• Title/Summary/Keyword: Water sorption

Search Result 388, Processing Time 0.027 seconds

A Study on Heavy Metal Removal Characteristics Using Bone Char (골탄(bone char)의 중금속 제거 특성에 관한 연구)

  • Kim, Jae-Young;Kim, Hwan-Gi
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.21 no.2
    • /
    • pp.253-258
    • /
    • 2007
  • The adsorption capacity of bone char for lead, cadmium and zinc was studied in both single and binary multiple component systems. Equilibrium experimental studies have been performed to determine the sorption capacity of bone char for each metal ion. These have been analysed using single and multi-component equilibrum models. The results show that the sorption of metal ions for multi-component systems can be predicted reasonably well from the IAS theory with the Langmuir equation, the Freundlich and the Slip equation for metal ions.

Moisture Sorption Characteristics of Lactobacillus brevis-fermented Sea Tangle Saccharina japonica, Mekabu Fucoidan, and These Mixture Powders (발효 다시마(Saccharina japonica) 분말, 미역귀 후코이단 분말 및 이들 혼합분말의 수분 흡습 특성)

  • Lee, Changheon;Sim, Jin Ha;Kim, Jin Hyeon;Yu, Daeung
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.54 no.1
    • /
    • pp.107-110
    • /
    • 2021
  • The goal of this study was to investigate moisture sorption characteristics of Lactobacillus brevis-fermented sea tangle Saccharina japonica, Mekabu fucoidan, and these mixture powders. Moisture sorption isotherms of powders were determined at 37℃ using the static gravimetric technique in a water activity (aw) range of 0.11-0.93. Equilibrium moisture content (Xeq) values of the fermented sea tangle powder were almost 3 times when aw<0.7 and increased upto almost 4 times when aw<0.9 higher than mekabu fucoidan powder. In these reason, to improve strong hygroscopic nature of the fermented sea tangle powder, fermented sea tangle and mekabu fucoidan powders were dissolved as ratios of 7:3, 5:5, and 3:7 (w/w) in a distilled water and then freeze dried. Xeq values of mixture powders were around average value of sum of both powders at all aw ranges. All moisture sorption isotherms of powders exhibited typical J-shaped type III. Xeq of mixture powders increased with increasing aw and decreased as increasing proportion of mekabu fucoidan powder. The Peleg model was found to accurately describe moisture sorption isotherms of powders. The results can be used to understand hygroscopic nature of powders, improve shelf life, and retain quality across postharvest processing.

Moisture Sorption Isotherm and Quality Deterioration of Dry Jujube (건대추의 등온흡습곡선 및 품질열화특성)

  • 김영숙;안덕순
    • Food Science and Preservation
    • /
    • v.4 no.1
    • /
    • pp.33-38
    • /
    • 1997
  • In order to provide informations for designing packaging and storage condition of dry jujube (Zizyphus jujuba MILLER), moisture sorption isotherm was determined for temperatures of 20, 30 and 4$0^{\circ}C$, and quality changes were evaluated as function of temperature and water activity. Dry jujube at a given water activity showed higher equilibrium moisture content for lower temperature. Moisture isothem could be fitted by GAB model equation, giving higher C value, lower m0 and relatively constant k value with increase in temperature. Ascorbic acid was lost more highly at higher temperature and water activity, and showed negligible retention for whole range of water activity and temperature studied after 141 days. Browning increased with water activity up to 0.73 at 30 and 4$0^{\circ}C$. Dry jujube of high water activity had high L value in surface color, which represent brightness of surface color. Considering quality retention in the storage, dry jujube is desired to be dried to water activity of 0.42 and be stored at temperature below 3$0^{\circ}C$

