• Asian Journal of Turfgrass Science
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• v.11 no.4
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• pp.289-294
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• 1997

The cycles of heavy metals, mercury, lead and cadmium, were investigated on in dynamic grassland ecosystems at a steady state in Zoysia japonica and Miscanthus sinensis in Mt. Kwanak, Korea. Estimates of decay constants of heavy metals based on experimental and methomatical model, were Hg 0.14, Pb 0.17 and Cd 0.41 of Z. japonica grassland, and Hg 0.33, Pb 0.13 and Cd 0.56 of M sinensis grassland. The durations of reaching half of initial amounts in Z. japonica and M. sinensis grassland, were Hg 4.95, Pb 4.07 and Cd 1.69 years, and Hg 2.10, Pb 5.33 and Cd 1.24 years respectively. Times needed for 99% decomposed were longer in Z. japonica than M. sinensis grassland. Decay velocity of constituents of surface soil layers were more rapidly in M. sinensis than Z. japonica grassland. Key words: Cycles of heavy metals, Mercury, Lead, Cadmium, Zoysia japonica. Miscanthus sineusis, Mt. Kwanak, Decay constants.

• International journal of advanced smart convergence
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• v.9 no.1
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• pp.19-28
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• 2020

We studied the on-site treatment of soil contaminated by heavy metals and petroleum was tested using relocatable soil washing equipment for greater remediation efficiency. Different combinations of pH and solid/liquid ratio were tested to determine the optimum balance, settling on values of 5 and 1:2, respectively. Next, soils containing Pb, Hg, and petroleum were further tested to assess the optimum number of washing cycles. The remediation efficiency of Pb and Hg in soil contaminated solely by heavy metals was 90.1% and 86.4% after three and two washings, respectively. The remediation efficiency of petroleum in soil contaminated solely by petroleum was 98.8% after one washing. When soil contaminated by both heavy metals and petroleum was cleaned, up to 91.0% of Pb, 86.9% of Hg, and 96.1% of petroleum was removed after two, one, and one washings, respectively. We conducted all remediation efficiencies and concentration reductions satisfied the standard threshold for soil contamination in South Korea.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1059-1072
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• 2018

Bioremediation has been recognized as a suitable alternative to conventional methods of removing contaminants, and it uses fungi, bacteria and microalgae. In contrast to other organisms, microalgae are unique in that they have the ability to perform photosynthesis like plants and to utilize organic/inorganic carbon substrates, in a process called phytoremediation. Microalgae can populate a reaction site rapidly and enhance the bioremediation efficiency. In this study, Chlorella vulgaris was used to evaluate the removal potentials of the nutrients (N and P) and heavy metals (Cu and Zn) from swine wastewater. The optimum growth conditions for Chlorella vulgaris and the removal potentials of N, P, Cu, and Zn from synthetic wastewater using Chlorella vulgaris were investigated. Based on the results, the applicability of this microalga to on-site wastewater treatment was examined. Optimal growth conditions for Chlorella vulgaris were established to be $28^{\circ}C$, a pH of 7, and light and dark cycles of 14:10 h. As the concentrations of the nutrients were increased, the efficiencies of N and P removal efficiencies by Chlorella vulgaris were decreased in the single and binary mixed treatments of the nutrients, respectively. Further, the efficiencies of Cu and Zn removal also decreased as the heavy metals concentrations added were increased, both in the single and binary mixed treatments. In addition, the efficiency of Cu removal was higher than that of Zn removal. Our results indicate that Chlorella vulgaris could be used in treatment plants for the removal of nutrients and heavy metals from swine wastewater.

• Magazine of the Korea Concrete Institute
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• v.9 no.1
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• pp.143-151
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• 1997

Chemical resistance of the cement mortar containing the Thermally Activated Diaomite(TAD) and H.M.(Heavy Metals) has been studied. The H.M.. extracted from EAF(Electrica1 Arc Furnace) Dust. were saturated with diatomite. The diatomite was then thermally activated at $750{\circ}C$ for 30minutes and powdeled. The powder was mixed with a portland cement on a weight basis from 0%. 2.5%. 5.0%. 10%. 20%. The optimum mixture. after those mixtures were subjected to compressive strength(7 and 28days) and leaching bchaviour of H.M.. was tested for its experiment on Wet/Dry cycles and chemical resistance(e.q. imrncrsion in 5%(Conc.) of H2S04, CaC12 and hlgSO4. It was shown that the cement, mortar containing 10% of' P.D. gave a rise to the remarkable increase in compressive strength. The compressive strength was generally decrease beyond the addition of 10% of P.D. The maximum $496kgf/cm^2$ of 28days compressive strength was acheiveti when 10% of P.D. was added to the cement mortar.

