• Environmental Engineering Research
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• v.20 no.3
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• pp.230-236
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• 2015

26 multi-regional water treatment plants (WTPs) were investigated, to determine the characteristics of manganese (Mn) concentration and removal in Korea. Mn concentrations of raw water in most WTPs were higher than the drinking water standard (i.e., 0.05 mg/L); thus, proper removal of Mn at the WTPs is needed. Mn concentration was generally higher in lakes than rivers due to seasonal lake turnovers. The Mn concentrations of treated water at 26 WTPs in 2012 were less than 0.05 mg/L, due to strict law enforcement and water treatment processes optimization. However, before 2010, those concentrations were more than 0.05 mg/L, which could have led to an accumulation of Mn oxides in the distribution system. This could be one of the main reasons for black water occurrence. Therefore, regular monitoring of Mn concentration in the distribution system, flushing, and proper Mn removal at WTPs are needed, to supply clean and palatable tap water.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.2
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• pp.145-152
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• 2018

This study is focused on manganese (Mn(II)) removal by ozonation in surface water. Instant ozone demand for the water was 0.5 mg/L in the study. When 0.5 mg/L of Mn(II) is existed in water, the optimum ozone concentration was 1.25 mg/L with reaction time 10 minutes to meet the drinking water regulation. The ozone concentration to meet the drinking water regulation was much higher than the stoichiometric concentration. The reaction of soluble manganese removal was so fast that the reaction time does not affect the removal dramatically. When Mn(II) is existed with Fe, the removal of Mn(II) was not affected by Fe ion. However As(V) is existed as co-ion the removal of Mn(II) was decreased by 10%. Adding ozone to surface water has limited effect to remove dissolved organic matter. When ozone is used as oxidant to remove Mn(II) in the water, the existing co-ion should be evaluated to determine optimum concentration.

• Applied Chemistry for Engineering
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• v.31 no.1
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• pp.7-12
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• 2020

Astragalus uliginosus L.-stems as a by-product of oriental medicine are produced largely in a northern area of Chungbuk province. These by-products do not have any demand and thus usually discarded into the fields as a waste. In this work, a biochar was prepared from the Astragalus uliginosus L.-stem waste for recycling. The biochar was used to investigate the removal characteristics of cadmium and manganese ions dissolved in water. When adsorption equilibrium experiments were performed to treat 50 and 100 mg/L of cadmium ions, the removal efficiencies of cadmium were 100 and 95%, respectively. In addition, the maximum of adsorption amount for manganese ions in 5 h at an initial concentration of 50 and 100 mg/L was found to be as 36.1 and 37.9 mg/g, respectively. Based on the experimental results, it was found that the adsorption amount of Astragalus uliginosus L.-stem biochar for the removal of both cadmium and manganese ions was four times higher than that of the activated carbon. The surface analysis of both biochar and activated carbon samples using X-ray photoelectron spectroscopy (XPS) analysis showed that the oxygen content and O/C ratio of biochar was 2.1 and 2.4 times higher than that of the activated carbon, respectively. In order to enhance the removal capability of manganese, 50 and 100 mg/L of manganese ions were operated at different temperatures. It was observed that these equilibrium was attained in 4 h under 45 ℃ and removal efficiencies were 92 and 53%, respectively. Consequently, the experimental results can be utilized as a new removal technology for eco-friendly and economically treating cadmium and manganese ions dissolved in water.

• Journal of environmental and Sanitary engineering
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• v.12 no.2
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• pp.43-49
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• 1997

Iron and manganese problems in ground water affect far more water systems than almost any other water quality concern. The purpose of this study is to find the optimum condition of ozonation for the removal of dissolved iron, manganese and other organics in the polluted ground water. We proposed 4mg/l, 8mg/l as optimum ozone dose for the removal of $Fe^{2+},{\;}Mn^{2+}$, respectively. The removal efficiencies of $COD_{Mn}$ and $COD_{Cr}$ in ozone dose of 2mg/l - 6mg/l were about 40-50%. The removal efficiency of $NH_{3}-N$ was about 30-40% at pH8.5. In conclusion, it needs further systematic study and research concerned to treatability of $Fe^{2+},{\;}Mn^{2+}$ and biodegradability of organic compounds using Ozonation followed by biological filtration process in ground water treatment train.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.1-9
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• 1996

Experiments have been made to test the practical feasibility of using calcined manganese ore to desulfurize hot reducing gas. In this study, the effects of particle size of sorbents, temperature of sulfidation, flow rate and sorbent characteristics on the $H_2S$ removal efficiency of calcined manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about 800$\circ$C and that the smaller particle size the higher the $H_2S$ removal efficiency. When the temperature was above 800$\circ$C, the reactivity of sorbent has lowered because agglomeration of sorbent increased intraparticle transport resistance, and this phenomenon was confirmed by SEM photographs. As the temperature increases, capacity for the $H_2S$ removal was increased but the equilibrium concentration of $H_2S$ was not affective.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.5
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• pp.641-648
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• 2013

