• Title/Summary/Keyword: H&N Ca.

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Determining Effect of Oyster Shell on Cadmium Extractability and Mechanism of Immobilization in Arable Soil (농경지 토양에서 패화석에 의한 카드뮴의 용출성 및 부동화 기작 구명)

  • Hong, Chang-Oh;Noh, Yong-Dong;Kim, Sang-Yoon;Kim, Pil-Joo
    • Korean Journal of Environmental Agriculture
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    • v.33 no.4
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    • pp.245-253
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    • 2014
  • BACKGROUND: Oyster shell(OS) is alkaline with pH 9.8, porous, and has high concentration of $CaCO_3$. It could be used as an alternative of lime fertilizer to immobilize cadmium(Cd) in heavy metal contaminated arable soil. Therefore, this study has been conducted to compare effects of calcium(Ca) materials [OS and $Ca(OH)_2$] on Cd extractability in contaminated soil and determined mechanisms of Cd immobilization with OS. METHODS AND RESULTS: Both Ca materials were added at the rates of 0, 0.1, 0.2, 0.4, and 0.8% (wt Ca wt-1) in Cd contaminated soil and the mixtures were incubated at $25^{\circ}C$ for 4 weeks. Both Ca materials increased pH and negative charge of soil with increasing Ca addition and decreased 1N $NH_4OAc$ extractable Cd concentration. 0.1 N HCl extractable Cd concentration markedly decreased with addition of OS. 1 N $NH_4OAc$ extractable Cd concentration was related with pH and net negative charge of soil, but not with 0.1 N HCl extractable Cd concentration. We assumed that Cd immobilization with $Ca(OH)_2$ was mainly attributed to Cd adsorption resulted from increase in pH-induced negative charge of soil. Scanning electron microscope (SEM) images and energy dispersive spectroscopy(EDS) analyses were conducted to determine mechanism of Cd immobilization with OS. There was no visible precipitation on surface of both Ca materials. However, Cd was detected in innerlayer of OS by EDS analyses but not in that of $Ca(OH)_2$. CONCLUSION: We concluded that Cd immobilization with OS was different from that with $Ca(OH)_2$. OS might adsorbed interlayer of oyster shell or have other chemical reactions.

Effect of Apple Hemicellulose on the Ca-Pectate Gel Formation (사과의 Hemicellulose가 Ca-Pectate Gel형성에 미치는 영향)

  • Kim, Young-Ji;Kim, Chang-Sik
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.17 no.1
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    • pp.13-17
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    • 1988
  • $HF_1$(1H KOH soluble hemicellulose fraction), $HF_2$(2H KOH soluble hemicellulose fraction) $HF_3$(3H KOH soluble hemicellulose fraction) and $HF_4$(4H KOH soluble hemicellulose fraction) were fractionated from Fuji crude cell wall and purified using Sephacryl S-500 to determine the effects of these hemicellulosic fractions on the Ca- pectate gel formation. By increasing of KOH concentration, from 1 to 4N, hexose peas became higher in led, and molecula weights, especially pentose peaks in high molecular weight. Hemicellulose fractions using gel filtration were composed of $8{\sim}10$ peaks which were $10^4{\sim}143{\times}10^4$ molecular weight. Higher values of hardness, adhesiveness and gumminess were found in low molecular weight than in high molecular weight, also in hexose and uronic acid contained than in hexose contained.

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Synthesis of AlN Powder from $Al_2(SO_4)_3.18H_2O$: II. Deoxidation Effect ($Al_2(SO_4)_3.18H_2O$로부터 AlN 분말의 합성: II. 탈산화 효과)

  • 송태호;이홍림
    • Journal of the Korean Ceramic Society
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    • v.29 no.6
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    • pp.471-479
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    • 1992
  • AlN powder was synthesized by carbothermal reduction and nitridation using Al2(SO4)3.18H2O as the starting material. The synthesized AlN powder was fine but contained oxygen. Therefore carbonaceous material (carbon black or phenol novolac) was added teogether with the sintering aids (CaO, CaF2, CaCl2, Y2O3 and YF3). It was found that pressureless sintering at 1700~180$0^{\circ}C$ after deoxidation at 150$0^{\circ}C$ suppressed the formation of second phase (27R) and reduced the contents of lattice oxygen within AlN ceramics.