• Biotechnology and Bioprocess Engineering:BBE
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• v.2 no.2
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• pp.126-131
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• 1997

The biosorption and desorption of Cr, Cu and Al were carried out using brown marine algae Sargassum fluitans biomass, known as the good biosorbent of heavy metals. The content of alginate bound to light metals could be changed by physical and chemical pretreatment. The maximum uptake of Cr, Cu and Al was independent of the alginate content. The maximum uptaker of Al was two times(mole basis) than those of Cu and Cr. The aluminum-alginate complex was found in the sorption solution of raw and protonated biomass. Most of Cu, Al and light metals sorbed in the biomass were eluted at pH 1.1. However, only 5 to 10% of Cr sorbed was eluted at pH 1.1. The stoiceometric ion exchange between Cu and Ca ion was observed on Cu biosorption with Ca-loaded biomass. A part of Cr ion was bound to biomass as Cr(OH)2+ or Cr(OH)2+. Al was also bound to biomass as multi-valence ion and interfered with the desorbed Ca ion. The behavior of raw S. fluitans in ten consecutive sorption-desorption cycles has been investigated in a packed bed flow-through-column during a continuous removal of copper from a 35 mg/L aqueous solution at pH 5. The eluant used was a 1%(w/v) CaCl2/HC solution at pH 3.

• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.227-244
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• 2021

Objectives: The Korean National Environmental Health Survey provides representative biomonitoring data for environmental pollutants in South Korea. Over the last decade, there have been various studies published using this data. In this study, we aimed to provide information and implications by reviewing each study. Methods: We searched comprehensive electronic databases from PubMed, Google Scholar, and Naver Academic database using the key words 'Korean National Environmental Health Survey' and 'KoNEHS' through March 2021. A total of 57 studies were selected after reviewing the relevance of the data. Results: The most frequently studied pollutants were heavy metals (10), Cotinine (8), Bisphenol A (7), and Phthalates (6), in that order. In particular, Phthalates, Bisphenol A, and Parabens were often studied together (6). A decline in urinary cotinine and heavy metals in the body was shown over time among studies on exposure association. It was demonstrated that Phthalates and Bisphenol A were significantly related to obesity and diabetes from the studies of health impacts. Cross-section study design, spot urine, and insufficient health status information were mostly reported as limitations of the data. Conclusion: Since research has been focused on adults, further investigations of children and adolescents are required. In this regard, it is necessary to maintain the consistency of the data structure and provide integrated weights for all ages. In addition, it would allow the measurement of several environmental pollutants by considering subsample design. Lastly, integrated studies with multi-cycles and the health effects from co-exposure to multiple chemicals would be expected to provide important knowledge.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.82-92
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• 2020

Since swine wastewater contains high concentrations of nutrients and heavy metals, it deteriorates water quality when discharged. Compared to conventional methods, bioremediation can be a promising method for its treatment. Specifically, microalgae have the potential to remove these pollutants. In this study, the removal of nutrients (nitrogen (N) and phosphorus (P)) and heavy metals (copper (Cu) and zinc (Zn)) from swine wastewater by Ankistrodesmus bibraianus was evaluated and the organism's optimal growth conditions were investigated. The optimal growth conditions were established at 28℃, pH 7, and light and dark cycles of 14:10 h. The removal efficiencies of N and P by a single treatment (500, 1,000, 5,000, and 10,000 mg L^-1) ranged from 22.9 to 80.6% and from 11.9 to 50.0%, respectively. The removal efficiencies of N and P in the binary treatments ranged from 16.4 to 58.3% and from 7.80 to 49.8%, respectively. The removal efficiencies of Cu and Zn by a single treatment(10, 30, and 50 mg L^-1) ranged from 15.5 to 81.5% and from 6.28 to 34.3%, respectively. Similarly, the removal efficiencies of Cu and Zn in the binary treatments ranged from 16.7 to 74.5% and from 5.58 to 27.5%, respectively. In addition, the study showed the optimal growth conditions for microalgae and the removal efficiency of nutrients (N and P) and heavy metals (Cu and Zn), which could be applied to swine wastewater. Based on the results in this study, it appears that Ankistrodesmus bibraianus could be used for the removal of nutrients and heavy metals present in swine wastewater.

