• Advances in environmental research
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• 제7권1호
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• pp.53-71
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• 2018

Waste glass disposal causes environmental problems in the cities. To find a suitable green environmental solution for this problem low cost adsorbent in this study was prepared from waste glass. An effective new green adsorbent was synthesized by hydrothermal treatment of waste glass (WG), followed by acidic activation of its surface by HCl (WGP). The prepared adsorbent was characterized by scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), and BET surface measurement. The developed adsorbent was used for the removal of heavy metals (Cd, Cu, Fe, Pb and Zn) from well water. Batch experiments were conducted to test the ability of the prepared adsorbent for the removal of Cd, Cu, Fe, Pb and Zn from well water. The experiments of the heavy metals adsorption by adsorbent (WGP) were performed at different metal ion concentrations, solution pH, adsorbent dosage and contact time. The Langmuir and Freundlich adsorption isotherms and kinetic models were used to verify the adsorption performance. The results indicated high removal efficiencies (99-100%) for all the studied heavy metals at pH 7 at constant contact time of 2 h. The data obtained from adsorption isotherms of metal ions at different time fitted well to linear form of the Langmuir sorption equation, and pseudo-second-order kinetic model. Application of the resulted conditions on well water demonstrated that the modified waste glass adsorbent successfully adsorbed heavy metals (Cd, Cu, Fe, Pb and Zn) from well water.

• 한국환경농학회지
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• 제23권4호
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• pp.240-244
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• 2004

The objective of this research was to develop the adsorbent far heavy metals by activating the bark sample. Barks from pine tree with diameters of $2{\sim}4\;mm$ were activated in the muffle furnace under a high relative humidity condition at temperatures of $600{\sim}900^{\circ}C$. The removal efficiency of the activated bark (ACTBARK) for Cu and Cd was temperature dependent showing the order of $900^{\circ}C$ > $800^{\circ}C$ > $700^{\circ}C$ > $600^{\circ}C$. The critical temperature was considered to be $900^{\circ}C$ to become an efficient adsorbent for Cu and Cd. The bark samples activated at temperatures lower than $700^{\circ}C$ showed a less removal efficiency than the crude bark. The ACTBARK activated at $900^{\circ}C$ removed more Cu and Cd from solution than the commercial activated carbon and charcoal. The ACTBARK (activated at $900^{\circ}C$) adsorbed all of the Cu and Cd in solution with concentrations less than 150 mg/L. The selectivity of the ACTBARK was in the order of Cu > Zn > Ni > Pb > Fe > Cd > Mn.

• 한국잡초학회지
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• 제5권2호
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• pp.149-154
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• 1985

열대성(熱帶性) 수생식물(水生植物)인 부레옥잠(Eichhornia crassipes)의 오염물질(汚染物質) 제거효율(除去效率)에 관한 실험(實驗)을 통해 나타난 결과(結果)를 요약(要約)하면 다음과 같다. 1. 초기농도(初期濃度) 10, 25 및 50 ppm 용액(溶液)에 대해 처리(處理) 3일후(日後) 질산성질소(窒酸性窒素)는 0.7, 0.9 및 1.2ppm 그리고 인산염(燐酸鹽)은 0.1, 0.2 및 0.5ppm 으로 제거(除去)되었으며, 이러한 영양염류(營養鹽類)의 제거능력(除去能力)은 초기(初期)에서 더욱 높았다. 2. 중금속(重金屬)의 제거(除去)는 Cu, Pb에서 컸으며, 중금속(重金屬)에 의한 부레옥잠 피해는 Cu, C에서 심하였고, 식물체에 의한 중금속(重金屬) 제거경향(除去傾向)은 대상 중금속의 종류(種類)에 따라 서로 달랐다. 3. 식물체(植物體)로 흡수(吸收) 제거(除去)된 중금속량(重金屬量)은 농도(濃度)가 높을수록 많았고, 중금속별(重金屬別)로는 Cu, Pb, Cr, Cd의 순이었으며, 식물체내(植物體內)에서의 분포는 뿌리 부분에 많았다. 4. 부레옥잠 처리(處理) 10일후(日後)의 식물체내(植物體內)로의 중금속(重金屬) 흡수(吸收)와 뿌리에 흡착(吸着)은 모두 Cu와 Pb는 Cr과 Cd에 비하여 컸으며, 뿌리에의 흡착량(吸着量)은 농도(濃度)가 높을수록 많았고, 중금속별(重金屬別)로는 Cu, Pb, Cd, Cr 순(順)이었다.

