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INTERNATIONAL ARTICLES 2020-04-21T17:21:33+00:00

Abstract

Application methods (i.e., pouring and mixing method) of Microbially Induced Calcite Precipitation (MICP) and its effect on wind erosion were investigated on four soil types (i.e., medium sand, fine sand, loamy fine sand and loam). With mixing method, calcite precipitated evenly throughout the upper part (0 – 5 cm) of all the soils tested, but with pouring method, only medium sand showed even calcite distribution. The reason can be ascribed to the limited permeability of MICP-inducing solution (i.e., calcium, urea and Sporosarcina pasteurii) through loamy fine sand and loam due to their low hydraulic conductivity (i.e., < 10-5 cm/s). Moreover, bacterial penetrability was also reduced by calcium (i.e., 70 to 20%) in fine sand. Hence, pouring method for medium sand and mixing method for the others were applied with various MICP-inducing solution concentrations (i.e., 0.1 to 1 M of urea and calcium). When exposed to wind of 15 m/s after MICP application, 0.25 M solution in medium and fine sand, and 0.1 M solution in loamy fine sand and loam showed little or no soil loss. The results suggest that a proper application method be chosen considering soil properties that affect even calcite distribution to mitigate soil erosion.

Keywords

Microbially induced calcite precipitation(MICP), Soil erosion, Soil treatment, Wind erosion control

DOI

Abstract

Biotic ligand model (BLM) was extended to predict the toxicity of inorganic arsenate (iAs(V)) to the luminescent bacteria, Aliivibrio fischeri. As the pH increased from 5 to 9, the HAsO42- form predominated more than the H2AsO4 form did, and the EC50[As]T (50% effective iAs(V) concentration) decreased drastically from 3554 ± 393 to 39 ± 6 μM; thus, the HAsO42- form was more toxic to A. fischeri than H2AsO4. As the HPO42- activity increased from 0 to 0.44 mM, the EC50{HAsO42-} values (50% effective HAsO42- activity) increased from 31 ± 6 to 859 ± 128 μM, indicating that the toxicity of iAs(V) decreased, owing to the competition caused by the structural similarity between iAs(V) and phosphate ions. However, activities of Ca2+, Mg2+, K+, SO42-, NO3, and HCO3 did not significantly affect the EC50{HAsO42-} values. The BLM was reconstructed to take into account the effects of pH and phosphate, and the conditional binding constants for H2PO4, HPO42-, H2AsO4, and HAsO42- to the active binding sites of A. fischeri were obtained; 3.424 for logKXH2PO4, 4.588 for logKXHPO4, 3.067 for logKXH2AsO4, and 4.802 for logKXHAsO4. The fraction of active binding sites occupied by iAs(V) to induce 50% toxicity (fmix50%) was found to be 0.616.

Keywords

Arsenate toxicity, Biotic ligand model, pH, Phosphate, Aliivibrio fischeri

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Abstract

Many of the procedures for assessing the bioavailability of contaminant including arsenic (As) in soil are time-consuming, thus there is need to develop more effective methods. In this regard, a direct analysis of the binding resin in the diffusive gradient in thin film (DGT) by using wavelength dispersive X-ray fluorescence spectrometry (WDXRF) was tested in determining bioavailable As concentrations in soil. The binding resin obtained from the DGT was dried at room temperature in a desiccator with silica gel for 2 h, and directly analyzed by the WDXRF. The mass of As loaded in the DGT binding resin was plotted against the X-ray intensity obtained from the WDXRF analysis to a draw calibration curve, which showed good linearity (R2 = 0.997) with a limit of quantification of 0.2 μg. A correction factor (CF) for compensating the spectral interference between As-Kα and Pb-Lα was determined by considering the slope between the X-ray intensity measured at a Bragg angle of 48.781° for As-Kα and the Pb mass on the DGT binding resin. The use of the derived CF value (0.113) is reasonable to obtain As concentrations with a high accuracy. The relation between phytotoxicity of As to barley Hordeum vulgare and bioavailable As concentrations in soils, which were determined by means of the combined use of DGT and WDXRF, was observed. The study supports that the DGT-WDXRF can be a promising tool to predict soil phytotoxicity for As-contaminated soil risk management.

Keywords

Bioavailability, Arsenic, Diffusive gradients in thin film, Wavelength dispersive X-ray fluorescence spectrometry, Soil

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Abstract

Carbonate treatment was tested as a means to mitigate the generation of alkaline leachate from basic oxygen furnace (BOF) slag. BOF slag was treated with 0.1, 0.5, and 1.0 M concentrations of NaHCO3 solution for 48 h at a liquid/solid ratio of 5 L/kg. At 1.0 M NaHCO3, the pH of the leachate decreased from 12.0 to 11.3 because less free CaO was dissolved from the treated slag. Approximately 1.59 mg-Ca2+/g-slag of free CaO was dissolved from the untreated BOF slag while only 0.06 mg-Ca2+/g-slag was liberated from the treated slag. When the data from X-ray photoelectron spectroscopy and thermogravimetric analysis were taken together, formation of CaCO3 precipitates on the surface of the treated BOF slag was evident. Surface precipitation of CaCO3 was more pronounced when CO2 gas was used as an alternative carbonate source. Carbon dioxide treatment further decreased the leachate pH to 8.3, probably because it liberated more Ca2+ from BOF slag during the treatment than 1.0 M NaHCO3 solution due to the pH difference (pH 6.6 and 9.6, respectively), in turn generating more CaCO3 precipitates. Scanning electron microscopy analysis revealed that more CaCO3 was precipitated on the CO2 gas-treated slag surface than on the NaHCO3-treated slag. This study identifies the leachate pH reduction-mechanism and the effect of carbonate source which are expected to contribute to the environmentally safe management of BOF slags.

Keywords

Alkaline leachate, BOF slag, Free CaO, CaCO3, Surface precipitation, Carbonate source

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Abstract

Calcium carbonate–based biominerals are considered self-healing materials in concrete. The morphology and mineralogy of biominerals depend highly on the self-healing efficiency of concrete cracks. This study examined the morphology and mineralogy of biominerals with a new isolate, Bacillus sp. BY1, and various organic calcium compounds (i.e., calcium formate, calcium acetate, and calcium lactate). In addition, compressive strength and crack self-healing efficiency were investigated under various other conditions. Biominerals formed in the presence of calcium formate and calcium lactate were mostly calcite (ca. 95% by weight) and contained more rhombohedral faces, whereas calcium acetate induced spherulite-shaped biominerals with a smaller fraction of calcite (ca. 61.5% by weight). With the addition of bacteria and organic calcium compounds, the compressive strengths decreased and increased, respectively; however, the loss of strength by the bacteria was compensated when both bacteria and organic calcium compounds were added together. Self-healing of cracks did not occur by the addition of bacteria alone and was more prominent when calcium lactate was used as a biomineral precursor.

Keywords

Self-healing concrete; Biomineral; Crystal morphology; CaCO3; Bacillus pseudofirmus; Calcium formate; Calcium acetate; Calcium lactate.

DOI

Abstract

Pyrosequencing analyses to determine soil bacterial communities were conducted with forty-two soil samplescollected from rice paddy and forest/farmland soils (Group A and B, respectively) at a long-term As-con-taminated site. Soil physicochemical properties, such as the concentrations of As, Fe, Al, and Mn, pH, organicmattercontent,andclaycontent,werefoundtobesignificantlydifferentwithlanduse,andmoreimportantly,strongly affected thebacterial community structure of the soil samples. When fitting the soil properties onto anonmetric multidimensional scale plot of soil bacterial communities, clay content was found to be the mostimportant factor in clustering the bacterial communities (R2=0.4831,p-value=0.001). PhylumChloroflexi(-1.03 of bioplot score) andPlanctomycetes(1.31 of bioplot score) showed a significant relationship with claycontentinsoilsamples.Interestingly,thebacterialphylotypeslinkedtoclaycontentwereonlyfoundinthesoilsamplesofgroupBwithlowclaycontent,andhadastrongrelationshiptoAscontaminationintheredundancyanalysis and the correlation analysis.Our results suggest that clay content seems to be negatively related to Ascontamination in soils, which, in turn, strongly influences the structure of bacterial communities in As-con-taminated soil.

