• Reproductive and Developmental Biology
• /
• v.31 no.2
• /
• pp.121-126
• /
• 2007

The objective of this study was to establish the optimal conditions for hypoosmotic swelling (HOS) test to assess the functional integrity of the membranes of boar fresh or frozen/thawed spermatozoa. When pooled semen sample was incubated for 30 min at $37^{\circ}C$ with different test solution of varied osmolarity, the highest percentage of HOS positive spermatozoa was observed in a 150 mOsmol fructose/Na-citrate solution (33.6%). Incubation time did not affect significantly the score of HOS positive spermatozoa observed in a 150 mOsmol fructose/Na-citrate solution at $37^{\circ}C$, but the osmolarity affected the score of HOS positive spermatozoa under the same condition above. Fresh semen was significantly better than frozen/thawed semen in semen parameters evaluated such as motility, viability, membrane integrity and lipid peroxidation (p<005). In the relationships of sperm parameters, motility vs viability, motility vs membrane integrity and viability vs membrane integrity were positively correlated ($0.82{\sim}0.94$) but lipid peroxidation vs other estimated factors was negatively correlated ($- 0.90{\sim}- 0.98$). Among the evaluation methods, motility vs Viability, motility vs membrane integrity and lipid peroxidation vs other estimated factors were significantly correlated (p<0.05). These results of this. study indicate that the optimal condition of HOST in boar spermatozoa is a 150 mOsmol fructose/Na-citrate solution for 30 min incubation at $37^{\circ}C$ and HOST can substitute the examination of motility, viability and lipid peroxidation.

• Membrane Journal
• /
• v.32 no.4
• /
• pp.253-263
• /
• 2022

This study suggests a guideline for designing unit process of wastewater reuse in terms of a maintenance of the process based on critical parameters to draw a high quality performance of RO unit. Defining the parameters was done by applying membrane integrity test (MIT) in pretreatment process utilizing lab-scale MF. SDI is utilized for judging whether permeate is suitable to RO unit. However, result said TOC concentration matching with particle count analysis is better for judging the permeate condition. When membrane test pressure (P_test) was measured to derive log removal value in PDT, virgin state of membrane fiber was used to measure dynamic contact angle utilizing surface tension of the membrane fiber. Actually, foulant affects to the state of membrane surface, and it decreases the P_test value along with time elapsed. Consequently, LRV_DIT is also affected by P_test value. Thus, sensitivity of direct integrity test descends with result of P_test value change, so P_test value should be considered not the virgin state of the membrane but its current state. Overall, this study focuses on defining design parameters suitable to MF pretreatment for RO process in wastewater reuse by assessing its impact. Therefore, utilities can acknowledge that the membrane surface condition must be considered when users conduct the direct integrity test so that P_test and other relative parameter used to calculate LRV_DIT are adequately measured.

• Journal of Korean Society on Water Environment
• /
• v.24 no.6
• /
• pp.793-800
• /
• 2008

Recently domestic drinking water industry has recognized membrane-based technology as a promising alternative for water treatment. To ensure successful application of membrane processes, the integrity of membrane systems should be maintained. According to US EPA guidance, the pressure decay test based on the bubble point theory is recommended to detect any membrane defection of which size is close to the smallest diameter of Cryptosporidium oocysts, $3{\mu}m$. Proper implementation of the pressure decay test is greatly affected by initial test pressure, and the interpretation of the test results is associated with upper control limit. This study is conducted to investigate various factors affecting determination of initial test prtessure and upper control limit, including membrane-based parameters such as pore shape correction factor, surface tension and contact angle, and system-based parameters, such as volumetric concentration factor and total volume of system. In this paper, three different hollow fibers were used to perform the pressure decay test. With identical initial test pressure applied, their pressure decay tendency were different from each other. This finding can be explained by the micro-structure disparity of those membranes which is verified by FESEM images of those membranes. More specifically, FESEM images revealed that three hollow fibers have asymmetry, deep finger, shallow finger pore shape, respectively. In addition, sensitivity analysis was conducted on five parameters mentioned above to elucidate their relation to determination of initial test pressure and upper control limit. In case of initial pressure calculation, the pore shape correction factor has the highest value of sensitivity. For upper control limit determination, system factors have greater impact compared to membrane-based parameters.

