• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.5-13
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• 2006

This study was conducted to evaluate the application of $UV/TiO_2/H_2O_2$ process for treating humic acid and heavy metals in surface water. Removal efficiency of $UV/TiO_2/H_2O_2$ process was much more efficient than that of $UV/TiO_2$ process for humic acid and heavy metals removal. The removal rate of humic acid and heavy metals increased with the increase of $TiO_2$ dosage and UV intensity, however decreased with more than 0.3 g/L of $TiO_2$ dosage. The addition of $H_2O_2$ as an oxidant was a positive effect for the removal rate of humic acid and heavy metals especially in the concentration of 50 mg/L $H_2O_2$.

• Journal of Environmental Science International
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• v.27 no.2
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• pp.109-122
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• 2018

This study was conducted to investigate the removal characteristics of heavy metals and sulfate ion from acid mine drainage by porous zeolite-slag ceramics (ZS ceramics) that was prepared by adding wood flour as pore-foaming agent while calcining the mixtures of natural zeolite and converter slag. The batch test showed that the removal efficiency of heavy metals by pellet-type porous ZS ceramics increased as the particle size of wood flour was decreased and as the weight mixing ratio of wood flour to ZS ceramics was increased. The optimal particle size and weight mixing ratio of wood flour were measured to be $75{\mu}m$ and 7~10%, respectively. The removal test with the porous ZS ceramics prepared in these optimal condition showed very high removal efficiencies: more than 98.4% for all heavy metals and 73.9% for sulfate ion. Relative to nonporous ZS ceramics, the increment of removal efficiency of heavy metals by porous ZS ceramics with $75{\mu}m$ and 10% wood flour was 5.8%, 60.5%, 36.9%, 87.7%, 10.3%, and 57.4% for Al, Cd, Cu, Mn, Pb, and Zn, respectively. The mechanism analysis of removal by the porous ZS ceramics suggested that the heavy metals and sulfate ion from acid mine drainage are eliminated by multiple reactions such as adsorption and/or ion exchange as well as precipitation and/or co-precipitation.

• Resources Recycling
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• v.10 no.4
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• pp.10-17
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• 2001

The present work investigates the possible use of fly ash for the removal of heavy metal ions from aqueous solutions. Batch experiments were conducted and the influences of metal concentration, pH, and fly ash concentration were investigated. Heavy metals used in these studies were lead and zinc. Adsorption studies were done over a range of pH values (3~10) at $25^{\circ}C$ and heavy metal concentrations of 10~400 mg/L using fly ash concentrations of 10 and 20 g/L. Experiments were also conducted without fly ash to determine the extent of heavy metal removal by precipitation. Kinetic and equilibrium experiments were performed and adsorption data were correlated with both Langmuir and Freundlich adsorption models. The results of these studies indicate that 리y ash can be used as an adsorbent for heavy metals in the aqueous solutions, yet the degree of removal depends on the pH.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1542-1546
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• 2015

The purpose of this study was to investigate the potential of zeolite-supported sulfatereducing bacteria (SRB) in enhancing the removal of Cu²⁺, Ni²⁺, and Cr⁶⁺ in contaminated seawater. Our results show that SRB-immobilized zeolite carriers can enhance the removal of heavy metals. In addition, heavy metals were generally better removed at conditions of 37°C. Cu²⁺, Ni²⁺, and Cr⁶⁺ were effectively removed by 98.2%, 90.1%, and 99.8% at 100 parts per million concentration of the heavy metals, respectively. These results indicate that SRB-zeolite carriers hold great potential for use in the removal of cationic heavy metal species from marine environment.

• Journal of Soil and Groundwater Environment
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• v.15 no.3
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• pp.27-33
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• 2010

The purpose of this study was in search of native plant species showing metal-resistant property and excessively accumulating heavy metals in metal-contaminated soil or abandoned mines as well as in evaluation of applicability of phytoremediation. In the study area, species showing excessively accumulating heavy metals were a shepherd´s purse, pampas grass, a Korean lettuce, a Hwansam vine, the Korean persicary, a foxtail, a goosefoot, and a water pepper. The first screened plant species in Sambo mine were as shepherd's purse, Korean lettuce and pampas grass Among them the shepherd´s purse can be excluded because it is a seasonal plant and has lower removal capacity for heavy metals. The Korean lettuce was also excluded because of having lower removal capacity for heavy metals. Pampas grass is a highly bionic plant species constantly growing from spring. However it has weak points such as little accumulation capacity for zinc as well as small values of an accumulation factor and a translocation factor. Another problem is regarded as removal of roots after the clean up if pampas grass is applied to a farmland. In Sanyang mine, wormwood and Sorijaengi were considered as adaptable species.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.57-67
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• 2012

