• 한국환경과학회지
• /
• 제2권4호
• /
• pp.357-365
• /
• 1993

This study was conducted for the efficient utilization of biomaterials such as starch residue, tangerine skin, and green tea residue, which are agricultral by-products discarded in Cheju Province annually, as adsorbents and biomaterials were examined for their removal ability of heavy metal ions in waste water by batch adsorption experiments. The removal efficiency of biomaterials for heavy metal ions was above 80-90% and almost similar to activated carbon and the adsorption ability of those treated with 포르말린 was improved in the green tea residue only for $Pb^{2+}$, $Cu^{2+}$, and $Zn^{2+}$. In the conditions of pH, the removal efficiency of heavy metal ions was high in the range of 5-7. In the solutions which heavy metal ions were mixed, the removal efficiency was similar at $Ag^+$, $Pb^{+2}$ and reduced to about 10% at the other ions, as compared with the solutions they were not mixed. Adsorption isotherm of biomaterials was generally obeyed to Freundlich formular than Langmuir formular and Freundlich constant, 1/n were obtained in the range of 0.1-0.5.

• Environmental Engineering Research
• /
• 제12권1호
• /
• pp.1-7
• /
• 2007

Most of the herb residue producing from oriental medical clinics(OMC) and hospitals(OMH) is wasted in Korea. To develop of adsorbent for removing heavy metal from wastewater, the various pre-treatment methods of the herb residue were evaluated by potentiometric titration, Freundlich isotherm adsorption test and the kinetic adsorption test. The herb residue was pre-treated for increasing the adsorption capacity by cleaning with distilled water, 0.1 N HCl and 0.1 N NaOH and by heating at $370^{\circ}C$ for 30 min. It showed a typical weak acid-weak base titration curve and a short pH break like commercial activated carbon during photentiometric titration of pre-treated herb residue. The log-log plots in the Freundlich isotherm test were linear on the herb residue pre-treated with NaOH or HCl like commercial activated carbon. The adsorption capacity(qe) in the Freundlich isotherm test for $Cr^{6+}$ was 1.5 times higher in the pre-treated herb residue with HCl than in activated carbon. On the other hand the herb residue pre-treated with NaOH showed the good adsorption capacities for $Pb^{2+}$, $Cu^{2+}$ and $Cd^{2+}$ even though those adsorption capacities were lower than that of activated carbon. In kinetic test, most of heavy metals removed within the first 10 min of contact and then approached to equilibrium with increasing contact time. The removal rate of heavy metals increased with an increase of the amount of adsorbent. Likewise, the removal rates of heavy metals were higher in the herb residue pre-treated with NaOH than in that pre-treated with HCl. The adsorption preference of herb residues pre-treated with NaOH or HCl was $Pb^{2+}>Cu^{2+}$ or $Cd^{2+}>Cr^{6+}$ in the order. Conclusively, the herb residue can be used as an alternative adsorbent for the removal of heavy metals depending on pr-treatment methods.

• 한국분말재료학회지
• /
• 제27권4호
• /
• pp.287-292
• /
• 2020

The subject of this study is a zeolite generated as a by-product of recycling LAS (lithium-aluminum-silicate) resources, a kind of glass and ceramic produced by induction. The zeolite by-product is modified into Mg-zeolite using Mg as a cation to absorb Pb, a heavy metal generated from water pollution caused by recent industrial wastewater. An ion-exchange method is used to carry out the modification process, from zeolite byproduct to Mg-zeolite, and simultaneously absorb the Pb in the heavy-metal solution (99.032 mg/L). It is found that the sodium zeolite in the raw material residue can be modified to magnesium zeolite by reacting it with a mixture solution at 1 M concentration for 24 h. As a result, it is found that the residual Pb (0.130 mg/L) in the heavy metal solution is shown to be absorbed by 99.86%, with successful formation of a Mg-modified zeolite.

• The Plant Pathology Journal
• /
• 제32권4호
• /
• pp.329-339
• /
• 2016

The short-term effects of low-level contamination by heavy metals (As, Cd, Cu, and Pb) on the soil health were examined by analyzing soil nematode community in soils planted with tomatoes. For this, the soils were irrigated with five metal concentrations ([1, 1/4, $1/4^2$, $1/4^3$, and 0] ${\times}$ maximum concentrations [MC] detected in irrigation waters near abandoned mine sites) for 18 weeks. Heavy metal concentrations were significantly increased in soils irrigated with MC of heavy metals, among which As and Cu exceeded the maximum heavy metal residue contents of soil approved in Korea. In no heavy metal treatment controls, nematode abundances for all trophic groups (except omnivorous-predatory nematodes [OP]) and colonizer-persister (cp) values (except cp-4-5) were significantly increased, and all maturity indices (except maturity index [MI] of plant-parasitic nematodes) and structure index (SI) were significantly decreased, suggesting the soil environments might have been disturbed during 18 weeks of tomato growth. There were no concentration-dependent significant decreases in richness, abundance, or MI for most heavy metals; however, their significant decreases occurred in abundance and richness of OP and cp-4, MI2-5 (excluding cp-1) and SI, indicating disturbed soil ecosystems, at the higher concentrations (MC and MC/4) of Pb that had the most significant negative correlation coefficients for heavy metal concentrations and nematode community among the heavy metals. Therefore, the short-term effects of low-level heavy metal contamination on soil health can be analyzed by nematode community structures before the appearance of plant damages caused by the abiotic agents, heavy metals.

