• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.3
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• pp.71-81
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• 2005

Anaerobic digestion is employed worldwide as the oldest and most important process for sludge stabilization. An additional advantage is the production of methane during anaerobic digestion. However, the waste activated sludge(WAS) has poor anaerobic degradability and less gas production due to the cell wall of bio-solid. In order to improve and enhance stabilization and dewatering of the WAS, a number of pretreatment processes have been developed and investigated. In this research, a pilot-scale study of pulse power pretreatment was performed to improve anaerobic degradability and dewaterability of the WAS. A pilot plant was designed and operated based on a previous laboratory study. Change of the sludge characteristics by pulse power pretreatment was estimated to assess the increasing soluble organics. The increased soluble organics could be used as a good substrate in the anaerobic digesion process. Gas production and methane potential of the anaerobic digestion were estimated as the parameters of anaerobic degradability. For evaluation of the dewaterability of pretreated WAS, capillary suction time(CST) and specific resistance were measured. The efficiency of energy recovery was also estimated by calculating energy balance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.117-127
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• 1983

An experimental research was performed employing the two stage anaerobic digestion of the mixture of the nightsoil and septic tank sludge to determine the effects of various hydraulic retention time of the digestion on chemical characteristics and treatment effeciency, thus determining the proper retention time. Results of the research are as follows, 1. Volatile-acid decreased as HRT increased. 2. Alklinity and ammonia-N tended to increase as HRT increased as did pH values, however, were observed to be constant at higher HRT values than 15 days. 3. The removal efficiencies of TBOD, TCOD and VS increased as HRT increased. 4. The removal efficiency of volatile solid decreased as VS loading increased. 5. It was observed that the rates of gas production were: 0.33 with HRT of 5 days, 0.58 with HRT of 15 days and $0.57m^3/kg$ VS fed/day with HRT of 25 days respectively. It is believed that the highest rate of gas production was at HRT of 15 days. 6. The sludge settling experiment showed that the minimum settling time required to ensure the desired underflow concentraton was estimated to be 8.6 days.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.475-481
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• 1999

Yeast extracts were prepared using either autolysis or enzymatic digestion methods for industrial application of the Saccharomyces cerevisiae B24 strain developed previously to have high RNA content. Extraction ratio of yeast extract from yeast cell reached 65% when autolysis of yeast slurry having 10% solid content was induced at $50^{\circ}C$ and pH 5.0 by agitating with 100 rpm. However, neither 5'-IMP nor 5'-GMP was detected from the autolyzate. In another attempt to prepare a yeast extract S. cerevisiae B24 culture was treated at $90^{\circ}C$ and then treated by various enzymes including ${\beta}-1,3-glucanase$, phosphodiesterase (nuclease P1), adenylic deaminase, and a protease. The yeast extract prepared by the enzymatic digestion method contained 3.2g of 5'-IMP and 5'-GMP/100g dry yeast extract.

• Clean Technology
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• v.16 no.1
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• pp.51-58
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• 2010

Methane was produced from the anaerobic digestion of marine macro-algae. Elemental analysis was first performed to estimate the theoretical methane production of three macro-algae (Undaria pinnatifida, Laminaria japonica, Hizikia fusiformis). Three algae were found to contain C 34 ~ 36%, H 5%, O 37 ~ 43%, N 2 ~ 4%, S 0.4 ~ 0.7%, and ash 14~21%, and the theoretical methane content was in the range of 56 ~ 60%, which can produce 442 ~ 568 mL $CH_4$ per g of volatile solid (VS). Using the biological methane potential (BMP) test, we found that L. japonica resulted in the highest yield of methane (52%). Moreover, various operational conditions, such as algae amount, pH, salinity, particle size, and pre-treatment, were investigated in order to find an optimal condition of anaerobic digestion. At pH 8.0, the autoclaved L. japonica (5g VS/200 mL), when used without washing salt, produced 268.5 mL/g VS which is 65% of the theoretical methane productions. Furthermore, using a CSTR (with the working volume of 7 L out of the total volume of 10 L), we have successfully operated the reactor for 65 days and obtained maximum methane production rate of 1.4 L/day with purity of 70%.

• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.666-673
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• 1988

The enhancement of the growth of lactic bateria in rice-based beverage was achieved by the prefermentation of cereals with a mixed culture of Bacillus and yeast followed by extrusion cooking. The rice-soybean milk blend was inoculated with a mixed culture of Bacillus laevolactis and Saccaromyces cerevisiae, and fermented in solid state at $45^{\circ}C$. It was extruded in an autogenous single screw extruder for sterilization as well as for partial digestion, and subjected to lactic fermentation in liquid state. The combined prefermentation and extrusion cooking increased the content of water soluble solid. It stimulated the growth of lactic bacteria as well as the acid production and increased dispersion stability and sensory acceptability.