The midge samples were undertaken at three streams, representing different surrounding environments, to investigate the contaminant exposure of midge. The content of heavy metals in midge collected in Singil stream were generally higher as a result of input to the industrial effluents with respect to other streams. Adsorption experiments were done to evaluate the possibility of removing contaminants from water with midge. Diazinon and heavy metals were contaminant target compounds in this study. The removal rate of diazinon in water by midge was 60-75%. In the case of Cu, the removal rate was reached around 90% at the lower initial concentration of 1.87 and 0.81 ppm rather than 4.25 ppm. The reduction of concentration of Cr and Cd according to the lapse of time was similar to the Cu, but their removal rates were shown 50% and 60-74%, respectively. The removal rate of Zn by midge represented relatively high level within the experimental condition. No change in concentration of Cr and As with time were occurred at all experimental conditions. It accounts for the fact that the reduction of Cr and As could not be achieved through the adsorption process, using midge.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.687-690
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• 2010

The objective of this study is to investigate the effect of aldehyde compounds and ploysulfide as accelerating agents on removal of heavy metals and CN in plating wastewater. As a results of the experiments, the removal efficiency of cyanide using the formaldehyde type of aldehydes was the highest at pH 9. Next types were sodium formaldehyde bisulfite addut> paraldehyde> paraformaldehyde. Also, optimum pH and dosage for treating the residual heavy metals by using polysulfide were pH 9 and 30 mg/L, respectively. The removal efficiencies of cyanide, chromium, zinc and copper were above 96.7% at optimum condition.

• Journal of environmental and Sanitary engineering
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• v.11 no.3
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• pp.21-27
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• 1996

Chitosan is a natural polyelectrolytic compound. Researches of adsorption capacity using chitosan have been doing actively. We prepared bead type gel, simple modifier of chitosan, And then experimented adsorption test of heavy metals (Cd etc) using it. According to the result adsorption capacity of chitosan bead was five times higher than chitosan powder. Removal rate of cadmium resulted 90% over in the test that initial concentration of Cd was 100mg/L and bead dosage was 6g/100mL. Adsorption type of heavy metals was similar to general adsorption curve. And optical pH range was 4 - 10 in the adsorption test. In the experiments of other heavy metals (Pb, Zn, Cu, Mn) adsorption types had two stages, highly removal rate-stage at the short time (20minutes) and then slow rate-stage at the after. And removal efficiency at the variable pH ranges revealed relatively good.

• Economic and Environmental Geology
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• v.32 no.1
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• pp.43-51
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• 1999

In order to remediate hazardous waste site, a process of electrokinetically purging chemicals from saturated soil is examined by laboratory experiments. Electrokinetic soil remediation is one of the most promising soil decontamination processes that habe igh removal efficiency and time-effectiveness in low-permeability soils such as clay. Being combined with several mechanisms-electromigration, elec troosmosis, diffusion and electrolysis of water, electrokinetic soil processing can remove non-polar organics as well as ionic contaminants. The objectives of this study are; 1) the exploration of the feasibility of electrokinetic soil processing on the removal of heavy metals, 2) the investigation of applicability to the tailing-soils in aban doned mining area, 3) the examination of effects of soil pH and conductivity on the transport phenomena of elements in soils, and 4) the investigation of the applicability of the ionexchange membrance to the efficient collection of heavy metals removed from contaminated soils. With the result of this study, it is suggested that the removal efficiency is significantly influenced by applied voltage & current, type of purging solutions, soil pH, permeability and zeta potentials of soil. Although further study should be needed, it is possible to collect removed heavy metals with ion-exchange membrance in cathode compartment.

• Journal of Environmental Science International
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• v.21 no.6
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• pp.667-676
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• 2012

This research investigated to reduce mass of heavy metals in AMD(acid mine drainage) by microbial mats formed on the channel bed. As, Cd, Cu, Fe, Mn and Zn components were monitored in water and microbial mats, at three points (AMD1, AMD2 and AMD3), in a total of six times. Average daily discharge mass of heavy metals was highest in July, Fe component contained more than 76% of total discharge mass. Discharge mass of heavy metals of AMD and heavy metal contents in microbial mats decreased with downstream at channel. Heavy metal components that average daily discharge mass is over 0.5 kg were Fe, Cu and Zn, and they were highest in July. Average removal efficiency of heavy metals in AMD was highest about 21% in Fe, this microbial mats were due to form from precipitation of Fe component in AMD by aerobic iron bacteria. Relative content for As component in microbial mats than AMD was over 16 times, this As components were due to absorb at iron oxide and iron hydroxide on the surface of microbial mats.