• 한국산학기술학회논문지
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• 제16권3호
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• pp.2314-2320
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• 2015

MBR (Membrane Bio-Reactor) 공정은 막 오염을 해결하기 위해 막대한 에너지 소비를 하는 공정으로 알려져 있다. 이를 해결하기 위한 일환으로 전기응집 기술을 MBR에 적용하는 시도가 보고되고 있다. 본 연구에서는 전류밀도를 변화시켜가며 활성슬러지의 막 여과를 수행하여 전기응집이 막 오염 저감에 미치는 영향과 메커니즘을 파악하고자 하였다. 활성슬러지 혼합액을 전기응집한 후 회분식교반셀로 분리 막의 여과성능을 평가하였다. 전류밀도(A/m2)를 10에서 40으로 증가시켰을 때 총 오염 저항 (Rc+Rf) 값이 18%에서 79%까지 감소하여 전기응집으로 인해 분리 막의 여과성능이 향상됨을 확인할 수 있었다. 전기응집 전후로 유기물 농도와 활성슬러지 입도분포 변화는 거의 일어나지 않았다. 여과 성능의 향상은 수산화알루미늄, Al(OH)3이 생성되어 막 표면에 부착되면서 오염물질이 쌓이게 됨을 방지하는 역할, 즉 dynamic membrane 으로 작용하였기 때문인 것으로 판단되었다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.378-378
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• 2006

The preparation, characterization, and bio-testing of biocide incorporated silicone coatings for marine applications have been conducted. Derivatives of the biocide, Triclosan (5-chloro-2-(2, 4-dichlorophenoxy) phenol), were used to covalently attach the biocide moiety to a silicone backbone. The synthetic process allowed for control of the resulting coating's mechanical properties as well as antifouling/fouling release performance in laboratory and ocean site testing. The test results showed significantly reduce macro fouling with sustained fouling release characteristics for the coatings produced.

• Membrane and Water Treatment
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• 제11권1호
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• pp.31-39
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• 2020

Anaerobic membrane bioreactor (AnMBR) treatment has been widely studied in recent years because of the potential for production of bio-energy from wastewater and energy-positive operation of wastewater treatment plants. Several AnMBR systems, including those that incorporate ceramic membranes, take advantage of enhanced water permeability and low membrane fouling potentials. Given that differences in the ceramic membranes may influence the results of AnMBR studies, relevant details are discussed in this review, which focuses on the profiles of common ceramic membranes used in AnMBR, treatment and filtration performances of different anaerobic ceramic membrane bioreactors (AnCMBRs), and the membrane fouling mitigation methods available for effective AnCMBRs operation. The aim of this review is to provide a comprehensive summary of AnCMBR performance, feed wastewater characteristics, operating conditions, and the methods available for effective fouling mitigation.

• 상하수도학회지
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• 제30권6호
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• pp.645-652
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• 2016

A membrane module including grid was designed and introduced to MBR (membrane bio-reactor) for the purpose of better control of membrane fouling. It could be anticipated that the grid enhances the shear force of fluid-air mixture into the membrane surface by even-distributing the fluid-air to the membrane module. As MLSS concentration, packing density which is expressed in the ratio of the housing and the cross-sectional area of membrane fibers ($A_m/A_t$) and air-flow rate were changed, membrane foulings were checked by monitoring fouling resistances. The total fouling resistance ($R_c+R_f$) without grid installation (i.e., control) was $2.13{\times}10^{12}m^{-1}$, whereas it was reduced to $1.69{\times}10^{12}m^{-1}$ after the grid was installed. Regardless of the grid installation, the $R_c+R_f$ increased as the packing density increased from 0.09 to 0.28, however, the increment of resistance for the grid installation was less than that of the control. Increase in the air flow rate did not always guarantee the reduction of fouling resistance, indicating that the higher air flow rate can partially de-flocculate the activated sludge flocs, which led to severer membrane fouling. Consequently, installation of grids inside the housing have brought a beneficial effect on membrane fouling and optimum air flow rate is important to keep the membrane lowering fouling.

• Membrane and Water Treatment
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• 제2권2호
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• pp.105-119
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• 2011

This study presents the tests of an Immersed Membrane BioReactor (IMBR) equipped with a draft tube and focuses on the influence of hydrodynamic conditions on membrane fouling in a pilot-scale using a hollow fiber membrane module of ZW-10 under ambient conditions. In this system, the cross-flow velocities across the membrane surface were induced by a cylindrical draft-tube. The relationship between cross-flow velocity and aeration strength and the influence of the cross-flow on fouling rate (under various hydrodynamic conditions) were investigated using Multi-Dimension Scaling (MDS) analysis. MDS technique is especially suitable for samples with many variables and has relatively few observations, as the data about Membrane Bio-Reactor (MBR) often is. Observations and variables are analyzed simultaneously. According to the results, a specialized form of MDS, CoPlot enables presentation of the results in a two dimensional space and when plotting variables ratio (output/input) rather than original data the efficient units can be visualized clearly. The results indicate that: (i) aeration plays an important role in IMBR performance; (ii) implementing the MDS approach with reference to the variables ratio is consequently useful to characterize performance changes for data classification.

