2005 Fiscal Year Final Research Report Summary
Mutual Relationship of Arsenic Release Mechanism and salinity of Groundwater in Bangladesh
| Project/Area Number |
15404005
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 海外学術 |
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| Research Field |
Environmental technology/Environmental materials
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| Research Institution | Tohoku Gakuin University |
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Principal Investigator |
ISHIBASHI Yoshinobu Tohoku Gakuin University, Faculty of Engineering, Professor, 工学部, 教授 (10111246)
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| Co-Investigator(Kenkyū-buntansha) |
MANO Akira Tohoku University, School of Engineering, Professor, 大学院・工学研究科, 教授 (50111258)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Bangladesh / Arsenic Contamination / Release of Arsenic / Fluidization Model of Groundwater / Cell Surface Engineering / Adverse effect of salination |
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| Research Abstract |
Factors analysis of arsenic release, arsenic removal by cell surface engineering and Arsenic Transport analysis for pumping from deep aquifer in South Bangladesh were performed, mainly.
A marked increase in arsenic release was recognized With sewage sludge content as organic matter from laboratory experiments. Maximum arsenic release was reconfirmed when the value of oxidation-reduction potential was around -80 mV. However, the relationship between divalent iron or hydrogen carbonate ion and arsenic release did not find out.
On the other hand, distribution coefficient (k) in equilibrium between arsenic adsorption from water to solids and arsenic release from solids to water was 0.69×10^<-7> m^3/mg. The value was similar to the distribution coefficient of shallow aquifer in Bangladesh.
lamB and arsR genes were combined with plasmid pTV118N for cell surface engineering, and more than 70 percent of arsenic was removed. But a problem, which lamB and arsR were inserted suitably or not, was still remained.
At present, Bangladeshi people are using arsenic contaminated shallow groundwater. In the years ahead, deep aquifer which arsenic concentration is low would be the water sources. Therefore, model analyses of arsenic transport were performed in each depth of wells using field data in Bangladesh. As a result, arsenic concentration in shallow aquifer would be low, gradually, with the passage of time. On the contrary, arsenic concentration in deep aquifer would be increased little by little. If a time until reaction of adsorption and desorption becomes equilibrium condition assumed five years, arsenic contamination would progress to deep aquifer where the depth is -70 m in one hundred years later as one calculation.
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