• 환경위생공학
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• 제9권2호
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• pp.110-119
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• 1994

The objective of the this study was to evaluate the effects of heavy metals on the sewage treatment process designed to remove organic material and nutrients using Water- hyacinth ( Eichhornia crassipes ). Batch experiments were carried out using domestic sewage spiked with different level of heavy metal mixtures ( Cd, Pb and Cu ). The specific growth rates of Water- hyacinth ranged from 0.0008 to 0.0015 1/day( operated at water temperatures of 22 ∼30$\circ $c ) and increased as the concentration of heavy metals decreased. The test result showed that the permissible maximum concentrations Cd, Pb and Cu for the growth of Water- hyacinth were 0.5, 1, and 6 mg/ℓ respectively. Under these maximum permissible heavy metal loads, removal rate of organic material, nitrogen and phosphorus were 85%,75% and 75% , respectively, during 40days of the test period.

• 한국환경과학회지
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• 제24권12호
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• pp.1601-1608
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• 2015

This study evaluates heavy metal(Cu and Cr) adsorption characteristics produced from food waste charcoal extracted in an optimal operation condition after analyzing activated charcoal of iodine adsorption and heavy metals that derived from an activation process of carbide by the developed by-products of food waste treatment facility using the methods from previous studies. As experiment apparatus, this study used a tube-shaped high temp furnace. The mixing ratio of by-products of food waste treatment facility, carbide, and activation component($ZnCl_2$) was 1:1. The experiment was proceeded as adjusting the activation temperature from 400 to $800^{\circ}C$ and activation time from 30 to 120 minutes. The optimal activation condition for iodine absorption was 90 minutes at $700^{\circ}C$ and by using the produced food waste charcoal, this study conducted an experiment on absorption of heavy metals (Cu and Cr) as changing pH of artificial wastewater and stirring time. As a result, pH 7 showed the highest heavy metal decontamination ratio and in terms of stirring time, it revealed balance adsorption after 10 minutes. This result can be particularly applied as basic data for recyclability of high concentration organic waste, by-products of food waste treatment facility, as an food waste charcoal.

• The Korean Journal of Ecology
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• 제21권3호
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• pp.179-186
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• 1998

Effects of lead(Pb) and calcium(Ca) on growth responses, accumulation of heavy metals and nitrogen fixation activities of Melilotus suaveolens seedlings were quantitatively analyzed during growing period. Pb contents of the root treated with 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca were 54.1, 90.9 and 26.1 folds higher than that of the control, respectively, at pH 4.2 in 28th days, and heavy metal content of plant increased with increasing of pH and Pb concentration. The melilot plant was classified as a Pb accumulator by higher accumulation of Pb in shoot than that of root. Pb treatments resulted in inhibiton of height and chlorophyll contet, and Ca treatment increased height and chlorophyll content insignificantly at pH 4.2 in 28 days. The plant biomass reduced 49, 60 and 54% at pH 4.2 and 47,53 and 50% at pH 6.5, respectively, by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca treatment. Specific nitrogen fixation of nodules reduced 68.4% and 46.6% by 100 ppm Pb treatment and 3.7% and 24.9% by 100 ppm Pb added 100 ppm Ca at pH 4.2 and pH 6.5, respectively, so Ca inhibited significantly Pb activity and toxicity in acdic pH. Nodule formation were reduced to 33, 33 and 50% at pH 4.2 and 50, 33 and 38% at pH 6.5 by 30, 100 ppm Pb and 100 ppm Pb added 100 ppm Ca, respectively.

