• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.41-53
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• 2013

The study is to propose the optimal separation technique of heavy metals (Pb and Zn) contaminated in soil for improving the removal efficiency by various applicable techniques. The heavy metal contaminated soil samples near abandoned mine X-1 and X-2 were used for the study. Firstly, the wet classification process was shown more than 80% of removal efficiency for lead and zinc. Meanwhile, the magnetic separation process was shown low removal efficiency for lead and zincs because those heavy metals were non-magnetic materials. For the next step, the flotation separation process was shown approximately 24.4% of removal efficiency for zinc, while the gravity concentration process was shown approximately 57% of removal efficiency for lead, and 19.9% of removal efficiency for zinc, respectively. Therefore, zinc contaminated in soil would be effectively treated by the combination technique of the wet classification and the flotation technique. Meanwhile, lead contaminated in soil would be effectively treated by the combination technique of the wet classification process and the flotation process. Furthermore, the extraction of organic matter was shown more effective with aeration, 3% of hydrogen peroxide and 3% of lime such as calcium hydroxide.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.379-381
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• 2003

Metal sorption onto the ICS (Iron oxide coated sand) was studied in batch experiments. Heavy metal cations such as Cd, Pb, and Cu, and a metal anion, As, which sporadically exist in mine sites, were tested for the sorptive removal by ICS. In low pH conditions As showed the highest removal efficiency compared to the other metal cations. And the sorption removal of As was apparently pH-independent reaction. However, removal of metal cations increased with pH and above pH 7 most metal cations showed very low soluble concentrations after treatment. Such a high removal ratio of metal cations above the neutral pH appeared predominantly due to precipitation.

• Resources Recycling
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• v.31 no.4
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• pp.49-55
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• 2022

In this study, the heavy metal ions (of Pb, Cd, Cr, and Hg) in wastewater were removed using a spent Li₂O-Al₂O₃-SiO₂-based crystallized glass previously used as an induction top plate material. Changes in the removal efficiency of heavy metals according to different reaction parameters, such as the amount of zeolite used as a heavy-metal adsorbent, adsorption time, initial concentration of the heavy metals, and pH of the initial solution, were investigated. As the amount of zeolite added increased, the heavy-metal removal efficiency also increased. Adsorption time had a considerable influence on adsorption characteristics, and the removal efficiency of all heavy metals increased with increasing adsorption time. In the case of Cd, the removal efficiency was greatly improved depending on the adsorption time. The initial concentration of the heavy-metal solution did not affect the removal efficiency; however, the initial pH of the heavy-metal solution affected the removal efficiency. More specifically, the removal efficiency of Cd increased while that of Pb and Cr decreased with increasing pH. The adsorption characteristics of Hg were not significantly affected by pH.

• Environmental Engineering Research
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• v.13 no.2
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• pp.79-84
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• 2008

Adsorption of heavy metals by sawdust was investigated to evaluate the effectiveness of using sawdust to remove heavy metals from aqueous solutions. Kinetic and isotherm studies were carried out by considering the effects of initial concentration and pH. The adsorption isotherms of heavy metals fitted the Langmuir or Freundlich model reasonably well. The adsorption capacity of metal was in the order $Pb^{2+}$ > $Cu^{2+}$ > $Zn^{2+}$. A high concentration of co-existing ions such as $Ca^{2+}$ and $Mg^{2+}$ depressed the adsorption of heavy metal. Adsorption data showed that metal adsorption on sawdust follows a pseudo-second-order reaction. Kinetic studies also indicated that both surface adsorption and intraparticle diffusion were involved in metal adsorption on sawdust. Column studies prove that sawdust could be effective biosorbent for the removal of heavy metals from aqueous phase.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.595-599
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• 1998

A batch experiment was conducted to evaluate the removal capacity of welsh onion(Allium fistulosum L.), shallot (Allium ascalonicum L.), garlic (Allium sativum L.) roots as an adsorbent for Ni and Pb in aqueous solution. One gram of the dried Allium root powder was reacted in 100ml of solution containing 10mg of each heavy metal and effects of metal concentration, pH, temperature, and size of adsorbent on the removal efficiency were evaluated. The results were as follows ; The amount of adsorption of heavy metal ions were higher with the smaller particles size of adsorbent. Garlic root was high adsorption capacity of Pb, especially. The higher concentration of heavy metal solution was, the more amount of adsorption of heavy metals was. The adsorption ratio was differed from a kind of heavy metal. As the temperature increased, the amount of adsorption of Ni and Pb by shallot and welsh onion were decreased. The amount of adsorption of Ni was high under alkali conditions but the amount of adsorption of Pb was high under neutral and acidity condition.

