• Journal of the Korean Chemical Society
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• v.66 no.5
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• pp.416-419
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• 2022

• Journal of Microbiology and Biotechnology
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• v.8 no.1
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• pp.53-60
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• 1998

This study examines the effect of pH, temperature, metal ion concentration and culture density on metal biosorption by the nuisance cyanobacterium Microcystis aeruginosa. Ni biosorption was higher at pH 9.2 than at neutral and acidic pH. In contrast the biosorption of Cu and Zn was maximum at pH 7.0. However, biosorption of Zn was difficult to measure at pH values 9.2 and 10.5, owing to the formation of insoluble complexes. All the test metals (Cu, Zn, and Ni) showed maximum biosorption rate at low culture densities of 40 mg dry wt $1^{-1}$. The biosorption of Cu, Zn, and Ni was maximum at $40^{\circ}C$. However, no worthwhile difference in Zn and Ni sorption was noticed at 4 and $29^{\circ}C$ as compared to $40^{\circ}C$. Of these three metals used Microcystis showed a greater binding capacity ($K_{f}$ value=0.84, Freundlich adsorbent capacity) and accelerated biosorption rate for Cu under various environmental conditions. Fitness of mathematical models on metal biosorption by Microcystis confirmed that the biological materials behave in the same way as physical materials. These results suggest that before using a biosorbent for metal recovery, the environmental requirements of the biosorbent must be ascertained.

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.393-400
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• 2017

This study was investigated on pH, heavy metals, oils and solvents in 34 surface soil samples and the samples are collected at two times for 17 farmland sites around 7 industrial areas in Northern Gyeonggi Province. As a result of pH for soil contamination monitoring network, the range of pH showed 4.4~8.4 and average was 6.3. The range of pH for Agricultural land around industrial area was 6.7~7.5 and average indicated 7.1 that mostly showed neutral condition in this area. he average concentrations of Cu, Pb, Ni, As and $Cr^{6+}$ are lower than Korea soil contamination worrisome levels at region 1 and the mean levels of farmland from the soil quality monitoring network. The average concentrations of Zn, Cd and Hg didn't exceed the soil contamination worrisome levels at region 1 but slightly higher than the mean levels of farmland from the soil quality monitoring network. The heavy metal levels of all samples are within Korea soil contamination worrisome levels at region 1. The results showed that the detected heavy metal concentrations ranged from N.D. to ~32.7% of Korea soil contamination worrisome levels at region 1. BTEX, TPH, TCE and PCE were not detected in all samples and thus the farmland around the industrial areas were free from oils and solvents contamination.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.20-27
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• 2001

Stream water chemistry in the abandoned Boeun Jeil coal mine area was studied for a period of 3 months, including rainy and dry season. The stream waters were a nearly neutral and slightly alkali condition, and $Mg-SO_4$ type with Mg>Ca>Na>K and $SO_4>HCO_3>Cl>NO_3$. Chemical composition of the stream water was quite irregular during the experimental period. Concentrations of Na, K, $HCO_3$, U, Sr, and Cr decreased by $10{\sim}30%$ during rainy season, caused by dilution effects with rain. The concentration of Ca, Mg, $NO_3$, Cd, and Co increased during the rainy season, caused by more easily dissolved from bedrocks or mine drainage with slightly acidic condition than dry season. The stream water was enriched in Mg, Ca, $HCO_3$, $SO_4$, Al, Fe, Zn, Ni, Co, Cr, Cd, Sr and U. Concentrations of Na, Mg, Ca, $SO_4$, $HCO_3$, Fe, Zn, Ni, Sr, and U decreased linearly with distance from the mine adit. These elements were strongly controlled by dilution of unpolluted water influx and/or adsorption on the clay minerals and iron oxyhydroxide precipitates. This mine area exhibited two main weathering processes ; 1) oxidation with acidification derived from Fe sulphides, and 2) pH buffering due to Ca and Mg carbonate dissolution. This weathering processes were followed by adsorption of metals on iron oxyhydroxides and precipitation.