• Title/Summary/Keyword: Adsorption/Removal

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Zeolite Based Membrane for Removal of Ammonium: A Review (효소 고정화막의 응용에 대한 총설)

  • Lee, Joo Yeop;Patel, Rajkumar
    • Membrane Journal
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    • v.32 no.3
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    • pp.173-180
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    • 2022
  • Presence of ammonia in drinking water is very toxic to human health. Soluble ammonia contaminates ground water due to activities such as the use of fertilizer in crop, industrial effluents and burning of fossil fuel. Even low concentration of ammonia present in water will damage aqua environment such as marine organism. Membrane technology is an important process to remove ammonia from effectively from water. Flat sheet membrane, membrane contactor and membrane distillation are some of the methods used for water purification from ammonia. Membrane contractor is an efficient process in which ammonia is removed through liquid-gas or liquid-liquid mass transfer without change of phase unlike membrane distillation. However, the cost of ammonia removal in this method is high due to maintenance of very high pH. Zeolite has excellent ion exchange ability that enhances its ability to interact with ammonia and adsorb from wastewater. Mixed matrix membranes containing zeolite enhance the efficiency of ammonia adsorption and separation from wastewater. In this review the above discussed issues are summarized in detail.

Adsorption and Redox State Alteration of Arsenic, Chromium and Uranium by Bacterial Extracellular Polymeric Substances (EPS) (박테리아 세포외 중합체(EPS)에 의한 비소, 크롬, 우라늄의 흡착 및 산화상태 변화)

  • Park, Hyun-Sung;Ko, Myoung-Soo;Lee, Jong-Un
    • Economic and Environmental Geology
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    • v.43 no.3
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    • pp.223-233
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    • 2010
  • The effects of extracellular polymeric substances (EPS) of Pseudomonas aeruginosa on adsorption and redox state alteration of dissolved As, Cr and U were investigated through batch experiments. Surfaces of bacterial cells were either vigorously washed or unwashed. Solutions of As(V), Cr(VI) and U(VI) were inoculated with the bacterial cells under no nutrient condition, and total aqueous concentrations and redox state alteration were monitored over time. No As adsorption occurred onto bacteria or EPS; however, unwashed bacteria reduced about 60% As(V) to As(III). Unwashed bacteria also led to removal of 45% total dissolved Cr and reduction of 64% Cr(VI). About 80% U(VI) was removed from solution with unwashed bacteria as well. Such electrochemical reduction of the elements was likely due to reducing capacity of EPS itself or detoxifying reduction of the bacteria which kept their viability under protection of EPS. The results indicated that bacterial biofilm may significantly control the redox state and subsequent mobility of As, Cr and U in natural geologic settings.

A Study on the Deposition of Chitosan for Enhancing the Adsorption Ability of Activated Carbon (활성탄의 흡착력 향상을 위한 키토산 첨착에 관한 연구)

  • Ju, Han-Shin;Kim, Byung-Hoon;Jung, Sang-Chul;Ra, Deog-Gwan;Chung, Min-Chul;Ahn, Ho-Geun
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.2
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    • pp.203-210
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    • 2000
  • The preparative methods of a chitosan-deposited activated carbon and its characteristics were studied by using three kinds of chitosan with different degree of deacetylation and average molecular weight. The procedure was consisted of the dissolution of chitosan into acid solution, impregnation of activated carbon, agitation, evaporation, and drying. When the chitosan-dissolved acid and its concentration, amounts of chitosan deposited, and agitation conditions were changed, the specific surface area, deposition state on surface, and stability were investigated, and amounts of Cr(VI) adsorbed was measured. In the preparation process, it was proper to agitate the chitosan-dissolved acetic acid solution at room temperature for 1hr. In the deposition of chitosan with low molecular weight, the specific surface area of activated carbon was greatly decreased even at low chitosan loading, but in the case of high molecular weight it was not nearly changed to 10wt% loading. It was known that chitosan was uniformly and physically deposited on activated carbon. The chitosan-deposited activated carbon was stable into the solution over about pH 6. The removal of Cr(VI) was remarkably enhanced by adding the adsorption function of chitosan to the surface of activated carbon with about 5wt% chitosan. It may be therefore used as an adsorbent for removing the pollutants in air and wastewater.