• Advances in environmental research
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• 제6권4호
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• pp.281-299
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• 2017

Single (0.005 M DTPA), sequential (six-step) and kinetic (0.05 M EDTA) extractions were performed to assess Cd, Cr, Cu, Ni, Pb, and Zn mobilization and their potential ecological risks in Abuja (Nigeria) water (WTS) and wastewater (WWTS) treatment sludges. Total metal levels (mg/kg) in WTS and WWTS, respectively were: Cd(3.67 and 5.03), Cr(5.70 and 9.03), Cu(183.59 and 231.53), Ni(1.33 and 3.23), Pb(13.43 and 17.87), Zn(243.45 and 421.29). DTPA furnished metal extraction yields (%) in WTS and WWTS, respectively as: Cd(11 and 6), Cr (15 and 7), Cu(17 and 13), Ni(23 and 3), Pb(11 and 12), and Zn(37 and 33). The metals were associated with the soluble/exchangeable, carbonate, Mn/Fe-oxide, organic matter and residual forms to varying degrees. Kinetic extractions cumulatively leached metal concentrations akin to the mobilizable fractions extracted sequentially and the leaching data fitted well into the Elovich model. Metal mobilities were concordant for the three leaching procedures and varied in the order:WTS>WWTS. Calculated ecological risk indices suggested moderate and considerable metal toxicity in WTS and WWTS, respectively with Cd as the worst culprit. The findings may be useful in predicting heavy metals bioavailability and risks in the sludges to guide their disposal and use in land applications.

• Macromolecular Research
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• 제10권2호
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• pp.103-107
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• 2002

High purity water soluble chitosans (WsCs) were employed as a flocculant to remove heavy metal ions from wastewater of industrial plating wastewater treatment complex. Their weight average molecular weights and polydispersities were 272,000~620,000 g/mol and 1.4~1.9 range, respectively and were readily soluble in water in the pH range of 3~11. Heavy metal ions such as chromium, iron and copper were removed well by WsCs. When WsCs was blended with either sodium N, N-diethyldithiocarbamate trihydrate (SDDC$_{T}$) or sodium salicylate (SSc), the removal efficiency was further increased primarily due to the excess amount of hydrophilic sulfonic and carboxylic groups. Especially, in the case of WsCs-SSc the remaining chromium and copper concentrations were 0.1 mg/L and 9.5 mg/L, which are 1/15 and 1/3 compared with that of pure WsCs, respectively. The former is within the acceptable limit, but the latter is not. Therefore, the effective copper flocculant remains to be studied.d.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권6호
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• pp.16-23
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• 2023

Heavy metal (Zinc, Cadmium, Lead) adsorption onto surface modified activated carbon was performed in order to better understand the effect of sodium ion addition to activated carbon. Surface modification methods in this research included water washing, nitric acid washing, and sodium addition after nitric acid washing. These surface modifications generated oxygen functional groups with sodium ions on the surface of the activated carbon.. This caused the change of the specific surface area as well as in the ratio of the carboxyl groups. Heavy metal adsorption onto sodium-containing activated carbon was the most among the three modifications. After the adsorption of heavy metals, the carboxyl group ratio decreased and sodium ions on the surface of the activated carbon were almost non-existent after the adsorption of heavy metals onto sodium-containing activated carbon. The results from this research indicated that ion exchange with sodium ions in carboxyl groups effectively improved heavy metal adsorption rather than electrostatic adsorption and hydrogen ion exchange.

• 한국습지학회지
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• 제20권4호
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• pp.390-397
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• 2018

