• Economic and Environmental Geology
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• v.41 no.1
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• pp.57-62
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• 2008

The application of constructed subsurface-flow wetlands for treatment of wastewater from abandoned mines is being increased. Crushed limestone, oak chips, and mushroom composites are often employed in a bulk form, as the substrates in the bed media. Efficiency of the subsurface-flow treatment system drops with time as the hydraulic conductivity of the wetland soil decreases significantly, presumably due to chemical reactions with the wastewater. The purpose of this study is to investigate the applicability of immobilized beads carrying sulfate reducing bacteria for acid mine drainage treatment system. The ingredients of immobilized beads are organic materials such as mushroom composite and oak chips, limestone powder for a pH buffer, mixed with a modified Coleville Synthetic Brine. It was found that immobilized beads are more efficient than the bulk form for pH recovery, sulfate and heavy metal removal.

• Journal of Soil and Groundwater Environment
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• v.20 no.2
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• pp.22-31
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• 2015

In the present study, surface of laccase producing Ceriporia lacerata was modified using 4-bromobutyryl chloride and polyethylenimine. The modified biomass was freeze dried and utilized as a biosorbent for the removal of Ni(II) from aqueous solution. The physicochemical properties of the biosorbent were analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. Batch experiments were carried out as a function of contact time (0-60 min), pH (2 to 8), adsorbent dosage (25-150 mg), and initial Ni(II) concentration (25-125 mg/L). The results indicate that surface modified biosorbent effectively adsorbed (9.5 mg/0.1 g biomass) Ni(II) present in the solution. The equilibrium adsorption data were modeled with different kinetic and isotherm models. The Ni(II) adsorption followed pseudo-first-order kinetics (R² = 0.998) and Langmuir isotherm (R² = 0.994) model. Hydroxyl and carbonyl functional groups present in biomass play a major role in the adsorption of Ni(II). The adsorbed Ni(II) from the biosorbent was successfully desorbed (85%) by 1M HCl. The results of the study indicate that the surface modified C. lacerate biomass could be used for the treatment of Ni(II) contaminated ground waters.

• Membrane Journal
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• v.31 no.6
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• pp.384-392
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• 2021

Growing pollution due to industrialization leads to difficulties in survival of mankind. Generation of clean water from wastewater by membrane separation process is emerging cost efficient technology. Membrane prepared from renewable resources are in lots of demand to reduce burden on synthetic polymers which is one of the source of environmental pollution. Bacterial cellulose (BC) is very pure and distinct form of cellulose nanofibrils (CNF). Nanopapers prepared from CNF are used ad ultrafiltration (UF) and nanofiltration (NF) membrane for different applications. High crystallinity of BC gives rise to excellent mechanical property, an essential criterion for wastewater treatment membrane. In this review, BC based membrane for application in dye, oil, heavy metal and chemical removal from wastewater is discussed.

• Clean Technology
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• v.15 no.1
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• pp.38-41
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• 2009

Red mud is generated as a waste byproduct during the production of aluminum hydroxide/alumina from bauxite ore in the Bayer process. In this study coagulants for wastewater treatment were prepared by leaching iron and aluminum from red mud with hydrochloric acid. The removal efficiency of heavy metal ions by the red mud coagulant increased with increasing the adjusted pH value of the synthetic wastewater. When the red mud coagulant was prepared, the leaching efficiency of Fe decreased with increasing the weight of red mud, while the pH value of the red mud coagulant increased. The solution of the red mud coagulant mixed with water was reacted again with red mud to produce the leached solution, which had higher concentrations of Fe and Al and a higher pH value than the red mud coagulant. Also, its pH value was comparable to that of other coagulants: $FeCl_3$ and $Fe_2(SO_4)_3$.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.432-440
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• 2015