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The nature of non-specific inhibitor and natural agglutinin for goose erythrocytes in chicken serum (계혈청(鷄血淸)에 들어 있는 뇌염(腦炎)바이러스에 대한 비특이물질 및 거위 혈구(血球)에 대한 응집소의 성상(性狀)에 관한 연구(硏究))

  • CHUNG, Y.S.
    • Korean Journal of Veterinary Research
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    • v.11 no.2
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    • pp.123-136
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    • 1971
  • (1) The non-specific inhibitors (NSI) in normal chicken sera were active against all the tested group A and group B arboviruses, but the group B arbovirus were more sensitive than group A arboviruses. (2) The titres of the NSI were distributed nearly uniformly among chickens from seven different age groups to group A arboviruses. In contrast, the NSI titres to group A arboviruses were found to increase with age. (3) No significant difference could be demonstrated between acetone-ether extraction and kaolin adsorption for removal of the NSI in normal chicken sera. (4) After heating, the NSI titres in chicken sera were increased for both group A and group B arboviruses. (5) After heating the sera at $80^{\circ}C$ and $100^{\circ}C$, kaolin adsorption was less efficient for removing the NSI than it, was in unheated serum. Acetone-ether extraction of the NSI was unimpaired after heating at $80^{\circ}C$ but was less efficient after heating at $100^{\circ}C$. (6) The NSI activity was found mainly in the first peak (IgM) and diffused to a part of second peak (IgG) by fractionation of chicken serum by gel filtration through Sephadex G200. After zonal centrifugation of chicken serum in a linear ten to 40 percent sucrose gradient all of the NSI activities were found on the top of the centrifugal tubes. These properties of large molecular size and low density indicated that the NSI in chicken serum were probably lipoproteins. (7) The natural agglutinins for goose erythrocytes in chicken sera were partially destroyed by acetone-ether extraction but not by kaolin adsorption, and were efficiently adsorbed with ten percent goose erythrocytes. No difference of the NA titre was demonstrated with diluents of different pH. (8) The NA in chicken serum was found to possess the properties of IgM by gel filtration through Sephadex G200 and zonal centrifugation in linear ten to 40 percent sucrose gradient.

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Heavy Metal Adsorption Capacity of Zoogloea ramigera 115 and Zoogloea ramigera l15SLR. (Zoogloea ramigera 115와 Zoogloea ramigera l15SLR의 중금속 흡착능 비교)

  • Lee, Han-Ki;Bae, Woo-Chul;Jin, Wook;Jung, Wook-Jin;Lee, Sam-Pin;Jeong, Byeong-Chul
    • Microbiology and Biotechnology Letters
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    • v.26 no.1
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    • pp.83-88
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    • 1998
  • Heavy metal removal by Z. ramigera 115 and soluble slime polymer producing mutant Z. ramigera 115SLR was investigated. Both strains showed similar tolerance against $Cd^{2+}$, $Co^{2+}$, $Cu^{2+}$, $Ni^{2+}$ and $Fe^{2+}$. When cells were cultivated in the presence of 500 ppm $Cd^{2+}$, the mutant strain removed 1.5 fold more metal than the wild type did at same biomass. Metal adsorption capacities were in the order of Z. ramigera l15SLR polymer > Z. ramigera 115 polymer > Z. ramigera 115 cell >Z. ramigera l15SLR cell. The optimum pH for metal adsorption was 7.5. Langmuir and Freundlich isotherms indicated that Qmax and 1/n of Z. ramigera l15SLR polymer were 164.2 mg $Cd^{2+}$/g dw and 0.496, respectively. These results showed that the polymer of Z. ramigera l15SLR could be used as an effective metal adsorbate.

