury contamination, the most tragic example
being the organic mercury poisoning of Minamata Bay, and the subsequent
outbreak of Minamata disease, which killed so many people. Today in Japan
there are many cases of mercury contamination of soils in the vicinity of
agricultural and industrial chemical plants etc. In other parts of the world,
mercury contamination problems, such as those caused by the smelting of gold
in the Amazon basin and other tropical regions, have become a worldwide
concern.
In Japan, mercury-contaminated soils have generally been treated with sodium
sulfide (Na2S) or cement, which makes the mercury insoluble. One of the
problems with this approach, however, is that the contaminant, mercury,
remains in the soil after the treatment is completed, which limits the use of the
soil. In the United States and Europe it is still common to treat mercurycontaminated soils with the method used in Japan, which is to make the mercury
insoluble and stable. In recent years, however, other methods have been
proposed. One is the soil-washing method, which involves washing mercurycontaminated soil with chelating agents or acids to remove the mercury. Another
is the soil-heating method, which involves heating mercury contaminated soil to
moderate to high temperatures (600-900 °C) to steam and remove the mercury
(Larry and Jose 1990). These methods, however, present the following problems.
1. Treatment is expensive and thorough safety measures for workers must be
implemented.
2. Heating of soil to such high temperatures may have the disadvantage of
inducing a substantial change in the soil characteristics. Given these problems,
a new soil treatment method is required to ensure the safe treatment of
contaminated soils. Based on this understanding, we studied another method
for removing mercury from contaminated soil in our laboratory.
The results of heating tests on minerals containing mercury indicate that
mercury compounds tend to be unstable, and, even if in a stable form such as
mercuric sulfide, start to evaporate when heated at a low temperature of 200210 0c. The results particularly tend to occur in such as minerals as granite
(Hamaguchi et al. 1976).
Environmental Science
Mercury Contaminated Siles (ed. by R. Ebinghaus el al.)
(0 Springer-Verlag Berlin Heidelberg 1999