• Environmental Engineering Research
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• 제24권3호
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• pp.434-442
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• 2019

The present study investigated a novel calcium hydroxide-coated dairy manure-derived biochar (Ca-BC) for adsorption of phosphate from water and dairy wastewater. The Ca-BC showed much higher adsorption of phosphate than that of dairy manure-derived biochar. The Ca-BC possessed mainly the calcium hydroxide and various functional groups resulting in high reactivity between phosphate and calcium hydroxide in the Ca-BC. The adsorption of phosphate onto Ca-BC followed pseudo-second order kinetic and Freundlich isotherm models indicating chemisorptive interaction occurred on energetically heterogeneous surface of Ca-BC. The maximum adsorption capacity of the Ca-BC was higher than those of iron oxide and zinc oxide-coated biochars, but lower than those of CaO- and MgO-coated biochars. However, the Ca-BC showed high reactivity per surface area for adsorption of phosphate indicating importance of surface functionalization of biochar. On the other hand, the adsorption of phosphate in dairy wastewater on Ca-BC was lower than that in water owing to competition between other anions in wastewater and phosphate. Overall, the Ca-BC would be a low cost and effective adsorbent for recovery of phosphate from water and wastewater.

• 한국폐기물자원순환학회지
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• 제34권5호
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• pp.468-473
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• 2017

This study was carried out to examine the characteristics of hydrogen sulfide adsorption using an iron hydroxide-based adsorbent. The prepared adsorbent was discussed with regard to its adsorption capacity and analyzed via surface analysis methods to illustrate the physical characteristics of hydrogen sulfide adsorption. As the drying temperature increased, the adsorption capacity of the adsorbent decreased from 29.15wt% to 22.73wt%. The adsorption capacity was decreased as the space velocity increased and showed an adsorption capacity of about 3.65 at $3,157.6h^{-1}$. The effect of sulfur dioxide was to decrease the adsorption capacity from 29.15wt% to 27.94wt%. The adsorbent exhibited the amorphous type in its physical appearance based on XRD and EDS analysis.

• 한국대기환경학회지
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• 제31권2호
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• pp.173-180
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• 2015

The purpose of this study was to fabricate a ferric nitrate impregnated activated carbon, and the performance for hydrogen sulfide by adsorption was evaluated. Sodium hydroxide was utilized to control pH in the process during generation of ferric hydroxide on the surface of the carbon. Critical mixing duration for generation of ferric hydroxide on the carbon was 48 hrs at pH 1 of the solution, in which the chemical adsorption of hydrogen sulfide was enhanced. The adsorption capacity of the impregnated carbon increased up to 0.10 g hydrogen sulfide/g carbon, which was 4.3 times higher than that of the raw carbon. Presence of FeOOH on the surface of the impregnated carbon was examined by X-ray diffraction.

• Journal of Microbiology and Biotechnology
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• 제25권12호
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• pp.2016-2023
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• 2015

Xylanase plays important roles in a broad range of industrial production as a biocatalyst, and its applications commonly require immobilization on supports to enhance its stability. Aluminum hydroxide, a carrier material with high surface area, has the advantages of simple and low-cost preparation and resistance to biodegradation, and can be potentially used as a proper support for xylanase immobilization. In this work, xylanase from Thermomyces lanuginosus was immobilized on two types of aluminum hydroxide particles (gibbsite and amorphous Al(OH)₃) through adsorption, and the properties of the adsorbed enzymes were studied. Both particles had considerable adsorptive capacity and affinity for xylanase. Xylanase retained 75% and 64% of the original catalytic activities after adsorption to gibbsite and amorphous Al(OH)₃. Both the adsorptions improved pH and thermal stability, lowered activation energy, and extended lifespan of the immobilized enzyme, as compared with the free enzyme. Xylanase adsorbed on gibbsite and amorphous Al(OH)₃ retained 71% and 64% of its initial activity, respectively, after being recycled five times. These results indicated that aluminum hydroxides served as good supports for xylanase immobilization. Therefore, the adsorption of xylanase on aluminum hydroxide particles has promising potential for practical production.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2217-2221
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• 2011

We investigated the selective deoxyribonucleic acid (DNA) adsorption on layered double hydroxide (LDH) nanoparticles via studying the interaction between positively charged LDH nanoparticle as adsorbent and negatively charged adsorbates such as methyl orange (MO), fluorescein (FL), and DNA strands. The size controlled LDH $(Mg_{0.78}Al_{0.22}(OH)_2(CO_3)_{0.11}{\cdot}mH_2O)$ was prepared by conventional coprecipitation method, followed by the hydrothermal treatment. According to the adsorption isotherms, the adsorbed amounts of MO and FL were similar, however, that of DNA were much larger. The adsorption behaviors were well fitted to Freundlich adsorption model. The concentration dependent adsorption behavior on LDH surface was described in order to verify the selective DNA separation ability. The result showed that the LDH has advantages in selective adsorption of DNA competing with single molecular anions.