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Characterization of Natural Zeolite and Study of Adsorption Properties of Heavy Metal Ions for Development of Zeolite Mine (제올라이트 광산개발을 위한 천연 제올라이트의 특성 분석 및 중금속 이온 흡착 특성 연구)

  • Kim, Hu Sik;Kim, Young Hun;Baek, Ki Tae;Lim, Woo Taik
    • Journal of the Mineralogical Society of Korea
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    • v.28 no.4
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    • pp.299-308
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    • 2015
  • The six natural zeolites collected in Pohang area, Kyungsangbuk-do, Korea, were characterized by XRD, XRF, DTA, TGA, and CEC analysis. The primary species of these zeolite are modenite, albite, and quarts in Kuryongpo-A (Ku-A), Kuryongpo-B (Ku-B), Kuryongpo-C (Ku-C), Donghae-A (Dh-A), Donghae-B (Dh-B), and Donghae-C (Dh-C) samples. The XRF analysis showed that the six zeolites contain Si, Al, Na, K, Mg, Ca, and Fe. Cation exchange capacity of Kuryongpo-C (Ku-C) zeolite was the highest compared to other zeolites. The capabilities of removing heavy metal ions such as $Pb^{2+}$, $Cd^{2+}$ and $Cu^{2+}$ were compared. The effect of reaction time in removing heavy metal ions was studied. The experimental results showed that the efficiency of removal was low for $Pb^{2+}$, $Cd^{2+}$ and $Cu^{2+}$ ions. These may be caused by the low content of zeolite in the six natural zeolites. This indicates that the adsorption capacity roughly tends to depend on the zeoite contents, ie., the grade of zeolite ore.

Utilization of Zeolite in Waste Water Treatment. (폐수처리제(廢水處理劑)로서의 Zeolite의 이용(利用))

  • Lee, Jeon-Sig;Lee, Jyung-Jae;Choi, Jyung
    • Korean Journal of Environmental Agriculture
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    • v.6 no.2
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    • pp.46-52
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    • 1987
  • This study of adsorption and column percolation was conducted to examine the utilization of natural zeolite for the removal of heavy metals from waste water to compare with that of absorption activated carbon. The adsorption of heavy metals by natural zeolite was conformed to the Freundlich isotherm (1/n values: $0.12{\sim}0.45$, K values: $18.77{\sim}59.48$) and natural zeolite was turned out to be an effective adsorbent of heavy metals. At the same particle size and percolation velocity, zeolite adsorbed a greater amount of heavy metals was adsorbed on natural zeolite than activated carbon. The smaller the particle size, the more heavy metals that were adsorbed. It was postulated that the most effective size as an adsorbent of heavy metals from waste water ranged from 0.5 to 2.0mm. The slower the percolation velocity that of the heavy metal solution in column, the more heavy metals were adsorbed. Natural zeolite in a single solution adsorbed more heavy metals than that in mixed solution, and the order of the adsorption amount on natural zeolite was Cu>Zn>Cd.

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Microbial Influence on Soil Properties and Pollutant Reduction in a Horizontal Subsurface Flow Constructed Wetland Treating Urban Runoff (도시 강우유출수 처리 인공습지의 토양특성 및 오염물질 저감에 따른 미생물 영향 평가)