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Seasonal Changes in the Nutrient Content of Soil and Soil Water Affected by Urea Application in Forest (요소(尿素)를 시용(施用)한 삼림토양(森林土壤)과 토양수중(土壤水中) 양분함량(養分含量)의 계절적(季節的) 변화(變化))

  • Jin, Hyun-O;Joo, Yeong-Teuk;Son, Yo-Hwan;Oh, Jong-Min;Chung, Doug-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.32 no.2
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    • pp.115-122
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    • 1999
  • Investigation of nutrient movement in soil and soil water is necessary to clarify water purification functions and nutrient circulation within a forest ecosystem. In this study, seasonal changes in the nutrient content of soil and soil water was investigated in Korean white pine(Pinus koraiensis) and Japanese larch(Larix leptolepis) forest applied urea ($150kg\;ha^{-1}$). Soil pH was decreased rapidly in Japanese larch plot for a long period. On the other hand, soil pH was increased slightly in Korean white pine plot. T-C and T-N content were increased in both plots. In Japanes larch plot, exchangeable Ca and Mg contents were decreased remarkably than those in korean white pine plot while exchangeable K was increased rapidly after application. The effect of urea application on exchangeable K was not obvious compared to other cations. The pH, Ca, $NH_4-N$, $NO_3-N$, $SO_4-S$ and Cl concentrations in the sampled soil water at surface soil were increased only temporarily after fertilization, with the only exception of the decrease in pH of the soil water in Japanese larch plot. On the other hand, the peak value of K, Mg concentrations in the soil water was shown between 2 and 5 months after fertilization. The concentrations of Ca, $NO_3-N$, $SO_4-S$ and Cl returned to the values found before fertilization after about 1 month. Those of K, Mg, and $NO_3-N$ after 6-12 months.

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A Study on the Mechanism of Solved Phosphate and $Ca^{2+}$ ion in Wastewater (廢水에서 용존隣(P)과 $Ca^{2+}$이온의 反應機構에 대한 점토)

  • 이순기;강현찬
    • Resources Recycling
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    • v.10 no.4
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    • pp.24-33
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    • 2001
  • For making a high degree of efficiency, this study attempts to gather each arisen-sludge from experiments and examine into its characteristics, in order to compare the biological reason of removing phosphorus with sintered body using calcite and the artificial reason of removing with a chemical reagent. First, it can be seen that sludge, which is identified CaCO$_3$, of 0.1∼0.2$\mu$m is regularly formed when using sintered body, calcite. And it is one of the results of the chemical methods in order to remove phosphorus that can be seen that sludges of 100∼50 $\mu$m are formed and that the forms of Ca$_2$P$_2$O$\_$7/, Ca$_3$(PO$_4$)$_2$$.$nH$_2$O, $\beta$-Ca$_2$P$_2$O$\_$7/ are shown when using a reagent, CaO dissolved water. The other of the results of the chemical methods can be seen that a lumpof sludge is formed when using wastewater and a reagent Ca$^2$$\^$+/ are used, and that the lump consists of Ca$_3$(PO$_4$)$_2$$.$nH$_2$O와 Ca$_2$H$_2$P$_4$O$\_$14/.

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The Removal Rate of the Constituents of the Litters in the Aquatic Plant Ecosystems II. N, P, K, Ca and Na of the Litter in Phragmites longivalvis Grassland in the Deltaof the Nakdong River (수생식물 생태계에 있어서 낙엽의 구성성분의 유실률 II.낙동강 삼각주 지역의 갈대초지에 있어서 낙엽의 N,P,K,Ca 및 Na)

  • 장남기;안병하
    • Asian Journal of Turfgrass Science
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    • v.9 no.4
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    • pp.343-350
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    • 1995
  • Samples from the L, F, H and $A_1$ horizons of the Phragmites longivalvis grassland were collected in a delta of the Nakdong River and the removal rates of N, P, K, Ca and Na were investigated. The results obtained in this study can be abstracted as follows; The removal fractions of N, P, K, Ca and Na of the litter were 0.56, 1.22, 1.95, 0.65 and 0.53, respectively. The half times of N, P, K, Ca and Na required for the remove or accumulation of the litter on the grassland floor were 1.23, 0.57, 0.36, 1.06 and 1.32 years, respectively. The increasing order of the turnover parameters of the elements was Na, N, Ca, P and K.

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Basic Oxygen Furnace Slag as a Liming Agent for Paddy and Upland Field Soils (전로슬래그 시용의 토양개량 및 작물의 수량증대 효과)