Keywords

Arsenic, Bacterial communities, Clay, Soil properties, Pyrosequencing

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Abstract

Meeting the regulations based on the short-term leaching tests may not necessarily assure the environmental and human health safety of reusing mine wastes. This study investigated heavy metal leachability of four metal mine waste samples (e.g., Z, Y, H, and M) and human health risk of reusing them as construction materials. The heavy metal leachability did not depend on the total heavy metal contents. For example, the Z sample contained greater amounts of As and Fe than Zn, but the leachates contained only Zn at a detectable level. This can be attributed to the crystalline structure and heavy metal fractions of the mine wastes. The leaching test results suggested that the four mine waste samples are potentially reusable. But the Z and M samples reused in industrial areas imposed carcinogenic risks. This was largely attributed to As that is exposed via dermal contact. The Y and H samples reused in residential areas imposed carcinogenic risk. The major exposure route was the ingestion of crops grown on the mine wastes and Cr was the major concern. The two-stage assessment involving leaching tests and risk assessment can be used to promote safe reuse of mine wastes.

Keywords

DOI

Abstract

This study presents a promising approach that enhances the sludge fermentation by using basic oxygen furnace (BOF) slag as analkaline source for the first time.BOF slag added to thereactors could maintain astable alkaline condition due to continuous release of Ca(OH)2 from slag. The reactor pH could be adjusted to a target value by the choice of the BOF slag dose. Concentrations of soluble chemical oxygen demand (sCOD) and short-chain carboxylates (SCCs) were substantially increased in the presence of BOF slag. At a BOF slag mass to sludge volume ratio of 1/10g slag/L sludge, the reactor pH was maintained at 10 and the concentration of SCCs produced was the highest (i.e., 3510mg COD L−1 from 14,000mg VS L−1 of sludge mixture), followed by B/S ratios of 1/20, 1.50, 1/5, and 1/2.5g slag L−1 sludge with reactor pH of 9.4, 8.9, 10.5, and 11, respectively. Our data suggestthatthe pHvalue thatbest facilitates the degradation ofsludge into SCCs and inhibit theconversion of SCCs into biogas is around 10. Interestingly, compositions of the accumulated SCCs varied greatly depending on the BOF slag dose. BOF slag showed phosphorus removal ability due to enhanced precipitation of Ca-PO43–P complexes, which significantly lowered PO43− concentration of the reactor effluent.

Keywords

Alkaline sludge fermentation, Basic oxygen furnace slag (BOF slag), Phosphate removal, Acidogenesis

DOI

Abstract

The effectiveness of in situ stabilization in the long-term As-contaminated soil was assessed. In situ stabilization of As was conducted through a Fe-based sorbent amendment. Chemical extractability of As was first determined by solubility/bioavailability research consortium extraction method and any change in human health risk through oral ingestion was characterized. Also, nonspecifically bound As in soil was determined by five-step sequential extraction. The results indicate that such extractable fractions of As decreased, and consequently risk through oral ingestion decreased probably due to hematite transformed from both the goethite in the original soil and the Fe-based sorbent, which was identified through the X-ray absorption spectroscopy. In ecotoxicity test with Hordeum vulgare, root and shoot elongation and germination rate decreased which was contrary to the chemical extraction data. Such increase in As toxicity is because of increased exchangeable Ca2+concentration causing As accumulation in the membrane surface of H. vulgare. Also, adsorption of phosphorus onto the Fe-based sorbent decreased available phosphorus concentration causing phosphorus deficiency for growth. Our results demonstrate that the effectiveness of in situ stabilization should be evaluated by means of both chemical extractability and biological response, as chemical analysis alone may not be sufficient to assess the ecotoxicity.

Keywords

In situ stabilization, Arsenic, Chemical extractability, Biological response, Soil

DOI

Abstract
This study assessed the effects of hot water, acid, and alkali pretreatments on the lignocellulosic composition of rice straw and methane production potential of the pretreated solids-reagent mixture. Autoclaving (121 °C, 1.45 atm, 60 min) after addition of 2% H2SO4 showed the highest lignocellulose decomposition efficiency of 65.4%. However, the methane production potential was even smaller than that of the untreated sample, indicating the inhibitory effect of the acid in the biogas production process. On the other hand, hot water- and alkali-pretreated samples showed a factor of 2.1 greater methane production potential than untreated sample despite the relatively lower lignocellulose decomposition efficiency of 17.0–50.4%. By simply keeping the rice straw immersed in water at 100 °C for 30–60 min. or autoclaving prior to anaerobic digestion, the methane production potential of 805.8–824.2 mL of CH4/g total carbon and the overall lignocellulose degradability of 73.6–84.4% was achieved. The results of this study show the potential of hot water pretreatment as an efficient, chemical-free method to improve the feasibility of methane production from rice straw.

Keywords

Anaerobic degradation, Pretreatment, Hydrolysis, Biogas production, Lignocellulosic biomass

DOI
doi.org/10.1016/j.bej.2018.09.012

Abstract
Fuel cell technology can be applied to remove pyrite from pyrite containing mine waste (PCMW) and to generate electricity. This study investigated the effect of pH, presence of Acidithiobacillus ferrooxidans, operating temperature, and dissolved oxygen (DO) concentration on the performance of pyrite-fuel cells (PFCs). These factors affect the pyrite dissolution rate, which affects the electron movement for electricity generation, hence electrical performance. The PFCs performance based on the maximum power density and maximum current density, obtained on the 28th day, was better at pH 2.2 (0.74 mW m−2, 28 mA m−2) than at pH 4.3 and pH 6.5 and in the presence of A. ferrooxidans (i.e., biotic PFCs) than in the abiotic PFCs. The biotic PFCs showed more consistent performance regardless of the operating temperature than the abiotic PFCs. The PFCs performance was better at higher DO concentrations (30–33 mg L-1) than at lower DO concentrations (8–9 and 0–2 mg L-1); however, gas purging used to adjust DO concentrations could adversely affect the biotic PFCs performance. This study demonstrates that PCMW treatment and electricity generation can be achieved using the fuel cell-based technology, and the PFCs performance can be optimized by adjusting the operating conditions.

Keywords

Acidithiobacillus ferrooxidans, Pyrite, Fuel cell, Mine waste, Pyrite oxidation

DOI
DOI.org/10.1016/j.jhazmat.2018.08.034

Abstract
Arsenic stabilization mechanism in a mine waste was investigated using a basic oxygen furnace (BOF) slag. A lab-scale batch test was carried out to stabilize As in the mine waste samples for 1 h, where various amounts of the BOF slag and distilled water were introduced. Different stabilization efficiencies were observed depending on the stabilizing conditions (i.e., BOF slag content and water to mine waste (L/S) ratio). The stabilization efficiencies ranged 75–92% and 92–95% for 5% (w-slag/w-mine waste) and 10% BOF slag treated mine waste samples, respectively. Interestingly, a notable effect of the L/S ratio on the stabilization efficiency was observed (78% at 0.05 L/kg, and 23% at 1.0 L/kg) at the 3% BOF slag treatment. The point of zero charge and the stabilizing pH indicated that the BOF slag surface was negatively charged. Based on the comparison of fresh and Ca-reduced BOF slags, As stabilization mechanism was determined to be adsorption through cation bridges by Ca2+. The Surface analysis using X-ray photoelectron spectroscopy(XPS) and the stabilization experiment conducted at lower pH provided evidence that the hindrance of As adsorption resulted from Ca(OH)2 precipitation on the BOF slag surface when excess water (1.0 L/kg) was added. Such effect of water content seemed to be overcome by providing an excessive amount of the BOF slag. When an ample amount of Ca2+ is provided and pH is maintained around 11, not only As adsorption but also calcium arsenate precipitation occur, and both contributed to the stabilization mechanisms of As.

