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Trace Elements in Ground and Packaged Water in Akwa Ibom State, Nigeria
김경웅,Edu Inam,Godwin Ebong,Ubong Eduok 한국자원공학회 2010 Geosystem engineering Vol.13 No.2
About 20 trace elements were measured in 165ground water samples, 8 commercial brands of bottled and sachet water in Akwa Ibom State, Nigeria to ascertain their quality and suitability for drinking purposes. A comparison of the elemental concentrations with World Health Organization (WHO) guidelines and Nigerian Standard for Drinking Water Quality (NSDWQ) showed that with the exception of Al, Cd,Pb, and Fe in some of the ground and packaged water samples,the levels of all the other elements investigated were below the maximum allowable limits. Hierarchical cluster analysis grouped 16 sampling local government councils into four clusters of similar water quality characteristics. Based on the obtained information, it is possible to design a future, optimal sampling strategy for monitoring programs which could reduce the number of sampling stations and associated costs.
김경웅,Lunchakorn Prathumratana,김지원 한국자원공학회 2010 Geosystem engineering Vol.13 No.1
Nine soil and three tailing samples collected from a historical Pb mining and smelting site including a vicinity area in Europe were investigated for the chemical fractions and human bioavailability. A five-step sequential extraction procedure was performed to characterize the forms of Pb. A simple bioavailability extraction test (SBET) was conducted as an assessment to determine the bioavailability of Pb in human gastrointestinal condition. Total concentration of Pb in soil and tailing samples ranged from 383 to 73800 mg/kg. Eleven from twelve samples had exceeded the USEPA standard of 400 mg/kg. Fractionation of Pb showed that seven from twelve samples were mainly associated with a reducible fraction (Fe-Mn oxides) for 37.8 to 71.6%. Carbonate fractions were found dominantly in three soil samples of 62.0%, 57.4%,and 68.6%, repectively, with high pH and high total concentration of Pb. A residual fraction was prevalent for tailing samples. Low pH in tailing samples may influence the mobility of Pb and increasing of soil pH seemed to increase Pb content in the carbonate fraction. Extremely high values of Pb from human bioavailability assessment (SBET) (more than 60%) indicated that long-term exposure of these soils could pose a potential health effect to the local population.