• Journal of the Korea Organic Resources Recycling Association
• /
• v.11 no.1
• /
• pp.149-153
• /
• 2003

This study was conducted to survey the utilization possibility of composting system of small scale static pile with animal manure produced from cattle shed and the effect of addition of microorganism on the maturity of compost. Microorganisms added in composting substrate were bacteria+lactobacillus(BL)+photo.(BLP). The composting practiced was a windrow system without aeration equipment and turning was practiced periodically. The water content of substrate mixed with cow manure, rice husk, and sawdust was about 60%. The temperature during the composting process was increased at over $60^{\circ}C$ within 3 days after composting starting. Increase of temperature at the early stage of composting was fasten in BLP and BL than Control. Because the pH of the raw material was high, the changes of pH during composting was little and stabilized in weak alkaline condition. EC value was high for accumulation of manure and urine excreted continuously by animal and the changes of those during composting occurred in 5~10% increase. Reduction rates of C/N ratio were the largest as the 22.7% in BLP and 19.2and 17.5% in BL and Control respectively. In the evaluation of phytotoxicity, there was stabilized within the short time in BLP and not the difference between BL and Control. Treatment of animal manure produced from small scale cattle shed was possible by using the small scale static pile composting system with reasonable water content and turning and the addition of microorganism in composting substrate was effected on the temperature increase at the early stage of composting and reduction of plant toxicity compounds but little on the maturity of compost.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.42 no.4
• /
• pp.493-499
• /
• 2022

The standards pertaining to the quality of discharged water in sewage treatment plants are strengthening, and accordingly, facilities in sewage treatment plants are being upgraded. In addition, the discharge water quality of sewage treatment plants must be maintained at a high level, and efficient sewage treatment plant operations have thus emerged as a very important issue. For the efficient operation of sewage treatment plants, this study applied a basic blowing amount calculation method based on sewage facilities to evaluate the required oxygen amount and blowing amount according to inflow water quality by logicizing various influencing factors. As a result of calculating the amount of air blown by applying actual April water quality data from sewage treatment plant A to the blower demand calculation developed through this study, it was found that the average amount of air blown was reduced by about 12%. When the blower demand calculation developed here is applied to an actual sewage treatment plant, the amount of air blown can be controlled based on the inflow water quality. This can facilitate the realization of an autonomous control of sewage treatment plants, in contrast to the existing sewage treatment operation method that relies on operational experience of operator. In addition, it is expected that efficient sewage treatment plants can be operated by reducing blowing amounts and power costs, which will contribute to both energy and carbon savings.

• Journal of Energy Engineering
• /
• v.23 no.2
• /
• pp.49-56
• /
• 2014

It is important to keep stable effluent water quality and minimize operation cost in biological wastewater treatment plant. However, the optimal operation is difficult because of the change of influent flow rate and concentrations, the nonlinear dynamics of microbiology growth rate and other environmental factors. Therefore, many wastewater treatment plants are operated for much more redundant oxygen or chemical dosing than the necessary. In this study, the optimal control scheme for dissolved oxygen (DO) is suggested to prevent over-aeration and the reduction of the electric cost in plant operation while maintaining the dissolved oxygen (DO) concentration for the metabolism of microorganisms in oxic reactor. For optimal control, The oxygen uptake rate (OUR) is realtime measured for the identification of influent characterization and the identification of microorganisms' oxygen requirement in oxic reactor. Optimal DO seT-Point needed for the microorganism is suggested based on real time measurement of oxygen uptake of microorganism and the control of air blower. Therefore, both stable effluent quality and minimization of electric cost are satisfied with a suggested optimal setpoint decision system by providing the necessary oxygen supply requirement to the microorganisms coping with the variations of influent loading.

• Korean Chemical Engineering Research
• /
• v.52 no.5
• /
• pp.581-586
• /
• 2014

Main objects for wastewater treatment operation are to maintain effluent water quality and minimize operation cost. However, the optimal operation is difficult because of the change of influent flow rate and concentrations, the nonlinear dynamics of microbiology growth rate and other environmental factors. Therefore, many wastewater treatment plants are operated for much more redundant oxygen or chemical dosing than the necessary. In this study, the optimal control scheme for dissolved oxygen (DO) is suggested to prevent over-aeration and the reduction of the electric cost in plant operation while maintaining the dissolved oxygen (DO) concentration for the metabolism of microorganisms in oxic reactor. The oxygen uptake rate (OUR) is real-time measured for the identification of influent characterization and the identification of microorganisms' oxygen requirement in oxic reactor. Optimal DO set-point needed for the micro-organism is suggested based on real-time measurement of oxygen uptake of micro-organism and the control of air blower. Therefore, both stable effluent quality and minimization of electric cost are satisfied with a suggested optimal set-point decision system by providing the necessary oxygen supply requirement to the micro-organisms coping with the variations of influent loading.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
• /
• 2001.06a
• /
• pp.3104-3104
• /
• 2001

