• Journal of the Korean Society of Industry Convergence
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• v.11 no.3
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• pp.107-111
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• 2008

Usually, flow mediation earth and settling pond etc. of processing plant to handle water or wastewater. Mediation is the wastewater that flowed past settling pond than material of heavy particles, water weight colloid particles that big solids are removed but are suspensibility material settlement exclusion impossible. So, we need flocculation and coagulation action to remove materials from this colloid state. Flocculation and coagulation by addition of chemical agents forms floc settle size. That is, shorten the sedimentation time and quality of processing water because promoting sedimentation doing to do fines or suspended solids and colloid can materials large size and also, flocculation to annex efficiency of filtration augment. Therefore, I executed this research to prove that COD efficiency for wastewater by using inorganic coagulant.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2193-2194
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• 2007

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.3
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• pp.279-296
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• 2022

The fundamental characteristics of groundwater colloids, such as composition, concentration, size, and stability, were analyzed using granitic groundwater samples taken from the KAERI Underground Research Tunnel (KURT) site by such analytical methods as inductively coupled plasma-mass spectrometry, field emission-transmission electron microscopy, a liquid chromatography-organic carbon detector, and dynamic light scattering technique. The results show that the KURT groundwater colloids are mainly composed of clay minerals, calcite, metal (Fe) oxide, and organic matter. The size and concentration of the groundwater colloids were 10-250 nm and 33-64 ㎍·L^-1, respectively. These values are similar to those from other studies performed in granitic groundwater. The groundwater colloids were found to be moderately stable under the groundwater conditions of the KURT site. Consequently, the groundwater colloids in the fractured granite system of the KURT site can form stable radiocolloids and increase the mobility of radionuclides if they associate with radionuclides released from a radioactive waste repository. The results provide basic data for evaluating the effects of groundwater colloids on radionuclide migration in fractured granite rock, which is necessary for the safety assessment of a high-level radioactive waste repository.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.209-219
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• 2018

Colloidally stable organic-inorganic (O-I) hybrid nanoparticles could be prepared using an alkoxysilanefunctionalized amphiphilic polymer (AFAP) precursor. O-I hybrid sols could maintain colloidal stability for six months even at 45% solid content and be coated onto glass as well as PET film to form transparent O-I hybrid films. The formation of O-I hybrid nanoparticles dispersed in cured coating films could be confirmed using scanning electron microscopy. The cured coating film showed 3H and 5H pencil hardness on PET and glass, respectively. Nanoindentation measurements also showed that their modulus and hardness was varied with the type of AFAP used in its preparation.

• Analytical Science and Technology
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• v.17 no.3
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• pp.251-262
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• 2004

It is for the purpose of investigating the tritium distribution in the leachates, the raw and treated leachates and the condensates of the methane gas, which have occurred from domestic solid waste landfills. Also it aims to measure the tritium distribution level on the colloid size of the leachates, the raw and treated leachates. It was found that the major inorganic contaminants of the leachates were Na, K, Ca, Mg, $NH{_4}^+$-N and $Cl^-$. The mean tritium level of the raw leachates of the investigated 13 landfill sites for 6 months was 17 ~ 1196 TU. It corresponded to a several scores or hundreds of magnitude higher value than that of the normal environmental sample level except for two landfill sites. Also such a high concentration of the tritium was found in the treated leachates and methane gas condensates as well. Nevertheless it is important to emphasize that the tritium level which was found in this research is about 100 times lower than the tritium limit for the drinking water quality. And most of the tritium existed in the dissolved colloid of the leachate of which the colloid size is below $0.45{\mu}m$. Also, according to the tritium analysis results of the leachates after filtration with $0.45{\mu}m$ membrane filter for some landfills, it is likely that some tritium of the leachate would be distributed in a colloid size over $0.45{\mu}m$. In general the relationship between the tritium and other contaminants in the raw leachate was low, but it was relatively high between the tritium and TOC. However, the tritium content in the leachate had no meaningful relationship with the scale, hydrological characteristics and age of the landfill.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.704-707
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• 1997

