• Title/Summary/Keyword: scale removal

Search Result 1,230, Processing Time 0.031 seconds

Technologies for the Removal of Water Hardness and Scaling Prevention

  • Ahn, Min Kyung;Han, Choon
    • Journal of Energy Engineering
    • /
    • v.26 no.2
    • /
    • pp.73-79
    • /
    • 2017
  • In nucleation assisted crystallization process formed $CO_2$ leaves as colloid gas and is used as the template by the rapidly growing crystals in the nucleation site. This emulsion of $CaCO_3$ micro-crystals & $CO_2$ micro-bubbles forms hollow particles. Formed hollow particles are double walled, both internal and external faces belonging to the cleavage aragonites which separate the surrounding water from the enclosed gas cavity. Hence, the reverse reaction of $CO_2$ with water forming Carbonic Acid is not possible and the pH stability is maintained. In fact every excess $CaCO_3$ crystals are buffering any carbonic acid left over. This $CO_2$ based nucleation technology prevents scale formation in water channels, but it also helps to reduce the previously formed scales. This process takes out water dissolved $CO_2$ in almost-visible micro-bubbles forms that helps reducing previously formed scale over a period of time (depends on the usage period). The aragonite crystals can't form scale because of its stable molecular structure and neutral surface electro potentiality.

Effect of Temperature on Treatment of Nitrogen and Phosphorus of Pig Wastewater in Bench Scale Reactor (실험실 수준의 반응조 온도가 양돈폐수중 질소, 인의 처리에 미치는 영향)

  • 박석환
    • Journal of Environmental Health Sciences
    • /
    • v.21 no.1
    • /
    • pp.86-92
    • /
    • 1995
  • This study was performed to evaluate the effect of temperature on operating parameters for reactor in pig wastewater treatment using sequencing batch reactor method which is one of the biological treatment methods. Study was accomplished by experimental apparatus of bench scale, and the degradation rate coefficient and temperature correction factor were derived. The followings are the conclusions that were derived from this study. 1. In the characteristics of pig wastewater, concentrations of TKN and T-P were very high as 590 mg/l and 40 mg/l, respectively. 2. Removal efficiency of BOD and $COD_{Mn}$ as organic compound indicators were the highest mark as 97% at 25$\circ$C. 3. When temperature was incresed from 10$\circ$C to 25$\circ$C, removal efficiencies of TKN and T-P were proportionally increased. Especially, the former was greatly effected by temperature of reactor. 4. In experiment of bench scale, the degradation rate coefficients were increased as temperature increased, but decreased at the temperature range of 25~35$\circ$C. Temperature adjustment coefficients for $COD_{Mn}$, BOD, TKN and T-P were 1.1460, 1.1356, 1.1140 and 1.0565, respectively.

  • PDF

Feasibility Study on Production of Liquid Fertilizer in a 1 ㎥ Reactor Using Fishmeal Wastewater for Commercialization

  • Gwon, Byeong-Geun;Kim, Joong-Kyun
    • Environmental Engineering Research
    • /
    • v.17 no.1
    • /
    • pp.3-8
    • /
    • 2012
  • A scaled-up bioconversion of fishmeal wastewater (FMW) into liquid fertilizer was performed five times in a $1m^3$ reactor in order to examine the feasibility of commercialization. The importance of aeration was marked. Analyses indicated that dissolved oxygen (DO) level was closely related to the value of oxidation-reduction potential (ORP) and it was crucial to achieve high-quality liquid fertilizer. When pure oxygen was supplied through four diffusers into the reactor, DO levels and ORP values were maintained over 1.2 mg/L and 0.2 mV, respectively all the time during 52 hr of bioconversion. The pH changed from 6.8 to 5.9. The average removal percentages of chemical oxygen demand ($COD_{Cr}$) and total nitrogen (TN) were 75.0% and 71.6%, respectively. Compared to the result acquired in a 5-L reactor, bioconversion of FMW into liquid fertilizer was achieved in a shorter time under the same removal percentages of $COD_{Cr}$ and TN. The 52-hr culture of inoculated FMW was phytotoxic-free and it possessed comparable fertilizing ability to a liquid fertilizer made from the fish waste in hydroponic culture with amino acid contents of 5.93 g/ 100 g sample. From all the above results, transferring lab-scale data to large-scale production appeared to be successful. As a result, the commercialization of a liquid fertilizer made from FMW was feasible.

