• Title/Summary/Keyword: sedimentation method

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Reduction of the Offensive Odor from Confectionery Wastewater Plant (제과공장의 폐수처리장에서 발생하는 악취 저감)

  • 김영식;손병현;조상원;정종현
    • Journal of Environmental Health Sciences
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    • v.24 no.1
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    • pp.62-69
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    • 1998
  • It has been studied that the measurement of odor component emission at confectionery manufacture. The objects of this study were to investigate reduction of offensive odor. The survey effects of odorous materials are presented as follows. The countermeasure of operating process is to minimize sludge sediment in each unit facility. Especially, in summer, we have to clean the sludge frequently, because anaerobic decomposing is likely to occur easily. The sludge or scum from sedimentation tank pond, and floating tank should be treated quickly. We should avoid overloading operation. In the case of overloading, dissolved oxygen should be increased, the quality of wastewater input should be decreased. When dried cakes from condense tank or floating tank are left in treatment plant, we should cover, to prevent diffusion of smell with masking materials. The seasonal condition of operating should be fixed and the kind of coagulants should be changed because the wastewater in each season have different loading rates and organic materials. Odorous materials are very sensitive to the seasonal temperature variation. Especially, when the amount of rainfall is small and the high temperature of maintenance in long periods, air diffusion rate is large, so odorous materials can make great effect on surroundings comparision with other periods. To reduce odorous gas, as short term method, we had better take ceramic addition method. Especially, in summer we should take ceramic addition method. Also, as long term method, the size of wastewater treatment facility is the most important in the normal operating of wastewater treatment facility. But wastewater treatment facilities in this factory are too old, treatment process is old fashion, and the size is too small. So, large wastewater quantity to treat in summer. As results, the expansion of wastewater treatment facility and the process of improvement are required. Restriction level of odor was exceed. As it is overloaded in summer, the basis cause of odor is that the size of wastewater treatment facility is small. The prediction of air quality equilibrium density variation show that the odorous materials from working place are Amine materials whose smell strength is about 2.5(a little strong degree). We can suppose that in summer is sensitive to temperature variation, smell strength is larger as to reduce the origin of odor. We must expand wastewater treatment facility and improve the process A.S.A.P.

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Determination of Characteristics of Laboratory Test and Proper Specification of Reformed Dredging Soil for Applying Pipe Mixing Method (관중혼합공법의 적용을 위한 개질처리 준설토의 실내실험 특성 및 적정 규격 결정)

  • Jeon, Sangok;Kang, Byungyoon;Baek, Seungcheol
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.5
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    • pp.15-24
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    • 2022
  • In order to improve dredged area, long time and high cost is needed because of bad engineering and physical conditions. And there is no suitable example of pipe mixing method at domestic site. Moreover, applicability and effectiveness of this method is uncertain and shows different results between site and laboratory test. In order to solve these problems, we determined proper grain size distribution and water content range using dredged soil and reformed material (standard sand & material controlling grain size distribution) in the laboratory test. As a result, we confirmed that coefficient of sediment consolidation is increased and there is an improvement about separation sedimentation. Undrained shear strength was derived by water content of reformed dredging soil through regression analysis of test results. We suggest the correlation equation for determining mixing ratio.

Opportunistic Parasites among Immunosuppressed Children in Minia District, Egypt

  • Abdel-Hafeez, Ekhlas H.;Ahmad, Azza K.;Ali, Basma A.;Moslam, Fadia A.
    • Parasites, Hosts and Diseases
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    • v.50 no.1
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    • pp.57-62
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    • 2012
  • A total of 450 stool samples were collected from inpatient and outpatient clinics of Pediatric Department, Minia University Hospital, Minia District, Egypt. Two groups of patients were studied, including 200 immunosuppressed and 250 immunocompetent children. Stool samples were subjected to wet saline and iodine mounts. A concentration technique (formol-ether sedimentation method) was carried out for stool samples diagnosed negative by wet saline and iodine mounts. Samples were stained by 2 different methods; acid fast stain (modified Ziehl-Neelsen stain) and Giemsa stain. Total 188 cases (94%) were diagnosed positive for parasitic infections among immunosuppressed children, whereas 150 cases (60%) were positive in immunocompetent children ($P$<0.0001). The most common protozoan infection in immunosuppressed group was $Cryptosporidium$ $parvum$ (60.2%), followed by $Blastocystis$ $hominis$ (12.1%), $Isospora$ $belli$ (9.7%), and $Cyclospora$ $caytenensis$ (7.8%). On the other hand, $Entamoeba$ $histolytica$ (24.6%) and $Giardia$ $lamblia$ (17.6%) were more common than other protozoans in immunocompetent children.

