• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2642-2646
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• 2012

Pretreatment of spent FCC catalyst and its application in remove trace olefins in aromatics were investigated in this research. The most effective pretreatment route of spent FCC catalyst was calcining at $700^{\circ}C$ for 1 h, washing with 5% oxalic acid solution in ultrasonic reactor and dried. Treated spent FCC catalyst was modified with metal halides, then to prepare catalyst to remove trace olefins in aromatics. X-ray diffraction, Pyridine-FTIR, $N_2$ adsorption-desorption and inductively coupled plasma optical emission spectrometer (ICP-OES) were used to investigate the pretreatment process. The result showed that the performance of the treated spent FCC catalyst was much greater than that of the spent FCC catalyst, which indicted the possibility and improvement of this research.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.13-18
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• 2003

The effect of ultrasonic decomposition was introduced to develop a pretreatment method for the analysis of potassium ion in human urine by potentiometry. N-(4’-benzo-15-crown-5)-anthracene-9-imine, which has a good selectivity coefficient for potassium against ammonium, was used as an ion-selective material for the determination of potassium in urine with relatively high concentration of $NH_4{^+}$. Protenis in urine be removed by 85.1% when the sample acidified with 1.0 M $HNO_3$ was preteated for 100 s by sonication. Potential response of the membrane electrode in the pretreated urine had a slope of 54.6(${\pm}0.2,\;n=5$) mV/decade over the linear range of log $[K^+]$=-5~-1(r=0.9997). When an oxidant, $H_2O_2$, was addwd to the urine sonicated with $HNO_3$, the deproteinization increased 10% more than that in case if only $HNO_3$ and then the maximum ratio of ca. 95% was obtained. Moreover, the Nernstian slope for $K^+$ added to the urinary sample increased to 56.7(${\pm}0.1,\;n=3$) mV/decade. When the calibration curves were measured, the slopes did not vary even after the electrode was successively used 20 times with ultrasonic cleaning. The results showed that an ultrasonic pretreatment method provides simplicity in use, reduced treatment time and improved potentiometric characteristics of the membrane as the method effectively removes ca. 95% of proteins in urine.

• Environmental Engineering Research
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• v.11 no.3
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• pp.143-148
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• 2006

The ultrasonics is a new technology in waste activated sludge(WAS) treatment. Ultrasonic treatment is well known method for the break up of microbial cells to extract out a variety of intercellular materials inside microorganism cell. This study was done to investigate the effects of the ultrasonic frequency and power on disruption of biosolids in WAS and to examine the effect on methane production of WAS treated by ultrasonics. Biosolids disruption with ultrasound is more effective at ultrasonic frequency of 40 kHz and power of 0.3 watt/mL. In the digestion with WAS pretreated by sonication time for 10 minute at 40 kHz and 0.3 watt/mL, the total quantity of generated methane increased by 75%, as compared with experimental control(non-treatment).

• Korean Journal of Medicinal Crop Science
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• v.23 no.2
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• pp.155-160
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• 2015

This research evaluate antioxidant and skin-whitening effect of Abeliophyllum distichum Nakai by extraction processes. First, antioxidant effects were follows: EE (70% ethanol extract) showed higher DPPH scavenging activity of 69.66% than WE (hot water exract) 59.13% at $0.3mg/m{\ell}$, also UE's (70% ethanol extract by sonication process) higher than EE. Reducing power was that also EE showed higher than WE, and it was the highest value with UE's because of ultrasonic pretreatment. Next, the whitening effect tyrosinase inhibition activity was measured that EE was 23.88%, WE's was 16.69%, and UE was 23.34%. Ultrasonic pretreatment did not influence to tyrosinase inhibition activity. Cell viability showed low cell toxicity in all groups. UE's inhibited melanin synthesis, 55.1%, that is higher than EE and WE, 52.7% and 39.5%, respectively. As a result, we confirmed that antioxidant activities and skin-whitening effect by extraction process. Also, this results confirmed that the Abeliophyllum distichum Nakai extracts worth as cosmetic materials.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.83-88
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• 2012

The algal bloom, resulting from eutrophication, has caused serious water quality problems in river and lake. Therefore, it has to be removed by any means including physicochemical or biological treatment for preserving water quality. This study was conducted to investigate the microalgae removal and energy production using combined electro-flotation and anaerobic hydrogen fermentation processes. The result showed that algae removal efficiency based on chlorophyll a removal increased with the current. At a current of 0.6A, the maximum microalgae removal efficiency of 95.9% was achieved. The treatability of anaerobic hydrogen fermentation was investigated to recover energy from microalgae removed by electro-flotation. The ultimate hydrogen yields of algae before and after ultrasonic pretreatment were 17.3 and 61.1 ml $H_2/g$ dcw(dry cell weight), respectively. The ultrasonic pretreatment of algae led to 3.4-fold higher $H_2$ production due to the increase of hydrolysis rate.

• Journal of Korean Society on Water Environment
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• v.26 no.5
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• pp.810-815
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• 2010

Ultrasonic sludge pre-treatment has been studied to enhance the performance of anaerobic digestion by increasing sludge hydrolysis which is regarded as the rate-limiting-step of anaerobic digestion. In this study, the effect of ultrasonic pre-treatment on sludge hydrolysis (solubilization) and methane production was investigated. Sludge solubilization efficiency increased with ultrasonic energy input. However, it is uneconomical to apply more than 720 kJ/L as the solubilization efficiency per energy input declines afterwards. Volatile fatty acids concentration increased after the ultrasonic sludge hydrolysis. Anaerobic batch digestion showed that methane volume reached 64.7 and 84.5 mL after 18 days of incubation with the control sludge and ultrasonically hydrolyzed sludge, respectively. Methane production potential, maximum methane production rate, and the lag time of modified Gompertz equation were changed from 70 mL, 6.4 mL/day, and 1.2 days to 89 mL, 9.6 mL/day, and 0.5 day, respectively, after the ultrasonic sludge treatment. The results proved that ultrasonic pre-treatment contributed significantly not only for the methane production but also for the reduction of anaerobic digestion time which is critical for the performance of anaerobic sludge digestion.

