• Advances in environmental research
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• 제6권2호
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• pp.127-137
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• 2017

Cotton is the major fiber crop in Pakistan that accounts for 2% of total national gross domestic product (GDP). After picking of cotton, the dry stalks are major organic waste that has no fate except burning to cook food in villages. Present research focuses use of cotton stalks as feedstock for biochar production, its characterization and effects on soil characteristics. Dry cotton stalks collected from agricultural field of Bahauddin Zakariya University, Multan, Pakistan were combusted under anaerobic conditions at $450^{\circ}C$. The physicochemical analysis of biochar and cotton stalks show higher values of % total carbon, phosphorus and potassium concentrations in biochar as compared to cotton stalks. The concentration of nitrogen was decreased in biochar. Similarly biochar had greater values of fixed carbon that suggest its role for carbon sequestration and as a soil amendment. The fourier transformation infrared spectroscopic spectra (FTIR) of cotton stalks and biochar exposed more acidic groups in biochar as compared to cotton stalks. The newly developed functional groups in biochar have vital role in increasing surface properties, cation exchange capacity, and water holding capacity, and are responsible for heavy metal remediation in contaminated soil. In a further test, results show increase in the water holding capacity and nutrient retention by a sandy soil amended with biochar. It is concluded that cotton stalks can be effectively used to prepare biochar.

• 펄프종이기술
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• 제36권5호
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• pp.29-35
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• 2004

Fiber dimensions, their derived values and chemical properties of cotton stalks (Gosypium hirsutum L), jute stick (Corchorus capsularis) and dhancha (Sesbania aculeate) have been examined to assess their suitability for paper production. Cotton stalks have a good derived values especially slender ratio, which is comparable to hardwood. The flexibility coefficient of these three non wood plants is better than hardwood. Anatomical analysis shows higher percentage of fibers and vessels than in general non wood plants. Lignin, $\alpha$-cellulose and pentosan contents in these three nonwood plants are within the range of hardwood. Neutral sugar analysis of cotton stalks, jute stick and dhancha shows that the glucose in the major sugar followed by xylose and mannose. The arabinose and galactose are present in minor amount. Alkaline nitrobenzene oxidation of cotton stalks, jute stick and dhancha wood meal exhibits that these nonwood plant lignins mainly consist of syringyl (S) and guaiacyl (V) units. The S/V ratios are 1.6, 1.2 and 2.1 for cotton stalks, jute stick and dhancha, respectively.

• Carbon letters
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• 제14권1호
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• pp.14-21
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• 2013

Physically and chemically activated carbons (ACs) exhibited high adsorption capacities for organic and inorganic pollutants compared with other adsorbents due to their expanded surface areas and wide pore volume distribution. In this work, seven steam-ACs with different burn-off have been prepared from cotton stalks. The textural properties of these sorbents were determined using nitrogen adsorption at $-196^{\circ}C$. The chemistry of the surface of the present sorbents was characterized by determining the surface functional C-O groups using Fourier transform infrared spectroscopy, surface pH, $pH_{pzc}$, and Boehm's acid-base neutralization method. The textural properties and the morphology of the sorbent surface depend on the percentage of burn-off. The surface acidity and surface basicity are related to the burn-off percentage. A theoretical model was developed to find a mathematical expression that relates the % burn-off to ash content, surface area, and mean pore radius. Also, the chemistry of the carbon surface is related to the % burn-off. A mathematical expression was proposed where % burn-off was taken as an independent factor and the other variable as a dependent factor. This expression allows the choice of the value of % burn-off with required steam-AC properties.

• Carbon letters
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• 제11권3호
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• pp.224-234
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• 2010

Four activated carbons were produced by two-stage process as followings; semi-carbonization of indigenous biomass waste, i.e. cotton stalks, followed by chemical activation with KOH under various activation temperatures and chemical ratios of KOH to semi-carbonized cotton stalks (CCS). The surface area, total pore volume and average pore diameter were evaluated by $N_2$-adsorption at 77 K. The surface morphology and oxygen functional groups were determined by SEM and FTIR, respectively. Batch equilibrium and kinetic studies were carried out by using a basic dye, methylene blue as a probe molecule to evaluate the adsorption capacity and mechanism over the produced carbons. The obtained activated carbon (CCS-1K800) exhibited highly microporous structure with high surface area of 950 $m^2/g$, total pore volume of 0.423 $cm^3/g$ and average pore diameter of 17.8 ${\AA}$. The isotherm data fitted well to the Langmuir isotherm with monolayer adsorption capacity of 222 mg/g for CCS-1K800. The kinetic data obtained at different concentrations were analyzed using a pseudo-first-order, pseudo-second-order and intraparticle diffusion equations. The pseudo-second-order model fitted better for kinetic removal of MB dye. The results indicate that such laboratory carbons could be employed as low cost alternative to commercial carbons in wastewater treatment.