A Case Report of a Patient with Active Ulcerative Colitis Treated with Do-Che Decoction-based Korean Medicine (도체탕(導滯湯) 위주의 한방치료로 호전된 활동성 궤양성 대장염 환자 치험 1례)

  • Yoon, Seong Woo
    • Journal of Korean Traditional Oncology
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    • v.17 no.2
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    • pp.17-22
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    • 2012
  • Background : Sulfasalazine for treating ulcerative colitis has a clinical limitation due to its adverse effects. This case is about a patient with ulcerative colitis who could not tolerate sulfasalazine and was improved by Do-che decoction-based Korean medicine. Method and Results : Purulent and bloody diarrhea more than 20 times a day, mild fever, chilling and tenesmus were main symptoms of this patient who was diagnosed as ulcerative colitis 10 years ago. Do-che decoction-based Korean medicine which was recommended for purulent and bloody diarrhea in Dong-Ui-Bo-Gam, the classic literature of Traditional Korean Medicine was given to the patient for more than 1 month. After treatment, the frequency of purulent and bloody diarrhea, tenesmus and fever was decreased remarkably, and C-reactive protein, erythrocyte sedimentation rate, white blood cell count and maximum temperature also dropped to the normal range. Conclusion : Do-che decoction-based Korean medicine has a potential effect and may be a alternative therapeutic option in patients with ulcerative colitis who cannot tolerate sulfasalazine due to its adverse effects.

The Effect of the Binder to Zeolite Thin Film Coating by Heat Treatment (열처리를 통한 제올라이트 박막 코팅 시 바인더의 영향)

  • Yoo, Young-Seok;Jo, Jun-Ho;Kim, I-Tae
    • Journal of the Korean institute of surface engineering
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    • v.46 no.6
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    • pp.277-282
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    • 2013
  • This study is an experimental attempt to confirm the binder effect of zeolite coating on glass plate by heat treatment. As a result, zeolite was successfully formed with low concentratios of pressure, whose concentration was effective in 10% or more for thin film zeolite coating. And as the content of the binder (TEOS) in mixed coating solution was higher, the zeolite was fastened better on the surface. Above 5% content of the binder in the coating solution, TEOS hindered zeolite synthesis of the precursor and brought to zeolite capacity decrease. Furthermore, when the concentration of the precursor, sedimentation rate of the precursor was higher and the coating efficiency is reduced thereby. Therefore, the most effective concentrations of the precursor and TEOS in the coating solution was 10% and 5%, respectively. It was concluded that zeolite coating is produced by heat treatment method after dipping without hydrothermal synthesis.

Nanostructured Hydroxyapatite for Biomedical Applications: From Powder to Bioceramic

  • Eslami, Hossein;Tahriri, Mohammadreza;Moztarzadeh, Fathollah;Bader, Rizwan;Tayebi, Lobat
    • Journal of the Korean Ceramic Society
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    • v.55 no.6
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    • pp.597-607
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    • 2018
  • In this study, a wet chemical method was used to synthesize nanostructured hydroxyapatite for biomedical applications. Diammonium hydrogen phosphate and calcium nitrate 4-hydrate were used as starting materials with a sodium hydroxide solution as an agent for pH adjustment. Scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, differential thermal analysis, thermal gravimetric analysis, atomic absorption spectroscopy, and ethylenediaminetetraacetic acid (EDTA) titration analysis were used to characterize the synthesized powders. Having been uniaxially pressed, the powders formed a disk-like shape. The sinterability and electrical properties of the samples were examined, and the three-point bending test allowed for the measurement of their mechanical properties. Sedimentation analysis was used to analyze the slurry ability of hydroxyapatite. As in-vitro biological properties of the samples, biocompatibility and cytotoxicity were assessed using osteoblast-like cells and the L929 cell line, respectively. Solubility was assessed by employing a simulated body fluid.

Preparation and characterization of PVDF/TiO2 composite ultrafiltration membranes using mixed solvents

  • Tavakolmoghadam, Maryam;Mohammadi, Toraj;Hemmati, Mahmood
    • Membrane and Water Treatment
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    • v.7 no.5
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    • pp.377-401
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    • 2016
  • To study the effect of titanium dioxide ($TiO_2$) nanoparticles on membrane performance and structure and to explore possible improvement of using mixed solvents in the casting solution, composite polyvinylidene fluoride (PVDF) ultrafiltration membranes were prepared via immersion precipitation method using a mixture of two solvents triethyl phosphate (TEP) and dimethylacetamide (DMAc) and addition of $TiO_2$ nanoparticles. Properties of the neat and composite membranes were characterized using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), Atomic force microscopy (AFM) and contact angle and membrane porosity measurements. The neat and composite membranes were further investigated in terms of BSA rejection and flux decline in cross flow filtration experiments. Following hydrophilicity improvement of the PVDF membrane by addition of 0.25 wt.% $TiO_2$, (from $70.53^{\circ}$ to $60.5^{\circ}$) degree of flux decline due to irreversible fouling resistance of the composite membrane reduced significantly and the flux recovery ratio (FRR) of 96.85% was obtained. The results showed that using mixed solvents (DMAc/TEP) with lower content of $TiO_2$ nanoparticles (0.25 wt.%) affected the sedimentation rate of nanoparticles and consequently the distribution of nanoparticles in the casting solution and membrane formation which influenced the properties of the ultimate composite membranes.

