- Email: [email protected]
Characteristics of activated sludge process using a multistage tower aeration tank
J. FERMENT. BIOENG.,
Abstracts of the Articles Printed in Hakkokogaku Kaishi V o l . 70, N o . 5 (1992)
Effects of Dissolved Oxygen on Sake Brewing. HIDEO NAGAI,* KYotcm KONDO, HIDEO MISHIMA, and SmoEzo
of Sanitary and Environmental Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060)
TAKEMXmA (Hakutsuru Sake Brewing Co., Ltd., 4-5-5 Sumiyoshiminami-machi, Higashinada-ku, Kobe-shi, Hyogo 658) Hakko-
Hakkokogaku 70: 379-385. 1992. The advantages of a multistage tower activated sludge process which were visualized experimentally could be shown quantitatively by use of the axial dispersion model in conjunction with the kinetics which involved the biosorption and subsequent oxidative biodegradation process of organic substances. The theoretical analysis indicated that partial fluid mixing closer to the plug flow possessed higher treatment ability. Also, the influence caused by the difference in Peclet number grew as the organic loading rate increased. A calculation showed that the upper limit of the volumetric loading rate to maintain good sludge settleability below an SVI of 100 was 2.3 kg CODcr/m 3.d for the complete mixing aeration tank. However, when an aeration tank with a Peclet number over 4 is used, the allowable volumetric loading rate can be increased to 4.0 kg CODcr/m3.d.
kogaku 70: 361-369. 1992. The effects of dissolved oxygen (DO) in sake mash were investigated using a newly developed sensor for measuring DO in the ppb range. The concentration of DO was as high as 2-4 ppm in the early phase of fermentation because of air carried with materials and forced aeration, while it was as low as 0-5 ppb during the main fermentation. To estimate the effects of DO on the fermentation and on the quality of the product, various DO profiles were applied to the sake mash process by means of DO control system of pulse aerating system. Difference in the DO profiles did not affect the fermentation rate, except for a very low DO concentration (under 2 ppb). Analysis of main components of the sake was carried out, which showed that the total acidity, amino acidity, volatile compounds and composition of organic acids were influenced by DO. Acetic acid and succinic acid increased at higher DO, while isoamyt acetate and other volatile esters decreased. From the view point of sake quality, DO should be controlled at 2-5 ppb for several days in the early phase, and at under 2 ppb during the main fermentation.
* Corresponding author. Azo Dye Wastewater Treatment with Immobilized Yeast. TOSI-nTAKA KAKUTA, l* YOSHIYUKI TATENO,t TAKEO Komu2vfl,t KENKICItl KODAMA,2 K/YOSHI YosmzAwA, ~ and IOKUO NoJmo 3
(Department of Fermentation, Tokyo University of Agriculture, Sakuragaoka l-chome, Setagaya-ku, Tokyo 156~; Kodama Brewing Co., Ltd., lidagawa-machi, Akita 018-152; Brewing Society of Japan, Takinogawa 2-chome, Kita-ku, Tokyo 1143) Hakkokogaku
* Corresponding author. Characteristics of Activated Sludge Process Using a Multistage Tower Aeration Tank. TATSUO SHIMIZU,*KENZO KUDO, and YosamAzu Nnsu (Department
70: 387-393. 1992. With the aim of treating effluents from dye works with yeast, a yeast strain, AN723, capable of decolorizing azo dyes was screened from a stock culture in our laboratory, and identified as Candida curvata. The strain was able to decolorize methylene blue and many kinds of azo dyes, such as Chrysoidine, New Coccine, Orange I, Orange II, Amaranth, C.I. Acid Blue 92, C.I. Acid Blue 113, C.I. Acid Red 37, C.I. Direct Blue 168 and C.I. Direct Red 2. Yeast strain AN723 immobilized on granular ceramic maintained a high decolorizing ratio for 90 d for 0.01% chrysoidine solution, and a decolorizing ratio of 65-75% for 30 d for a mixture of dyes.
