• 한국토양비료학회지
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• 제21권2호
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• pp.169-175
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• 1988

토양중(土壤中)에서의 계면활성제(界面活性劑)의 분해(分解)와 pH, 유기물(有機物) 및 음(陰)이온이 토양(土壤)에 의한 계면활성제(界面活性劑)의 흡착(吸着)에 미치는 영향(影響)을 밝히고자 상이(相異)한 2개(個) 답토양(沓土壤)(안미통(安美統), 강서통(江西統))의 경작층(耕作層)에 대해 Dodecylbenzensulfonate(ABS)를 사용(使用)하여 실내시험(室內試驗)을 실시(實施)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 토양(土壤)에 의한 ABS의 흡착(吸着)은 ABS의 평균농도(平衡濃度)와 정(正)의 상관관계(相關關係)를 보여 주었다(안미통(安美統) r=0.9855, 강서통(江西統) r=0.9931). 2. 토양(土壤) 현탁액(懸濁液)의 pH가 4~5 일 때 토양(土壤)에 의한 ABS의 흡착(吸着)은 처리농도(處理濃度)($600{\mu}g$ ABS/g soil)의 약(約) 70%, pH 8 부근(部近)에서는 약(約) 20%가 흡착(吸着)되었다. 3. 전해질(電解質)의 종류(種類)에 의해서는 ABS의 흡착(吸着)을 영향(影響)을 받지 않았으나, 전해질(電解質)의 농도(濃度)는 ABS의 흡착(吸着)에 영향(影響)을 주어 저농도(低濃度)보다는 고농도(高濃度)에서 많은 흡착(吸着)이 일어났다. 4. 토양(土壤)에 의한 ABS의 흡착(吸着)은 토양(土壤) 유기물(有機物) 함량(含量)에 의해 영향(影響)을 받지 않는 것으로 나타났다. 5. 토양(土壤)과 ABS의 현탁액(懸濁液)을 1주간(週間) 항온(恒溫)할 경우, ABS는 $30^{\circ}C$에서 약(約) 85%, $10^{\circ}C$에서 약(約)10~15%가 분해(分解)되었다. 오수(汚水)를 넣어줄 경우에는 온도(溫度)에 관계(關係)없이 약(約) 85%가 분해(分解)되었다.

• 한국토양비료학회지
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• 제11권2호
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• pp.75-80
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• 1979

암모니움 탈착(脫着)을 16개(個) 토양에 대하여 $(NH_4)_2HPO_4$를 처리하여 0.01M $CaCl_2$로 7회(回) 연속침출(連續浸出)하여 검토하였다. 1. 탈착(脫着)은 2~4개의 속탈(速脫) 또는 완탈단계(緩脫段階)의 반복(反復)으로 진행(進行)된다. 2. 탈착단계(脫着段階)는 탈착량(脫着量)(y)과 침출회수(浸出回數)(x)간(間)에 log y=b-ax의 관계식(關係式)이 성립(成立)된다. 3. 탈착율(脫着率)(100${\times}$탈착량(脫着量)/흡착량(吸着量))은 15개(個) 토양평균이 65%였고 최고(最高)는 김천통(金泉統)의 87% 최소(最小)는 삼각통(三角統)의 32%였으며 이탄토(泥炭土)인 용호통(龍湖統)은 156%로 토양 ammonium 이 다량방출(多量放出)되었다. 4. 탈착률(脫着率)은 흡착량(吸着量)과 부(否)의 상관을 보이며 이 관계에서 토양은 세개의 계열(系列)로 분류(分類)되었다. 5. 탈착누적곡선(脫着累積曲線)은 최대치(最大値)에 접근(接近)하고 있으며 7회탈착(回脫着)으로 모든 토양이 최대치(最大値)에 접근(接近)하였다. 이때의 흡착량(吸着量)은 CEC의 502%(삼각통(三角統))에서 25%(김해통(金海統))의 범위(範圍)에 있었다. 6. 탈착량(脫着量) 또는 탈착률(脫着率)은 LAMA, (암모니움 Langmuir 최대흡착) CEC, 점토함량(粘土含量), 유효인산, 유기물함량등(有機物含量等)과 아무런 관계가 없었다. 7. 이상(以上)의 결과(結果)들은 ammonium의 흡착(吸着)과 탈착(脫着)에 있어 Fe, Al Si 등(等)의 관련성과 동반음(同伴陰) ion 흡탈착(吸脫着)이 관여함을 강하게 암시하는 것 같다.