• 한국농공학회논문집
• /
• 제54권3호
• /
• pp.1-9
• /
• 2012

As topographic characteristics of Korea where 64 % of the national land area is forest and only 17 % is being used as farmland, remediation of farmland contaminated by heavy metals is a considerably important issue. In this study, as an alternative of practically and effectively remediating farmland which was abandoned as its crop plants exceeded maximum residue limit of heavy metals due to mining impact, applicability of stabilization method was examined through the pilot-scale field experiment. Three plots ($L{\times}W{\times}D=3m{\times}2m{\times}0.3m$) were installed at the selected farmland and in plot 1, only soil of the selected farmland was applied, in pilot 2, soil of the selected farmland plus 3 % limestone (w/w) was applied and in pilot 3, soil of the selected farmland plus 3 % limestone was applied and then uncontaminated soil was covered thereon (0.3 m). After that, seeds of radish, Korean cabbage and soybean of which characteristics of edible portions are different were sowed on each plot and cultivated. Afterwards, at a proper harvesting time (app. 80 days later), crop plants and soil were collected and phytoavailability (0.11 M HOAc extractable) of heavy metals in soil and accumulated concentration of heavy metal in edible portion of crop plants were examined. As a result, it was revealed that phytoavailability of heavy metals in soil added with limestone (plot 2) was clearly reduced compared with plot 1 (untreated) and owing to this treatment, accumulated concentration of heavy metals in edible portion of crops was also clearly reduced compared with plot 1. While radish cultivated in plot 1 had exceeded maximum residue limit of agricultural products, in particular, plot 2 using limestone had shown concentration lower than maximum residue limit and this plot had shown little difference with 3 plot where crop was cultivated in uncontaminated soil cover. Therefore, it was considered that for abandoned farmland like the selected farmland, reducing mobility and phytoavailability of heavy metals and reducing crop uptake through stabilization method would be an effective and practical alternative for producing safe agricultural products on a sustained basis.

• 한국환경보건학회지
• /
• 제41권1호
• /
• pp.30-39
• /
• 2015

Objectives: This study was conducted to determine the heavy metal contents in commercial herbal medicines in Korea. Methods: Monitoring of lead, arsenic, cadmium and mercury was carried out on 116 samples of eleven types of herbal medicines. Among the total samples, 71 samples were domestic and 45 were imported. The samples were digested using the microwave method. The heavy metal contents were measured by inductively coupled plasma atomic emission spectrometry (ICP-AES) and a mercury analyzer. ICP-AES was used to analyze lead, arsenic cadmium. Mercury was analyzed by the amalgamation method. Results: The mean values of the heavy metal contents in the herbal medicines were Pb 0.64mg/kg, As 0.26mg/kg, Cd 0.07mg/kg and Hg 0.004mg/kg. Of the total samples, one violated the MFDS (Ministry of Food and Drug Safety) regulatory guidance on heavy metals in herbal medicines. Lead was detected at more than 5mg/kg in one sample. The measured values of arsenic, cadmium and mercury in the herbal medicines showed levels lower than the recommended levels for herbal medicines in MFDS regulatory guidance. In the comparison of domestic samples with imported herbal medicines, it was found that one domestic sample surpassed the maximum residue limits for lead. Conclusion: These results will be used to establish the regulation and control of heavy metal contents in herbal medicines. In addition, continuous monitoring is needed to ensure confidence in and the safety of these herbal medicines.

• 펄프종이기술
• /
• 제45권4호
• /
• pp.65-74
• /
• 2013

In the manufacture of corrugated box, the fibrous raw materials are mainly consisted of recycled papers, such as KOCC(Korean Old Corrugated Container), kraft sack, and AOCC(American Old Corrugated Container). Among these recycled waste paper, the proportion of KOCC is relatively higher than others in fibrous raw materials. Generally, KOCC shows some poor fiber properties and contains hazardous heavy metal sources. Therefore, it is to evaluate the property of recycled paper sources for eco-friendly corrugated box manufacture. In this study, the physical and mechanical properties of 3 kinds of recycled fibers and their mixed stocks were analyzed. The environmental assessment was also evaluated by analyzing the 4 representative heavy metal contents and evaporation residues in waste papers. As the results, KOCC showed the poorest fiber qualities and had the highest heavy metal contents and evaporation residues among the recycled fibers. Finally, the mechanical strength properties were increased by decreasing KOCC proportion of mixed stock conditions. In addition, the heavy metal contents and evaporation residues were also decreased by increasing recycled AOCC and kraft sack proportion.