o f Sanitary and Environmental Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060) Hakkokogaku 70: 371-377. 1992. The objective of this study was to clarify experimentally the advantages, if any, of a vertical multistage tower aeration tank system, particularly with respect to purification efficiency and sludge settleability, in comparison with a complete mixing system. The following conclusions could be drawn by comparing both systems. (i) The experimental results showed that in a multistage tower aeration tank with a large Peclet number, the effluent CODcr concentration and sludge yield can be reduced and activated sludge with good settleability can be produced for any applied CODcr loading rate compared with a complete mixing aeration tank. (ii) The distribution of the CODcr concentration and respiration rate of activated sludge showed that organic substances were rapidly transferred from the liquid phase to activated sludge floe by biosorption in the inlet compartment and that subsequent oxidative biodegradation occurred throughout the other compartment. (iii) The removal of organic substances by the biosorption mechanism followed the first order reaction kinetics. The biosorption rate constant and maximum adsorbed organic substance content of activated sludge were 25 m3/kg MLSS. d and 0.53 kg CODo/kg MLSS, respectively.
* Corresponding author. Optimization and Control in Fed-Batch Cultures. --Monograph-SLITEAKI SBIOYA (Department of Biotechnology, Osaka University, Suita, Osaka 565) Hakkokogaku 70: 395-404. 1992. A method for obtaining maximum production of the bioproduct in fed-batch cultures is explained, and its validity is demonstrated by experimental data. The approach is based on a model which describes the relationship between the specific production rate, p, and specific growth rate,/~. Using a mathematical model, an optimal profile of the specific growth rate could then be obtained easily by the Maximum Principle. Finally, the optimal profile was realized by changing the feed rate of the substrate in a practical fed-batch culture. Practical examples of bioproduction, such as histidine, lysine, and glutathioue, as well as production of an enzyme, showed that the two-stage production process could be realized experimentally, thus demonstrating the validity of the method.
* Corresponding author. A Model for Evaluation of Activated Sludge Process Performance. TATSUO S ~ , * KI~NZOKUDO, and Yosmro~'u NAsu (Department
254
Abstracts of the Articles Printed in Hakkokogaku Kaishi V o l . 70, N o . 5 (1992)
Effects of Dissolved Oxygen on Sake Brewing. HIDEO NAGAI,* KYotcm KONDO, HIDEO MISHIMA, and SmoEzo
of Sanitary and Environmental Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060)
TAKEMXmA (Hakutsuru Sake Brewing Co., Ltd., 4-5-5 Sumiyoshiminami-machi, Higashinada-ku, Kobe-shi, Hyogo 658) Hakko-
Hakkokogaku 70: 379-385. 1992. The advantages of a multistage tower activated sludge process which were visualized experimentally could be shown quantitatively by use of the axial dispersion model in conjunction with the kinetics which involved the biosorption and subsequent oxidative biodegradation process of organic substances. The theoretical analysis indicated that partial fluid mixing closer to the plug flow possessed higher treatment ability. Also, the influence caused by the difference in Peclet number grew as the organic loading rate increased. A calculation showed that the upper limit of the volumetric loading rate to maintain good sludge settleability below an SVI of 100 was 2.3 kg CODcr/m 3.d for the complete mixing aeration tank. However, when an aeration tank with a Peclet number over 4 is used, the allowable volumetric loading rate can be increased to 4.0 kg CODcr/m3.d.
kogaku 70: 361-369. 1992. The effects of dissolved oxygen (DO) in sake mash were investigated using a newly developed sensor for measuring DO in the ppb range. The concentration of DO was as high as 2-4 ppm in the early phase of fermentation because of air carried with materials and forced aeration, while it was as low as 0-5 ppb during the main fermentation. To estimate the effects of DO on the fermentation and on the quality of the product, various DO profiles were applied to the sake mash process by means of DO control system of pulse aerating system. Difference in the DO profiles did not affect the fermentation rate, except for a very low DO concentration (under 2 ppb). Analysis of main components of the sake was carried out, which showed that the total acidity, amino acidity, volatile compounds and composition of organic acids were influenced by DO. Acetic acid and succinic acid increased at higher DO, while isoamyt acetate and other volatile esters decreased. From the view point of sake quality, DO should be controlled at 2-5 ppb for several days in the early phase, and at under 2 ppb during the main fermentation.