• Environmental Engineering Research
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• v.21 no.1
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• pp.22-28
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• 2016

The aim of this study was to recycle the waste livestock blood as one of the waste biomass by turning proteins, the main constituent of blood, into effective biological resources like amino acid. Ultrasonic technology was applied to solubilize the proteins in the waste livestock blood. And of the multiple ultrasonic frequencies tested, 20 kHz was confirmed to yield the highest solubilization rate. The optimum pretreatment conditions were determined to be 30-min treatment at an ultrasonic irradiation density of 0.5 W/mL, which resulted in a solubilization rate of 96.01%. Also, a gel permeation chromatography (GPC) confirmed that a large amount of proteins were solubilized, and in an experiment where ultrasonic treatment was applied to kill bacteria, death rates of general bacteria and total coliforms were found to be reduced by 99.93% and 100%, respectively. Based on these results, ultrasonic technology was confirmed to be a crucial part of treating and recycling the proteins in waste livestock blood.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.893-906
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• 2011

The effect of ultrasound pretreatment on sludge degragability was investigated at different condotions: ultrasonic frequency(28, 40, 50kHz), intensity(10, 25, 50W), sonication time(10, 20, 30, 60min). Total suspended solid(TSS) and soluble chemical oxygen demand(SCOD) concentration were measured for the evaluation of pretreatment efficiency. The pretreated sludge was used as the feedstock for anaerobic digestion process. Biogas production and volatile suspended solid(VSS) removal were determined for evaluating the process performance. 1. TSS concentration of the sludge decreased at a constant rate as sonication operation was applied. The degradation rate of TSS increased when ultrasound frequency was decreased from 50kHz to 28kHz and intensity was increased from 10W to 50W. Efficiency of TSS degradation per input energy increased as ultrasonic frequency and intensity were decreased. At the frequency of 28 and 40kHz, SCOD concentration rapidly increased during the initial 30min of sonication time, and then it gradually increased. At 50kHz, SCOD concentration constantly increased for 60min of the sonication time. The SCOD production rate increased with increasing intensity under all ultrasound frequencies. 2. The optimum condition of ultrasound treatment was 28kHz, 50W and 60min for maximizing the biogas production, methane fraction, VSS removal. The highest values in biogas production, methane fraction in biogas, VSS removal were 370ml, 70%, 2.45g, respectively. Methane production rate per input energy increased at ultrasonic frequency and intensity decreased. 3. When raw sludge was pretreated at the condition of ultrasonic frequency of 28 and 40kHz in series, sequential-frequency sonication, intensity of 50W and 60min, biogas production, methane fraction, VSS removal were about the same that of 28kHz single-frequency sonication. When sequential-frequency sonication of 28 and 50kHz was applied in series, biogas production, methane fraction, VSS removal were 356 ~ 423ml, 69 ~ 71%, 2.41 ~ 2.78g, respectively. The pretreatment efficiency of 28-50kHz sequential-frequency sonication which sonication time of 28kHz and 50kHz was 40min and 20min was higher than that of 28kHz single-frequency sonication.

• Environmental Engineering Research
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• v.20 no.2
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• pp.163-169
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• 2015

In this study, we attempted to solubilize protein in slaughter blood (SB) using ultrasonic technology. The application of ultrasonic technology can make enzymatic degradation of SB more effective, which has no comparable alternative for treatment. The SB was homogenized by grinding it for 10 minutes at 10,000 rpm as a pretreatment for preventing its clotting, and then ultrasonic treatment was attempted to solubilize protein in SB. To maximize the efficiency of ultrasonic treatment for SB, the optimum condition of ultrasonic frequency (UF) was determined to be 20 kHz. To optimize the operation conditions of ultrasonification with 20 kHz of frequency, we used response surface methodology (RSM) based on ultrasonic density (UD) and ultrasonification time (UT). The solubilization rate (SR) of protein (%) was calculated to be $101.304-19.4205X_1+0.0398X_2+7.9411X_1{^2}+0.0001X_2{^2}+0.0455X_1X_2$. From the results of the RSM study, the optimum conditions of UD and UT were determined at 0.5 W/mL and 22 minutes, respectively, and SB treated under these conditions was estimated to have a 95% SR. Also, experimentally, a 95.53% SR was observed under same conditions, accurately reflecting the theoretical prediction of 95%.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.121-129
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• 2004

Anaerobic digestion is the most common process for sewage sludge stabilization and has benefits of VS reduction and biogas production. Many pretreatment methods have been studied to improve hydrolysis rate because the rate of sewage sludge degradation is slow in anaerobic digestion. This study mainly focused upon the effects on disintegration of sewage sludge by ultrasonic pretreatment according to the variation of acoustic density and duration of sonication time. In this study, acoustic density has been changed as follows : 33W/L, 70W/L, 88W/L, 139W/L in case of 40 kHz with the test time changes of 10min, 20min, 25min, 30min and 40min. In the comparison of $SCOD_{Cr}/TCOD_{Cr}$ variation for excess sludge and mixed sludge disintegration, the rates of $SCOD_{Cr}/TCOD_{Cr}$ have been increased in the condition of denser acoustic density and longer sonication time with acoustic frequency of 40kHz. The pH of the excess sewage sludge and mixed sewage sludge has been decreased in the condition of denser acoustic density and longer sonication time with acoustic frequency of 40kHz.