• 한국지반신소재학회논문집
• /
• 제13권1호
• /
• pp.63-70
• /
• 2014

본 연구에서는 강우가 석산개발 주변에 위치한 하천의 오염도에 미치는 영향을 평가하기 위하여, 강우량과 중금속 오염도의 관계 및 강우량과 수질 오염도의 관계를 분석하였다. 석산개발 부지 인근의 하천에 대한 중금속 오염도 조사 결과, 매립부지에 사용된 전석, 잔사 및 석분이 직접적인 오염원으로 작용한 것으로 분석되었다. 또한 강우량 증가에 따른 하천 내 유수량이 중금속 오염도에 큰 영향을 미치는 것으로 확인되었다. 수질오염도는 우기철에서 건기철로 변화되는 시기에 증가하였으며, 강우량이 증가하면서 과거 석산개발 부지로부터 많은 부유물질이 배출된 후, 강우가 감소함에 따라 하천에 저류되어 오염도가 증가하는 것으로 나타났다. 따라서 S하천에서 지속적인 중금속 오염 및 수질오염이 발생하고 있는 원인으로는 과거 석산개발 완료 후, 매립층에 사용된 재료 및 석산개발 부지에서 오염원이 강우에 의해 배출되는 것으로 판단되었다.

• 한국약용작물학회지
• /
• 제15권3호
• /
• pp.220-226
• /
• 2007

우리나라 인삼의 대표적 재배지인 금산군에서 GAP인삼 생산을 희망하는 10농가를 선발하여, GAP인삼의 안전성에 영향을 미칠 수 있는 농약 및 중금속의 잔류 그리고 미생물 등의 위해요소가 오염되었는지 여부를 검토하였다. 검토 대상은 경작되고 있는 인삼을 비롯하여 인삼밭의 토양, 수질 등 3종류로 하였다. 토양에서의 농약잔류를 검사한 결과, 인삼농가 및 일반농가 토양에서 자주 사용되는 Carbendazim등 81개의 농약을 선발하여 분석하였으나, 인삼에 등록된 농약별 최대잔류허용수준을 초과하지 않고 모두 적합판정의 결과로 나타났다. 또한 인삼재배 토양에 중금속의 오염우려가 되는 비소 등8종류의 조사 하였으나 기준치 보다 적게나와 전부 적합 판정을 받았다. 한편 관개수 및 농약희석 살포 등으로 사용되는 수질을 조사한 결과도 조사된 10농가가 모두 안전하였다. 참여농가 밭에서 직접 채취한 인삼에서 24종의 농약을 분석한 결과도 적합 판정으로 나타났다. 조사농가 수삼에 존재하는 위해성 미생물 검사에서 Pantoea spp등 2종의 Gram 음성균과 1종의 그람양성균(Staphylococcus sciuri)이 동정되었으며, 일반세균 수는 $1.5{\times}10^3$ cfu/ml 로 다른 농산물보다 적은 수로 발견되었다. 따라서 이번 조사한 금산 지역에서는 GAP 인산재배 생산에 적합한 토양, 수질을 보였으며, 기존 생산한 인삼에서도 GAP 농산물 생산 기준에 적합하였다.

• 사상체질의학회지
• /
• 제22권3호
• /
• pp.132-140
• /
• 2010

1. Objective: To compare the contents and transfer rate of hazardous substances in crude, washing solution, crude after washing, decoction and remnant after boiling. 2. Methods: The heavy metal contents of each step were measured by inductively coupled plasma mass spectrometer (ICP-MS) and mercury analyzer (MA-2). In order to analyze pesticides in each sample we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide (SO2) were performed by Monier-Williams distillation method. 3. Results: 1) Contents (mg/kg) of heavy metals in decoction of all herbal medicine prescriptions were not detected. 2) Transfer rates (%) of heavy metals from crude to remnant were As (83.3%), Cd (100.0%), Pb (182.6%) and Hg (100.0%). 3) Contents (mg/kg) of residual pesticides were not detected. 4) Transfer rate (%) of sulfur dioxide (SO2) from crude to remnant was 44.2%. 4. Conclusion: Our results showed that boiled herbal medicine prescriptions which we take is safe from the hazardous substances.