* Corresponding author. Azo Dye Wastewater Treatment with Immobilized Yeast. TOSI-nTAKA KAKUTA, l* YOSHIYUKI TATENO,t TAKEO Komu2vfl,t KENKICItl KODAMA,2 K/YOSHI YosmzAwA, ~ and IOKUO NoJmo 3
(Department of Fermentation, Tokyo University of Agriculture, Sakuragaoka l-chome, Setagaya-ku, Tokyo 156~; Kodama Brewing Co., Ltd., lidagawa-machi, Akita 018-152; Brewing Society of Japan, Takinogawa 2-chome, Kita-ku, Tokyo 1143) Hakkokogaku
* Corresponding author. Characteristics of Activated Sludge Process Using a Multistage Tower Aeration Tank. TATSUO SHIMIZU,*KENZO KUDO, and YosamAzu Nnsu (Department
70: 387-393. 1992. With the aim of treating effluents from dye works with yeast, a yeast strain, AN723, capable of decolorizing azo dyes was screened from a stock culture in our laboratory, and identified as Candida curvata. The strain was able to decolorize methylene blue and many kinds of azo dyes, such as Chrysoidine, New Coccine, Orange I, Orange II, Amaranth, C.I. Acid Blue 92, C.I. Acid Blue 113, C.I. Acid Red 37, C.I. Direct Blue 168 and C.I. Direct Red 2. Yeast strain AN723 immobilized on granular ceramic maintained a high decolorizing ratio for 90 d for 0.01% chrysoidine solution, and a decolorizing ratio of 65-75% for 30 d for a mixture of dyes.
o f Sanitary and Environmental Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo 060) Hakkokogaku 70: 371-377. 1992. The objective of this study was to clarify experimentally the advantages, if any, of a vertical multistage tower aeration tank system, particularly with respect to purification efficiency and sludge settleability, in comparison with a complete mixing system. The following conclusions could be drawn by comparing both systems. (i) The experimental results showed that in a multistage tower aeration tank with a large Peclet number, the effluent CODcr concentration and sludge yield can be reduced and activated sludge with good settleability can be produced for any applied CODcr loading rate compared with a complete mixing aeration tank. (ii) The distribution of the CODcr concentration and respiration rate of activated sludge showed that organic substances were rapidly transferred from the liquid phase to activated sludge floe by biosorption in the inlet compartment and that subsequent oxidative biodegradation occurred throughout the other compartment. (iii) The removal of organic substances by the biosorption mechanism followed the first order reaction kinetics. The biosorption rate constant and maximum adsorbed organic substance content of activated sludge were 25 m3/kg MLSS. d and 0.53 kg CODo/kg MLSS, respectively.
* Corresponding author. Optimization and Control in Fed-Batch Cultures. --Monograph-SLITEAKI SBIOYA (Department of Biotechnology, Osaka University, Suita, Osaka 565) Hakkokogaku 70: 395-404. 1992. A method for obtaining maximum production of the bioproduct in fed-batch cultures is explained, and its validity is demonstrated by experimental data. The approach is based on a model which describes the relationship between the specific production rate, p, and specific growth rate,/~. Using a mathematical model, an optimal profile of the specific growth rate could then be obtained easily by the Maximum Principle. Finally, the optimal profile was realized by changing the feed rate of the substrate in a practical fed-batch culture. Practical examples of bioproduction, such as histidine, lysine, and glutathioue, as well as production of an enzyme, showed that the two-stage production process could be realized experimentally, thus demonstrating the validity of the method.
* Corresponding author. A Model for Evaluation of Activated Sludge Process Performance. TATSUO S ~ , * KI~NZOKUDO, and Yosmro~'u NAsu (Department
254