• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.143-146
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• 2004

Natural zeolites have exhibited high sorption capacity for inorganic cations including heavy metals and ammonium. Moreover, they were proven to be effective for environmental applications such as permeable barriers for controlling the spread of cation-contaminated groundwater. However zeolites have little or no affinity for anionic species like chromium, as they possess a net negative structural charge. To achieve the simultaneous sorption for anionic contaminants, surfactant-modified zeolite (SMZ) has been employed as the possible sorbents. Current study focuses on simultaneous removal of heavy metals having different ionic form in aqueous solution, cadmium (C $d^{2+}$) and chromium (Cr $O_{4}$$^{2-}$), using newly developed materials, ZanF. ZanF, a potential alternative to SMZ, was derived from zeolite modified by Fe(II) chloride followed by reduction with sodium borohydride. Batch experiments were performed to estimate the removal efficiency of ZanF at different conditions. Under different pH ranging from 2 to 6, removal efficiency was investigated. And C $d^{2+}$ removal efficiency was estimated by varying background concentration of Cr $O_{4}$$^{2-}$, and vice versa. With the test results, ZanF was expected to be a possible reactive materials alternative to SMZ in permeable reactive barriers (PRBs) for treating the contaminated groundwater with cationic and anionic heavy metals.als.

• Journal of Soil and Groundwater Environment
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• v.9 no.4
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• pp.24-31
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• 2004

A cold mix asphalt (CMA) treatment process was proposed as a tool to recycle soils contaminated with petroleum hydrocarbons. Experimental studies were conducted to characterize performances of the CMA process in treating soils contaminated with diesel or diesel compounds. From the screening experiments, it was found that performances of five types of asphalt emulsions that contained a cationic or an anionic or a nonionic surfactant were not substantially different. In consideration of higher affinity for soils and higher sorption coefficients obtained, an emulsion containing Lauryl Dimethyl Benzyl Ammonium Chloride (LDBAC) was selected as a promising asphalt emulsion for treating diesel-contaminated soils. When the asphalt emulsion LDBAC was applied to treat three compounds that originated from diesel, the removal efficiencies obtained in the order of decreasing efficiencies were as follows: docosane > pentadecane > undecane. Leaching experiments on the specimen formulated by the emulsion LDBAC found that the selected treatment method could treat soils with diesel concentrations as high as 10,000 mg/kg. Leaching of the diesel from the specimen was controlled by diffusion for the first four days and then leaching rate diminished substantially. The latter behavior was characterized as depletion, which represents that the contaminant released amounts to more than $50\%$ of the total amount of the contaminant that can be leached. The amounts of three diesel compounds leached from the specimen in the order of decreasing amount were undecane, pentadecane, and docosane. The curing of the soil contaminated with pentadecane was relatively slow.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.3
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• pp.422-428
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• 2000

At present, analytical methods available for determining the amount of cationic surfactants(DSDMAC) on the fabrics are spectrophotometric method based on formation and extraction of the colored ion pair with anionic dye, radiochemical analysis and HPLC analysis. This study presents new analytical methods based on the formation of cationic surfactant(DSDMAC)-disulfine blue complex on the cotton fabric. Test methods for determining the amount of DSDMAC-disulfine blue complex on the cotton fabrics are measuring the reflectance of the colored fabric and the absorbance of the methanol solution of DSDMAC-disulfine blue complex extracted from dyed cotton fabric. Linear relationships between the K/S value of the fabric treated with DSDMAC followed by disulfine blue and the amount of DSDMAC sorbed by cotton fabric were obtained. Thus, the amount of DSDMAC sorbed by cotton fabric can be determined by K/S value of the fabric. DSDMAC-disulfine blue complex on the cotton fabric was extracted with methanol. The amount of DSDMAC sorbed by cotton fabric was estimated by measuring the absorbance of the methanol solution extracted from dyed cotton fabric.

