• Applied Chemistry for Engineering
• /
• v.30 no.4
• /
• pp.460-465
• /
• 2019

In this study, the optimization of active materials and the preparation of particulate adsorbents for the application of metal oxide-based adsorbents for the treatment of $H_2S$, an air pollutant and odorant, occurred in various industrial facilities were investigated. The adsorbents were prepared by using $TiO_2$, which has a high physicochemical stability and relatively high specific surface area among metal oxides and also by different kinds and contents of active materials. The correlation between the physicochemical property and adsorption performance of the adsorbents confirmed that the adsorbent containing KI, which is a typical alkali metal among the active metals, showed the highest adsorption performance. The relationship between the contents and the adsorption performance was non-proportional, but a volcano plot. From XRD, SEM and BET analyses, it was confirmed that the active material was exposed to the surface above a certain amount and also the adsorption performance was the best when the specific surface area and pore volume were $40{\sim}100m^2/g$ and $0.1{\sim}0.3cm^3/g$, respectively. For practical application, the adsorbent was granulated or coated on a ceramic support. It was also confirmed that the adsorbent showed high adsorption performance when the adsorbent was coated on the ceramic rather than that of the granulated support.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.3
• /
• pp.286-297
• /
• 2010

This study deals with the effect of pretreatment on the $CO_2$ adsorption capacity of zeolitic adsorbents including a commercial A-type zeolite and cation exchanged adsorbents. The pre-heating could change the intrinsic properties such as specific surface area and adsorption capacity of the adsorbent. As a result of the experiment, the moisture previously filled inside might affect the potential adsorption capacity of the adsorbent, and could be disappeared throughout the heat treatment. An optimum pretreatment temperature for the test adsorbent was found to be $400^{\circ}C$, at which temperature enabled more than 90% refreshment. Precise examination through the TPD test showed that the TSA (Temperature Swing Adsorption) process would be desirable in dry adsorption of $CO_2$.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.3
• /
• pp.191-193
• /
• 2000

To find out the countermeasure to plant damage at soil contaminated with oil, several adsorbents such as muck, peat, sawdust and PEAT SORB were treated at diesel oil contaminated soil. As the results, sawdust and PEAT SORB showed better effect of oil adsorption than muck and peat. Removal rate of diesel oil with sawdust treatment was higher than 95% at the condition which the ratio of adsorbent amount to oil was higher than 1:2(w/v). And the releasing amount of oil from adsorbent-oil complex was very small. With the oil treatment of $4,000\;L{\cdot}ha^{-1}$ at tillering stage, rice plant height and chlorophyll content were lower than control at non-adsorbent treatment, but those were increased at sawdust treatment.

• Journal of Korean Society for Atmospheric Environment
• /
• v.15 no.2
• /
• pp.121-138
• /
• 1999

This study was carried out to evaluate the performance of a sampling and analytical methodology for the measurement of selected volatile organic compounds (VOCs) in the ambient air. VOCs were determined by the adsorbent tube sampling and automatic thermal desorption coupled with GC/FID and GC/MSD analysis. Target analytes were aromatic VOCs, including BTEX, 1,3,5-and 1,2,4,-trimethylbenzenes(TMBs), and naphthalene. The methodology was investigatedwith a wide range of performance criteria such as repeatability, linearity, lower detection limits, collection efficiency, thermal conditioning, breakthrough volume and calibration methods using internal and external standards. standards. Stability of samples collected on adsorbent tubes during storage was also investigated. In addition, the sampling and analytical method developed during this study was applied to real samples duplicately collected in various indoor and outdoor environments. Precisions for the duplicate samples and distributed volume samples appeared to be well comparable with the performance criteria recommended by USEPA TO-17. The audit accuracy was estimated by inter-lab comparison of both duplicate samples and standard materials between the two independent labs. The overall precision and accuracy of the method were estimated to be within 30% for major aromatic VOCs such as BTEX. This study demonstrated that the adsorbent sampling and thermal desorption method can be reliably applied for the measurement of BTEX in ppb levels frequently occurred in common indoor and ambient environments.

• Clean Technology
• /
• v.19 no.3
• /
• pp.342-346
• /
• 2013

Several types of mesoporous silica-alumina adsorbents with varied $SiO_2/Al_2O_3$ ratios were prepared by spray pyrolysis and were used for the purification of the anticancer agent paclitaxel. When $S_{0.5}A_{0.5}$ (Silica/Alumina molar ratio = 0.5/0.5) was used, the highest purity (~27%) and yield (~63%) of paclitaxel were obtained from adsorbent treatment and hexane precipitation. Removal of impurities was confirmed by TGA analysis of the organic substances that were adsorbed to the adsorbent.