Arsenic (As) contamination in drinking water is severe problem for about 100 million people who live in Bangladesh, Cambodia, Nepal, India, Vietnam, Myanmar, Mongolia, and Ethiopia etc. Chronic doses cause skin cancer, blackfoot disease, and cardiac damage. Even though the biosand filter (BSF) is popular in many developing countries, it could not remove effectively hazardous ions as As. Adsorbent is effective and feasible to reduce As. In this study the improved biosand filter (iBSF) was embedded with adsorbent, was tested to evaluate As removal as well as organic removal. In 20 days removal of turbidity, bacteria, and $UV_{254}$ have shown 60-95 % removal. Arsenic was removed more than 99.9 % in the columns embedded with silica oxides of ferric manganese ($FM{\alpha}$) while 5.8 ~ 38.3 % in columns without $FM{\alpha}$. Isotherm test showed that average amount of the adsorbed arsenic on the oxides was 0.56 mg/G.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.3
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• pp.341-349
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• 2010

It is well known that manganese is hard to oxidize under neutral pH condition in the atmosphere while iron can be easily oxidized to insoluble iron oxide. The purpose of this study is to identify removal mechanism of manganese in the D water treatment plant where is treating bank filtered water in aeration and rapid sand filtration. Average concentration of iron and manganese in bank filtered water were 5.9 mg/L and 3.6 mg/L in 2008, respectively. However, their concentration in rapid sand filtrate were only 0.11 mg/L and 0.03 mg/L, respectively. Most of the sand was coated with black colored manganese oxide except surface layer. According to EDX analysis of sand which was collected in different depth of sand filter, the content of i ron in the upper part sand was relatively higher than that in the lower part. while manganese content increased with a depth. The presence of iron and manganese oxidizing bacteria have been identified in sand of rapid sand filtration. It is supposed that these bacteria contributed some to remove iron and manganese in rapid sand filter. In conclusion, manganese has been simultaneously removed by physicochemical reaction and biological reaction. However, it is considered that the former reaction is dominant than the latter. That is, Mn(II) ion is rapidly adsorbed on ${\gamma}$-FeOOH which is intermediate iron oxidant and then adsorbed Mn(II) ion is oxidized to insoluble manganese oxide. In addition, manganese oxidation is accelerated by autocatalytic reaction of manganese oxide. The iron and manganese oxides deposited on the surface of the sand and then are aged with coating sand surface.

• Resources Recycling
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• v.20 no.5
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• pp.64-68
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• 2011

The typical properties of manganese nodules are its high porosity and high specific surface area and manganese in nodules is existed as ${\delta}$-MnO$_2$. These properties suggest that manganese nodules ran be used as an adsorbent for heavy metal ions. This study investigated the practical applicability for the removal of copper ions in the waste water by manganese nodules as an adsorbent using fixed column and fix bed systems. Manganese nodules of 1kg (size 1-3 cm) can absorb 4.0g Cu in fixed column system and 2.3g Cu in fixed bed system from waste water for 3 hours respectively.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.105-111
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• 2012

Manganese (Mn) catalysts were generated using $CeO_2$ and $ZrO_2$supports synthesized by the supercritical hydrothermal method and two different Mn precursors, aimed at an application for a low-temperature selective catalytic reduction process. Manganese acetate (MA) and manganese nitrate (MA) were used as Mn precursors. Effects of the kind and the concentration of the Mn precursor used for catalyst generation on the NOx removal efficiency were investigated. The characteristics of the generated catalysts were analyzed using $N_2$ adsorption-desorption, thermo-gravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. De-NOx experiments were carried out to measure NOx removal efficiencies of the catalysts. NOx removal efficiencies of the catalysts generated using MA were superior to those of the catalysts generated using MN at every temperature tested. Analyses of the catalyst characteristics indicated that the higher NOx removal efficiencies of the MA-derived catalysts stemmed from the higher oxygen mobility and the stronger interaction with support material of $Mn_2O_3$ produced from MA than those of $MnO_2$ produced from MN.

• Mycobiology
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• v.49 no.5
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• pp.507-520
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• 2021

Papiliotrema huenov was previously reported to be highly tolerant of a range of extremely toxic heavy metals. This study aimed to identify the potential of P. huenov to remove manganese and copper from aqueous solution. Physical conditions which affect removal of Mn(II) and Cu(II) were determined. Optimal temperature for adsorption of both metal ions was 30 ℃, and optimal pH for maximum uptake of Mn(II) and Cu(II) were 5 and 6, respectively. Under these conditions, living cells of P. huenov accumulated up to 75.58% of 110 mg/L Mn(II) and 70.5% of 128 mg/L Cu(II) over 120 h, whereas, the removal efficiency of metal ions by dead cells over 1 h was 60.3% and 56.5%, respectively. These results indicate that living cells are more effective than dead biomass for bioremediation, but that greater time is required. The experimental data extends the potential use of P. huenov in biosorption and bioaccumulation of toxic heavy metals to copper and manganese, two of the most common industrial contaminants.