• Carbon letters
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• v.13 no.4
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• pp.212-220
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• 2012

Orange peel (OP) exhibits a sorption capacity towards anionic dyes such as reactive blue 19 (RB19). Cetyltrimethylammonium bromide (CTAB) as a cationic surfactant was used to modify the surface nature of OP to enhance its adsorption capacity for anionic dyes from an aqueous solution. Four adsorbents were investigated: the OP, sodium hydroxide-treated OP (SOP), CTAB-modified OP and CTAB-modified SOP. The physical and chemical properties of these sorbents were determined using nitrogen adsorption at 77 K and by scanning electron microscope and Fourier transform infrared spectroscopy techniques. The adsorption of the RB19 dye was assessed with these sorbents at different solution pH levels and temperatures. The effect of the contact time was considered to determine the order and rate constants of the adsorption process. The adsorption data were analyzed considering the Freundlich, Langmuir, Elovich and Tempkin models. The adsorption of RB19 by the assessed sorbents is of the chemisorption type following pseudo-first-order kinetics. CTAB modification brought about a significant increase in RB19 adsorption, which was ascribed to the grafting of the sorbent with a cationic surfactant.

• Environmental Engineering Research
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• v.10 no.3
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• pp.138-143
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• 2005

Laboratory batch experiments were conducted to evaluate the Fenton degradation rates of phenanthrene. Fenton reactions for the degradation of phenanthrene were carried out with aqueous and slurry phase, to investigate the effects of sorption of phenanthrene onto solid phase. Various types of surfactants and electrolyte solutions were used to evaluate the effects on the phenanthrene degradation rates by Fenton's reaction. A maximum 90% removal of phenanthrene was achieved in aqueous phase with 0.9% of $H_2O_2$ and 300 mg/L of $Fe^{2+}$ at pH 3. In aqueous phase reaction, inhibitory effects of synthetic surfactants on the removal of phenanthrene were observed, implying that surfactant molecules acted as strong scavenger of hydroxyl radicals. However, use of $carboxymethyl-{\beta}-cyclodextrin$ (CMCD), natural surfactant, showed a slight enhancement in the degradation of phenanthrene. It was considered that reactive radicals formed at ternary complex were located in close proximity to phenanthrene partitioned into CMCD cavities. It was also show that Fenton degradation of phenanthrene were greatly enhanced by addition of NaCl, indicating that potent radical ion ($OCI^-$) played an important role in the phenanthrene degradation, although chloride ion might be acted as scavenger of radicals at low concentrations. Phenanthrene in slurry phase was resistant to Fenton degradation. It might be due to the fact that free radicals were mostly reacting with dissolved species rather than with sorbed phenanthrene. Even though synthetic surfactants were added to increase the phenanthrene concentration in dissolved phase, low degradation efficiency was obtained because of the scavenging of radicals by surfactants molecules. However, use of CMCD in slurry phase, showed a slight enhancement in the phenanthrene degradation. As an alternative, use of Fenton reaction with CMCD could be considered to increase the degradation rates of phenanthrene desorbed from solid phase.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.719-724
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• 2011

The excessive phosphate in water causes eutrophication which destroys water environment. In this study, mesoporous silica was synthesized and several functional groups were attached on it. Samples were tested to identify the ability to remove phosphate. The structures of synthesized materials were analyzed by X-ray diffractions (XRD), Fourier transform-infrared (FT-IR) and surface area analysis, Brunauer-Emmett-Teller (BET). To determine the maximum phosphate adsorption capacities and sorption rate, the equilibrium test and kinetic test was conducted. Among functionalized SBA-15 samples, pure SBA-15 didn't adsorb phosphate but Al-SBA-15 and Ti-SBA-15 showed good performances to remove phosphate. The maximum phosphate adsorption capacity of Al-SBA-15 was efficient compared to other adsorbents.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.193-201
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• 2000