A Study on Denitrification Efficiency with External Carbon Sources in Pilot-scale Modified SBR (Pilot-scale modified SBR 공정에서 외부탄소원의 종류에 따른 탈질효율 비교 연구)

  • 서인석;김병군;홍성택;정위득
    • Journal of environmental and Sanitary engineering
    • /
    • v.17 no.3
    • /
    • pp.52-59
    • /
    • 2002
  • Pilot-scale PSSBR(Phase Separated Sequencing Batch Reactor) was operated to evaluate requirement of external carbon sources(${\Delta}gCOD/{\Delta}gNO_3^{-}-N$) in denitrification. Methanol and fermented food waste were used as external carbon sources. Methanol and fermented food waste were fed to the anoxic state of first reactor and concentration were 50 and 40 mgCOD/L on the basis of concentration in reactor, respectively. In case that external carbon source was not used, average $NO_3^{-}-N$ concentration in effluent was 22.49 mg/L. When methanol and fermented food waste were fed, average $NO_3^{-}-N$ concentration in effluent were 10.13 mg/L and 6.3 mg/L, respectively and requirement of external carbon sources were 4.04 and 2.5 ${\Delta}gCOD/{\Delta}gNO_3^{-}-N$, respectively. Fermented food waste was better than methanol in denitrification efficiency. Therefore fermented food waste could be one of the excellent external carbon sources for nitrogen removal in biological nutrient removal process.

Biological Removal of Explosive 2,4,6-Trinitrotoluene by Stenotrophomonas sp. OK-5 in Bench-scale Bioreactors

  • Oh, Kye-Heon;Lee, Myung-Seok;Chang, Hyo-Won;Kahng, Hyung-Yeel;So, Jae-Seong
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.7 no.2
    • /
    • pp.105-111
    • /
    • 2002
  • The biological removal of 2,4,6-trinitrotoluene (TNT) was studied in a bench-scale bioreactor using a bacterial culture of strain OK-5 originally Isolated from soil samples contaminated with TNT. The TNT was completely removed within 4 days of incubation in a 2.5 L bench-scale bioreactor containing a newly developed medium. The TNT was catabolized in the presence of different supplemented carbons. Only minimal growth was observed in the killed controls and cultures that only received TNT during the incubation period. This catabolism was affected by the concentration ratio of the substrate to the biomass. The addition of various nitrogen sources produced a delayed effect for the TNT degradation. Tween 80 enhanced the degradation of TNT under these conditions. Two metabolic intermediates were detected and identified as 2-amino-4, 6-dinitrotoluene and 4-amino-2, 6-dinitrotoluene based on HPLC and GC-MS analyses, respectively. Strain OK-5 was characterized using the BIOLOG system and fatty acid profile produced by a microbial identification system equipped with a Hewlett Packard HP 5890 II gas chromatograph. As such, the bacterium was identified as a Stenotrophomonas species and designated as Stenotrophomonas sp. OK-5.

Complex odor removal in pilot-scale biofilter with microorganisms immobilized on polymer gel media (미생물 포괄고정화 담체를 적용한 파일럿 스케일 바이오필터에서의 복합악취 제거)

  • Kim, Sun-Jin;Kim, Tae-Hyeong;Lee, Yun-Hee;Jang, Hyun-Sup;Song, Ji-Hyeon;Hwang, Sun-Jin
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.25 no.5
    • /
    • pp.741-750
    • /
    • 2011
  • A pilot-scale biofilter was constructed to discover degradation characteristics of the complex odor discharged from Ansan wastewater treatment plant. Candida tropicalis for volatile organic compounds, sulfur oxidizing bacteria(SOB) for hydrogen sulfide, and bacteria extracted from feces soil were immobilized on a polymer gel media. According to this study, the EBCT was varied from 36 sec to 18 sec. Toluene was removed as 80% along the variations, but it was recovered as 100% within 1 week. All benzene and xylene were removed during the operation while the efficiency of hydrogen sulfur was temporary decreased at 18 sec of EBCT, thereafter it was recovered to 100% within a week. The maximum elimination capacities of the benzene, toluene, xylene, and hydrogen sulfur were 6.6 g/$m^{3}$/hr, 31.7 g/$m^{3}$/hr, 7.8 g/$m^{3}$/hr, and 133.6 g/$m^{3}$/hr, respectively. There were merits on removal both organic and inorganic complex odor using the pilot-scale biofilter embedded with microorganisms immobilized on polymer gel media.

A simple culture technique of Rhodobacter azotoformans EBN-7 for public use: application to NH4+-N removal in shrimp aquaculture water

  • Cho, Kyoung Sook;Kim, Joong Kyun
    • Fisheries and Aquatic Sciences
    • /
    • v.25 no.10
    • /
    • pp.525-536
    • /
    • 2022
  • Photosynthetic bacteria (PSB) attract considerable interest as useful microorganisms; nevertheless, a generalized culture technique has not been previously reported owing to difficulty in their cultivation. Therefore, a simple culture technique suitable for public use was investigated. Among the PSB tested, the strain Rhodobacter azotoformans EBN-7 was the most suitable for scale-up production because it showed the highest specific growth rate (0.20 h-1) on basal medium. In scale-up cultivation (500 L), R. azotoformans EBN-7 showed 4.50 × 1010 colony-forming units mL-1 (number of viable cells), dry cell weight of 26.8 g/L, and a specific growth rate of 0.15 h-1. Cultivation using this final culture broth (as seed culture) in a 15 L simple reactor was successful, with maintenance of cell activity evident. For use as seed culture, the maximum allowable preservation period of R. azotoformans EBN-7 at 4℃ was 3 months. When R. azotoformans EBN-7 cultivated in a simple technique was applied to shrimp aquaculture water, NH4+-N was reduced from 0.61 mg/L to 0.24 mg/L (by 60.7%) in 4 days in comparison with the control. Thus, this simple culture technique using R. azotoformans EBN-7 has the potential for a good removal efficiency of NH4+-N, making seed culture easier and suitable for public use.