• 상하수도학회지
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• 제19권4호
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• pp.404-410
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• 2005

A series of batch type adsorption experiments were performed to remove aquatic phosphorus, where the layered double hydroxide (HTAL-CI) was used as an powdered adsorbent. It showed high adsorption capacity (T-P removal: 99.9%) in the range of pH 5.5 to 8.8 in spite of providing low adsorption characteristics (pH<4). The adsorption isotherm was approximated as a modified Langmuir type equation, where the maximum adsorption amount (50.5mg-P/g) was obtained at around 80mg-P/L of phosphorus concentration. A phosphate ion can occupy three adsorption sites with a chloride ion considering the result that 1 mol of phosphate ion adsorbed corresponded to the 3 moles of chloride ion released. Although the chloride ion at less than 1,000mg-CI/L did not significantly affect the adsorption capacity of phosphate, carbonate ion inhibited the adsorption property.

• 한국물환경학회지
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• 제27권4호
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• pp.486-490
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• 2011

As(V) adsorption on aluminum oxide powder which was recycled from industrial wastes containing aluminum hydroxide was evaluated. Aluminum oxide powder in this study was prepared by calcinating aluminum hydroxide wastes at$550^{\circ}C$. Spectroscopic analysis indicated that the aluminum hydroxide wastes were changed to aluminum oxide by calcination. Arsenic adsorption isotherm was conducted with variation of ionic strength and multiple-ion systems using Ca(II) and Cu(II). As(V) removal showed typical anionic adsorption characteristics that the removal efficiency decreased with increasing pH in single As(V) system as well as in binary and ternary system. More than 80% of As(V) at an initial concentration of $5{\times}10^{-5}$ M was removed from aluminum oxide powder in As(V) single system. The effect of ionic strength on As(V) adsorption was negligible, which indicated the strong bonding between aluminum oxide powder and As(V). The removal efficiency of As(V) was higher in a binary system with Cu(II) than in a binary system with Ca(II).

• 약학회지
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• 제15권1호
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• pp.1-7
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• 1971

When a large quantity of insoluble drugs was added into a solution containing a small amount of soluble drugs, the latter was adsorbed to the former. Their adsorption was expected to alter the drug activity. Berberine hydrochloride (BH) was selected as a soluble drug and tested with frequently combined insoluble drugs and antacids for their adsorption phenomena in prufied water, gastric and intetinal fluid test solutions, respectively. The adsorption isotherms of kaolin and natural anuminum silicate with BH in the three media fitted the Langmuir (LM) equation, and that of talc in purified water and gastric fluid fitted it, but in intestinal fluid it fitted the Freudlich quation. The adsorption isotherm of aluminum hydroxide fitted the LM equation only in intestinal fluid. The degree of adsorption of BH in purified water and gastric fluid is in the following order: magnesium trisilicate, kaolin, natural aluminum silicate and talc; in intestinal fluid: magnesium trisilicate, kaolin, talc, natural aluminum silicate and aluminum hydroxide. Magnesium stearate did not adsorb BH.

• 대한토목학회논문집
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• 제29권1B호
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• pp.91-96
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• 2009

LDH(Layered double hydroxide) 물질을 제조하고 이를 이용하여 비소를 흡착시키는 실험을 수행하였다. TEM을 이용하여 제조한 LDH 물질의 형상을 살펴본 결과 열처리를 거친 시료는 나노크기의 결정화된 구조를 가지고 있고 열처리를 거치지 않은 시료는 아직 결정화가 완전히 이루어지지 않았으며 크기도 마이크로 범위에서 나타났다. X선 회절분석 결과를 보면 이 같은 결과가 뚜렷이 나타났으며, 열처리를 거친 경우는 뚜렷한 결정화를 보이고 있었다. $N_2$ 흡착 및 탈착 결과를 통해 LDH가 mesoporous한 공극 형태를 가지고 있다는 것을 알 수 있었다. 비표면적은 열처리를 거친 시료가 열처리를 거치지 않은 시료보다 2배 이상 크게 나타났다. 흡착 등온 실험 결과에서도 두 시료는 비슷한 흡착량을 보이며 기존 철산화 물에 못지않은 흡착능을 나타내고 있다. 금번에 합성한 Mg Fe-LDH 물질을 이용하여 토양 및 지하수의 비소 제거 공정에 적용할 수 있음을 확인하였다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 추계학술논문집 1부
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• pp.364-366
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• 2011

Polyimide (PI) grafted magnesium hydroxide was synthesised and characterised by XRD, TGA, SEM analysis. XRD patterns of $PI/Mg(OH)_2$ carried the peaks due to $Mg(OH)_2$ with decreased intensity. The $CO_2$ adsorption capacity of $PI/Mg(OH)_2$ at $50^{\circ}C$ was found to be 14 wt% revealing chemisorption of $CO_2$ on $Mg(OH)_2$ which could be regenerated at higher temperatures.