• Membrane Journal
• /
• v.27 no.4
• /
• pp.367-373
• /
• 2017

Pressurized membrane module systems, including hollow fiber type of Microfiltration (MF) and Ultrafiltration (UF) membranes are being increasingly used in drinking water treatment due to their high removal efficiency of pathogen. However, when fibers are damaged in pressurized membrane system, the pathogen will be able to penetrate the membrane. Therefore, it is essential to guarantee the regulatory requirements for water quality by an effective on-line or off-line condition integrity monitoring methods. Recently, pressure decay test (PDT) which is one of membrane integrity tests has been reflected to drinking water treatment plants using pressurized membrane module. In this paper, three different method were used to perform PDT and three different sensitivity values were analyzed through experiments. Three types of direct integrity test methods were applied to pressure feed side, filtrate side and bidirectional pressure decay test. The results of these experiments show that the sensitivity was increasing when the volume of pressurized gas was decreasing. The sensitivity is inversely proportional to the gas volume. Furthermore, it is desirable to increase pressure difference between feed side and permeate side in order to achieve higher sensitivity in the PDT by membrane damage.

• Journal of Korean Society on Water Environment
• /
• v.24 no.4
• /
• pp.423-429
• /
• 2008

Microfiltration (MF) and ultrafiltration (UF) processes for removal of particulate materials (i.e., turbidity, microorganisms and viruses) have been used to produce drinking water with higher quality. As membrane filtration technique has become widely applied for drinking water treatment, the importance of membrane integrity test (MIT) has also been increasingly emphasized. The results of pressure decay test (PDT) were presented in the paper to monitor membrane integrity. In this paper the PDT was carried out with deliberately-defected membrane fibers to evaluate the sensitivity of PDT on membrane fiber damage. Variation of pressure decay rate and removal rate were investigated to evaluate the impact of defection (defection ratio) and pore size of membrane. The membrane integrity could be successfully monitored by the PDT. The pressure decay rate varied from $0.002{\sim}0.189kg_f/cm^2hr$ with the initial pressure ranged from 0.2 to $1.0kg_f/cm^2hr$. Higher initial pressure which provided with higher pressure decay rate was preferred to evaluate the defection of membrane fiber. As for the particle removal rate, the Log Removal Rate (LRV) of kaolin solution decreased significantly from 3.78 to 2.31 when one fiber out of 3,200 fibers was cut. The membranes with different pore size were tested to evaluate virus removal efficiency. The virus removal rate of the MF membrane ($0.1{\mu}m$) was about 30% although the poliovirus was smaller than the pore size of the MF membrane, indicating that the removal rate was much lower than Korea Water Works Association (KWWA) certificate LRV of 1.5.

• Proceedings of the KSAR Conference
• /
• 2004.06a
• /
• pp.277-277
• /
• 2004

The purpose of this study was to investigate the effect of different conditions (osmolity, solution, incubation times, comparison of fresh and frozen/thawed semen and storage times) on the swelling of canine spermatozoa. Employing the hypoosmotic swelling test (HOST), the membrane integrity of spermatozoa in different solutions (sucrose, fructose, latose, Na-citrate, Na-citrate plus sucrose, Na-citrate plus fructose and Na-citrate plus lactose were 61.4%, 66.2%, 62.5%, 68.1%, 62.0%, 68.5% and 60.2%, respectively. (omitted)

• Membrane Journal
• /
• v.27 no.3
• /
• pp.248-254
• /
• 2017

In order to secure the reliability of pathogenic microorganisms such as Cryptosporidium and Giaridia, which are chlorophilic protozoans, membrane filtration systems have been widely used in water purification process. hese integrity tests are classified into direct and indirect methods. Based on the bubble point theory, the pressure-based test in the direct method is presented in the USEPA Guidance Manual with sensitivity to detect a minimum size of pathogenic microorganisms of $3{\mu}m$ or more. Indirect methods are widely used in that they are capable of continuous operation in on-line state, but there is a very low sensitivity of damage detection compared to the direct method, and there is a limit that can not specify the damage area, so it is necessary to improve this sensitivity. In this study, we compared the LRVDIT and UCL values according to the type of membrane defect, number of fiber breaks, and initial set pressure value through the Integrity Test by Pressure Decay Test (PDT).