  • 이충일
    • Resources Recycling
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    • v.7 no.1
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    • pp.50-56
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    • 1998
  • Basic oxygen furnace @OF) slag. a by-pradud of thc iron and steelmaking industry produced in largc quantities in Korea, poszs a subslantial disposal challenge. The BOF slag used in this study was if3 CaCO, in total n e u ~ ~ pnowger and application of 7-8 Mgha' was needed to bring soil pH to 6.5 horn pH 5.0-5.5 m silly clay or clay loam sod wnlained about 10% orgaoic matter. A field assay was conducted to shldg whether BOP slag could bc used as a dolomitic k i n g agent for agricullural soils. Four slag rates (0, 4, 8, 12 Mgha-')were investigated for their effcfect on soil pmperti~, mineral concentralions in leaf tissues of rice and soybean, and yield of the crops. Slag application at 8 Mgha-' rate in paddy field increased pH, Ca Mg, P, Si and Fe wntenl in sail and rice yield by 4.3-14.25 depending an the soil type. h upland field the 8 Mghaf ratc increa3ed pH, Ca and Fe wntent m soil and soybean yield by 36.6%. Thus, BOF slag appears to be a useful liming mate&\ulcornerl for corrzch~gs oil acidity on both paddy and upland ficld soils and for innwing Ca, Mg, P, Si, and Fe wncenhation in plants.

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Improvements of Protoplast Fusion Efficiency between Petunia hybrida and Nicotiana sandarae (Petunia hybrida와 Nicotiana sanderaer간(間) 원형질체(原形質體) 융합효율증진(融合效率增進))

  • Chung, Jae Dong;Roh, Young Hee;Jee, Sun Ok
    • Current Research on Agriculture and Life Sciences
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    • v.10
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    • pp.147-155
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    • 1992
  • This study was conducted to get basic information for factors affecting protoplast fusion between Petunia hybrida 'Titan red' and Nicotiana sanderae. The experiments such as fusogen, time of PEG treatment, temperature at fusion, $CaCl_2{\cdot}2H_2O$ concentration in fusion solution, and $CaCl_2{\cdot}2H_2O$ concentration and pH in eluting solution were carried out to increase the fusion efficiency. The results obtained were as follows; Fusion between P. hybrida and N. sanderae was accelerated when the mixture of the protoplasts was treated with 30% PEG 6,000 solution containing 5.5 mM $CaCl_2{\cdot}2H_2O$ for 10 minutes at $25^{\circ}C$, and subsequently eluted with a eluting solution containing 50 mM $CaCl_2{\cdot}2H_2O$ adjusted to pH 9.0.

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The Soil pH in Relation to the Ratio of Soil and Solution (침출액량(浸出液量)을 달리할 경우(境遇)에 있어서의 토양(土壤)의 pH.)

  • Oh, W.K.;Park, Y.S.;We, J.W.
    • Korean Journal of Soil Science and Fertilizer
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    • v.2 no.1
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    • pp.27-30
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    • 1969
  • The present notes summarize the results obtained from the effect of soil-solution ratio on pH values of soils having widely different physico-chemical characteristics. The pH was determined in deionized water N-KCl and 0.01 M $CaCl_2$ solution The results obtained are: 1. With deionized water, the pH values increase with the increase in soil-solution ratio. The increase is more in upland soils than in paddy soils. 2. With N-KCl solution, there is also an increase in pH values with the increase in soil-solution ratio but the increase is less than the corresponding increase with deionized water. 3. With 0.01 M $CaCl_2$ solution, there is practically no change in pH values with the increase in soil-solution ratio except for saline soils. 4. In case of saline soils, the pH increase even in case of 0.01 M $CaCl_2$ solution with increase in soil-solution ratio, the reason for increase may be due to decrease of electric potential by high concentration of salts.

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Modeling the electric transport of HCl and H3PO4 mixture through anion-exchange membranes

  • Koter, Stanislaw;Kultys, Monika;Gilewicz-Lukasik, Barbara
    • Membrane and Water Treatment
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    • v.2 no.3
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    • pp.187-205
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    • 2011
  • The electric transport of the mixture of hydrochloric and phosphoric acids through strong base (Neosepta ACM) and weak base (Selemion AAV) anion-exchange membranes was investigated. The instantaneous efficiency of HCl removal from the cathode solution, $CE_{Cl}$, with and without $H_3PO_4$ was determined. It was found that $CE_{Cl}$ was 0.8-0.9 if the number of moles of elementary charge passed through the system, $n_F$, did not exceed ca. 80% of the initial number of HCl moles in the cathode solution, $n_{Cl,ca,0}$. The retention efficiency of $H_3PO_4$ in that range was close to one. The transport of acid mixtures was satisfactorily described by a model based on the extended Nernst-Planck and Donnan equations for $n_F$ not exceeding $n_{Cl,ca,0}$. Among the tested model parameters, most important were: concentration of fixed charges, the porosity-tortuosity coefficient, and the partition coefficient of an undissociated form of $H_3PO_4$. For the both membranes, the obtained optimal values of fixed charge concentration, $\bar{c}_m$, were up to 40% lower than the literature values of $\bar{c}_m$ obtained from the equilibrium measurements. Regarding the $H_3PO_4$ equilibria, it was sufficient to consider $H_3PO_4$ as a monoprotic acid.