  • PDF

Naphthalene Sorption on HPTMA-Modified Clays

  • 이승엽;김수진
    • Proceedings of the Mineralogical Society of Korea Conference
    • /
    • 2001.06a
    • /
    • pp.52-52
    • /
    • 2001
  • Clays coated with cationic surfactants (organoclays) have been investigated due to their effectiveness in sorbing organic compounds from water The objectives of this study were to (1) study the sorption characteristics or a cationic surfactant (HDTMA) to clay minerals; (2) examine the partitioning of HOC (naphthalene) to the adsorbed surfactants within the context of the first objective, and (3) develop overall HOC distribution coefficients that consider sorbed surfactant amounts. The sorption of hydrophobic organic contaminant was due to partitioning of the organics into the organic pseudophase created by the surfactant tail groups. Sorption of naphthalene by HDTMA-clays at different surfactant surface coverages revealed that the naphthalene K$\_$d/ values were affected by the surface concentration of surfactant. In our study the kaolinite was modified with a cationic surfactant to achieve different fractional organic carbon contents and different surfactant molecule configurations on the surface. All of the sorption isotherms were nearly linear and could be described by a distribution coefficient (K$\_$d/). The sorption of naphthalene by the surfactant-modified kaolinite was found to be dependent on the bound surfactant molecule configuration as well as on the fractional organic carbon content but halloysite was not affected by the increase of surfactant amounts. Results from this investigation provide additional insight into the role that sorbed surfactant structure plays in HOC partitioning.

  • PDF

Innovative Technology for Removal of Dispersants used in Oil Spill Remediation Using the Magnetic Separation (자성 분리를 이용한 해상 유류오염제어에 사용되는 유화제를 제거하는 새로운 기술에 대한 연구)

  • Chun, Chan-Lan;Park, Jae-Woo
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.22 no.4
    • /
    • pp.679-688
    • /
    • 2000
  • Dispersants, which are used to break water-in-oil emulsions and to remediate oil-spills, are another water pollutants. In this study, magnetic separation technology was applied to remove dispersants from the sea. Magnetite and maghemite were used as magnetic sorbents and SDDBS, an anionic surfactant and Triton X-100, a nonionic surfactant, were employed as dispersants. Batch experiments were undertaken to study the sorption capacity and sorption equilibrium, and water-bath experiments were conducted to simulate the real situation and to describe the recovery of magnetic particles by the permanent magnet or electromagnet. Maghemite has rather constant removal efficiency for dispersants, regardless of surfactant species. On the other hand, removal efficiency by magnetite is higher for anionic surfactant than maghemite and is higher in distilled water than in seawater which contains more ions. The sorption of dispersants to magnetite is explained by electrostatic attraction and that of maghemite is described not only by electrostatic attraction, but also by structural characteristics that provide high sorption ability and surface condition. Water bath experimental results showed that recovery efficiency of magnetic particle after sorption for dispersants is nearly 100%. It is suggested that this magnetic separation technology is an effective way of dispersant removal because of short operating time, high sorption capacity, and high recovery efficiency of sorbents.

  • PDF

Conceptual Development of a Subminiature Cool Pad Applying Sorption Cooling Effect (흡습 냉각 원리를 이용한 소형 냉각 패드에 관한 연구)

  • 황용신;이대영;김우승
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.16 no.2
    • /
    • pp.121-127
    • /
    • 2004
  • This paper describes conceptual development and idea-verification of a sub-miniature portable cooler which dose not necessitate any pre-cooling nor any external energy supply. The basic principle of the cooling mechanism is the vaporization of water and sub-sequent cooling due to the evaporative latent heat loss. In this work, the vaporization of the water is stimulated by desiccant material to improve the cooling effect. The evaporative cooling caused by the desiccant is modeled and analyzed considering the sorption characteristics of the desiccant. In addition, the portable cooler is fabricated in the shape of a thin pad, and its cooling characteristics are tested and compared with the analytic results.

Effect of Cooking on Moisture Sorption Properties of Corn (삶은 옥수수의 수분흡습성질)

  • Mario, Carranza;Kim, Sung-Kon
    • Korean Journal of Food Science and Technology
    • /
    • v.22 no.5
    • /
    • pp.530-532
    • /
    • 1990
  • The moisture sorption behaviors of dry corn(DC). dry-corn (DCC) and soaked-rooked corn(SCC) at $25^{\circ}C$ were analyzed. The corn was soaked in water at $26^{\circ}C$ for 8hr. The cooking times for DCC and SCC were 30 and 20min. respectively, at $80^{\circ}C$. Desorption occurred for DC and DCC at RH below 23% and SCC at RH below 33% during storage. Moldiness was observed in all samples at RH 97%, after 192hr for DC and 288 hr for both DCC and SCC. At the same water activity. SCC sample had the highest moisture content, followed by DC. The SCC sample had the highest monolaver value and sorption heat. Stability isotherms indicated that DC and SCC had better storability than DCC.