• Carbon letters
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• 제12권1호
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• pp.1-7
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• 2011

In the present study, the removal of Pb (II) ions on oxidized activated carbons (ACs) was investigated. ACs were derived from activation of indigenous cotton stalks waste with potassium hydroxide (KOH) in two-stage process. The KOH-ACs were subjected to liquid-phase oxidation with hot $HNO_3$ and one untreated sample was included for comparison. The obtained carbons were characterized by Fourier transform infrared (FTIR), slurry pH and $N_2$-adsorption at 77 K, respectively. Adsorption capacity of Pb (II) ions on the resultant carbons was determined by batch equilibrium experiments. The experimental results indicated that the oxidation with nitric acid was associated with a significant increase in mass of yield as well as a remarkable reduction in internal porosity as compared to the untreated carbon. The AC-800N revealed higher adsorption capacity than that of AC-800, although the former sample exhibited low surface area and micropore volume. It was observed that the adsorption capacity enhancement attributed to pore widening, the generation of oxygen functional groups and potassium containing compounds leading to cation-exchange on the carbon surface. These results show that the oxidized carbons represented prospective adsorbents for enhancing the removal of heavy metals from wastewater.

• 한국잠사곤충학회지
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• 제47권2호
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• pp.78-87
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• 2005

본 연구는 우리 야생화중 비교적 대량번식이 가능한 종인 물레나물의 줄기, 꽃, 잎을 채취하여 염액을 추출하고, 다양한 염색 조건에서 견과 면 소재를 염색하여 염색거동을 살펴보고 염색된 색상에 대하여 고찰하여 다음과 같은 결과를 얻었다. 1. pH에 따른 염색에서 견이 면보다 진하게 염색되었고 pH가 중성일때 물레나물은 견 일때 가장 진하게 염색되었다. 2. 염색온도에 따른 염착량은 견과 면 구분 없이 큰 차이가 없었으나 물레나물의 경우 온도가 높아질수록 견이 면보다 약간 진하게 염색되었다. 3. 염색시간이 1시간에서 2시간 사이에서 급격한 Y값의 감소를 보여 이 시간대에서 많은 염착이 이루어 졌다. 4. 면은 염 첨가 농도로 높을수록 Y값이 낮아져 염이 촉염효과 역할을 하는 것으로 보여 졌으나 견의 경우 염 첨가에 따른 Y의 값은 끈 변화가 없는 것으로 나타났다. 5. 물레나물의 염액 농도에 따른 염색성은 견, 면 모두 농도가 작아지면 염착량이 작아졌다. 6. 견의 경우 매염제의 대한 매염효과가 높게 나타나고 있으나 농도는 큰 영향을 미치지 않았다. 면에서 물레나물은 매염효과가 전혀 없는 것으로 나타났다.

• 원예과학기술지
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• 제16권1호
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• pp.42-44
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• 1998

호접란의 화경액아배양을 호르몬의 첨가없이 대량번식에 이용할 수 있도록 PLB 형성과 증식, 유식물분화를 위한 배지조성을 구명한 결과는 다음과 같다. PLB 형성을 위해서는 1.2X VW 배지에 사과추출물과 감자추출물, sucrose 1%, PVP 1.5g/l 또는 활성 탄소 2.5g/l, gellan gum 4g/l을 첨가하는 것이 가장 양호하였다. PLB 증식을 위해서는 sucrose 2%와 사과추출물과 감자추출물을 첨가한 VW에 cotton plate를 지지물로 사용한 것이 가장 양호하였다. 유식물의 재분화를 위해서는 Hyponex 3g/l에 사과와 감자추출물을 각각 3%, 바나나추출물은 4%를 혼용첨가한 배지가 가장 효과적이었다.

• 한국잠사곤충학회지
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• 제48권2호
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• pp.46-55
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• 2006

본 연구는 우리 야생화중 비교적 대량번식이 가능한 종인 산비장이의 줄기, 꽃, 잎을 채취하여 염액을 추출하고, 다양한 염색 조건에서 견과 면 소재를 염색하여 염색거동을 살펴보고 염색된 색상에 대하여 고찰하여 다음과 같은 결과를 얻었다. 1. pH에 따른 염색에서 견은 pH가 낮을수록 진하게 염색되었고 면은 pH가 중성일 때 가장 진하게 염색되었다. 2. 염색온도에 따른 염착량은 견과 면 구분 없이 큰 차이가 없었다. 3. 염색시간이 1시간에서 2시간 사이에서 급격한 Y값의 감소를 보여 이 시간대에서 많은 염착이 이루어 졌다. 4. 면은 염 첨가 농도로 높을수록 Y값이 낮아져 염이 촉염효과 역할을 하는 것으로 보여 졌으나 견의 경우 염첨가에 따른 Y의 값은 큰 변화가 없는 것으로 나타났다. 5. 염액 농도에 따른 염색성은 견, 면 모두 농도가 작아지면 염착량이 작아졌다. 6. 견의 경우 매염제의 대한 매염효과가 높게 나타나고 있으나 매염제 농도는 큰 영향을 미치지 않았다. 면에서 철(Fe)과 구리(Cu)에 대한 매염효과만 조금 있었다.