Keywords

Arsenic, Stabilization, BOF slag, Adsorption, Cation bridging effect, Hindrance of adsorption

DOI
DOI.org/10.1016/j.chemosphere.2018.05.173

Abstract
Estrogens originated from humans can reach ambient water and possibly cause significant ecological risks. In this study, the quantities of human-origin estrone (E1) and 17β-estradiol (E2) in the influent and effluent of four sewer treatment plants (STPs) in Seoul, South Korea were estimated using a demographic model. A Monte Carlo simulation was used to assess the quantitative uncertainty of estimated E1 and E2 concentrations. Mean concentrations of E1 and E2 estimated for STP influents ranged from 29.5 to 38.4 and 7.5 to 9.7 ng/L, respectively. Meanwhile, mean concentrations of E1 and E2 estimated for STP effluents were 4.9 to 6.6 and 0.28 to 0.36 ng/L, respectively. These estimated values are similar to measured data as reported in the literatures within the range of uncertainty based on the Monte Carlo simulation. The hazard quotient (HQ) value in the main stem of the Han River was calculated to be far less than 1 because of the dilution effect of the Han River’s abundant flow, indicating that most of the Han River ecosystem will not be influenced by these endogenous estrogens. With a 95% cumulative probability, HQ values in the main stem of the Han River for the Jungrang, Nanji, Tanchun, and Seonam STPs were less than 0.18, 0.07, 0.08, and 0.15, respectively. Nevertheless, HQ values >1 were observed in the vicinity of the STP outlets when using the numerical modeling. Our results show that the endocrine disruption potential of E1 and E2 around STP outlets in the main stem of the Han River must be monitored carefully.

Keywords

Estrone, 17β-estradiol, Uncertainty, Human-origin, Mega city

DOI.org/10.1016/j.scitotenv.2018.03.248

Abstract
Purpose This study is aimed to assess the long-term leaching of inorganic constituents from structural fills composed of reused coal bottom ash in Korea and identify key parameters that affect the amount of the constituents leached. Materials and methods A model for the prediction of longterm leaching by percolation of stormwater through a structural fill is adopted and used. The long-term leaching model is applied to five field sites in Korea using site-specific parameters obtained for each site and coal bottom ash specific parameters determined using column studies for two coal bottom ash samples collected from coal-fired power plants.

Results and discussion The long-term leaching of trace inorganic constituents, As, Cu, Sb, and Zn, is variable among the sites primarily due to the variation in the total amount of leachable constituents and application depth of a structural fill. First-order leaching rate constant is also one of the key parameters when the leaching rate is relatively small. Because of the significant variability in the leaching rate constants and application depths, the time for the leachate constituent concentration to reach half the initial value, t50%, ranges fromless than a year to more than hundreds of years for the studied sites and constituents.
Conclusions The long-term leaching characteristics of the trace inorganic constituents are predicted to significantly vary by the type of reused bottom ash and the site conditions, suggesting the need to determine the model parameters in a case specific manner.

Keywords
Application depth, Coal bottom ash, Leaching, rate, Long-term leaching, Structural fill

DOI
DOI 10.1007/s11368-017-1709-1

Abstract
The aim of this work was to study the effect of the differential development of microbe-substrate aggregates at different mixing intensities on the performance of anaerobic digestion of rice straw. Batch and semi-continuous reactors were operated for up to 50 and 300 days, respectively, under different mixing intensities. In both batch and semi-continuous reactors, minimal mixing conditions exhibited maximum methane production and lignocellulose biodegradability, which both had strong correlations with the development of microbe-substrate aggregates. The results implied that the aggregated microorganisms on the particulate substrate played a key role in rice straw hydrolysis, determining the performance of anaerobic digestion. Increasing the mixing speed from 50 to 150 rpm significantly reduced the methane production rate by disintegrating the microbe-substrate aggregates in the semi-continuous reactor. A temporary stress of high-speed mixing fundamentally affected the microbial communities, increasing the possibility of chronic reactor failure.

Keywords
Anaerobic digestion, Mixing intensity, Hydrolysis, Microbial aggregates, Rice straw

DOI
http://dx.doi.org/10.1016/j.biortech.2017.09.006

Abstract
A lightweight aggregate was produced by sintering the mixture of gold mine tailings, red mud, and limestone at 1150 C. The physical (i.e., skid resistance, abrasion resistance, and bond strength) and environmental (i.e., leachability) feasibility of this aggregate was assessed to consider its potential use as a construction material for bicycle lanes. The skid resistance (British pendulum number of 71) and bond strength (1.5 Nmm􀀀2) of the aggregate were found to be appropriate for this use. However, the abrasion loss value of the aggregate was found to be 290 mg, which exceeds the limit of Korean Standard KS F 281 (200 mg). Heavy metals were found to not leach from the aggregate in various leaching tests. These include Korean (Korea Standard Method for Solid Waste), American (Toxic Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP)), and European (BS EN 12457-1) leaching tests, despite the raw materials containing significant amounts of Pb, As, and F. However, leachate extracted from the aggregate exhibited an aquatic toxicity to Daphnia magna of 13.94 TU24hr and 14.25 TU48hr, most likely due to a high pH and Ca concentration originating from the free CaO present in the aggregate. The data suggests that the physical properties of the reconstructed aggregate are appropriate for use in bicycle lane construction, however the dissolution of Ca and the pH level of the leachate need to be controlled to protect aquatic ecosystems.

Keywords
mine tailings; red mud; waste limestone; leachability; toxicity; lightweight aggregate

DOI
doi:10.3390/met7100390

Abstract
A new kinetic model that combines Monod kinetics and a constant denitrification rate is proposed to predict bacterial nitrate removal in groundwater. The model, which was developed with an indigenous bacterium Pseudomonas sp. KY1 isolated from a nitrate-contaminated site using molasses as a carbon source, takes into account the dual-mode substrate utilization pattern depending on the degradability of the compounds that constitute molasses. At the early stage of a batch reactor study with various C/N ratios, the nitrate reduction and molasses degradation was likely to be associated with microbial growth, while at the later stage of the total 48 hr of the study, a significant nitrate reduction occurred without substantial cell growth and molasses degradation. The new model was able to simulate the differential substrate utilization pattern, which could not be explained by either Monod kinetics or a constant denitrification rate model. Although further validation using other types of substrates and inoculums should follow, the new model shows the potential to accurately predict the denitrification kinetics in a heterogeneous carbon substrate system with minimum input parameter determination requirements.

Keywords
denitrification, kinetic model, molasses, groundwater, C/N ratio, Pseudomonas

DOI
DOI 10.1007/s12205-016-0780-2

Abstract
This study was conducted to test the field applicability of a well-type barrier system containing Slowly Released Molasses (SRM) as an extra carbon and energy source to promote the indigenous bacterial denitrification activity. A total of 22 wells were placed as a grid system in the 4 m × 4 m square by 1-m interval in one alluvial area. A total of 70 SRM rods were placed in the center of the grid system to consist of a field-scale SRM system. Nitrate-N plume (72 mg N L−1 of nitrate-N) was introduced into the SRM system and change in nitrate-N concentration was monitored for 90 hours. Nitrate-N concentration decreased up to only 39% while 79-85% of removal efficiency was attained from lab/pilot experiments. Such a difference probably resulted from heterogeneity/anisotropy of the aquifer, DO concentration in the shallow groundwater, and a wide SRM rods-containing well distance. Spatial heterogeneity/ anisotropy induced the referential  groundwater flow paths in which nitrate plume moved so fast and met the limited quantity of molasses molecules within or near the paths. Relatively aerobic condition of the shallow aquifer had not changed during the test period. Relatively far distance (100 cm) between the wells led to the incomplete mixing of the released molasses and nitrate-N plume. A detailed characterization of a target site should proceed before applying the SRM system for more effective nitrate-N
treatment in the field.