산업단지 인근에 위치한 하수처리장은 유입되는 산업폐수 내 중금속으로 인해 질산화 효율이 감소하는 문제점이 있다. 본 연구에서는 실험실 규모 반응조 운전 결과를 바탕으로 산업폐수가 유입되는 하수처리장의 질산화 효율 개선을 위해 중금속과 체류시간이 질산화에 미치는 영향을 분석하였다. 또한 운전 결과를 바탕으로 질산화율 향상을 위한 하수처리장 운전 방법을 제시하고자 한다. 실험실 반응조 운전 결과 체류시간 0.5일 이상으로 운전 할 경우 60% 이상의 질산화율을 확보할 수 있을 것으로 나타났다. 하지만, 동일한 조건에서 일반 도시하수처리장 시료를 이용하는 경우보다 낮은 효율을 보이는 것으로 조사되었다. 이와 같은 결과를 보인 원인으로 산업 폐수 내 함유된 중금속의 영향으로 질산화 미생물의 활성(SNR 기준)을 분석하였다. S 하수처리장과 일반 하수처리장 시료(A MWTPame )를 이용한 반응조의 SNR은 각각 0.13 ~ 0.21 mg NH4/gMLSS/hr과 0.74 mg NH4/gMLSS/hr의 범위를 보였다. 이는 S 하수처리장 시료를 유입수로 하는 반응조 내 미생물의 활성이 낮음을 확인 할 수 있다. 따라서 산업폐수가 유입되는 하수처리장에서 질산화 효율개선을 위해 체류시간 증가 및 전처리를 통한 중금속 처리가 필요할 것으로 판단된다.

• 한국토양비료학회지
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• 제43권6호
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• pp.864-871
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• 2010

At the current situation of continuous utilization of heavy metal contaminated upland for agricultural purpose in Korea, minimizing transport of heavy metals from soil to crops is important for securing safety of human health. The present study (in field scale) examined the efficiency of several soil amendments (dolomite, steel slag, lime, zeolite, and compost) on reduction of phytoavailable heavy metals (Cd, Cu, Pb, and Zn) in soil through comparison with no amendment treatment and clean soil cover treatment. For determination of the phytoavailability, 1 M $NH_4NO_3$ extraction and red pepper cultivation were introduced. Among the amendments, in general, dolomite and steel slag were the most effective in reduction of metal (Cd, Pb, and Zn) phytoavailability resulting in less accumulation of these metals in shoot and fruit of red pepper. However, dolomite and steel slag treatment was not as effective as clean soil cover treatment which showed the least metal accumulation in red pepper fruit. Nevertheless, with taking into account the cost, treatment of dolomite or steel slag can be competitive method because the current study showed that dolomite or steel slag treatment reduced accumulated heavy metal concentration effectively in both shoot and fruit of red pepper compared to those from control soil and the concentration in fruit was within the standard value (<0.2 mg $kg^{-1}$ for both Cd and Pb).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.296-300
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• 2001

In order to recycle the incineration ash (bottom ash and fly ash) generated from the incineration of municipal waste for a cement material, salts as well as heavy metal should be removed by the stabilization treatment. Most of these heavy metal and over 80% of salts are removed by a washing as a pre-treatment. However, wastewater which is another pollutant is generated by a washing, then proper treatment should be developed. First the characteristics of incineration ashes collected from two domestic full-sized incinerators were investigated and removal rate of salts and heavy metals from them also studied. The wastewater quality was compared to the criteria of the regulation by analyzing the characteristics of generated wastewater during the washing of incineration ash as a condition of liquid/solid ratio. Also, we tried to used this experimental results for the basic data to develop proper processing technique of municipal waste.

• 한국환경과학회지
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• 제15권11호
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• pp.1053-1059
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• 2006

This study was performed to investigate the possible uses of waste sludge for the removal of heavy metal ions. The adsorption experiments were conducted with wastes such as sewage treatment sludge, water treatment sludge and oyster shell to evaluate their sorption characteristics. Heavy metals selected were cadmium, copper and lead. in the sorption experiments on the sewage treatment sludge, water treatment sludge, oyster shell and soil, sorption occurred in the beginning and it reached equilibrium after 40 minutes on the oyster shell and 4 hour on the sewage treatment sludge and water treatment sludge. Results of Freundlich isotherms indicated that sewage treatment sludge could be properly used as an adsorbent for heavy metals and sorption strength of heavy metals was in the order of Pb > Cu > Cd. In the influence of pH on the adsorbents, sorption rate was more than 80% in pH 4 and most of heavy metals were adsorbed in pH 9. Adsorption rate of Cd decreased with decreasing pH and then adsorption rate of Cu was lower in soil.