The preparation of alumina sol for fine chemical field from kaolin-derived aluminum sulfate solution is performed. Noncrystalline AlO(OH) was prepared by dropping ammonia water into aluminum sufate solution with stirring. Acetetic acid was added to form the electrical double layers on the particle surface of the slurry, which resulted in a stable sol. The influence of the reaction temperature, reaction time, acetetic acid concentration on the preparation of alumina sol were investigated. Dispersed colloid particles of AlO(OH) were prepared at the reaction temperature of $50{\sim}90^{\circ}C$ and 1.6 A/C = 1.6 (molar ratio), regardless of the reaction time. Stable alumina sol having a particle size of about 5~10 nm was prepared in the range 1~5 vol% alumina content.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.31-40
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• 2015

Various types of inorganic and organic colloids are present in natural water including groundwater. Previous studies showed that Fe, Mn and Al are colloid-forming elements and dissolved concentrations can be erroneous for these elements if water samples are not properly filtered. Dissolved concentrations of elements including Ca, Na, Mg, K, Fe, Mn, Si and Al in groundwater from alluvial and bedrock aquifers, and surface water near Nakdong River were determined to evaluate effects of colloids on dissolved concentrations in natural water samples using various pore sizes of filters. Groundwater is mostly anoxic and have elevated concentrations of Fe and Mn, which provides a unique opportunity to observe the effects of colloids on dissolved concentrations of colloid-forming elements. Membrane filters with four kinds of pore sizes of 1000 nm, 450 nm, 100 nm, and 15 nm were used for filtration of water samples. Concentrations of dissolved concentrations in each filtrate did not show significant differences from 1000 nm to 100 nm. However, concentrations of all elements considered were decreased in the filtrates obtained using 15 nm pore size filters by 10 to 15% compared to those using 450 nm except for bedrock groundwater. Al in surface water showed a distinct linear decrease with the decrease of filter pore sizes. These results showed that 100 nm pore size had little effect to remove colloidal particles in alluvial groundwater and surface water in our study. In contrast, significant concentration decreases in 15 nm pore size filtrates indicate that the presence of 15 to 100 nm colloidal particles may affect determination of dissolved concentrations of elements in natural water.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.693-697
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• 2005

We researched in the optimization of unit process and the stabilization of discharged water quality through the treatment of the occurrence of wastewater classified by place of production which has high COD load and non degradable COD load in paper industry. As the result, using polymer, inorganic flocculants and alum at the same time is effective to advance the COD value through the colloid material removal with SS in the first treatment process. Moreover, it is determined to keep optimum of $FeCl_2/H_2O_2$ in the concentration of 1000 ppm in the ratio of 1/1. Because It is confirmed that to input excess chemicals using Fenton oxidation method gives adverse effect to water quality.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.624-630
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• 1997

Zeolite A helps an increase of detergency performance according to showing the ion exchange effect for polyvalant ions and it's detergency performance could be calculated quantitatively by using the disperse stabilization theory because it is water-insoluble material and is as colloid particles in aqueous solution. In this study, zeta potential of carbon black, cellulose, and Zeolite A were measured in each inorganic salt solutions and applied to the theory of Heterocoagulation in order to evaluate the detergency performance of Zeolite A about the particulate soil at the view point of interaction potential energy. Zeolite A was shown help an increase of detergency performance according to the increasing of the steric repulsion between Zeolite A and cellulose in $Na2CO_3$ solution and the decrease of re-deposition of carbon black on the fabric by rapid coagulation with carbon black in $Na_2SO_4$ solution.

• Journal of the Korean Chemical Society
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• v.40 no.9
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• pp.599-606
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• 1996

The effects of chemical species in groundwater on the solubility of the uranyl hydrolysis precipitates formed at pH 6.4 and 9.7 were investigated. Based on the chemical composition of the groundwater, the synthetic groundwater was prepared. The colloid-free (separated) groundwater was also prepared by removal of both organic and inorganic colloids from the sampled groundwater. Solubilities of precipitates formed in the hydrolysis of uranyl ion in groundwater, separated groundwater, synthetic groundwater and 0.1 M NaCl solution were measured over neutral to alkaline pH range, and especially, the effect of the anions and cations found in groundwater on the solubility was investigated. Solubility in groundwater was approximately two orders of magnitude greater than that in 0.1 M NaCl solution. Soubililties of uranyl hydrolysis precipitates formed at pH 9.7 and 6.4 were compared in groundwater and synthetic groundwater. Solubilities of the precipitates formed at different pH were found to be in the same order of magnitude in groundwater and synthetic groundwater, however the uranyl hydolysis precipitates formed at higher pH values showed a tendency of higher solubility.