• Journal of Applied Biological Chemistry
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• 제65권4호
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• pp.457-462
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• 2022

망간은 다양한 산화수로 존재하며 Mn(II)은 망간 중 가장 이동성이 높은 종으로 식물에 독성을 미치며 성장을 제한한다. 따라서, 본 연구의 목적은 다양한 흡착제를 이용하여 망간을 안정화함으로써 망간의 독성을 저감시키는 것이다. Ferrihydrite, schwertmannite, goethite를 합성하여 XRD로 확인하였고 망간 흡착에 사용하였다. Hematite는 구매하여 망간 흡착제로 사용하였다. CaNO₃, CaSO₄, CaCO₃와 같은 칼슘 화합물은 pH를 높이고 망간을 산화시키기 위해 사용하였다. 망간의 흡착을 위해 다양한 농도의 Mn(II) 용액을 4가지 철산화물, CaNO₃, CaSO₄, CaCO₃와 24시간 반응시킨 후 여과하여 용액에 남아있는 망간 농도를 ICP-OES로 분석하고 망간의 흡착율과 흡착등온식을 계산하였다. 그 결과, 철 산화물 중에서는 hematite에 의한 망간 흡착율이 가장 높았으며 ferrihydrite가 다음으로 흡착율이 높았다. 칼슘 화합물의 경우 CaCO₃>CaNO₃>CaSO₄ 순으로 흡착율이 높았다. CaCO₃은 hematite보다 높은 흡착율을 보였고 CaCO₃를 처리하면 pH를 증가시켜 망간의 독성을 감소하는 데 가장 효과적일 것으로 판단된다.

• 한국환경보건학회지
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• 제21권3호
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• pp.77-86
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• 1995

Lead(II) removal efficiency by natural kaolinite was investigated through laboratory experiments. This study was conducted in two phases-sorption and desorption. In the adsorption study, the influence of sorption kinetics and sorption isotherm and various parameters such as pH, temperature, coexisting other heavy metal ions on the lead adsorption was investigated. And desorption study was carried out in order to find the re-usability of kaolinite as an adsorbent. The results of the study are as follows. 1. Sorption kinetics was investigated under the condition of 2.5 mg/l adsorbent concentration, pH 6.5$\pm$0.05, temperature $30\pm 0.5\circ$C, initial lead(II) concentration 25 mg/l. Adsorption rate was initially rapid and the extent of adsorption arrived at adsorption equilibrium with 73% adsorption efficiency in an hour. 2. The sorption isotherm experiment was made with different initial lead(II) concentration. A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the sorption intensity (1/n) was 0.47 and the measure of sorption (k) was 2.44. So, it was concluded that sorption of lead(II) by kaolinite is effective. 3. The effect of pH on lead(II) sorption by kaolinite shows that at a pH of 3, only 6% of the total lead(II) was adsorbed and at a pH 9, 97% of the lead(II) was removed. And the effect of temperature on lead(II) sorption by kaolinite shows that as the temperature increased, the amount of lead(II) sorption per unit weight of kaolinite increased. But the effect was minor (p<0.05). 4. Sorption isotherm of lead coexisting cadmium (II) or zinc (II) was lower than that of lead itself. It was caused by the result of competitive sorption to adsorption site. And there was no difference between the sorption isotherm of cadmium and zinc. 5. In desorption studies, only 5.12% desorption took place in distilled water, while 52.08% in 0.1 N hydrochloric acid. Consequently used kaolinite could be regenerated by hydrochoric acid.

