• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.813-822
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• 2006

Soluble manganese removal was analyzed as a function of filter media, filter depth, presence or absence of chlorination, and surface manganese oxide concentration in water treatment processes. Sand, manganese oxide coated sand (MOCS), sand+MOCS, and granular activated carbon(GAC) were used as filter media. Manganese removal, surface manganese oxide concentration, turbidity removal, and regeneration of MOCS in various filter media were investigated. Results indicated that soluble manganese removal in MOCS was rapid and efficient, and most of the removal happened at the top of the filter. When filter influent (residual chlorine 1.0mg/L) with an average manganese concentration of 0.204mg/L was fed through a filter column, the sand+MOCS and MOCS columns can remove 98.9% and 99.2% of manganese respectively on an annual basis. On the other hand, manganese removal in sand and the GAC column was minimal during the initial stage of filtration, but after 8 months of filter run they removed 99% and 35% of manganese, respectively. Sand turned into MOCS after a certain period of filtration, while GAC did not. In MOCS, the manganese adsorption rate on the filter media was inversely proportional to the filter depth, while the density of media was proportional to the filter depth.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.86-93
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• 2006

In the drinking water treatment, the aesthetic and color problem are caused by the manganese which is occurring and present in the surface, lake and ground water. The most common treatment processes for removing manganese are known for oxidation followed by filtration. In this study, the manganese sand process was used for removing manganese with river bank filtrate as a source. In the manganese sand process, the residual chlorine and pH are important factors on the continuous manganese oxidation. In addition, space velocity (SV) and alum dosage are play a role of manganese removal. Even though manganese removal increased with increasing chlorine concentration, the control of residual chlorine is actually difficult in this process As the results of tests, the residual chlorine concentration as well as manganese removal were effectively achieved at pH 7.5. The optimum attached manganese concentration on manganese sand was confirmed to 0.3mg/L by the experimental result of a typical sand converting to manganese sand.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.44-52
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• 2006

Bio-filtration processes using honeycomb tubes (process 1) and aeration and manganese-sand filtration (process 2) were evaluated for the biological manganese removal efficiency. The concentration of manganese at effluent was stabilized after 20days operation in process 1. It was estimated the required time for attaching and growing microorganisms to honeycomb tubes. In long term of operation periods, manganese removal efficiency was dropped for the excessively attached biofilm and manganese dioxide to honeycomb tubes. It took several days for normal operation in process 2, after that manganese removal efficiency was increased to 98% and stabilized for 1.5 years. Microorganisms in process 1 and 2 were isolated and cultured to characterize manganese-oxidizing bacteria. Among the four types of colony, light brown colony was turned blue color by leuco crystal violet spot test. Stenotropomonas genus, known as manganese-oxidizing bacteria, was identified by 16S rDNA partial sequencing analysis which was isolated in process 1 and 2. For the biological treatment to remove manganese, these two considerations are important. One is to choose the proper media attaching manganese oxidant, another one is to define the cultural condition of isolated manganese-oxidizing bacteria.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.595-604
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• 2005

To determine the characteristics of manganese removal in Korea, 31 multi-regional water treatment plants (WTPs) were examined. The concentration of manganese in raw water was higher than the standards for drinking water at 2 WTPs. Manganese should be properly removed during water treatment processes to reduce the occurrence of black water in the distribution system because $Mn^{+2}$ can cause black deposits when it is oxidized. Manganese can effectively removed by oxidation, followed by sedimentation and filtration as well as absorption by greensand. Manganese absorption by greensand was the major mechanism for the removal of manganese, and it is effectively removed using this process. Regeneration of greensand using an oxidation agent was necessary for continuous and adequate removal of manganese.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.409-414
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• 2004

Pilot-scale experiments were performed for the treatment of bank filtrate contammg high manganese concentration around 2mg/L using rapid manganese sand filtration to investigate effects of oxidant dose and pH control on the removal efficiency of manganese. For theoretical dose ranges of oxidant (sodium hypochlorite) between 3 and 4mg/L, the manganese concentration of effluent was 0.57 mg/L, which corresponded to 72.5% removal and was higher than drinking water quality standards of 0.3mg/L. For excess dose ranges of oxidant between 4 and 8mg/L, the manganese concentration of effluent was reduced to 0.14mg/L, which corresponded to 94.5% removal, but the residual chlorine concentration was over 1.0mg/L. On the other hand, manganese removal efficiency drastically increased up to the value of 98.0%, which is equivalent to the effluent concentration of 0.03mg/L by controling pH to the range between 7 and 8 for the theoretical dose of oxidant. Consequently, these results indicated that appropriate dose of chemicals, such as oxidant and alkali, and continuous monitoring of manganese should be necessary to obtain efficient removal of manganese and to optimize the maintenance of treatment facilities for the treatment of bank filtrate with high concentration of manganese.