• Environmental Engineering Research
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• v.24 no.2
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• pp.181-190
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• 2019

Constructed wetlands are improvised man-made systems, designed for adopting the principle of natural wetlands for purifying wastewater - the elixir of life. They are used widely as a cost-effective and energy-efficient solution for treating greywater generated from different tertiary treatment sources. It provides an elaborate platform for research activities in an attempt to recycle earth's natural resources. Among the several organic impurities removal mechanisms existing in constructed wetland systems, the earth's active microbial population plays a vital role. This review deals with the recent advancements in constructed wetland systems from a microbiological perspective to (effect/ devise/ formulate) chemical and physical treatment for water impurities. It focuses on microbial diversity studies in constructed wetlands, influence of wetland media on microbial diversity and wetland performance, role of specific microbes in water reuse, removal of trace elements, some heavy metals and antibiotics in constructed wetlands. The impurities removal processes in constructed wetlands is achieved by combined interactive systems such as selected plant species, nature of substrate used for microbial diversity and several biogeochemical effected reaction cycles in wetland systems. Therefore, the correlation studies that have been conducted by earlier researchers in microbial diversity in wetlands are addressed herewith.

• Advances in environmental research
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• v.6 no.3
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• pp.173-187
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• 2017

Heavy metals, such as vanadium, are some of the most toxic types of water contaminants. In this study, vanadium was removed using a new composite adsorbent called BAZLSC. The impacts of pH and initial concentration of vanadium(V) on the elimination effectiveness of this metal by using BAZLSC were investigated in the first step of the study. Vanadium removal increased as pH increased to 3-3.5, and initial concentration increased to 60-70 mg/L. The removal efficiency then decreased. Central composite design and response surface methodology were employed to examine experimental data. Initial concentration of V ($mg.L^{-1}$), pH, and dosage of adsorbent (g/L) were the independent factors. Based on RSM, the removal effectiveness of vanadium was 86.36% at the optimum of initial concentration (52.69 mg/L), pH (3.49), and adsorbent dosage (1.71 g/L). Also adsorption isotherm investigations displayed that the Freundlich isotherm could explain vanadium adsorption by BAZLSC better than the Langmuir isotherm. Beside them, desorption studies showed sorption was slightly diminished after six continuous cycles.

• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.73-79
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• 2011

Based on the results of Part 1 of our two-parts paper, the possibility on field applicability of CMDS(Coal Mine Drainage Sludge) mixed with bentonite and cement as a liner in landfill sites was investigated. The optimum moisture content that met the landfill liner condition was obtained when the ratio of CMDS: bentonite: cement was 1: 0.5: 0.3 in a lab-scale. The relative compaction was measured in 90.1%, which results for construction field have been generally acceptable. In this study, a large-scale Lysimeter($1.0m{\times}1.5m{\times}2.0m$) was used to simulate the effects of the layer on the freeze/thaw by -20 average temperature. The mixture after freezing/thawing showed compressive strength more than $5kg/cm^2$, which was satisfied with EPA standards. Initial permeability of CMDS was $7.10{\times}10^{-7}cm/s$ and permeability its mixture after freezing/thawing was increased to $9.80{\times}10^{-7}cm/s$. The change of temperature in the layers rises and falls with linear and temperature gradient keep maintain the present state. Moisture contents in the layers have not been radically changed. Through the leaching test determined by KSLT method, it was found that heavy metals excluding Zn and Ni were not leached out or leached out less than the standards during 7 cycles of freezing/thawing process. Since it shows the increased permeability about 1.5 times and slight change in moisture content, but it was satisfied with EPA standar through 7 cycles of freezing/thawing process, this mixture can be applied as a liner in landfill final cover system.