Biochar, a by-product from pyrolysis of biomass, is a promising option to mitigate climate change by increasing soil carbon sequestration. This material is also considered to have potential to remediate a soil with heavy metal pollution by increasing the soil's adsorptive capacity. This study conducted the assessment of two biochars considering the climate change mitigation potential and heavy metal removal capacity at the same time. Two kinds of biochars (BC_Ch, TW_Ch) were prepared by pyrolyzing the biomass of burcucumber (BC_Bm) and tea waste (TW_Bm). The soils polluted with Pb were mixed with biochars or biomass and incubated for 60 d. During the incubation, $CO_2$, $CH_4$, and $N_2O$ were regularly measured and the soil before and after incubation was analyzed for chemical and biological parameters including the acetate extractable Pb. The results showed that only the BC_Ch treatment significantly reduced the amount of Pb after 60 d incubation. During the incubation, the $CO_2$ and $N_2O$ emissions from the BC_Ch and TW_Ch were decreased by 24% and 34% compared to the BC_Bm and TW_Bm, respectively. The $CH_4$ emissions were not significantly affected by biochar treatments. We calculated the GWP considering the production of amendment materials, application to the soils, removal of Pb, and soil carbon storage. The BC_Ch treatment had the most negative value because it had the higher Pb adsorption and soil carbon sequestration. Our results imply that if we apply biochar made from burcucumber, we could expect the pollution reduction and climate change mitigation at the same time.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.68-74
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• 2013

This study was conducted to analyse the effectiveness of shading on growth and arsenic absorption of Pteris multifida, known as hyperaccumulator of arsenic, from paddy soils contaminated with heavy metals. Study was carried out in paddy soil polluted by arsenic near the former Janghang smelter. P. multifuda in the same growth stage was planted with $20{\times}20cm$ intervals in each experimental plot ($2{\times}2m$), and cultivated for 24 weeks. The growth of P. multifuda according to shading conditions was evaluated, the accumulated amount of arsenic in plants and arsenic variation in the soil was analyzed using ICP. In the result of this study, the growth of P. multifida cultivated under shading treatment was vigorous than non-shading. Accumulated amount of arsenic in aerial parts of P. multifida cultivated under non-shading ($169.8mg{\cdot}kg^{-1}$) was slightly higher than shading ($140.9mg{\cdot}kg^{-1}$), and those in underground part were almost the same. But the growth was great in 70% shading treatment. Therefore, arsenic contents absorbed from soils was much higher in shading treatment. Arsenic translocation rate (TR) of P. multifida was very high (0.87~0.89) regardless of shading conditions. So arsenic in soil could be efficiently eliminated by removal of aerial parts.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.120-126
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• 2004

Kenaf plants were hydroponically grown in reactor containing toxic metals as Cd, Cu, Cr, Ni and Zn to examine the ability to take up heavy metal. The plants were fertilized using a nutrient solution, which was appropriately adjusted to optimum pH, DO and conductivity. For n hydraulic retention time of 8 days, Cr, Cd, Cu, Ni and Zn were removed up to 90.5, 80.5, 66.1%, 71.1% and 79.4%, and reduced from 2.34 to 0.54 mg $L^{-1}$, 3.37 to 1.07 mg $L^{-1}$, 4.92 to 3.19 mg $L^{-1}$, 6.31 to 4.41 mg $L^{-1}$ and 6.27 to 2.09 mg $L^{-1}$. Especially, accumulation rate of Cr, Cd, Cu, Ni and Zn in the plant were measured up to 347.32, 275.39, 157.52, 50.48 and 211.01 mg DW kg $L^{-1}d^{-1}$, respectively. We considered that Kenaf plants removed Cr, Cd and Zn more effectively than other toxic metals applied.