Keywords
nitrate-N, molasses, SRM system, heterogeneity, anisotropy

DOI
DOI 10.1007/s12205-016-0754-4

Abstract
tBioaccessible concentrations of As associated with Fe oxide as different chemical binding types weredetermined in soils using the in vitro Physiologically Based Extraction Test (PBET). When compared tothe five-step sequential extraction data, most of the As extracted by in vitro PBET originated from theamorphous Fe oxide-bound fraction, and more importantly, the bioaccessibility of As ranged from 0 to58.8% in 24 soil samples. Two batches of ferrihydrite were synthesized separately. For one batch, Aswas adsorbed onto the ferrihydrite after synthesis; for the other one, As was added while synthesizingferrihydrite to co-precipitate. The bioaccessible concentration of As determined by in vitro PBET of theformer was 415 mg of As/kg of ferrihydrite and that of the latter was 67 mg of As/kg of ferrihydrite.X-ray photoelectron spectra (XPS) analysis indicated that As–O–Fe bonds were evident in As-associatedferrihydrite sample and especially, As was found within the Fe oxide lattice in the co-precipitated sample.Our data suggest that binding type between As and Fe oxide should be considered when determining thebioaccessibility of As in soil, which, in turn, greatly influences the realistic risk of As present in soil.

Keywords
Arsenic, Binding type, Bioaccessibility, Ferrihydrite, XPS analysis

DOI
http://dx.doi.org/10.1016/j.jhazmat.2017.02.009

Abstract
This study investigated the effect of chemical forms of arsenic (As) and soil-magnetite mixing regimes on As mass transfer in magnetite-amended soil. Two soil samples with different component ratios of As chemical forms were prepared. In the absence of magnetite, the amount of desorbable As was strongly dependent on the fraction of easily extractable As in soil. Contact of the soils with magnetite in a slurry phase significantly reduced soil As concentration for both soils. Changes in As concentrations in soil, magnetite, and water by the slurry phase contact were simulated using an As mass transfer model. The model parameters were determined independently for each process of As soil desorption and magnetite sorption. The experimentally measured As mass transfer from soil to magnetite was significantly greater than the simulation result. By sequential extraction, it was observed that the soil As concentration was significantly reduced
not only for easily extractable As, but also for relatively strongly bound forms of As. Enclosing the magnetite in a dialysis bag substantially limited the As mass transfer from soil to magnetite. These results suggest that improving the mixture between Fe oxides and soils can facilitate the effectiveness of As stabilization using Fe oxides.

Keywords
Arsenic, Magnetite, Soil, Mass transfer, Kinetics, Chemical form

DOI
DOI 10.1007/s11356-017-8510-y

Abstract
In the analysis of arsenic (As) with ICP-MS, it was observed that methanol addition to the sample decreases the amount of 40Ar35Cl+ formed in the previous study. To investigate the effect ofmethanol addition on generation of isobaric polyatomic ions and its mechanism, a diluted HCl solution and As solutions with varying concentrations of methanol (0, 1, 2, 3, and 4 v/v%)were analyzed using ICP-MS at a variety of mass spectra (m/z=35, 47, 75, 82, 117, and 152). With addition of methanol to the sample, the signal intensity of 12C35Cl+ increased 11.1-fold while that of 40Ar35Cl+ only increased 1.17-fold. In this regard, carbon atoms that are not ionized in the plasma (12C) originated from methanol seemed to convert 40Ar35Cl+ to 12C35Cl+ through the substitution reaction. Furthermore, carbon atoms ionized in the plasma (12C+) converted 75As into 75As+ via the charge transfer reaction and thus increased signal intensity for As. At the same time, the amount of 40Ar35Cl+ formed in the plasma decreased since the 12C regenerated from 12C+ during the charge transfer process can act as a reactant in the substitution reaction aforementioned.

Keywords
Isobaric polyatomic ions, 40Ar35Cl+, ICP-MS, Methanol addition, Arsenic

DOI
http://dx.doi.org/10.1016/j.microc.2016.12.001

Abstract
The total concentration-based regulations for soil remediation do not consider the possible changes in bioaccessibility of remaining arsenic (As) in soils due to biogeochemical interactions after remediation. This study used As-contaminated soil and pore water samples that were collected from the rice paddy and forest/farmland located in the vicinity of a former smelter site in Republic of Korea to elucidate the changes in As bioaccessibility due to biogeochemical interactions. Bioaccessibility and chemical forms of As in soils were determined by using an in vitro method and sequential extraction, respectively, and soil microbial community was evaluated. Bioaccessibility of As in the rice paddy soil samples was higher than that in the forest/farmland soil samples. This could be
attributed to relatively higher dependence of bioaccessible As in the rice paddy soils on the soil concentration of iron (Fe), aluminum, or manganese, which could lead to greater changes in bioaccessible As via reductive dissolution. The strong linear relationship (R2 = 0.90, p value B0.001) between the pore water As and Fe concentrations, and the greater portion of bacterial species related to reductive dissolution of Fe oxides in the rice paddies can support the higher As bioaccessibility promoted by reductive dissolution. Therefore, it is necessary to consider the potential changes in the bioaccessible As due to biogeochemical interactions in remediation of As-contaminated soils, particularly when soils are likely to be reused under reductive dissolution-promoting conditions (e.g., flooded conditions).

Keywords
Arsenic, Bioaccessibility, Biogeochemical interaction, Flooded condition, Reductive dissolution

DOI
DOI 10.1007/s10653-016-9800-x

Abstract
tThe effect of different feeding methods of the acid-digested rice straw hydrolysate on the contentsand composition of polyhydroxyalkanoates (PHAs) accumulated by Cupriavidus necator was studied.The results showed that the inhibitory effects of furanic compounds on bacterial PHAs synthesiscan be alleviated by dilution, and the hydrolysate-to-media (H/M) ratio of 2:8 was appropriate forpoly-3-hydroxybutyrate-co-3-hydroxyvalerate [P(3HB-co-3HV)] synthesis. At the H/M ratio of 2:8, theaccumulated PHAs content could be increased by using the split-fed method, and the rice strawhydrolysate fed in 4-pulses resulted in the highest P(3HB-co-3HV) concentration in this study. However,the 3-hydroxyvalerate (3HV) mol% decreased with increasing PHAs concentration, thus, the repeatedly-fed method was used to achieve a desirable 3HV fraction range of 20–30% for medical applications. Therepeated feeding of the hydrolysate increased the 3HV fraction of the accumulated P(3HB-co-3HV) tothe 20–30% range. Overall, this study demonstrates that the feeding methods of rice straw hydrolysatescontaining multiple carbon sources can be optimized for synthesis of desired PHAs.

Keywords
Rice straw, Polyhydroxyalkanoates, Cupriavidus necator, Feeding methods, 3HV fraction

DOI
http://dx.doi.org/10.1016/j.procbio.2016.09.014

Abstract
Two-chambermicrobial fuel cells (MFCs)were used to study the applicability of MFCs for hexavalent chromium (Cr(VI)) detection in water. The microbial acetate oxidation in the anode and the Cr(VI) reduction in the cathode together generated voltages, which were used to indicate the change in Cr(VI) concentrations of the cathode under varying conditions of pH, ionic strength, co-existing Fe(II) concentration, and organicmatter concentration. The MFC-based Cr(VI) detector showed a significant change in voltage with increasing Cr(VI) concentration at pH 1 and 2, but not at higher pH conditions. The detector also successfully measured the changes in Cr(VI) concentration at a range of ionic strength (i.e., 10–300 mM), and in the presence of different concentrations of fulvic acid (0–50 mg/L), which was used as a surrogate of organic matters, without interference. The Cr(VI) detection was not interfered by the presence of Fe(II) at the Cr(VI)/Fe(II) ratio of 1:1 and 1:15, but it was interfered at higher ratios (i.e., 1:164 and 1:848). The detector could measure the Cr(VI) concentration from0.1 to 15 mg/L at pH2. Overall, theMFC-based Cr(VI) detector may be applied to meet the growing need of real-time Cr(VI) monitoring in water.