The research described here was undertaken with the aim of monitoring, optimizing and ultimately controlling the production of heterofermentative microbes used as starters in the salami industry. The use of starter cultures in the fermented meats industry is a well-established technique used to shorten and standardize the ripening process, and to improve and control the organoleptic quality of the final product. Starter cultures are obtained by the submerged cultivation of suitable microorganisms in stirred, and sometimes aerated, fermenters where monitoring of key physiological parameters such as the concentration of biomass, substrates and metabolites suffers from the general lack of real-time measurement techniques applicable to aseptic processes. In this respect, the results of the present work are relevant to all submerged fermentation processes. Previous work on the application of on-line NIR spectroscopy to the lactic acid fermentation (Dosi et al. - Monreal NIR1995) had successfully used a system based on a measuring cell included in a circulation loop external to the fermenter. The fluid handling and sterility problems inherent in an external circulation system prompted us to explore the use of an in-line system where the NIR probe is immersed in the culture and is thus exposed to the hydrodynamic conditions of the stirred and aerated fluid. Aeration was expected to be a potential source of problems in view of the possible interference of air bubbles with the measurement device. The experimental set-up was based on an in-situ sterilizable NIR probe connected to the instrument by means of an optical fiber bundle. Preliminary work was carried out to identify and control potential interferences with the measurement, in particular the varying hydrodynamic conditions prevailing at the probe tip. We were successful in defining the operating conditions of the fermenter and the geometrical parameters of the probe (flow path, positioning, etc.) were the NIR readings were reliable and reproducible. The system thus defined was then used to construct and validate calibration curves for tile concentration of biomass, carbon source and major metabolites of two different microorganisms used as salami starters. Real-time measurement of such parameters coupled with the direct interfacing of the NIR instrument with the PC-based measurement and control system of the fermenter enabled the development of automated strategies for the interactive optimization of the starter production process.

• Journal of Environmental Science International
• /
• v.21 no.8
• /
• pp.931-938
• /
• 2012

The effects were investigated of different lengths and numbers of slitwalls in drainless containers on growth and change in soil moisture volumes on the growth of Diffenbachia amoena 'Marianne' and Begonia rex. Drainless containers filled with amended soil, with square shape ($240mm{\times}240mm$) were used, as well as three different sets of slitwalls (2, 4 or 8, respectively) in addition to non-slitwall containers. Two indoor foliage plants were grown in slitwall containers in randomized blocks with 3 replications in greenhouse conditions, from March to September, 2009. Soil moisture volumes per container were measured by weighing containers every 2 hours during the day. The change in soil moisture volumes showed considerable differences among slitwalls tested in comparison to control containers before and after twice-weekly irrigation. Particularly, the differences in the S2 (195mm, slitwall 2) containers were significantly greater than other containers tested. For Diffenbachia amoena 'Marianne', plant height, length of leaf, dry weight and fresh weight were higher with S2 containers than with those grown in other containers tested. The Begonia rex with the best quality in terms of plant height, length of leaf and width of leaf was grown in S8 (360mm, slitwall 8) containers. Particularly, statistical analysis has indicated that shoot fresh weights of Begonia rex grown in S8 were 3-fold higher than those grown in CS8 containers. The different results obtained within the two species led us to hypothesize a species-specific influence on indoor foliage plant performance. However, plants of both species grown in slitwall containers showed good results compared with plants grown in non-slitwall containers.

• Clean Technology
• /
• v.7 no.1
• /
• pp.35-42
• /
• 2001

This study was performed to evaluate the effect of zeolite addition on biofloc in aictvated sludge process. Two units were compared each other, in which one was operated as control unit (CU) and the other was managed by adding zeolite into aeration basin to sustain 4,000 mg/l (ZU). It was observed that flocs of both units were enduringly increased in medium size by extending SRT (Solid Retention Time), although their effect size of ZU was smaller than theirs of CU. Zeolite application excessively improved sludge settling property and ZU presented sludge settling velocity of 3.4 to 11 m/h regardless of SRT variation. The sludge volume index (SVI) was in the range of 50 and 108 ml/g. Conversely, the sludge settling velocity of CU seriously depended on SRT increase, and sludge sedimentation was not achieved at a 40 days of SRT due to Sphaerotilus appeared predominantly in reactor.