• Journal of Korean Society of Water and Wastewater
• /
• v.28 no.2
• /
• pp.171-179
• /
• 2014

In this study, a novel method was proposed to test the integrity of water treatment system specifically equipped with membrane filtration process. We applied the silica particles coated with a fluorescent agent (rhodamine B isothiocyanate) as a surrogate to detect a membrane process integrity and evaluate the reliability of effluent quality in the system. Additionally, a series of experiments was conducted to evaluate the sensitivity of the method through the laboratory scale experiment. The laboratory scale experiments showed that the feasibility of application of proposed method to detect a breach or damaged part on the membrane surface. However, the sensitivity on predicting the area of a breach was significantly influenced by the testing conditions such as a concentration of surrogate, filtration flux, and detection time. The lowest error of predicting the area of breach was 3.5% at the testing condition of surrogate concentration of 80 mg/L injected with flux of $20L/m^2/hr$ for 10 minutes of detection time for the breach having the actual area of $7.069mm^2$. However, the error of estimation was increased at the small breach with area less than $0.785mm^2$. A future study will be conducted to estimate a damaged area with more accuracy and precision.

• Journal of Embryo Transfer
• /
• v.28 no.4
• /
• pp.349-353
• /
• 2013

The objective of this study was to compare the effect of semen extenders on the sperm motility, viability, acrosome integrity and functional integrity of plasma membrane (HOST: hypo-osmotic swelling test) during liquid preservation of Korean Native boar semen. In this experiment, semen was diluted in Androhep plus, Beltsville Thawing Solution (BTS), ModenaTM, Seminark and Vitasem LD. Sperm-rich fractions were collected from three Korean Native boars and sub-samples were diluted ($30{\times}10^6$ spermatozoa/ml) in different semen extenders. Semen samples were stored at $17^{\circ}C$ for 96 hours. On everyday (0, 24, 48, 72, 96 h) after storage, the sperm characteristics relevant for fertility, such as sperm motility, viability, acrosome integrity and HOST positive were evaluated. The motility of spermatozoa stored in different extenders was no significantly different among other extenders (P>0.05). Also, no difference was observed among samples processed with different extenders in the percentage of sperm viability, acrosome integrity and HOST positive. All extenders maintained a high percentage (70%) of sperm motility, viability and acrosome integrity through 96 h of storage. The result of this study show that there was no significant differences among extenders in their capacity to preserve motility, viability and membrane integrity of spermatozoa from normal, fertile Korean Native boars for 96 h of liquid preservation at $17^{\circ}C$.

• Journal of Korean Society of Water and Wastewater
• /
• v.30 no.1
• /
• pp.33-40
• /
• 2016

In this study, a fluorescent silica nano particle is used as the surrogate for challenging test of membrane surface integrity. The particles are functionalized by a fluorescent dying agent so that as an ultraviolet light is imposed a bright fluorescent image from the particles can be taken. If a membrane surface is damaged and has a compromised part larger than the size of surrogate the fluorescent particles would pass through and contained in the permeate. An operator can directly notice whether the membrane surface is damaged or not by detecting a fluorescent image taken from the permeate. Additionally, the size of compromised part is estimated through analysing the fluorescent image in which we surmise the mass of particles included in the permeate by calculating an average RGB value of the image. The pilot scale experiments showed that this method could be applied successfully to determine if a membrane surface had a damaged parts regardless of the test condition. In the testing on the actual damaged area of $4.712mm^2$, the lowest error of estimating the damaged area was -1.32% with the surrogate concentration of 80 mg/L, flux of $40L/m^2/hr$ for 25 minutes of detection. A further study is still going on to increase the lowest detection limit and thus decrease the error of estimation.