Keywords
Microbial fuel cell, Biosensor, Chromium(VI), Real-time monitoring, Detection

DOI
DOI 10.1007/s10661-016-5625-4

Abstract
Bacterial synthesis of 3-hydroxybutyrate (3HB)and 3-hydroxyvalerate (3HV) copolymer [P(3HB-co-3HV)] using the hydrolysate of rice straw waste as a carbon
source was affected by the composition of the hydrolysate,which depends highly on the rice straw pretreatment condition. Acid digestion with 2 % sulfuric acid generated larger production of P(3HB-co-3HV) than 6 % sulfuric acid, but 3HV concentration in the copolymer produced with 2 % acid hydrolysate was only 8.8 % compared to 18.1 % with 6 % acid hydrolysate. To obtain a higher 3HV mole fraction for enhanced flexibility of the copolymer, an additional heating was conducted with the 2 % acid hydrolysate after removal of residual rice straw. As the additional heating time increased a higher concentration of levulinic acid was generated, and consequently, the mole fraction of 3HV in P(3HB-co-3HV) increased. Among the conditions tested (i.e., 20-, 40-, 60-min), 60-min additional heating following 2 % sulfuric acid digestion achieved the highest 3HV mole fraction of 22.9 %. However, a longer heating time decreased the P(3HB-co-3HV) productivity, probably due to the increased intermediates concentrations acting as inhibitors in the hydrolysates. Therefore, the use of additional heating needs to consider both the increase in the 3HV mole fraction and the decrease in the P(3HB-co-3HV) productivity.

Keywords
Rice straw hydrolysate, Polyhydroxyalkanoates, Levulinic acid, P(3HB-co-3HV), Cupriavidus necator

DOI
DOI 10.1007/s10924-015-0749-0

Abstract
Competitive sorption and resulting nonequilibrium transport of Cu and Pb were investigated using slag as a primary sorbent. A series of estimation models were applied based on the equilibrium, and nonequilibrium sorption respectively, and finally calibrated by incorporating the experimentally determined batch kinetic data. When applied individually, the behavior of metals in slag-sand column were well predicted by both equilibrium and nonequilibrium models in CXTFIT code. However, coexisting Cu and Pb exhibited competition for sorption sites, generating an irregular breakthrough curves such as overshoot (higher concentration in effluent than the feed concentration) of Cu and corresponding earlier peak of Pb followed by gradual re-rising. Although two-site nonequilibrium model further considers coupled hydrochemical process, desorption of the Cu from competition made the model prediction inaccurate. However, the parameter estimation could be improved by incorporating the experimentally determined mass transfer rate, uexp from batch kinetics. Based on the calibrated model, the fraction of instantaneous retardation, bexp of Pb decreased from 0.41 in the single system to 0.30 in the binary system, indicating the shift from equilibrium to nonequilibrium state, where which of Cu increased from 0.39 to 0.94, representing the shift towards equilibrium. The modified results were also compared with five-step sequential extraction data, confirming that the shift of particular metal fractions from the competition triggered the nonequilibrium transport.

Keywords
Competitive sorption, CXTFIT, Damk€ohler number, Nonequilibrium transport, Overshoot, Sequential extraction

DOI
http://dx.doi.org/10.1016/j.chemosphere.2016.03.108

Abstract
The objective of this study is to evaluate the level and characteristics of metal contamination for the samples from the artificial lake in the urban area. The results show that sediment concentrations of typical anthropogenic contaminants, Zn, Cu, and Ni, are overall high above the sediment quality guideline. The sequential extraction results for the sediment indicate that Pb as well as Zn and Cu show the high potential for the bioavailability to the aquatic organisms in the lake. The concentrations of Pb, Zn, Cr, are high for the runoff water, which is the major pollution source to the lake, but the lake water concentration is below regulatory level. Given high metal concentrations from soils near the polluted runoff path to the lake are higher than those from soils from other sides of the lake, this relatively low contamination of the lake water is likely due to the role of the surrounding soil as a buffer. Thus, when the artificial lake is designed in the urban area, application of soil buffer such as the grassplot or the plant strip along the vicinity of the lake is recommended.

Keywords
artificial lake, urban area, anthropogenic sources, sediment, runoff

DOI
https://doi.org/10.1007/s12205-015-0534-6

Abstract
The effect of different feeding methods of the acid-digested rice straw hydrolysate on the contents and composition of polyhydroxyalkanoates (PHAs) accumulated by Cupriavidus necator was studied. The results showed that the inhibitory effects of furanic compounds on bacterial PHAs synthesis can be alleviated by dilution, and the hydrolysate-to-media (H/M) ratio of 2:8 was appropriate for poly-3-hydroxybutyrate-co-3-hydroxyvalerate [P(3HB-co-3HV)] synthesis. At the H/M ratio of 2:8, the accumulated PHAs content could be increased by using the split-fed method, and the rice straw hydrolysate fed in 4-pulses resulted in the highest P(3HB-co-3HV) concentration in this study. However, the 3-hydroxyvalerate (3HV) mol% decreased with increasing PHAs concentration, thus, the repeatedly-fed method was used to achieve a desirable 3HV fraction range of 20–30% for medical applications. The repeated feeding of the hydrolysate increased the 3HV fraction of the accumulated P(3HB-co-3HV) to the 20–30% range. Overall, this study demonstrates that the feeding methods of rice straw hydrolysates containing multiple carbon sources can be optimized for synthesis of desired PHAs.

Keywords
Rice straw, Polyhydroxyalkanoates, Cupriavidus necator, Feeding methods, 3HV fraction

DOI
https://doi.org/10.1016/j.procbio.2016.09.014

Abstract
This study was conducted to test the field applicability of a well-type barrier system containing Slowly Released Molasses (SRM) as an extra carbon and energy source to promote the indigenous bacterial denitrification activity. A total of 22 wells were placed as a grid system in the 4 m × 4 m square by 1-m interval in one alluvial area. A total of 70 SRM rods were placed in the center of the grid system to consist of a field-scale SRM system. Nitrate-N plume (72 mg N L−1 of nitrate-N) was introduced into the SRM system and change in nitrate-N concentration was monitored for 90 hours. Nitrate-N concentration decreased up to only 39% while 79-85% of removal efficiency was attained from lab/pilot experiments. Such a difference probably resulted from heterogeneity/anisotropy of the aquifer, DO concentration in the shallow groundwater, and a wide SRM rods-containing well distance. Spatial heterogeneity/anisotropy induced the preferential groundwater flow paths in which nitrate plume moved so fast and met the limited quantity of molasses molecules within or near the paths. Relatively aerobic condition of the shallow aquifer had not changed during the test period. Relatively far distance (100 cm) between the wells led to the incomplete mixing of the released molasses and nitrate-N plume. A detailed characterization of a target site should proceed before applying the SRM system for more effective nitrate-N treatment in the field.

Keywords
nitrate-N, molasses, SRM system, heterogeneity, anisotropy

DOI
https://doi.org/10.1007/s12205-016-0754-4

Abstract
The total concentration-based regulations for soil remediation do not consider the possible changes in bioaccessibility of remaining arsenic (As) in soils due to biogeochemical interactions after remediation. This study used As-contaminated soil and pore water samples that were collected from the rice paddy and forest/farmland located in the vicinity of a former smelter site in Republic of Korea to elucidate the changes in As bioaccessibility due to biogeochemical interactions. Bioaccessibility and chemical forms of As in soils were determined by using an in vitro method and sequential extraction, respectively, and soil microbial community was evaluated. Bioaccessibility of As in the rice paddy soil samples was higher than that in the forest/farmland soil samples. This could be attributed to relatively higher dependence of bioaccessible As in the rice paddy soils on the soil concentration of iron (Fe), aluminum, or manganese, which could lead to greater changes in bioaccessible As via reductive dissolution. The strong linear relationship (R2 = 0.90, p value ≤0.001) between the pore water As and Fe concentrations, and the greater portion of bacterial species related to reductive dissolution of Fe oxides in the rice paddies can support the higher As bioaccessibility promoted by reductive dissolution. Therefore, it is necessary to consider the potential changes in the bioaccessible As due to biogeochemical interactions in remediation of As-contaminated soils, particularly when soils are likely to be reused under reductive dissolution-promoting conditions (e.g., flooded conditions).