• 청정기술
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• 제17권2호
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• pp.97-102
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• 2011

입상활성탄에 의한 아마란스 염료의 흡착특성을 회분식 실험을 통해 조사하였다. 아마란스 염료의 흡착동력학적 연구는 298, 308, 318 K에서 초기농도 100, 200, 300 mg/L의 수용액을 가지고 수행하였다. 입상활성탄에 의한 아마란스 염료의 흡착 평형관계는 298K에서 Langmuir 등온식이 잘 적용되었다. 유사일차반응속도식과 유사이차반응속도식을 사용하여 동력학 실험값을 평가한 결과, 유사이차반응속도식이 더 잘 맞았으며, 속도상수($k_2$) 값은 아마란스 초기농도 100, 200, 300 mg/L 에 대해 각각 0.1076, 0.0531 및 0.0309 g/$mg{\cdot}h$로 조사되었다. 활성화에너지, 표준엔탈피, 표준엔트로피 및 표준자유에너지를 평가하였다. 조사된 표준자유에너지값은 초기농도 200 mg/L 에서 -5.08 ~ -8.10 kJ/mol로 자발적인 공정임을 알 수 있었다. 엔탈피변화량이 양의 값인 38.89 kJ/mol을 나타내어 활성탄에 대한 아마란스 염료의 흡착이 흡열반응으로 일어난다는 것을 알 수 있었다.

• 한국환경과학회지
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• 제20권2호
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• pp.241-249
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• 2011

In this research, equilibrium of adsorption and kinetics of As(V) removal were investigated. The coal mine drainage sludge(CMDS) was used as adsorbent. To find out the physical and chemical properties of CMDS, XRD (X-ray diffraction), XRF (X-ray fluorescence spectrometer) analysis were carried out. The CMDS was consist of 70% of goethite and 30% of calcite. From the results, an adsorption mechanism of As(V) with CMDS was dominated by iron oxides. Langmuir adsorption isotherm model was fitted well more than Freundlich isotherm adsorption model. Adsorption capacities of CMDS 1 was not different with CMDS 2 on aspect of amounts of arsenic adsorbed. The maximum adsorption amount of two CMDS were respectively 40.816, 39.682 mg/g. However, the kinetic of two CMDS was different. The kinetic was followed pseudo second order model than pseudo first order model. Concentrations of arsenic in all segments of the polymer in CMDS 2 does not have a constant value, but the rate was greater than the value of CMDS 1. Therefore, CMDS 2, which is containing polymer, is more effective for adsorbent to remove As(V).

• Macromolecular Research
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• 제16권6호
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• pp.492-502
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• 2008

This study examined the adsorption of a synthetic cutting fluid and cutting fluid effluent on chitosan and SDS-modified chitosan, Chitosan and SDS-modified chitosan were prepared in form of beads and fibers. A series of batch experiments were carried out as a function of the initial concentration of cutting fluid, contact time and pH of the fluid. The contact angle study suggested that the SDS-modified chitosan was more hydrophobic than chitosan. The Zeta potential study showed that chitosan, SDS-modified chitosan and synthetic cutting fluid had a point of zero charge (PZC) at pH 7.8, 9 and 3.2, respectively. SDS-modified chitosan has a greater adsorption capacity than chitosan. The experimental results show that adsorption capacity of the cutting fluid on 1.0 g of SDS-modified chitosan at pH 3 and for a contact time of 120 min was approximately 2,500 g/kg. The adsorption capacity of chitosan and SDS-modified chitosan increased with decreasing pH. The Langmuir, Freundlich, and Brunauer Emmett and Teller (BET) adsorption models were used to explain the adsorption isotherm. The Langmuir isotherm fitted well with the experimental data of chitosan while the BET isotherm fitted well with the SDS-modified chitosan data. Pseudo first- and second-order kinetic models and intraparticle diffusion model were used to examine the kinetic data. The experimental data was fitted well to a pseudo second-order kinetic model. The significant uptake of cutting fluid on chitosan and SDS-modified chitosan were demonstrated by FT-IR spectroscopy, SEM and heat of combustion.