  • Chiny. C. Vispo;Miguel Enrico L. Robles;Yugyeong Oh;Haque Md Tashdedul;Lee Hyung Kim
    • Journal of Wetlands Research
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    • v.26 no.2
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    • pp.168-181
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    • 2024
  • Constructed wetlands (CWs) deliver a range of ecosystem services, including the removal of contaminants, sequestration and storage of carbon, and enhancement of biodiversity. These services are facilitated through hydrological and ecological processes such as infiltration, adsorption, water retention, and evapotranspiration by plants and microorganisms. This study investigated the correlations between microbial populations, soil physicochemical properties, and treatment efficiency in a horizontal subsurface flow constructed wetland (HSSF CW) treating runoff from roads and parking lots. The methods employed included storm event monitoring, water quality analysis, soil sampling, soil quality parameter analysis, and microbial analysis. The facility achieved its highest pollutant removal efficiencies during the warm season (>15℃), with rates ranging from 33% to 74% for TSS, COD, TN, TP, and specific heavy metals including Fe, Zn, and Cd. Meanwhile, the highest removal efficiency was 35% for TOC during the cold season (≤15℃). These high removal rates can be attributed to sedimentation, adsorption, precipitation, plant uptake, and microbial transformations within the CW. Soil analysis revealed that the soil from HSSF CW had a soil organic carbon content 3.3 times higher than that of soil collected from a nearby landscape. Stoichiometric ratios of carbon (C), nitrogen (N), and phosphorus (P) in the inflow and outflow were recorded as C:N:P of 120:1.5:1 and 135.2:0.4:1, respectively, indicating an extremely low proportion of N and P compared to C, which may challenge microbial remediation efficiency. Additionally, microbial analyses indicated that the warm season was more conducive to microorganism growth, with higher abundance, richness, diversity, homogeneity, and evenness of the microbial community, as manifested in the biodiversity indices, compared to the cold season. Pollutants in stormwater runoff entering the HSSF CW fostered microbial growth, particularly for dominant phyla such as Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroidetes, which have shown moderate to strong correlations with specific soil properties and changes in influent-effluent concentrations of water quality parameters.

Removal of Soluble Mn(II) using Multifunctional Sand Coated with both Fe- and Mn-oxides (철과 망간이 동시에 코팅된 다기능성 모래를 이용한 용존 Mn(II) 제거)

  • Lim, Jae-Woo;Chang, Yoon-Young;Yang, Jae-Kyu
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.2
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    • pp.193-200
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    • 2010
  • This study evaluated treatability of soluble Mn(II) using multifunctional sand media simultaneously coated with iron and manganese. In the preparation of IMCS(Iron and Manganese Coated Sand), 0.05 M Mn(II) solution and Fe(III) solution was mixed with sand at pH 7. The mineral type of IMCS was identified as the mixture of ${\gamma}-MnO_2$, goethite and magnetite($F_{e3}O_4$). The contents of Mn and Fe coated onto sand were 826 and 1676 mg/kg, respectively. The $pH_{pzc}$ of IMCS was measured as 6.40. The removal of soluble Mn(II) using IMCS and oxidants such as NaOCl and $KMnO_4$ was investigated with variation of the solution pH, reaction time and Mn(II) concentration in a batch test. The removal of Mn(II) on IMCS was 34% at pH 7.4 and the removals of Mn(II) on IMCS in the presence of NaOCl(13.6 mg/L) at pH 7 and $KMnO_4$(4.8 mg/L) at pH 7.6 were 96% and 89%, respectively. The removal of Mn(II) using IMCS and oxidants followed a typical cationic type, showing a gradual increase of removal as the solution pH increased. The removal of Mn(II) was rapid in the first 6 hrs and then a constant removal was observed. The maximum removed amount of Mn(II) on IMCS-alone and IMCS in the presence of oxidants such as NaOCl(13.6 mg/L) and $KMnO_4$(4.8mg/L) were 833.3, 1428.6 and 1666.7 mg/kg, respectively. Mn(II) removal onto the IMCS in the presence of oxidants was well described by second-order reaction and Langmuir isotherm expression.

Mapping the Research Landscape of Wastewater Treatment Wetlands: A Bibliometric Analysis and Comprehensive Review (폐수 처리 위한 습지의 연구 환경 매핑: 서지학적 분석 및 종합 검토)

  • C. C. Vispo;N. J. D. G. Reyes;H. S. Choi;M.S. Jeon;L. H. Kim
    • Journal of Wetlands Research
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    • v.25 no.2
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    • pp.145-158
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    • 2023
  • Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.