Drug-Induced Dyskinesia Treated with Korean Medicine: A Case Report

  • Soo Min Ryu;Jung Won Byun;You Jin Heo;Eun Yong Lee;Cham Kyul Lee;Na Young Jo;Jeong-Du Roh
    • Journal of Acupuncture Research
    • /
    • v.40 no.2
    • /
    • pp.150-155
    • /
    • 2023
  • Drug-induced dyskinesia is an involuntary muscle movement caused by various dopamine receptor-blocking drug exposure, such as antipsychotics, antidepressants, and antiemetics. Causative drug removal is the main treatment for drug-induced dyskinesia whenever possible because its pathophysiology lacks a universally accepted mechanism; however, the symptoms can persist for years or decades in many patients even after causative drug removal. Herein, we present a case of drug-induced dyskinesia in a 61-year-old female patient who consumed medication for approximately 10 years for her depression, anxiety, and insomnia. Cervical and facial dyskinesia was suggested to be related to perphenazine and levosulpiride administration. The patient received acupuncture, pharmacopuncture, herbal medicine, and chuna treatment for 81 days during hospitalization. The symptoms were evaluated using the Abnormal Involuntary Movement Scale, Toronto Western Spasmodic Torticollis Rating Scale, Tsui's score, and Numeric Rating Scale, which revealed remarkable improvement, suggesting the effectiveness of combined Korean medicine for drug-induced dyskinesia.

The Effect on Treatment Performance of Fiber Filter Under Various Packing-Density and Filtration Velocity (충진밀도와 여과속도가 섬유사 여과기의 처리 성능에 미치는 영향)

  • Im, Jeong-Hoon;Kim, Hyo-Kwan;Lee, Jung-June;Moon, Tae-Sup;Jeong, Min-Ki;Woo, Hae-Jin;Kim, Chang-Won
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.28 no.2
    • /
    • pp.216-222
    • /
    • 2006
  • A flexile fiber filter developed in Korea was operated to evaluate the effect of packing density and filtration velocity on particle removal. The pilot-scale fiber filter with 40 cm of diameter and 2 m of height was packed with polyamide fibers of which mean diameter was approximately 0.93 mm. While the filtration velocity was maintained at 325 m/hr, the particle removal efficiency was compared with various of packing density from $70kg/m^3\;to\;100kg/m^3$. On the contrary, when the packing density was maintained at $70kg/m^3$, the particle removal efficiency was examined with various filtration velocity from 65 m/hr to 400 m/hr. The filtration pressure increased with the packing-density increase. Below $80kg/m^3$ of packing density, the removal efficiencies of turbidity ad SS were less than 30% and 50%, respectively. At $100kg/m^3$ of packing density, the removal efficiencies of them were nearly 45% and 60% respectively. The filtration pressure increased with the filtration-velocity increase. A better removal efficiency was obtained at a lower filtration velocity, removal efficiency of them were 73% at 65 m/hr. Consequently, The filtration velocity was the more important factor to enhance the particle removal efficiency compared with the packing density in fiber filter.

Treatment Characteristics Using Full-Scale SBR System (Full-Scale SBR 공법을 이용한 처리특성)

  • Choo, Tai-Ho;Lee, Yong-Doo;Cho, Yong-Hyun
    • The Journal of the Korea Contents Association
    • /
    • v.6 no.10
    • /
    • pp.34-40
    • /
    • 2006
  • In this study, the treatment of organic matters and nutrients like Nitrogen and Phosphorus with sequencing batch reactors (SBR) was conducted. The following conclusions can be summarized from the study. The influent BOD concentration was varied 19.6 to 40.0mg/L and the effluent was 3.0 to 14.8mg/L. The variations of BOD removal efficiency during the experimental period was $47.9{\sim}88.4%$ and the average was 80.8%. The average removal efficiency was stabilized with the passage of time. Also the COD concentration was flowed into as $12.2{\sim}32.0mg/L$ and the effluent concentration was varied 3.3 to 18.6 mg/L, and then the average COD removal efficiency was 57.3%(minimun 19.2% and maximum 78.6%). But fortunately, the COD removal efficiency was also stabilized as 70.2% after 79days. In the case of T-N, the influent concentration range was $7.53{\sim}14.99mg/L$ and the effluent concentration was 6.59mg/L(the average removal efficiency was 40.3%) until the first experiment time 79days. But after normalizing the system, it was 4.44mg/L (the average removal efficiency was 56.4%). Also the influent T-P concentration was varied from 0.77 to 1.91mg/L and the effluent concentration was $0.26{\sim}1.53mg/L$. The removal efficiency was varied from 5.3 to 71.7%. considerably, therefore the average removal efficiency was 42.6%. The reason was concluded that the sludge wasn't discharged for increasing MLSS concentration.

  • PDF