• KSBB Journal
• /
• v.14 no.1
• /
• pp.31-35
• /
• 1999

A biosorption of azo and reactive dyes into the intact and modified biomass of Penicillium janthinellum were investigated. Initial pH of medium affected the initial adsorption rate and decolorization. The initial optimum pH was found to be 2.0, and the maximum adsorption rates of dyes were $40^{\circ}C$. The reactive dyes called Apollocion Red 7EB, Apollofix Red SF-3B and Apollocion Red H-E3B showed the high initial adsorption rates as 0.06, 0.086 and 0.079 mg/g.min, respectively. A mixture of dyes containing azo and reactive dyes was adsorbed to the biomass of Pen. janthinellum and revealed that the initial adsorption rate was 0.084 mg/g.min. Both percent decolorization and the influence on the dye adsorption rate. Modified biomass of Pen. janthinellum was also investigated for the dye adsorption and the superior dye loading performance was observed compared with the ion-exchange/chelating resins used for removal of Apollocion Red 7EB.

• Applied Chemistry for Engineering
• /
• v.25 no.2
• /
• pp.167-173
• /
• 2014

The adsorption characteristics of the pellet-type adsorbent prepared from water treatment sludge for trimethylamine and ammonia were studied. The surface area and pore volume of the pellet-type adsorbent increased during calcination at $500^{\circ}C$. It was confirmed that the adsorbent prepared from water treatment sludge contained Br$\ddot{o}$nsted and Lewis acid sites. The breakthrough time of the adsorbent for both trimethylamine and ammonia was measured at different adsorbent weights and linear velocities while maintaining constant amounts of trimethylamine and ammonia. The kinetic saturation capacity and the adsorption rate constant for trimethylamine and ammonia were determined at different linear velocities by using the Wheeler equation. It was found that the kinetic saturation capacity and the adsorption rate constant were dependent on the linear velocity. An experimental equation could be derived to predict the breakthrough time of the adsorbent prepared from water treatment sludge for trimethylamine and ammonia at different adsorption conditions.

• Journal of the Korean Geotechnical Society
• /
• v.16 no.4
• /
• pp.157-170
• /
• 2000

In this study, we conducted a combined adsorption-sequential extraction analysis(CASA) to investigate temperature effects of single and competitive adsorption of zinc and copper on natural clays. As a result, it was found out that in a single adsorption of zinc, the adsorption was mostly in the exchangeable phase, with increase n temperature. In a competitive adsorption of zinc, this trend was so strong that the exchangeable phase adsorption increase up to 80~90%. On the other hand, about 50% of copper was adsorbed in the carbonate occluded phase in single and competitive adsorptions. In the single adsorption the adsorption of carbonate occluded phase increased by 5% with the temperature increase and in the competitive adsorption the increase rate is about twice. The adsorption of zinc and copper on natural clays is an endothermic reaction with the exception of exchangeable phase adsorption.

• Journal of Environmental Science International
• /
• v.15 no.11
• /
• pp.1053-1059
• /
• 2006

This study was performed to investigate the possible uses of waste sludge for the removal of heavy metal ions. The adsorption experiments were conducted with wastes such as sewage treatment sludge, water treatment sludge and oyster shell to evaluate their sorption characteristics. Heavy metals selected were cadmium, copper and lead. in the sorption experiments on the sewage treatment sludge, water treatment sludge, oyster shell and soil, sorption occurred in the beginning and it reached equilibrium after 40 minutes on the oyster shell and 4 hour on the sewage treatment sludge and water treatment sludge. Results of Freundlich isotherms indicated that sewage treatment sludge could be properly used as an adsorbent for heavy metals and sorption strength of heavy metals was in the order of Pb > Cu > Cd. In the influence of pH on the adsorbents, sorption rate was more than 80% in pH 4 and most of heavy metals were adsorbed in pH 9. Adsorption rate of Cd decreased with decreasing pH and then adsorption rate of Cu was lower in soil.

• Journal of Environmental Science International
• /
• v.20 no.2
• /
• pp.223-229
• /
• 2011

Toluene desorption of modified activated carbon for microwave irradiation was evaluated. As a virgin GAC reacted from microwave energy, it created an "arcing" between GAC particles in desorption process. The arcing became more and more vigorous and achieved a red flame of GAC. The silica coated GAC(Si/GAC) was developed to prevent arcing phenomenon and temperature control problem. The result shows virgin GAC with 5wt%, 10wt% and 20wt% silica had no arcing and could control temperature very well. However, the adsorption rate of Si/GAC was decreased by coated silica amount due to decreasing surface area of GAC. The 5wt% Si/GAC adsorption rate was quite similar to virgin GAC adsorption rate. After adsorption, the toluene-loaded GAC and Si/GAC was reactivated by 2450MHz MW irradiation with 300W for 5 min. Quantitative desorption of the toluene was achieved at MW irradiation at 300W with desorption efficiencies as high as 98.59% to 84.65%% after four cycles.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.18 no.1
• /
• pp.20-31
• /
• 2008

A respirator is useful to protect a worker from the harmful gases and vapors in the workplace, and the evaluation of respirator cartridge service life is important for the worker's health and safety. The performance of cartridge is effected by several factors such as concentration of gas and vapor, humidity, temperature, adsorbents and cartridge packing density. Adsorption model was applied to both sampling tube and respirator cartridge to predict the service life for organic vapors. The variables of the adsorption model were measured from the experiment with the sampling tube, and it was used to predict the service life of respirator cartridge. In the experiment, we used carbon tetrachloride as a organic vapor and activated carbon take out respirator cartridge as activated carbon. As a result, it was possible to predict the service life of respirator cartridge and predicted service life was quite correct. Breakthrough time decreased with increase of CCl4 concentration. In case of sampling tube, adsorbed amount of CCl4 was larger than respirator cartridge due to linear velocity. Also, rate constant of sampling tube was larger than respirator cartridge, because of, effect of flow rate, packing density. In the prediction of service life of respirator cartridge by using sampling tube, the time required for 50% contaminant breakthrough(${\tau}$) is more effective than the rate constant(k').