Partitioning of hydrophobic organic compounds (HOCs) to a biosurfactant, hydroxypropyl-${\beta}$-cyclodextrin (HPCD), was conducted to evaluate the feasibility of using HPCD to remove HOCs from soil/groundwater. HOC partitioning to HPCD was very fast, with over 95% of the complexation occurring within 10 min. Some influence of solution chemistry and HOC concentration on HOC-HPCD complex formation coefficients was observed. HPCD sorption on soil as quantified by both a fluorescence technique and total organic carbon measurements was negligible, indicating no significant affinity of HPCD for the solid phase. Although the HOC solubilization capability of HPCD was lower than that of synthetic surfactants such as SDS and Tween 80, HPCD can be effective in removing sorbed HOCs from a model subsurface environment, primarily because of its negligible sorption to the solid phase (i.e., all the HPCD added facilitates HOC elution). However, in contrast with conventional surfactants, HPCD becomes relatively less effective for HOC partitioning with increasing HOC size and hydrophobicity. Therefore, comparisons between HPCD and synthetic surfactants for enhanced remediation applications must consider the specific HOC(s) present and the potential for surfactant material losses to the solid phase, as well as other more generally recognized considerations such as material costs and potential toxicological effects.

• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.3-13
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• 2001

It has been known that nonlinear characteristics of sorption affect the transport behavior of water soluble pollutants in soils. However detailed experimental studies have not been performed to verify the effect of non-linearity of adsorption isotherm on transport of chemicals in porous media. In this research, the distortion of breakthrough curves of a cationic surfactant (cetylpyridinium chloride, CPC) in a engineered stainless steel column packed with glass beads were investigated. Glass beads with about 110 $\mu\textrm{m}$diameter coated with a thin n-decane film were used as the media providing the sorption surface for CPC. The CPC adsorption isotherm on the surface of n-decane from aqueous solution was a typical Langmuir type. The breakthrough curve of CPC using step Input showed a late breakthrough on the front side and early breakthrough on the back side accordance to the shape of the isotherm. The retardation factor of CPC was found to be a strong function of the input concentration, which also a manifestation of the non-linearity of the isotherm. The retardation factors for the CPC with step input agreed with those of pulse input that the maximum concentrations are controlled to be the same as the step input concentrations. This results support the validity of the unproven field practices of using hydrogeotracers with non-linear adsorption isotherms to determine the hydrogeological parameters, e.g., NAPL saturation, air-water or NAPL-water interfacial areas.

• Journal of the Korean GEO-environmental Society
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• v.4 no.2
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• pp.39-46
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• 2003

An immobilization zone can be constructed by modifying soils in the vadose zone with surfactants, which can be used to promote retardation of organic contaminants in the subsurface. Column experiments were conducted to investigate the behavior of surfactants and organic contaminants in unsaturated and saturated conditions with different water contents (25%, 50%, 75%, 100%). Transport and sorption of surfactant (dialkylated disulfonated diphenyl oxide) in the columns containing aluminum oxide was similar under the conditions at different water contents. However, transport of a model organic compound (naphthalene) was retarded as the water content decreased by enhanced partitioning of the compound into the surfactants that were sorbed on the aluminum oxide. This suggests that the immobilization method could well be applied to vadose zone as well as to saturated zone.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.1-8
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• 2003

Three different surfactants, APG, Brij30, and SDS, were tested to study the characteristics of sorption on soil surfaces, washing ability, biodegradability, and electrokinetic removal. Kaolinite and phenanthrene were selected as a model soil and a representative HOC, respectively. Phenanthrene was sorbed on kaolinite up to 2,200 mg/kg dry soil. The APG, Brij30, and SDS were sorbed on soil to 40, 7, and 4g/kg soil, respectively. The washing ability of phenanthrene was in order of Brij30＆gt;SDS＆gt;APG. The biodegradability tested with sludge was in order of APG＆gt;Brij30＆gt;SDS. In the electrokinetic test, the highest removal efficiency was obtained with APG that exhibited the highest electroosmotic flow. To increase the removal efficiency of HOC in the electrokinetic remediation, the most important factor was the selection of surfactant which maximized the electroosmotic flow.