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Volume 41 (2005)
- Issue 4 Pages 159-
- Issue 3 Pages 113-
- Issue 2 Pages 51-
- Issue 1 Pages 1-
Volume 41, Issue 1
Displaying 1-5 of 5 articles from this issue
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ORIGINALS
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Nitrogen Removal from Dye-Industry Wastewater Using a Novel Nonwoven Support-Surrounded Cell ReactorYOSHINOBU YAMAGIWA, WATARU TAKATSUJI, MOTONOBU NAKAOKA, KENJI FURUKAWA2005 Volume 41 Issue 1 Pages 1-7
Published: 2005
Released on J-STAGE: July 07, 2006
JOURNAL FREE ACCESSDye-industry wastewaters contain high levels of organic nitrogen derived from urea. Thus, effective nitrogen removal methods are needed to meet regulatory standards prior to discharging effluent to receiving water bodies. A novel nonwoven support-surrounded cell (SSC) process was developed and continuous treatment experiments were conducted using a bench-scale SSC reactor. Nitrification efficiencies of the SSC treatment process using activated-sludge seeds from domestic and dye-industry wastewater treatment plants were about 22% and 55%, respectively. These efficiencies, though, could not be maintained more than 20 days. By adding NaHCO3 as an inorganic carbon source, nitrification efficiency could be improved to about 62%, but this could not be maintained more than 25days. In additions, dye chemicals and dye-reduction inhibitors added to the influent wastewater had no effect on nitrification and denitrification reactions. High nitrification efficiencies, however, could be maintained for more than 100 days by supplementing phosphorus to the influent wastewater. Using a synthetic dye wastewater supplemented with inorganic carbon, phosphoric acid, and organic carbon at 1.5 times of total-nitrogen, a total-nitrogen removal efficiency of about 56% was obtained.View full abstractDownload PDF (1528K) -
HIROSHI YAMAZAKI, KAZUHIRO HOSHINO, KIYOSHI HASEGAWA, KAI-QIN XU, YOSH ...2005 Volume 41 Issue 1 Pages 9-15
Published: 2005
Released on J-STAGE: July 07, 2006
JOURNAL FREE ACCESSIn ammonia-oxidizing autotrophic bacteria, coenzymes such as NAD+ and NADP+ act as intermediates linking the electron transfer system in the cell membrane and the CO2- fixing Calvin cycle in the cytoplasm. The influence of these physiologically active substances on the growth of ammonia-oxidizing bacteria (AOB) and their nitrification ability was examined by adding a trace amount of NAD+ or NADP+ into a wastewater treatment system. In pure cultures of Nitrosomonas europaea IFO 14298, when NAD+ or NADP+ were added in the wastewater oxidation of ammonia increased comparing a control culture, and the strain grew 1.6-1.9 times faster than that of the control. Similarly, in activated sludge, both the rate of formation of NOx-N and the growth of AOB increased when NAD+ or NADP+ were added. Furthermore, ammonia monooxygenase-coding mRNA (amoA-mRNA), an estimate of ammonia oxidation activity, increased over time only in the presence of these physiologically active substances. When activated sludge previously exposed to NAD+ or NADP+ was used for new sewage, these desirable effects continued. The types of AOB affected by adding NAD+ or NADP+ were characterized using TaqI -based T-RFLP (terminal restriction fragment length polymorphism) of amoA-mRNA. The results indicated that AOB with fragment sizes of 219 bp and 491 bp were the active species in the NAD+ and NADP+-containing systems, respectively. These results suggest that the simple technique of adding a trace amount of NAD+ or NADP+ into activated sludge can result in increased nitrification and the selective growth of a particular AOB.View full abstractDownload PDF (2721K) -
HIROSHI YAMAZAKI, KAZUHIRO HOSHINO, KIYOSHI HASEGAWA, RIE SUZUKI, YOSH ...2005 Volume 41 Issue 1 Pages 17-24
Published: 2005
Released on J-STAGE: July 07, 2006
JOURNAL FREE ACCESSThe influence of adjuster for BOD concentration on the treatment capacity, the sludge deposit, and the microbial community in the domestic wastewater treatment process was investigated. When methanol or sodium acetate was used as adjuster, the water quality of influent could be adjusted to standard water quality with less than 10% of error. In the continuous anaerobic-aerobic process, it was found that the BOD removal rate in methanol addition system is slightly high compared with that in sodium acetate. However, DGGE analysis targeting eubacteria revealed that microbial community in each tank was quite similar in both addition systems. Furthermore, conversion rate of BOD to sludge was almost same in each other. To clarify the occupation ratio of each phylum or class, quantitative FISH was carried out. Although the class β-proteobacteria was most dominant in both systems, the second dominant class was different. In the methanol addition system, α-Proteobactria is the second dominant class, whereas γ-proteobacteria and High G+C Gram-positive Bacteria were the secondary dominant classes in the sodium acetate addition system. However, a significant difference in both systems was not observed for the protozoan population. These results demonstrate that there is not so much of a difference between methanol and sodium acetate as a BOD adjuster.View full abstractDownload PDF (1360K) -
TRUONG QUY TUNG, NAOYUKI MIYATA, KEISUKE IWAHORI2005 Volume 41 Issue 1 Pages 25-39
Published: 2005
Released on J-STAGE: July 07, 2006
JOURNAL FREE ACCESSThe treatment of cassava starch processing wastewater was carried out in the airlift reactor (ALR) with an internal-loop by using Aspergillus oryzae pellets. This study demonstrated that the effective organic matter removal and biomass production were similar to those obtained in the shake flask culture. In ALR, the spore inoculation produced small and fluffy pellets because of the influence of the high concentration of suspended solids in the wastewater. The use of the precultured hyphae inoculation resulted in the compact and lager pellets in ALR, which were convenient for the mass transfer in ALR and the biomass separation. The ageing, aeration rate and nutrient composition strongly affected the fragmentation of mycelia. The supplementation of ammonium sulfate as nitrogen source improved the treatment efficiencies, biomass yield and protein content significantly. With the concentrations of (NH4)2SO4 in the range of 0.50-0.75 g l-1, TOC, COD and starch removal, biomass yield and crude biomass protein content were 76%, 84%, 93%, 0.57 g (g-COD)-1, and 34%, respectively, after 4 days at the initial COD loading of 8,700-8,900 mg l-1. In particular, the fragmentation was strongly diminished during the cultivation in the medium with plentiful nitrogen source. In addition, evaluating the volumetric oxygen transfer coefficient was considered to provide effectively the determination of the initial COD loading limitation suitable for batch process in ALR. The operation of ALR was highly efficient at the initial COD concentrations less than 10,000 mg l-1, corresponding to the initial starch concentrations less than 12,000 mg l-1 when the wastewater was supplemented with the reasonable amount of ammonium nitrogen.View full abstractDownload PDF (6077K)
TECHNICAL NOTE
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FENFGLIN YANG, ZHIJUN LIU, YINGYUN CHENG, HIROTAKA KAWASIMA, KENJI FUR ...2005 Volume 41 Issue 1 Pages 41-50
Published: 2005
Released on J-STAGE: July 07, 2006
JOURNAL FREE ACCESSWith the rapid economical development, the problems associated to water resources became more and more serious in the north parts of China. Water pollution problems are now severe especially in the north parts of China lacking of water resources. This paper introduces the distribution characteristics of water resources and explains the water pollution problems in the north part of China. Combining with the solution for the water environmental problems in Dalian city, some strategies and improving measures, which are now running, were introduced.View full abstractDownload PDF (1896K)
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