Keywords
Arsenic, Bioaccessibility, Biogeochemical interaction, Flooded condition, Reductive dissolution

DOI
https://doi.org/10.1007/s10653-016-9800-x

Authors

Hyeonyong Chung, Won Jung Ju, Eun Hea Jho, Kyoungphile Nam*

date

2016

Title

Applicability of a submersible microbial fuel cell for Cr(VI) detection in water

Journal

Environmental Monitoring Assessment 188:613

Impact Factor

Authors

Junmo Ahn, Eun Hea Jho, Moonkyung Kim, Kyoungphile Nam*

date

2016

Title

Increased 3HV Concentration in the Bacterial Production of 3HB and 3HV Copolymer with Acid-Digested Rice Straw Waste

Journal

Journal of Polymers and the Environment 24(2):98-103

Impact Factor

Authors

Jaeshik Chung, Young-Jin Kim, Gwanghun Lee, Kyoungphile Nam*

date

2016

Title

Experimental determination of nonequilibrium transport parameters reflecting the competitive sorption between Cu and Pb in slag-sand column

Journal

Chemosphere 154:335-342

Impact Factor

Authors

Junmo Ahn, Eun Hea Jho*, Kyoungphile Nam

date

2015

Title

Effect of C/N ratio on polyhydroxyalkanoates (PHA) accumulation by Cupriavidus necator and its implication on the use of rice straw hydrolysates

Journal

Environmental Engineering Research 20(3):246-253

Impact Factor

 

Authors

Jinwoo Im, Kyung Yang, Seheum Moon, Young-Jin Kim, Kyoungphile Nam*

date

2015

Title

Role of phosphate and Fe-oxides on the acid-aided extraction efficiency and readsorption of As in field-aged soil

Journal

Journal of Hazardous Materials 300:161-166

Impact Factor

Authors

Sangsoon Im, Jae-Woong Jung, Eun Hea Jho*, Kyoungphile Nam

date

2015

Title

Effect of soil conditions on natural attenuation of 2,4,6-trinitrotoluene (TNT) by UV photolysis in soils at an active

Journal

Journal of soils and sediments 15(7):1455-1462

Impact Factor

Authors

Jinwoo Im, Kyung Yang, Eun Hea Jho*, Kyoungphile Nam, 2015, Effect of different soil washing solutions on bioavailability of residual arsenic in soils and soil properties, Chemosphere 138:253-258 file

date

2015

Title

Journal

Impact Factor

Authors

Jinsung An, Junseok Lee, Gyuri Lee, Kyoungphile Nam, Hye-On Yoon*

date

2015

Title

Combined use of collision cell technique and methanol addition for the analysis of arsenic in a high-chloride-containing sample by ICP-MS

Journal

Microchemical Journal 120:77-81

Impact Factor

Authors

An, J., Jho, E. H.*, and Nam, K

date

2015

Title

Effect of dissolved humic acid on the Pb bioavailability in soil solution and its consequence on ecological risk

Journal

Journal of Hazardous Materials 286:236-241

Impact Factor

 

 

Authors

S. Jeong, H. S. Moon, K. Nam*

date

2015

Title

Increased ecological risk due to the hyperaccumulation of As in Pteris cretica during the phytoremediation of As contaminated site

Journal

Chemosphere 122:1-7

Impact Factor

Authors

K. Yang, J. Im, S. Jeong, K. Nam*

date

2015

Title

Determination of human health risk incorporating experimentally derived site-specific bioaccessibility of arsenic at an old abandoned smelter site

Journal

Environmental Research, 137, 78-84

Impact Factor

Authors

Eun Hea Jho, Jinwoo Im, Kyung Yang, Young-Jin Kim, Kyoungphile Nam*

date

2015

Title

Changes in soil toxicity by phosphate-aided soil washing: Effect of soil characteristics, chemical forms of arsenic~

Journal

Chemosphere, 119, 1399-1405

Impact Factor

Authors

Seulki Jeong, Hee Sun Moon, Kyoungphille Nam

date

2014

Title

Enhanced uptake and translocation of arsenic in Pteris cretica through siderophore-arsenic complex formation with an aid of rhizospheric

Journal

Journal of Hazardous Materials, 280, 536-543

Impact Factor

Authors

Jae-Woong Jung, Koungphile Nam

date

2014

Title

Mobility and bioavailability reduction of soil TNT via sorption enhancement using monopotassium phosphate

Journal

Journal of Hazardous Materials, 275, 26-30

Impact Factor

Authors

Inseon Park, Eun Hea Jho, Kyoungphile Nam

date

2014

Title

Optimization of Carbon Dioxide and Valeric Acid Utilization for Polyhydroxyalkanoates Synthesis by Cupriavidus necator

Journal

J polym Environ,22,244-251

Impact Factor

Authors

E.H. Jho, D Shin, SJ Turner, and N Singhal

date

2014

Title

Effect of Fenton reagent shock and recovery periods on anaerobic microbial community structure and degradation of chlorinated aliphatics

Journal

Biodegradation, 25(2): 253-264

Impact Factor

 

Authors

Byung Sun Lee, Sung-Ho Song*, Jin Sung Kim, Jae Yeon Um, Kyoungphile Nam

date

2014

Title

Availability of coastal groundwater discharge as an alternative water resource in a large-scale reclaimed land, Korea

Journal

Springer, 71, 1521-1532

Impact Factor

Authors

Byung Sun Lee, Kyuyeon Lee, Jae Yeon Um, Kyoungphile Nam

date

2014

Title

Slowly released molasses barrier system for controlling nitrate plumes in groundwater: A pilot-scale tank study

Journal

Chemosphere, 97, 135-139

Impact Factor

Authors

E.H. Jho, H Ryu, D Shin, Y-J Kim, YJ Choi, and K Nam*

date

2014

Title

Prediction of landfarming period using degradation kinetics of petroleum hydrocarbons: test with artificially contaminated and field-aged soils and commercially available bacterial cultures

Journal

Impact Factor

Authors

Doyun Shin, Kyoungphile Nam

date

2014

Title

Potential use of a self-dying reporter bacterium to determine thebioavailability of aged phenanthrene in soil: Comparison withphysicochemical measures

Journal

Journal of Hazardous Materials, 265, 1-7

Impact Factor

Authors

Seuilki Jeong, Hee Sun Moon*, Doyun Shin, Kyoungphile Nam

date

2013

Title

Survival of introduced phosphate-solubilizing bacteria (PSB) and their impact on microbial community structure during the phytoextraction of Cd-contaminated soil

Journal

Impact Factor

Authors

Doyun Shin, Kyoungphile Nam

date

2013

Title

Potential use of a self-dying reporter bacterium to determine thebioavailability of aged phenanthrene in soil: Comparison withphysicochemical measures

Journal

Journal of Hazardous Materials, 265, 1-7

Impact Factor

Authors

Seuilki Jeong, Hee Sun Moon, Kyoungphile Nam

date

2013

Title

Differential in vitro bioaccessibility of residual As in a field-aged former smelter site and its implication for potential risk

Journal

Science of The Total Environment, 463-464, 348-354

Impact Factor

Authors

Byung Sun Lee, Eungyu Park, Jae Yeon Um, Kyuyeon Lee, Jina Jeong, Kyoungphile Nam

date

2013

Title

Release characteristics of molasses from a well-type barrier system in groundwater: a large test tank study for nitrate removal

Journal

Environ Earth Sci, 70(1),167-174

Impact Factor

Authors

E. H. Jho, J-W Jung, K. Nam

date

2013

Title

Different Fate of Pb and Cu at Varied Peroxide Concentrations during the Modified Fenton Reaction in Soil and its Effect on the Degradation of 2,4-Dinitrotoluene