• Journal of Environmental Impact Assessment
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• v.19 no.5
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• pp.475-481
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• 2010

Lots of pollutants typically originating from urban transportation are accumulating on the paved surfaces during dry periods and are washed-off directly to the river during a storm. Also, paved surfaces are contributing to increase in peak flows and volume of stormwater flows. These are the main reasons why the water quality of rivers and lakes remain polluted and still below standards. Currently, several management practices are being applied in developed countries but the design standards are still lacking. This research was conducted to develop a treatment technology that can be useful to address the problems concerning runoff quality and quantity. A lab scale infiltration device consisting of a pretreatment tank and media zone was designed and tested for various flow regimes characterizing the low, average and high intensity rainfall. Based on the experiments, the high intensity flow resulted to increase in outflow event mean concentration (EMC) of pollutants, about twice as much as the average outflow EMC. However, 78 to 88% of the total suspended solids were captured and retained in the pretreatment tank because of sedimentation. The removal of heavy metals such as zinc and lead was greatly affected by the vertical placement of woodchip layer prior to the media zone. It was observed that the high carbon content (almost 50%) in the woodchip provided opportunity for enhancing its uptake of metal by adsorption. The findings implied that the reduction of pollutants can be greatly achieved by means of proper pretreatment to allow for settling of particles with a combination of using high carbon source media like woodchip and a geotextile mat to reduce the flow before filtering into the media zone and finally discharging to the drainage system.

• Resources Recycling
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• v.16 no.6
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• pp.3-9
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• 2007

Although the ferrous material was separated by the magnetic separation before the incineration process, the municipal solid waste incineration bottom ash generated during incinerator in metropolitan area consists of many iron products which account for about $3{\sim}11%$ as well as ceramics and glasses. The formation of $NiFe_2O_4$ and $FeCr_2O_4$ with a $Fe_3O_4-Fe_2O_3$ (similar to pure Fe) on the surface of iron product was found during air-annealing in the incinerator at $1000^{\circ}C$, because Ni and Cr has a chemical attraction about iron is using to coat with Ni and Cr metals for poish or to prevent corrosion. Therefore, Fe-Ni Cr oxide can be formed on durface of the iron product and it can be separated from bottom ash through the magnetic separation. So, in this study, the separation ratio of heavy metals as magnetic separation and mineralogical formation of Fe-ion(heavy metal) in ferrous metals corroded were investigated. As the result, the separation ratio of Ni and Cr based on particle sizes accounted for about $45{\sim}50%$, and Cu and Pb accounted for below 20%. Also, the leaching concentration of Ni and Cr in bottom ash separated by magnetic separation was lower than that in fresh bottom ash.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1302-1313
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• 2021

In this study, Gami-Sumiwon (GS; Cynanchi wilfordii R., Angelica gigantis R., Lycium chinense M., Betula platyphylla S., Cryptotympana atrata F. and Carthamus tinctorius L.) and/or Sinomenium acutum R. (SC) was extracted with 70% ethanol or water. And We investigated the antioxidant activity effect of GS±SC. The following experimental techniques were used to evaluate the antioxidant efficacy of GS±SC. HPLC chromatogram, heavy metal content, ABTS/DPPH radical scavenging analysis, SOD-like activity assay, FACS, and NO assay. As a result of the experiment, the sinomenine content was found to be higher in DW extracts, and decursin was found to be higher in 80% ethanol extracts. And, the amount of heavy metals in all extracts was below the standard value. ABTS, and DPPH radical scavenging activity was identified that GS±SC(EtOH) was found to have a higher scavenging activity than GS±SC(DW). But, SOD showed the opposite result. No cytotoxicity of GS was observed on Raw 264.7 cells at concentration of 1~100 ㎍/㎖. The ROS production was significantly decreased that GS±SC(DW) was found to have a higher scavenging activity than GS±SC(EtOH). However, NO production showed the opposite result. Looking at the results of SOD and ROS analysis, SC does not seem to have a function of prevention. SC is thought to have an effect on the removal of free radicals generated after oxidative stress. This result objectively confirmed the antioxidant effect of GS±SCs. We will continue to conduct in-depth research. Therefore, it is believed that the possibility of using GS±SCs as a functional material can be established. The more diverse the objectives, the higher the value of GS utilization is thought to be.