• 한국물환경학회지
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• 제35권2호
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• pp.123-130
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• 2019

Ethylenediaminetetraacetic acid-modified bentonite (EMB) was used for adsorption of zinc ion (Zn) from aqueous solution, compared with unmodified bentonite (UB). Parameters such as dose (0.750 ~ 3.125 g/L), mixing intensity (10 ~ 150 rpm), contact time (0.17 ~ 30 min), pH (2 ~ 7), and temperature (298 ~ 338 K), were studied. Zn removal efficiency for EMB was 20 ~ 30 % higher, than that for UB, in all experiments. Thermodynamic studies demonstrated that adsorption process was spontaneous with Gibb's free energy (${\Delta}G$) values, ranging between -5.211 and -7.175 kJ/mol for EMB, and -0.984 and -2.059 kJ/mol for UB, and endothermic with enthalpy (${\Delta}H$) value of 9.418 kJ/mol for EMB and 7.022 kJ/mol for UB. Adsorption kinetics was found to follow the pseudo-second order kinetics model, and its rate constant was 3.41 for EMB and $2.00g/mg{\cdot}min$ for UB. Adsorption equilibrium data for EMB were best represented by the Langmuir adsorption isotherm, and calculated maximum adsorption capacity was 2.768 mg/g. It was found that the best conditions for Zn removal of EMB within the range of operation used, were 3.125 g/L dose, 90 rpm intensity, 10 min contact time, pH 4, and 338 K. Therefore, EMB has good potential for adsorption of Zn.

• 한국환경과학회지
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• 제29권12호
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• pp.1261-1274
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• 2020

The characteristics of ammonia-nitrogen (NH4+-N) adsorption by a zeolitic material synthesized from Jeju scoria using the fusion and hydrothermal method was studied. The synthetic zeolitic material (Z-SA) was identified as a Na-A zeolite by X-ray diffraction, X-ray fluorescence analysis and scanning electron microscopy images. The adsorption of NH4+-N using Jeju scoria and different types of zeolite such as the Z-SA, natural zeolite, and commercial pure zeolite (Na-A zeolite, Z-CS) was compared. The equilibrium of NH4+-N adsorption was reached within 30 min for Z-SA and Z-CS, and after 60 min for Jeju scoria and natural zeolite. The adsorption capacity of NH4+-N increased with approaching to neutral when pH was in the range of 3-7, but decreased above 7. The removal efficiency of NH4+-N increased with increasing Z-SA dosage, however, its adsorption capacity decreased. For initial NH4+-N concentrations of 10-200 mg/L at pH 7, the adsorption rate of NH4+-N was well described by the pseudo second-order kinetic model than the pseudo first-order kinetic model. The adsorption isotherm was well fitted by the Langmuir model. The maximum uptake of NH4+-N obtained from the Langmuir model decreased in the order of Z-CS (46.8 mg/g) > Z-SA (31.3 mg/g) > natural zeolite (5.6 mg/g) > Jeju scoria (0.2 mg/g).

• 한국환경보건학회지
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• 제24권3호
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• pp.124-130
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• 1998

This study was to examine the utilization of waste egg snells for removal of heavy metals in laboratory wastewater. It was estimated that pH increasing formed heavy metals into a hydroxide and then settled to remove them. Removal rate of heavy metals were increased as increased dosage, low adsorbate concentration and passed reaction time. Average adsorption volumes of Cr, Cu, Mn and Pb per g were about 1.21 mg, 1.1 mg, 0.96 mg and 1.04 mg, respectively. If we reflected the adsorption capacity(k) and adsorption intensity(1/n) of Freundlich isotherm, we couldn't consider waste egg shells as a good adsorbent. It seemed that heavy metals contained in complex wastewater was removed to be influenced by inital pH, solubilities with passed reaction rime and competitive reaction.