• Journal of Environmental Science International
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• v.30 no.11
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• pp.945-956
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• 2021

In this study, the effects of single and binary heavy metals toxicity on the growth and phosphorus removal ability of Bacillus sp.. known as be a phosphorus-removing microorganism, were quantitatively evaluated. Cd, Cu, Zn, Pb, Ni were used as heavy metals. As a result of analysis of variance of the half of inhibition concentration and half of effective concentration for each single heavy metal treatment group, the inhibitory effect on the growth of Bacillus sp. was Ni < Pb < Zn < Cu < Cd. And the inhibitory effect on phosphorus removal by Bacillus sp. was Ni < Pb < Zn < Cu < Cd. When analyzing the correlation between growth inhibition and phosphorus removal efficiency of a single heavy metal treatment group, a negative correlation was found (R² = 0.815), and a positive correlation was found when the correlation between IC₅₀ and EC₅₀ was analyzed (R² = 0.959). In all binary heavy metal treatment groups, the interaction was an antagonistic effect when evaluated using the additive toxicity index method. This paper is considered to be basic data on the toxic effects of heavy metals when phosphorus is removed using phosphorus removal microorganisms in wastewater.

• Journal of environmental and Sanitary engineering
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• v.15 no.1
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• pp.54-61
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• 2000

We studied the adsorption characteristics on the treatment process of heavy metal wastewater by using cuttle fish bones powder. When adding the 0.25% cuttle fish born powder in the heavy metal solution, $Fe^{3+}$ and $Pb^{2+}$ were high removed than other heavy metals as above 95%. In the solution which was adjusted to pH 5, 7 and 9, there was not observed the difference thing on the heavy metal removal rate. At test using plating wastewater treatment, adding 1%, 1.5% and 2% of the cuttle fish born powder, the heavy metal removal rate were as follows; Zn 12.5 - 37.5%, Mn 18.0 - 62.2%, Cd 36.8 -93.0%, Cu 51.4 - 97.4%, Cr 70.8 - 99.1%, Fe 87.2 - 99.3% and Pb 92.8 - 99.9%. When adding the 0.15% cuttle fish born powder and mixing for 20 minutes, the solution was happened the adsorption equability. Applied this results to the Freundlich＇s iso-thermal equation, we found the cuttle fish born＇s probability as a good adsorbent.

• Journal of Environmental Science International
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• v.9 no.4
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• pp.325-330
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• 2000

The hydroxyapatite (HAp) for the present study was prepared by precipitation method in semiconductor fabrication and the crystallized at ambient to 95$0^{\circ}C$ for 30min in electric furnace. The ion-exchange characteristics of HAp for various heavy metal ions such as $Cd^{2+}, Cu^{2+}, Mn^{2+}, Zn^{2+}, Fe^{2+}, Pb^{2+}, Al^{3+}, and Cr^{6+}$ in aqueous solution has been investigated. The removal ratio of various metal ions for HAp were investigated with regard to reaction time, concentration of standard solution, amount of HAp and pH of solution. The order of the ions exchanged amount was as follws: $Pb^{2+}, Fe^{3+}>Cu^{2+}>Zn^{2+}>Al^{3+}>Cd^{2+}>Mn^{2+}>Cr^{6+}. The Pb^{2+}$ ion was readily removed by the Hap, even in the strongly acidic region. The maximum amount of the ion-exchange equilibrium for $Pb^{2+}$ ion was about 45 mg/gram of HAp. The HAp would seem to be possible agent for the removal of heavy metal ions in waste water by recycling of waste sludge in semiconductor fabrication.

• Journal of the Korean Wood Science and Technology
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• v.12 no.3
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• pp.9-14
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• 1984

The removal and readsorption effects of pine and oak bark grown in Korea on water pollution caused by heavy metal ions have been investigated. Bark saturated with heavy metal ions is refleshed with 0.1 N ammonium acetate and then its readsorption has been done. The results obtained are as follows: 1. Adsorption effect of pine bark is similiar to that of oak bark, and 20-40 meshed bark gives the best results. 2. 0.1 N amonium acetate of pH 7 shows more elutriative than the others such as pH 3 hydrochloric acid, pH 10 ammonium hydroxide and pH 7 water. 3 Pine bark refleshed with 0.1 N ammonium acetate gets two times as effective in adsorption as raw bark, and shows more effective than oak bark.

• Journal of Environmental Health Sciences
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• v.22 no.3
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• pp.81-87
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• 1996

The purpose of this research is to examine the utilization of oyster shells for neutralization and removal of heavy metal ions in plating wastewater, because oyster shells have been known to be very porous, to have high specific surface area and to have alkaline minerals such as calcium and magnesium. The results obtianed from this research showed that oyster shells had a buffer capacity to neutralize an acidic.alkali system in plating wastewater. Generally, it could be showed that the removal efficiencies of heavy metal ions were very influenced by reaction times and oyster shell dosages. In point of ocean waste, if oyster shells substituted for a valuable adsorbent such as actviated carbon, they could look forward to an expected economical effect.