• 한국환경농학회지
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• 제28권1호
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• pp.69-74
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• 2009

본 연구는 탄닌 성분이 다량 함유된 율피를 사용하여 폐수 중 중금속 3종(Cd, Pb, Cu)에 대한 흡착특성을 알아보고 향후 폐수처리공정에서 생물흡착소재의 적응가능성을 평가하고자 수행하였다. 실험에 사용한 인공폐수에는 Cu, Pb, Cd을 첨가하여 10, 20, 40, 60, 100, 150, 200 mg $L^{-1}$ 오염시켰으며 pH 5.5에서 흡착실험을 진행하였다. 율피의 중금속 흡착량은 중금속 유형별로 차이를 나타내었으며 중금속 농도가 증가함에 따라 흡착량이 증가하다가 점차 증가율이 감소하여 일절한 평형에 도달하는 경향을 나타내었는데 이는 율피의 표면이 피흡착물질로 채워져 비어있는 흡착가능 영역이 감소하기 때문인 것으로 판단되었다. 상기 연구 결과를 Freundlich 및 Langmuir 모델에 적응한 결과 $r^2$값은 Langmuir 모델에서 Pb, Cu, Cd 3가지 중금속 모두 0.99 이상으로 높게 나타났으며 각 중금속에 대한 율피의 흡착친화도는 Pb>Cu>Cd 순으로 최대흡착량($q_m$)은 Pb 31.25 mg $g^{-1}$, Cu 7.87 mg $g^{-1}$, Cd 6.85 mg $g^{-1}$로 조사되었다. FT-IR 분석결과 율피는 1080 $cm^{-1}$에서 carbonyl group, hydroxyl group, carboxyl group과 1200 $cm^{-1}$에서 1700 $cm^{-1}$ 사이의 carboxylate group, carboxyl group, methylene group, ester group 등이 존재하는 것으로 조사되었다. SEM 분석 결과 중금속 이온 흡착 전에는 표면이 매끄럽게 안정된 모습이 관찰되었지만 중금속 흡착 반응 후 전자밀도가 높은 부분이 관찰되어 중금속 이온이 흡착되었을 것으로 판단되었고 EDS 분석을 수행한 결과 중금속 이온의 흡착 후 표면의 납 이온 피크가 관찰되었다. 이상의 결과로부터 율피에 의한 중금속 이온의 흡착은 물리적인 흡착보다는 관능기에 의한 화학적 흡착일 것으로 판단되었다.

• Bulletin of the Korean Chemical Society
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• 제25권7호
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• pp.969-976
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• 2004

Cassava peelings waste, which is both a waste and pollutant, was chemically modified using mercaptoacetic acid (MAA) and used to adsorb $Cu^{2+}\;and\;Cd^{2+}$ from aqueous solution over a wide range of reaction conditions at $30^{\circ}C$. Acid modification produced a larger surface area, which significantly enhanced the metal ion binding capacity of the biomass. An adsorption model based on the $Cu^{2+}/Cd^{2+}$ adsorption differences was developed to predict the competition of the two metal ions towards binding sites for a mixed metal ion system. The phytosorption process was examined in terms of Langmuir, Freundlich and Dubinin-Radushkevich models. The models indicate that the cassava waste biomass had a greater phytosorption capacity, higher affinity and greater sorption intensity for $Cu^{2+}\;than\;Cd^{2+}$. According to the evaluation using Langmuir equation, the monolayer binding capacity obtained was 127.3 mg/g $Cu^{2+}$ and 119.6 mg/g $Cd^{2+}$. The kinetic studies showed that the phytosorption rates could be described better by a pseudo-second order process and the rate coefficients was determined to be $2.04{\times}10^{-3}\;min^{-1}\;and\;1.98{\times}10^{-3}\;min^{-1}\;for\;Cu^{2+}\;and\;Cd^{2+}$ respectively. The results from these studies indicated that acid treated cassava waste biomass could be an efficient sorbent for the removal of toxic and valuable metals from industrial effluents.

• 한국환경농학회지
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• 제35권1호
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• pp.79-86
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• 2016