  • PDF

Adsorption of Cu(II) from Aqueous Solutions Using Pinus densiflora Wood (Pinus densiflora 목질을 이용한 수용액 중의 Cu(II) 흡착)

  • Park, Se-Keun;Kim, Ha-Na;Kim, Yeong-Kwan
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.21 no.1
    • /
    • pp.27-36
    • /
    • 2007
  • Milled Korean pine (Pinus densiflora) wood was used to evaluate its adsorption capacity of Cu(II) ions from aqueous solution by running a series of batch experiments. Prior to the tests, the milled woods were pretreated with 1N NaOH, 1N $NHO_3$, and distilled water, respectively, to examine the effect of pretreatment. Within the tested pH range in this study between 3 and 6, copper adsorption efficiency of NaOH-treated wood(96~99%) was superior than $NHO_3$-treated wood(19~31%) and distilled water-treated wood(18~35%). Adsorption behavior of copper onto both raw and $NHO_3$-treated woods was mainly attributed to interaction with carboxylic acid group. For NaOH-treated wood, carboxylate ion produced by hydrolysis was a major functional group responsible for Cu sorption. NaOH treatment of wood changed the ester and carboxylic acid groups into carboxylate group, whereas $NHO_3$ treatment did not affect the production of functional groups which could bind copper. A pseudo second-order kinetic model fitted well for the sorption of copper ion onto NaOH-treated wood. A batch isotherm test using NaOH-treated wood showed that equilibrium sorption data were better represented by the Langmuir model than the Freundlich model.

AN EXPERIMENTAL STUDY ON PHYSICAL PROPERTIES OF VARIOUS POSTERIOR RESTORATIVE COMPOSITE RESINS (수종(數種) 구치부(臼齒部) 충전용(充塡用) 복합(複合)레진의 물리적(物理的) 성질(性質)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Park, Sun-Jae;Park, Sang-Jin;Min, Byang-Soon;Choi, Ho-Young
    • Restorative Dentistry and Endodontics
    • /
    • v.12 no.1
    • /
    • pp.7-24
    • /
    • 1986
  • The purpose of this study was to observe the compressive strength, compressive fatigue strength, surface hardness, water sorption and solubility of eight different posterior restorative composite resins. Eight composite resins were tested for their strength of the compressive and compressive fatigue with prepared two different types of specimens (I and T-type) using a Instron universal testing machine (model No. 1332). The hardness was measured with a Knoop hardness tester (MVH-2, Tokyo) for each cylindrical specimen, 7mm in diameter and 5mm thick. The water sorption and solubility were evaluated with the prepared composite resin disks, 20mm in diameter and 1mm thick. The results were as follows: 1. The compressive strength, compressive fatigue strength and hardness were noticed to be Increased by increasing the volume content of filler. 2. The compressive strength was appeared to be independent on the type of specimen, but the compressive fatigue strength was found to be greatly influenced by the type of specimens. 3. The composite resins having higher compressive strength had also higher compressive fatigue limits. 4. The compressive fatigue limits at $10^5$ stress cycles were about 50-80% of the compressive strength and were showen to be dependent on the materials and type of specimens. 5. The larger the filler particle size was, the lower was the water sorption. And the water sorption of BIS-GMA resin was higher than that of urethane resin. 6. The visible light-cured composite resin had a higher value of solubility than the chemically- cured composite resin. And the solubility tended to decrease by increasing the volume content of filler.

  • PDF

Exfoliated Graphite for Spilled Heavy Oil Recovery

  • Inagaki, Michio;Toyoda, Masahiro;Iwashita, Norio;Nishi, Yoko;Konno, Hidetaka
    • Carbon letters
    • /
    • v.2 no.1
    • /
    • pp.1-8
    • /
    • 2001
  • Exfoliated graphite was found to sorb selectively a large amount of heavy oil, about 80 g of heavy oil floating on water per 1 g of exfoliated graphite, which is highly possible to be applied to recovering spilled heavy oil. Sorption capacity, selectivity and kinetics of exfoliated graphite were reviewed. The possibility of recovery of heavy oil from exfoliated graphite and recycling of both recovered heavy oil and exfoliated graphite was also discussed. Its sorption performance was compared with other materials which were reported to show sorption of heavy oil.

  • PDF