Journal

Journal of Chemical Technology and Biotechnology

Impact Factor

Authors

Kyung Yang, Jung In Yoon, Hyerim Ryu, David Chung, Taekwoo Nam, Kyungphile Nam

date

2013

Title

Potential Health Risk of Reused Creosote-Treated Old Railway Ties at Recreational Sites in Korea

Journal

Human & Ecological Risk assessment, 19(3), 778-791

Impact Factor

Authors

Jae-Woong Jung, Gwanghun Lee, Sangsoon Im, Kyoungphile Nam

date

2013

Title

Human Health Risk Assessment of a Civilian-Accessible Active Firing Range

Journal

Human & Ecological Risk assessment, 19(3), 807-818

Impact Factor

Authors

Jho, E. H., Singhal, N. and Turner, S.

date

2012

Title

Tetrachloroethylene and Hexachloroethane Degradation in Fe(III) and Fe(III)-citrate Catalyzed Fenton Systems

Journal

Journal of Chemical Technology and Biotechnology, 87, 8, 1179-1186

Impact Factor

 

 

Authors

J.Y. Kim, M.C. Shin, J.-R. Park, K. Nam

date

2003

Title

Effect of soil solids concentration in batch tests on the partition coefficients of organic pollutants in landfill liner-soil materials

Journal

J. Mater. Cycles. Waste. Manag., 5(1): 55-62

Impact Factor

 

 

Authors

Seulki Jeong, Hee Sun Moon, Kyoungphile Nam, Jae Young Kim, Tae Sung Kim

date

2012

Title

Application of phosphate-solubilizing bacteria for enhancing bioavailability and phytoextraction of cadmium (Cd) from polluted soil

Journal

Chemosphere

Impact Factor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Authors

Doyun Shin, Kyoungphile Nam

date

Title

Determination of phenanthrene bioavailability by using a self-dying reporter bacterium: Test with model solids and soil

Journal

Journal of Biotechnology

Impact Factor

Authors

Jinsung An, Seulki Jeong, Hee S. Moon, Eun H. Jho, Kyoungphile Nam

date

2011

Title

Prediction of Cd and Pb Toxicity to Vibrio fischeri using Biotic Ligand-Based Models in Soil

Journal

Journal of Hazardous Materials

Impact Factor

Authors

Yongju Choi, Seulki Jeong, Hyerim Ryu, Kyuyeon Lee, Bum Han Bae, Kyoungphile Nam

date

2011

Title

Ecological Risk Characterization in a Heavy Metals- and Explosives-Contaminated Site: Effect of Reservoir Construction

Journal

Human & Ecological Risk assessment

Impact Factor

Authors

Jin Chul Joo, Jae Young Kim, Kyoungphile Nam

date

2011

Title

Sorption of nonpolar neutral organic compounds to model aquifer sands: Implications on blocking effect

Journal

Journal of Environmental Science and Health Part A, 46(9): 1008-1019

Impact Factor

Authors

Eun Hea Jho, Jinsung An, Kyoungphile Nam

date

2011

Title

Extended biotic ligand model for prediction of mixture toxicity of Cd and Pb using single metal toxicity data

Journal

Environmental Toxicology and Chemistry, Vol. 30, No. 7, pp. 1697?1703

Impact Factor

Authors

E.H. Jho, S.B. Lee, Y.J. Kim, K. Nam

date

2011

Title

Facilitated desorption and stabilization of sediment-bound Pb and Cd in the presence of birnessite

Journal

Journal of Hazardous Materials, 188(1-3), 206?211 f

Impact Factor

Authors

H.S. Cho, H.S. Moon, M. Kim, K. Nam, J.Y. Kim

date

2011

Title

Biodegradability and biodegradation rate of poly(caprolactone)-starch blend

Journal

Waste Management, 31(3), 475-480

Impact Factor

Authors

Seungbae Lee, Jinsung An, Young-Jin Kim, Kyoungphile Nam

date

2011

Title

Binding strength-associated toxicity reduction by birnessite and hydroxyapatite in Pb and Cd

Journal

Journal of Hazardous Materials, 186(2-3), 2117?2122

Impact Factor

Authors

Doyun Shin, Hee Sun Moon, Chu-Ching Lin, Tamar Barkay, Kyungphile Nam

date

2011

Title

Use of reporter-gene based bacteria to quantify phenanthrene biodegradation and toxicity in soil

Journal

Environmental Pollution, 159(2), 509-514

Impact Factor

Authors

E.H. Jho, N. Singhal, S. Turner

date

2010

Title

Fenton degradation of tetrachloroethene and hexachloroethane in Fe(II) catalyzed systems

Journal

Journal of Hazardous Materials 184, 234?240

Impact Factor

Authors

H. Ryu, J. S. Chung, T. Nam, H. S. Moon, K. Nam

date

2010

Title

Incorporation of Heavy Metals Bioavailability into Risk Characterization

Journal

Clean ? Soil, Air, Water 2010, 38 (9), 812?815 file

Impact Factor

Authors

H.-S. Moon, D. Shin, K. Nam, J.-Y. Kim,

date

2010

Title

Distribution of the Microbial Community Structure in Sulfur-Based Autotrophic Denitrification Columns

Journal

JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE, 136(5), 481-486

Impact Factor

Authors

D. Shin, D. Y. Sung, H. S. Moon, K. Nam

date

2010

Title

Microbial succession in response to 1,4-dioxane exposure in activated sludge reactors: Effect of inoculum source and extra carbon addition

Journal

J. Environ. Sci. Health, Part A, 45(2)

Impact Factor

Authors

Y. J. Choi, Y. J. Kim, K. Nam

date

2009

Title

Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

Journal

Environmental Pollution 157 (2009) pp. 2197?2202

Impact Factor

Authors

S. Lee, H. Ryu, K. Nam

date

2009

Title

Phenanthrene metabolites bound to soil organic matter by birnesite following partial biodegradation

Journal

Environ. Toxicol. and Chem., Vol. 28, No. 5, pp. 946?952

Impact Factor

Authors

J. Y. Park, Y. J. Choi, S. Moon, D. Y. Shin, K. Nam

date

2009

Title

Microbubble suspension as a carrier of oxygen and acclimated bacteria for phenanthrene biodegradation

Journal

Journal of Hazardous Materials, 163(2-3);761-767

Impact Factor

Authors

J. Im, S. Moon, K. Nam, Y.-J. Kim, J.Y. Kim

date

2009

Title

Estimation of mass transport parameters of gases in the soil layer

Journal

Waste. Manag., 29(2):869-875

Impact Factor

Authors

Y.-J. Kim, T.S. Steenhuis, K. Nam

date

2008

Title

Movement of Heavy Metals through Preferential Flow Paths

Journal

CLEAN-Soil, Air, Water, 36(12):984-989

Impact Factor

Authors

H.S. Moon, D.Y. Shin, K. Nam, J.Y. Kim

date

2008

Title

A long-term performance test on an autotrophic denitrification column for application as a permeable reactive barrier

Journal

Chemosphere, 2008 ,73(5):723-728

Impact Factor

anthracene in the presence of p-xylene and its impact on risk in the subsurface, Polycycl. Aromat. Comp., 28(4-5):598-610 file ” open=”no”]

Authors

Y.-J Kim, J.K. Han, H. Ryu, S.H. Lee, K. Nam

date

2008

Title

Altered mobility of benz[a]anthracene in the presence of p-xylene and its impact on risk in the subsurface

Journal

Polycycl. Aromat. Comp., 28(4-5):598-610

Impact Factor

Authors

S.H. Moon, K. Nam, J.Y. Kim, M.K Chung, K.H. Shim

date

2008

Title

Effectiveness of compacted soil liner as a gas barrier layer in the landfill final cover system