• Clean Technology
• /
• v.12 no.3
• /
• pp.171-174
• /
• 2006

The adsorbent for removal of heavy metal ions is prepared reutilizing the leached sludge generated in process of making the red mud coagulant we have develope. The pellet-type adsorbent is made by heat-treating a mixture of 10g of the leached sludge, 1g of kaolin, and 2 g of sodium silicate solution at $600^{\circ}C$ for 2 hours. In experiments of batch adsorption, the adsorbent shows good performance in adsorption of $Pb^{2+}$ ion.

• Carbon letters
• /
• v.15 no.2
• /
• pp.105-112
• /
• 2014

Wastewater from textile industries is a major cause of water pollution in most developing countries. In order to address the issues of water pollution and high cost for treatment processes, the use of an inexpensive and environmentally benign adsorbents has been studied. The objective was to find a better alternative to the conventional methods. Lemon grass waste (ash) collected from a lemon grass stream distillation subunit in Bhutan was tested for dye removal from aqueous solutions. The study investigated the removal of methylene blue using the following operational parameters: initial concentration (100-600 mg/L), contact time, adsorbent dose (0.1-0.55 gm/100 mL), and pH (3-10). It was found that the percentage removal of dye increased with a decrease of the initial concentration and increased contact time and dose of adsorbent. The basic pH solution of dye showed better adsorption capacity as compared to the acidic dye solution. Langmuir and Freundlich adsorption isotherms were fitted to the data well. Data fitted better to Lagergren pseudo 2nd order kinetics than a 1st order kinetic model. Surface morphology was also examined via scanning electron microscopy. An elemental analysis was also carried out and the chemical composition and functional groups were analyzed using energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy techniques, respectively. The obtained results indicate that lemon grass ash could be employed as a low cost alternative to commercial activated carbon in wastewater treatment for the removal of dyes.

• Asian Journal of Atmospheric Environment
• /
• v.8 no.4
• /
• pp.192-201
• /
• 2014

A comprehensive profile of volatile organic compounds (VOCs) in public spaces is needed for interpreting indoor air measurements. Seasonal differences in profiles are critical for epidemiological study and risk assessment. The purposes of this study were to establish profiles for individual VOCs in 50 indoor public places in Korea and to determine seasonal variations in their concentrations. Air samples were taken during working hours. Seventy-two of the 91 targeted VOCs were identified using multiple standards. Six VOCs detected in all summer and winter samples were toluene, acetone, m,p-xylenes, ethylbenzene, benzene, and styrene. In summer, methyl ethyl ketone and 1-butanol were also found in all samples. In both seasons, the dominant indoor VOCs were toluene, m,p-xylenes, ethylbenzene, acetone, and isopropyl alcohol. Other chemicals associated with gasoline emissions were dominant in summer. Limonene was dominant only in winter due to the consumption of tangerines. The nine VOCs with the highest concentrations comprised 64.8% and 49.6% of the TVOC in summer and winter, respectively. Comparing two types of adsorbent tube, a single adsorbent tube with Tenax-TA had similar detection performance as a double adsorbent tube with Tenax and Carbotrap.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.10a
• /
• pp.555-558
• /
• 2008

For trying to frontal attack of new solution by fusion of technical tasks and conditions with it's solving methods of the essential tasks of marine resource development and environmental conservation in addition with elements of electronic high-technologies, the skimmer robot was proposed by using of oil spill disaster prevention and its disposal system with sequentially circular collection type of magnetic oil spill adsorbent powder and fabrics on the electronic barge robot for the scheme of sustainable development of environment-friendly technology. It was verified from the experiment of electronic barge robot demonstrator that the skimmer system of magnetic oil spill adsorbent powder and fabrics was very effective and useful technique to collect oil spill samples. At this point, the barge-based electronic remote control was very useful system operating easily on the marine fields to skim oil spill with dangerous toxic substances of crude oil and very harmful to human. Therefore, fusion technology proposed in this study combined with electronic and marine technology is the novel contributable technology for developing marine environmental conservation and environment-friendly disaster prevention, and also its management techniques.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.2
• /
• pp.207-213
• /
• 2014

This study was carried out to investigate the feasibility and usefulness of a commercial synthetic adsorbent, Diaion HP 20, for the isolation of proanthocyanidins (PAs) from hot water extract (HWE) prepared from Pinus radiata bark. Most ultraviolet (UV) absorbing materials in HWE were adsorbed onto Diaion HP 20 and easily recovered by simple ethanol (EtOH) washing. More than 50% of the UV absorbing materials were adsorbed within 20 minutes, and the adsorption equilibrium was reached within 3 h. The recovered materials from Diaion HP 20 were mostly composed of PAs, but some monomeric flavonoids such as taxifolin and unidentified hydrophobic materials were also adsorbed. The impurities such as carbohydrates and inorganic materials contained in HWE were mostly removed by Diaion HP 20. The adsorption ability of the UV absorbing materials onto Diaion HP 20 was almost the same as the first cycle even after 14 times of repeating cycles of adsorption and desorption. The radical scavenging ability of the recovered materials from the adsorbent was slightly higher than that of the pure PAs prepared by Sephadex LH 20 from the same HWE.