• Journal of Animal Environmental Science
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• v.6 no.2
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• pp.73-81
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• 2000

A two-phase anaerobic digestion system for the treatment of swine waste was constructed in a commercial hog farm. The digester system was composed of 4 major units; slurry storage pit, acidogenic digester, methanogenic digester and sedimentation pit. A biogas boiler unit was also attached to maintain the digester temperature of 37$^{\circ}C$. Substrate lading was made with 2hr-interval by pumping about 2.1$m^3$ of slurry type swine waste from the slurry pit into the acidogenic digester, which corresponds to hydraulic retention time of 4 days for the acidogenic digester and of 11 days for the methanogenic digester. Digester temperature were well maintained as the set temperature of 37$^{\circ}C$ in the methanogenic digester, while the temperature in the acidogenic digester showed around 34$^{\circ}C$. pH also showed a steady-state results of 7.3 in the acidogenic digester and of 7.6 in the methanogenic digester during the operation period. Average biogas production rate was 0.66$m^3$/$m^3$ digester volume. Reduction rate of total solid and volatile solid were 42.8% and 5.8%, respectively. Total nitrogen and ammonia nitrogen were not reduced during the anaerobic fermentation, however, most of VFAs seemed to be converted to the biogas,. These fermentation performance data may suggest that he newly developed a two-phase anaerobic digester for the swine waste treatment worked so successfully.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.45-54
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• 1994

Cooking characteristics of ninety five non-glutinous and twenty six glutinous varieties were checked for understanding the varietal variation and interrelationship between the cooking and physicochemical properties of rice grain. The greatest variation in non-glutinous and glutinous rice varieties was observed in iodine blue value and the next large variation was recognized in amount of soluble solid in cooking water. Average values of volume expansion rate, iodine blue value and amounts of soluble solid in cooking water were different among domestic-bred japonica, Korean local and foreign rice varieties. Korean-bred japonica rice cultivars can be classified into several groups having same cooking quality such as <Jangan.·Seoan>, <Jinmi·Ilpum· Daeseong>, <Seohae·Namwon·Yeongduk>, <Chucheong·Bongkwang>, <Odae·Keumo> and <Hwacheong·Donghae·Palgong> by the distribution on the plane of 1st and 2nd principal components contracted from four cooking characteristics. Glutinous rice cultivars can be grouped into several different cooking quality types such as <Nonglimna 1·Suwon 357·Jodo·Inbujinado>, <Sangnambatbyeo·Jeokdo>, <Mujudo·Daigol-mochi>, <Daegoldo·Jindo>, <Jinbuchal·Colored Daegoldo>, <Shinseonchal·Hung-Tsan> and <Agudo·Irakdo> by the same analysis. Positive correlation was found between volume expansion rate and water absorption rate at 21℃. Iodine blue value was correlated negatively with amounts of soluble solid, and positively with amylose content in non-glutinous rices. In glutinous rices volume expansion rate showed positive relationship with iodine blue value, amounts of soluble solid and gel consistency. Iodine blue value was also positively correlated with alkali digestion value in glutinous rice.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.608-619
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• 1998

The small and the large intestine of swine represent the organs that extract nutrients from feedstuffs through digestion and fermentation and that allow their absorption and incorporation into the blood circulation. Special attention is directed towards the small intestine of young pigs since the transition to a solid diet at weaning exerts major impacts on the structural and functional integrity of the small intestine. Dietary factors involved in postweaning changes of gut morphology and biochemistry such as removal of bioactive compounds in sows milk at weaning, anti-nutritional factors in weaner diets, dietary fiber and the role of voluntary feed intake will be elucidated. The microbial function of the large intestine which is carried out by a diverse population of microorganisms is dependent on substrate availability. Short chain fatty acids as main fermentation products contribute to the energy supply of the host but they are also important for the maintenance of the morphological and functional integrity of the epithelium in the colon. As a result of bacterial nitrogen assimilation in the large intestine, nitrogen is shifted from the urinary to the fecal excretion route thus saving metabolic energy to the pig because less ammonia would become available for conversion to urea.

• Environmental Engineering Research
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• v.25 no.2
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• pp.212-221
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• 2020

This work discusses the palm oil mill processing carried out at Jugra Palm Oil Mill Sdn Bhd, situated at Selangor, Malaysia with the capacity of 45-t fresh fruit bunch (FFB)/h. Typically, oil palm residues and palm oil mill effluent (POME) from FFB are generated while processing. Prior to discharge, POME should be treated to remove pollutants in the effluent. As such, the performances of anaerobic and aerobic ponds were assessed in this study to determine temperature, pH, biological oxygen demand (BOD), sludge volume index (SVI), and dissolved oxygen (DO). From the experiments, mesophilic temperature due to better process stability was applied in anaerobic ponds. The pH results displayed a fluctuating trend between lower control limit and upper control limit, and, the pH value increased from one pond to another. The final discharge BOD and SVI appeared to be lower than 100 mg/L and 10 mL/L indicating low degree of pollution and good settling ability for biomass/solid. DO was close to normal, mostly below 2 mg/L. The experimental outcomes revealed the effective treatability of POME in adherence to the standard regulation, which is the priority for environmental sustainability within this industry domain.

• Ocean and Polar Research
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• v.26 no.1
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• pp.102-111
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• 2004

Recirculating aquaculture system (RAS) consists of different treatment compartments that maintain water quality within the ranges commonly recommended for fish cultures. However, common RASs still exert considerable environmental impact since concentrations of organic matter and nutrients in their effluents are high. Compared with the traditional RAS, the model RAS developed here use a sedimentation basin for digestion purposes and then use the released volatile organic matter to stimulate a denitrification process. Different treatment compartments for solids, total ammonia nitrogen, and nitrate removal have been reviewed. This paper provides the basic information on designing different treatment compartments as well as the engineering criteria in closed seawater RAS, consisting of circular tanks for fish cultures; dual drain systems, sedimentation basins and foam fractionators for removal of solids; nitrification biofilters for TAN removal; denitrification biofilters for nitrate removal; and aerators for aeration. The main purpose is to outline a common procedure in designing of closed RAS for marine fish culture with an emphasis on easy management and low expense, as well as reduction of the environmental impact.