• Journal of Korean Society on Water Environment
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• v.26 no.3
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• pp.454-459
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• 2010

This study investigated the applicability of manganese coated media such as manganese coated sand (MCS), manganese coated sericite (MCSe) and manganese coated starfish material calcined at $550^{\circ}C$ (MCSf) to remove Mn(II) in synthetic wastewater. Manganese coated media prepared at different pH was applied in the treatment of soluble Mn(II) in batch and column experiments at various Mn(II) concentrations. The amount of Mn coated on three different media was approximately 800~1100 mg/kg. From the stability test, negligible dissolution of Mn was observed above pH 3.0. In batch test, more than 40% of Mn(II) was removed by all sand media at various manganese concentrations. In order to see the effect of additional oxidant for the removal of Mn(II), 4 mg/L of hypochlorite was added in Mn(II) solution during column experiment. Breakthrough of Mn(II) was greatly retarded in the presence of hypochlorite in all column reactors packed with different media. Among the manganese coated media, MCSf prepared at pH 4 indicated the highest removal capacity. The removal efficiency of Mn(II) was also increased in the multi-layer system (0.5 g of MCS, MCSe, and MCSf each).

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.558-562
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• 2006

Filtration experiments were conducted to determine the characteristics of manganese removal in filtration using 4 different filter media including sand and manganese sand(MS). Filtration velocity was 123 m/d and the flow rate was $3.9m^3/d$ per column. Duration of these experiments was about one year, and manganese dioxide accumulation, turbidity removal, manganese removal, and organic material removal were examined depending on filter media. When filter influent(residual chlorine 1.0 mg/L) with an average manganese concentration of 0.208 mg/L was fed through a filter column, the sand+MS and MS columns removed 98.9% and 99.2% of manganese respectively on an annual basis. When there is need to replace the sand filters with a MS filter to remove manganese, it was shown that the replacement of a partial sand filter with MS had adequate manganese removal.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.3
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• pp.211-220
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• 2018

The water containing soluble manganese may cause problems such as discolored water, unpleasant taste, fouling or scaling of pipes in water distribution system, and so on. Conventional water treatment processes using sand filtration or sedimentation after oxidation, however, cannot often meet manganese standard for drinking water. Two types of oxidants, potassium permanganate ($KMnO_4$) and sodium hypochlorite (NaOCl), were utilized at the same time for manganese oxidation, and then the precipitated manganese oxides were removed by low pressure membrane filtration in this study. In batch experiments, the multiple injection of both oxidants showed more effective manganese removal than did the single injection using either of them. Moreover, the deterioration of manganese removal at low temperature was less serious for the multiple injection than that for the single injection. Manganese removal by the continuous system of oxidation by multiple injection combined with membrane filtration was higher than those by batch experiments at the same oxidation conditions. In addition, less membrane fouling was observed for membrane filtration with oxidation during continuous membrane filtration than membrane filtration without oxidation. These results indicate that the oxidation by multiple injection coupled with membrane filtration was efficient and applicable to actual water treatment for manganese removal.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.4
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• pp.503-508
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• 2007

Small scale D-water treatment plant(WTP) where has slow sand filtration was using raw water containing high concentration of manganese (> 2mg/l). The raw water was pre-chlorinated for oxidation of manganese and resulted in difficulty for filtration. Thus, sometimes manganese concentration and turbidity were over the water quality standard. Two stage rapid manganese sand filtration pilot plant which can treat $200m^3/d$ was operated to solve manganese problem in D-WTP. The removal rate of manganese and turbidity were about 38% and 84%, respectively without pH control of raw water. However, when pH of raw water was controlled to average 7.9 with NaOH solution, the removal rate of manganese and turbidity increased to 95.0% and 95.5%, respectively and the water quality of filtrate satisfied the water quality standard. Manganese content in sand was over 0.3mg/g which is Japan Water Association Guideline. The content in upper filter was 5~10 times more than that of middle and lower during an early operation but the content in middle and lower filter was increased more and more with increase of operation time. This result means that the oxidized manganese was adsorbed well in sand. Rapid manganese sand filter was backwashed periodically. The water quality of backwash wastewater was improved by sedimentation. Thus, turbidity and manganese concentration decreased from 29.4NTU to 3.09NTU and from 1.7mg/L to 0.26mg/L, respectively for one day. In Jar test of backwash wastewater with PAC(Poly-aluminum chloride), optimum dosage was 30mg/L. Because the turbidity of filtrate was high as 0.76NTU for early 5 minute after backwash, filter-to-waste should be used after backwash to prevent poor quality water.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.633-640
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• 2008

In this research, the $3.6m^3/day$ scale pilot plant consisting preozonation, coagulation, flocculation, and ceramic membrane processes was operated for long term period to evaluate the validity of ceramic membrane filtration process for treating lake water containing high concentration manganese. The higher concentration of dissolved manganese($Mn^{2+}$) was effectively oxidized to the bigger insoluble colloidal manganese ($MnO^2$) by 1~2 mg/L ozone. The colloidal manganese reacted with coagulant (poly aluminium chloride, PAC) and then formed the big floc. Ceramic membrane rejected effectively manganese floc during membrane filtration. Dissolved organic carbon(DOC) removal was dependent upon $Mn^{2+}$ concentration. While average $Mn^{2+}$ concentration was 0.43 and 0.85 mg/L in raw water, DOC removal rate in preozonation was 26.5 and 13.5%, respectively. The decrease rate of membrane permeability was faster without preozonation than with preozonation while membrane fouling decreased with NOM oxidation by ozone. In conclusion, raw water containing high concentration of manganese can be effectively treated in preozonation-coagulation-ceramic membrane filtration system.