Journal

Waste. Manag., 28: 1909?1914

Impact Factor

Authors

J.W. Jung, S.H. Lee, H. Ryu, K. Nam, K.-H. Kang

date

2008

Title

Enhanced reactivity of hydroxylated polycyclic aromatic hydrocarbons to birnessite in soil: Reaction kinetics and nonextractable residue formation

Journal

Environ. Toxicol. Chem., 27(5):1031-1038

Impact Factor

Authors

D.I. Oh, K. Nam, J.W. Park , J.H. Khimd, Y.K. Kim, J.Y. Kim

date

2008

Title

Impacts of environmental conditions on the sorption of volatile organic compounds onto tire powder

Journal

J. Hazard. Mater. 153(1-2):157?163

Impact Factor

Authors

Y.J. Choi, J.Y. Park, Y.-J. Kim, K. Nam

date

2008

Title

Flow characteristics of microbubble suspensions in porous media as an oxygen carrier

Journal

Clean-Soil, Air, Water(舊Acta hydrochimica et hydrobiologica), 36(1): 59-65

Impact Factor

Authors

J.W. Jung, S.H. Lee, H. Ryu, K.-H. Kang, K. Nam

date

2008

Title

Detoxification of phenol through bound residue formation by birnessite in soil: Transformation kinetics and toxicity

Journal

J. Environ. Sci. Health. A., 43(3): 255-261

Impact Factor

Authors

H. Ryu, J.K. Han, J.W. Jung, B. Bae, K. Nam

date

2007

Title

Human health risk assessment of explosives and heavy metals at military gunnery range

Journal

Environ. Geochem. Health., 29(4): 259-269

Impact Factor

Authors

S.-R. Lee, J.K. Han, Y.J. Choi, K. Nam

date

2007

Title

Reduction of Ammonia and Hydrogen Sulfide Emission from Swine Manure Using Aqueous Foams Amended with Microorganisms and Chemical Additives

Journal

Clean-Soil, Air, Water(舊Acta hydrochimica et hydrobiologica)

Impact Factor

Authors

H.S. Moon, S.W. Chang, K. Nam, J. Choe, J.Y. Kim

date

2006

Title

Effect of reactive media composition and co-contaminants on sulfur-based autotrophic denitrification

Journal

Environ. Pollut., 144(3): 802-807

Impact Factor

Authors

H.S. Moon, K. Nam, J.Y. Kim

date

2006

Title

Initial alkalinity requirement and effect of alkalinity sources in sulfur-based autotrophic denitrification barrier system

Journal

J. Environ. Eng., 132(9): 971-975

Impact Factor

Authors

J.Y. Park, S.-R. Lee, J.K. Han, K. Nam

date

2006

Title

Mitigation of Ammonia and Hydrogen Sulfide Emissions by Stable Aqueous Foam- Microbial Media

Journal

Environ. Sci. Technol., 40(9): 3030-3035

Impact Factor

Authors

H.S. Moon, H.-Y. Kahng, J.Y. Kim, J.J. Kukor, K. Nam

date

2006

Title

Determination of biodegradation potential by two culture-independent methods in PAH-contaminated soils

Journal

Environ. Pollut., 140(3): 536-545

Impact Factor

Authors

J.C. Joo, K. Nam, J.Y. Kim

date

2005

Title

Estimation of mass transport parameters of organic compounds through high density polyethylene geomembranes using a modified double-compartment apparatus

Journal

J. Environ. Eng., 131(5): 790-799

Impact Factor

Authors

J.-R. Park, S. Moon, Y.M. Ahn, J.Y. Kim, K. Nam

date

2005

Title

Determination of environmental factors influencing methane oxidation in a sandy landfill cover soil

Journal

Environ. Technol., 26(1): 93-102

Impact Factor

Authors

H.S. Moon, K.-H. Ahn, S. Lee, K. Nam, J.Y. Kim

date

2004

Title

Use of autotrophic sulfur-oxidizers to remove nitrate from bank filtrate in a permeable reactive barrier system

Journal

Environ. Pollut., 129: 499-507

Impact Factor

Authors

J.C. Joo, J.Y. Kim, K. Nam

date

2004

Title

Mass transfer of organic compounds in dilute aqueous solutions into high density polyethylene geomembranes

Journal

J. Environ. Eng., 130(2): 175-183

Impact Factor

Authors

J.S. Yoon, S. Moon, J.Y. Kim, K. Nam, M. Chung

date

2003

Title

Mass transport of organic contaminants through a self-sealing/self-healing mineral landfill liner

Journal

J. Mater. Cycles. Waste. Manag., 5(2): 130-136

Impact Factor

Authors

K. Nam, J.Y. Kim, D.I. Oh

date

2003

Title

Effect of soil aggregation on the biodegradation of phenanthrene aged in soil

Journal

Environ. Pollut., 121: 147-151

Impact Factor

Authors

H.-Y. Kahng, K. Nam, J.J. Kukor, B.-J. Yoon, D.-H. Lee, D.-C. Oh, S.-K. Kam, K.-H. Oh

date

2002

Title

PAH utilization by Pseudomonas rhodesiae KK1 isolated from a former manufactured-gas plant site

Journal

Appl. Microbiol. Biotechnol., 60(4): 475-480

Impact Factor

Authors

K. Nam, J.Y. Kim, H.S. Moon, J.J. Kukor

date

2002

Title

Linkage between biodegradation of polycyclic aromatic hydrocarbons and phospholipid profiles in soil isolates

Journal

J. Microbiol. Biotechnol., 12(1): 77-83

Impact Factor

Authors

H.-Y. Kahng, K. Nam

date

2002

Title

Molecular characteristics of Pseudomonas rhodesiae strain KK1 in response to phenanthrene

Journal

J. Microbiol. Biotechnol., 12: 729-734

Impact Factor

Authors

K. Nam, J.Y. Kim

date

2002

Title

Role of loosely bound humic substances and humin in the bioavailability of phenanthrene aged in soil

Journal

Environ. Pollut., 118(3): 427-433

Impact Factor

Authors

K. Nam, J.Y. Kim

date

2002

Title

Persistence and bioavailability of hydrophobic organic compounds in the environment

Journal

Geosci. J., 6(1): 13-21

Impact Factor

 

 

Authors

K. Nam, W. Rodriguez, J.J. Kukor

date

2001

Title

Enhanced degradation of polycyclic aromatic hydrocarbons by biodegradation combined with a modified Fenton reaction

Journal

Chemosphere., 45(1): 11-20

Impact Factor

 

Authors

K. Nam, M. Alexander

date

2001

Title

Relationship between biodegradation rate and percentage of a compound that becomes sequestered in soil

Journal

Soil Biol. Biochem., 33(6): 787-792 file

Impact Factor

 

 

Authors

K. Nam, J.J. Kukor

date

2000

Title

Combined ozonation and biodegradation for remediation of mixtures of aromatic hydrocarbons in soil

Journal

Biodegradation., 11: 1-9

Impact Factor

Authors

J.C. White, M. Hunter, K. Nam, J.J. Pignatello, M. Alexander

date

1999

Title

Correlation between the biological and physical availabilities of phenanthrene in soils and soil humin in aging experiments

Journal

Environ. Toxicol. Chem., 18(8): 1720-1727

Impact Factor

Authors

K. Nam, N. Chung, M. Alexander

date

1998

Title

Relationship between Organic Matter Content of Soil and the Sequestration of Phenanthrene

Journal

Environ. Sci. Technol., 32(23): 3785-3788

Impact Factor

Authors

K. Nam, M. Alexander

date

1998

Title

Role of nanoporosity and hydrophobicity in sequestration of phenanthrene and its bioavailability: Tests with model solids

Journal

Environ. Sci. Technol., 32(1): 71-74

Impact Factor

Authors

M. Alexander, P.B. Hatzinger, J.W. Kelsey, B.D. Kottler, K. Nam

date

1997

Title

Sequestration and realistic risk from toxic chemicals remaining after bioremediation

Journal

Ann. N. Y. Acad. Sci., 829:1-5

Impact Factor