Dexamethasone Release from Glutaraldehyde Cross-Linked Chitosan Microspheres: In Vitro/In Vivo Studies and Non-Clinical Parameters Response in Rat Arthritic Model

  • Dhanaraju, Magharla Dasaratha;Elizabeth, Sheela;Poovi, Ganesan
    • Journal of Pharmaceutical Investigation
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    • v.41 no.5
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    • pp.279-288
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    • 2011
  • The Dexamethasone (DEX) loaded chitosan microspheres were prepared by thermal denaturation and chemical cross-linking method using a dierent concentration of glutaraldehyde as chemical cross-linking agent. The prepared microspheres were evaluated for the percentage of Drug Loading (DL), Encapsulation Efficiency (EE) and surface morphology by Scanning Electron Microscopy (SEM). DL and EE were found to be maximum range of 10.0 to 10.79 % and 58.19 to 64.73 % respectively. The SEM Photographs of the resultant microspheres exhibited fairly smooth surfaces and predominantly spherical in appearance. In addition, Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) shown that there was no interaction between the drug and polymer. In vitro and in vivo release studies revealed that the release of dexamethasone was sustained and extended up to 63 days and effectively controlled by the extent of cross-linking agent. Non-clinical parameters such as paw volume, hematological parameters like Erythrocyte Sedimentation Rate (ESR), Paced Cell Volume (PCV), Total Leucocytes Count (TLC), Hemoglobin (Hb), Differential Cell Count (DCC) were investigated in Fruend's Complete Adjuvant (FCA) induced arthritic rats. Radiology and histopathological studies were also performed in order to evaluate the therapeutic efficacy of the DEX-loaded microspheres in extenuating the rat arthritic model.

A Study on the Characteristics of Microemulsion Containing Isoflavone (이소플라본을 함유한 마이크로에멀젼의 물성 연구)

  • Jeong, Noh-Hee;Moon, Young-Jin;Lee, Hyang-Woo;Kim, Hong-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.1
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    • pp.56-62
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    • 2002
  • Microemulsion is stable to aggregation, sedimentation, fusion and has $3nm{\sim}200nm$ of particle size which is transparent and semitransparent. The isoflavone as a derivatives of Flavone is colorless crystalline compounds. It has similar basic structure to steroid materials which is hormone that acts to skin physiological phenomenon. On this study, we tried to search and demonstrate system content rate of dermal translocation system for cosmetics using O/W type microemulsion containing isoflavone. We manufactured O/W microemulsions by phase inversion emulsification method. It's was found that POE(20) monostearate with HLB value 14 caused microemulsion to be formed, which had $4nm{\sim}18nm$ of average diameter and $3nm{\sim}33nm$ of particle size distribution. Apparent viscosities of the microemulsions have increased in proportion to add surfactant dose.

Mitigation of Harmful Algal Blooms by Sophorolipid

  • Baek, Seung-Hak;Sun, Xiao-Xia;Lee, Young-Ju;Wang, Song-Young;Han, Kyung-Nam;Choi, Joong-Ki;Noh, Jae-Hoon;Kim, Eun-Ki
    • Journal of Microbiology and Biotechnology
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    • v.13 no.5
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    • pp.651-659
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    • 2003
  • A new method was proposed to control Harmful Algal Blooms (HABs) by a biosurfactant sophorolipid. The effect of sophorolipid on the growth, motility, precipitation, and recovery of algal cells was investigated for four common HAB species, Scripsiella trochoidea, Prorocentrum minimum, Cochlodinium polykrikoides, and Heterosigma akashiwo. The motility and growth of algal cells were inhibited significantly at the concentration of 20 and 5 mg/l sophorolipid, respectively, and no recovery was observed under the above concentrations. The concentration of 20 mg/l sophorolipid was considered to be an effective concentration for the mitigation of HABs. A sedimentation test suggested that the maximum precipitation occurred at the end of 1 h, and the algicidal effect of sophorolipid was observed by a microscope. Comparative study showed that sophorolipid had marked algicidal capability. Analysis on biodegradability, toxicity, and cost effectiveness further demonstrated the potential of sophorolipid in future HABs mitigation.