• Economic and Environmental Geology
• /
• v.22 no.3
• /
• pp.277-283
• /
• 1989

For the study of attenuation phenomena of the radioactive elements in solution, the adsorption experiment of thorium, uranium, barium and strontium on kaolinite, gibbsite, quartz, granite and shale as a function of time, pH and the surface area was conducted under the competition condition each other. There are two steps of adsorption kinetics. The first step is faster and completes in hours or a day, and the second step is slower eqiulibrium reaction. The adsorption rate which is considered to be related to CEC differs with adsorbent and decreases in the order of shale, kaolinite, granite, gibbsite and quartz. On the other hand, the adsorption rate for the same adsorbent differs with elements in the order of thorium,uranium, barium and strontium in decreasing rate. It is also affected by pH of the solution and the surface area of adsorbent. In conclusion, we didn't find any different between noncompetition condition and competition condition, and this means that we only have to consider the pH of ground water, the characteristics of the geological materials and the kinds of radioactive element in the case of selection of the places for the radioactive waste disposal.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.8
• /
• pp.1375-1382
• /
• 2007

A column preconcentration method with pulverized Amberlite XAD-4 loaded with bismuthiol I (BI) has been developed for the determination of trace Cd(II) and Cu(II) in various real samples by flame atomic absorption spectrophotometry. Various experimental conditions, such as the size of XAD-4, adsorption flow rate, amount of bismuthiol I, stirring time for adsorbing bismuthiol I on XAD-4, pH of sample solution, amount of XAD-4- BI, desorption solvent, and desorption flow rate, were optimized. Also, the adsorption capacity and the adsorption rate of Cd(II) and Cu(II) on XAD-4-BI were investigated. The interfering effects of various concomitant ions were investigated, Bi(III), Sn(II) and Fe(III) were found to affect the determination. But the interference by these ions was completely eliminated by adjusting the amount of XAD-4-BI resin to 0.70 g, although the adsorption flow rate was slower. For Cd(II) our proposed technique obtained a dynamic range of 0.5-40 ng mL-1, a correlation coefficient (R2) of 0.9913, and a detection limit of 0.3 ng mL-1. For Cu(II), the corresponding values were 2.0-120 ng mL-1, 0.9921 and 1.02 ng mL-1. To validate this proposed technique, the aqueous samples (stream water, reservoir water, tap water and wastewater), the diluted brass sample and the plastic sample, as real samples, were used. Recovery yields of 91-103% were obtained. These measured data were not different from ICP-MS data at 95% confidence level. Our proposed method was also validated using rice flour CRM (normal, fortified) samples. From the results of our experiment, we found that the technique we present here can be applied to the determination of Cd(II) and Cu(II) in various real samples.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.8
• /
• pp.450-457
• /
• 2015

In this research a adsorbent, PVA-Zeolite bead, was prepared by immobilizing zeolite with PVA. The results of XRD and SEM analysis showed that the prepared PVA-Zeolite beads had porous structure and the zeolite particles were in mobilized within the internal matrix of the beads. The adsorption properties of Sr ion and Cs ion with the adsorbent were studied by different parameters such as effect of pH, adsorption rate, and adsorption isotherm. The adsorption of Sr ion and Cs ion reached equilibrium after 540 minutes. The adsorption kinetics of both ions by the PVA-Zeolite beads were fitted well by the pseudo-second-order model more than pseudo-first-order model. The equilibrium data fitted well with Langmuir isotherm model. The maximum adsorption capacities of Sr ion and Cs ion calculated from Langmuir isotherm model were 52.08 mg/g and 58.14 mg/g, respectively. The external mass transfer step was very fast compared to the intra-particle diffusion step in the adsorption process of Cs ion and Sr ion by the PVA-Zeolite beads. This result implied that the rate controlling step was the intra-particle diffusion step.

• Applied Chemistry for Engineering
• /
• v.29 no.4
• /
• pp.369-375
• /
• 2018

Batch experiments were conducted to investigate the effects of operating parameters such as the temperature, initial concentration, contact time and adsorbent dosage on the adsorption of antibiotics amoxicillin (AMX) by waste citrus peel based activated carbon (WCAC). The kinetics and isotherm experiment data can be well described with the pseudo-second order model and the Langmuir isotherm model, respectively. The maximum adsorption capacity of AMX by WCAC calculated from the Langmuir isotherm model was 125 mg/g. The adsorption of AMX by WCAC shows that the film diffusion (external mass transfer) and the intraparticle diffusion occur simultaneously during the adsorption process. The adsorption rate is more influenced by the intraparticle diffusion than that of the external mass transfer as the particle size of WCAC increases, and the intraparticle diffusion is the rate controlling step. The thermodynamic parameters indicated that the adsorption reaction of AMX by WCAC was an endothermic and spontaneous process.