• 한국균학회소식:학술대회논문집
• /
• 2014.05a
• /
• pp.21-21
• /
• 2014

A edible mushroom, Hypsizygus marmoreus is commercially cultivated in Northeast Asia. Japan's annual production is 110,000ton or more. Since 2002, cultivation is expanded in Korea. To investigate the morphological, cultural and microscopic characteristics of Hypsizygus marmoreus, 109 isolates were collected from Korea and other countries. Clamp connection, chlamydospore and arthrospore were present in all tested isolates of H. marmoreus except HYM-002 and HYM-004. Also pilealtrama, gilltrama, basidia, basidiospore and cystidia of fruiting body were no difference among the isolates in the present investigation. Morphological characteristics of fruiting body was that color of pileus was brown and white, irregular as marble, the average size 12~22mm and stipes was $46{\sim}91{\times}6{\sim}10mm$. Isolates HYM-031, HYM-047 and HYM-109 formed grayish-brown pileus with a faint pattern. Molecular analysis with RAPD and ITS rDNA sequence analysis were also performed to check the genetic relationships among H. marmoreus isolates. Based on the RAPD analysis using the URP-PCR, all isolates of H. marmoreus were clustered into large 3 groups but more than 90% showed high similarity. In addition, morphological and geographical differences have been classified as an independent cluster. The brown and white strains enclosed in same cluster. So genetically no significance difference was observed between these two strains. ITS gene sequences of 16 selected isolates which were 640 bp long, were aligned and compared. The similarity in ITS sequence was 94.8 to 99.1% among tested isolates and the H. marmoreus isolates in GeneBank. In conclusion the tested isolates were H. marmoreus. Morphological and molecular observations proved that all tested isolates were belonging to H. marmoreus. For the stable artificial cultivation, composition of optimum media, mature period and light condition were established. Optimal formula of artificial cultivation medium was Douglas sawdust: corn cob: soybean meal: wheat bran = 40:30:15:15. In addition, 7% rice bran and 3% yellow sucrose was the most effective composition for spawn's liquid medium. For the maturation of the isolates was favorable for growing for 20 to 30 days at $25^{\circ}C$ and the LED lights in mixture of white and blue was good for growth period. For effective growth, the temperature, humidity and aeration control in every step was important.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.298-300
• /
• 2001

Haematococcus pluvialis was cultured autotrophically and mixotrophically for astaxanthin production in bubble column photobioreactors with $CO_2$ and/or acetate supplements. Four different schemes were tested using 5% $CO_2$ balanced with 95% $N_2$ at the aeration rate of 0.1 vvm and supplementation of acetate (l g/L) to the basal medium, MBBM. Average specific growth rates based on cell total volume of each case were 0.138 $day^{-1}$ in control (without $CO_2$ and acetate supplements), 0.125 $day^{-1}$ with only acetate supplementation, 0.315 $day^{-1}$ with only $CO_2$ supplement, 0.304 $day^{-1}$with both $CO_2$ and acetate. The growth rate under $CO_2$ supply was much higher than that without $CO_2$ supply. DCO and DO seemed to be a possible limitation factor. Another interesting observation was the growth rate under $CO_2$ supplement (without acetate) was higher than that under both $CO_2$ and acetate supply. This result is the opposite of the previously reported works. From the result, the existence of acetate may suppress the dark reaction of $CO_2$ fixation or photosynthesis. Conclusively, the growth of H. pluvialis under photoautotrophic condition found to be higher than that under mixotrophic condition.

• Journal of Korean Society on Water Environment
• /
• v.26 no.5
• /
• pp.871-879
• /
• 2010

To figure out the removal efficiency of indicator and pathogenic bacteria by unit processes of a sewage treatment plant using activated sludge process, analyses were done for incoming sewage, influent and effluent of primary clarifier, aeration tank, secondary clarifier and final discharge conduit of the plant. A matrix of bacterial items (average of bacterial reduction [log/ml], p value of paired t-test, number of decreased cases of twenty analyses, removal percentage only for decreased cases) between incoming sewage and final effluent of the plant were heterotrophic plate counts (1.54, 0.000, 20, 95.01), total coliforms (1.38, 0.000, 19, 83.94), fecal coliforms (0.90, 0.000, 20, 94.84), fecal streptococci (0.90, 0.000, 20, 98.08), presumptive Salmonella (0.23, 0.561, 7, 99.09), and presumptive Shigella (1.02, 0.002, 15, 92.98). Total coliforms, fecal coliforms, heterotrophic plate counts, and fecal streptococci showed highest decrease through secondary clarifier about 1-log (p<0.001) between 88% and 96%, and primary clarifier represented the significant (p<0.05) decrease. However, final effluent through discharge conduit showed higher total coliforms and fecal streptococci than effluent of secondary clarifier (p<0.05). In addition, final effluent once violated the water quality standard while effluent of secondary clarifier satisfied the standard. Hence some control measures including elimination of deposits in discharge conduit or disinfection of final effluent are necessary.