본 연구는 인 축적능을 갖는 것으로 알려진 미생물인 Alcaligenes sp.의 생장 및 인 축적에 중금속이 미치는 영향을 정량적으로 평가하고자 실시되었다. 미생물의 생장 및 인 제거에 미치는 저해효과를 정량적 평가를 위해 생장저해 정도와 인 제거반응저해 정도를 IC₅₀와 EC₅₀를 이용하여 표현하였고, 중금속 간 교호작용의 평가를 위해 Additive Index Value method (A.I.V) 를 이용하여 중금속 간 혼합효과를 판단하였다. 실험 결과를 통해 Alcaligenes sp.의 생장 및 인 제거에 미치는 저해효과가 가장 큰 중금속은 카드뮴(Cd)이었다. 반면, 상대적으로 저해효과가 약한 중금속은 니켈(Ni)이었다. 모든 중금속은 처리 농도가 증가할수록 미생물의 생장과 인 제거율을 감소시키는 것을 확인할 수 있었다. 단일 중금속 처리시 IC₅₀에 해당하는 농도는 Cd 0.38, Cu 16.43, Zn 12.17, Pb 11.68, Ni 15.35 mg/L 이다. 연구에 사용된 균주 Alcaligenes sp. 의 인 제거율은 88.1%였고, EC₅₀에 해당하는 농도는 Cd 0.31, Cu 10.37, Zn 5.57, Pb 6.74, Ni 12.04 mg/L 이다. 두 종의 중금속을 혼합 처리하였을 때 IC₅₀에 해당하는 농도가 가장 낮은 중금속 처리구는 Cd + Cu 처리구였으며, 가장 높은 처리구는 Zn + Pb 처리구였다. EC₅₀의 농도는 Cd + Cu 처리구에서 가장 낮은 농도를, Cu + Ni 처리구에서 가장 높은 농도를 보였다. 중금속 간 교호작용은 대부분 길항효과(antagonistic effect)를 보였으나, IC₅₀의 경우, Cu + Zn, Cu + Pb, Cu + Ni, Pb + Ni 처리구에서 상승효과(synergistic effect)를 보이는 것을 확인할 수 있었고, EC₅₀에서는 Cu + Zn, Pb + Ni 처리구에서 상가효과(additive effect)를, Cu + Ni 처리구에서 상승효과(synergistic effect)를 보였다. 연구 결과는 중금속을 단일 및 2종 혼합 처리하였을 때 중금속이 인 제거 미생물의 생장 및 기능에 미치는 독성효과에 대한 기초자료를 제공함으로써 추후 진행될 미생물 단백질 동정, 중금속 독성평가에 관한 연구에 활용될 수 있을 것이라 사료된다.

• Carbon letters
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• 제7권4호
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• pp.249-258
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• 2006

Treatment of water hyacinth with sulphuric acid produces carbonaceous materials that have been used to remove Cu(II) and Cd (II) ions from aqueous solutions. Untreated water hyacinth was also used for the subject of comparison. The textural properties of the carbonaceous materials were determined from nitrogen adsorption at 77 K. The optimum pH for the sorption of Cu (II) and Cd (II) ions on the investigated sorbents was determined. Dynamic adsorption measurements have been taken at 298 K whereas equilibrium measurements were carried out at 298, 313 and 323 K. The adsorption of nitrogen at 77 K on the untreated sample was too low and the surface areas of the treated samples 2, 3 and 4 were found between $70-208\;m^2/g$. The total pore volumes of these samples which were determined for the carbonaceous materials investigated were found to be 0.076-0.140 ml/g. The kinetic adsorption data of Cu (II) and Cd(II) were applicable to both pseudo - first and pseudo-second order but fit more the latter order. The equilibrium adsorption data were found to fit Freundlich and Langmiur equations. The values of DG, DH and DS are all negative indicating the feasibility and the spontaneous nature of the sorption of Cu (II) and Cd (II) ions by the sorbents investigated.

• 한국환경보건학회지
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• 제45권6호
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• pp.561-568
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• 2019

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.

• 한국환경보건학회지
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• 제29권3호
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• pp.50-58
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• 2003

Removal of heavy metal ions (Cd$^{2+}$, Cr$^{3+}$, Cu$^{2+}$, Pb$^{2+}$) by several chitosans was studied and the molecular weight of chitosan was investigated in order to examine the effect of autoclaving. Chitosan were divided into 3 groups (A type, controlled chitosan; B type, autoclaved for 15 min; C type, autoclaved for 60 min). The heavy metal removal capacity and rate of B type chitosan were higher than those of A type and B type chitosan. The molecular weight of chitosan was decreased by the increase of autoclaving time. Therefore, the heavy metal capacity was not well correlated to the molecular weight. Freundlich and Langmuir isotherm was determined from the experimental results of equilibrium adsorption for individual heavy metal ions on chitosan. Langmuir isotherm was well fitted to this experimental data. The heavy metal removal capacity of B type chitosan was in the order of Pb$^{2+}$ > Cu$^{2+}$ > Cd$^{2+}$> Cr$^{3+}$.3+/.$.3+/.

• 분석과학
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• 제19권4호
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• pp.280-284
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• 2006

The objective of this study is to investigate the removal of heavy metal by using the coprecipitation of barium sulfate. Several parameters governing the efficiency of the coprecipitation method were evaluated by the pH of sample solution, amount of coprecipitant, and addition of sulfide for the removal of As(V), Cd(II), Cr(III), Cr(VI), Cu(II), Hg(II) and Pb(II) metal ions ($10{\mu}g/ml$ each). The coprecipitation was about 80% - 95% only for lead at low pH but under 10% for other ions. The amount of removal was about 95% - 100% for Cd, Hg, Pb, Cu in the all pH range by the addition of sulfide with barium sulfate but As(V) and Cr(III, VI) ions were not affected by the same conditions.