• 한국해양환경ㆍ에너지학회지
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• 제16권2호
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• pp.82-87
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• 2013

본 논문에서는 해수에 잠겨있는 물체표면의 물리적 성질과 생물오손현상 간의 상관관계를 관찰하기 위하여 생물오손에 미치는 소수성(hydrophobic) 표면의 효과에 대해 실험해석을 수행하였다. 시편으로서, 일반알루미늄, 소수성표면을 가진 알루미늄, 친수성(hydrophilic)표면을 가진 알루미늄 등 세 종류를 사용하였으며, 단, 소수성시편의 경우, AAO(Anodic Aluminum Oxide)기법으로 제작한 것과 HDFS(heptadecafluoro-1,1,2,2,-tetrahydrodecyltricholorosilane)코팅처리하여 제작한 것, 두 종류를 사용하였다. 세 종류, 네 개의 시편에서 확인된 생물오손정도는 중장기적인 면에서는 시편 간에 큰 차이가 없지만, 오손초기에는 괄목할 만한 차이가 관찰되었다. 생물 부착물의 두께가 소수성표면의 미세돌기 높이에 다다를 때 까지는 소수성표면의 오손지연효과가 현저하게 나타나나, 일단 이를 초과하면 소수성표면의 오손방지효과는 소멸됨을 확인하였다.

• Environmental Engineering Research
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• 제11권2호
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• pp.91-98
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• 2006

There is a possibility of the production of the air bubbles in membrane pores due to the reduction in pressure during membrane filtration. The effect of fine air bubbles from dissolved gases on microfiltration was investigated in the submerged membrane bio-reactor (SMBR). The $R_{air}$ (air bubble resistance) was defined as the filtration resistance due to the air bubbles formed from the gasification of dissolved gases. From the results of filtration tests using pure water with changes in the dissolved oxygen concentration, the air bubbles from dissolved gases were confirmed to act as a foulant and; thus, increase the filtration resistance. The standard pore blocking and cake filtration models, SPBM and CFM, respectively, were applied to investigate the mechanism of air bubble fouling on a hollow fiber membrane. However, the application of the SPBM and CFM were limited in explaining the mechanism due to the properties of air bubble. With a simple comparison of the different filtration resistances, the $R_{air}$ portion was below 1% of the total filtration resistance during sludge filtration. Therefore, the air bubbles from dissolved gases would only be a minor foulant in the SMBR. However, under the conditions of a high gasification rate from dissolved gases, the effect of air bubble fouling should be considered in microfiltration.

• Nuclear Engineering and Technology
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• 제55권2호
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• pp.674-680
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• 2023

The brine and seawater are important and largely untapped sources of critical trace metals and elements. The coupling of selective recovery of trace metals from seawater/brine with desalination plants gives an added advantage of energy credits to desalination plants and as well as reduce the cost of desalinated water. In this paper, status review on recovery of important trace metals and other alkali metals from seawater is presented. The potential of Indian desalination plants for recovery of trace metals, based on recovery ratio of 0.35 is also highlighted. Studies carried out by the process based on adsorption using Radiation Induced Grafted (RIG) polymeric adsorbents and then fractional elutions are presented. The fouling factors due to bio fouling and dirt fouling have been estimated for various locations of interest through field trails. The pay loader in the form of compact Contactor Assembly with minimum pressure drop, for loading specially designed radiation grafted sorbent in leaflet form has been briefed, as required for plant scale facility. The typical conceptual process design details of farm assembly of project CRUDE are described.

• 상하수도학회지
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• 제25권2호
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• pp.177-184
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• 2011

Membrane fouling is an unavoidable phenomenon in operation of seawater reverse osmosis (SWRO) and major obstacle for economic and efficient operation. When fouling occurs on the membrane surface, the permeate flux is decreased, on the contrary, the trans-membrane pressure (TMP) is increased, therefore operation and maintaining costs and potential damage of membranes are able to the pivotal risks of the process. Chemical cleaning process is essential to prevent interruptions for effective RO membrane filtration process. This study focused on proper chemical cleaning condition for polyamide RO membranes of 4 companies. Several chemical agents were applied for chemical cleaning under numbers of operating conditions. Additionally, a monitoring tool of FEEM as autopsy analysis method is adapted for the prediction of organic bio-fouling.

• 한국물환경학회지
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• 제22권5호
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• pp.865-870
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• 2006

The behavior and influence of EPS on membrane fouling by changing of hydraulic retention time was investigated, using lab. scale submerged membrane bio-reactor, which was operated with gravitational filtration and fed supernatant of primary sedimentation in waste water treatment plant as influent. The membrane was adopted micro-filter of polyethylene hollow fiber. EPS was analysed as polysaccharides and protein especially, into soluble and bound EPS separately. The concentration of soluble EPS was increased at short HRT, then membrane fouling was rapidly progressed and flux was depressed. The most of EPS clogged membrane pore were polysaccharides, while protein was important parameter affected on membrane fouling because of it's more accumulating in the more term operating.