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Sugiyama M.,Chiba University | Ikeda K.,Chiba University | Umeno D.,Chiba University | Saito K.,Chiba University | And 2 more authors.
Journal of Chemical Engineering of Japan | Year: 2013

Dimethylaminoethyl methacrylate (DMAEMA was graft-polymerized at a density of 1.7 mmol/g onto a 6-nylon fiberby radiation-induced graft polymerization. Urease was bound to the resultant anion-exchange fiberby electrostatic interaction. After crosslinking with transglutaminase, 80% of the bound urease was immobilized at a density of 41 mg/g of the fiber. Urea in water was quantitatively hydrolyzed during the permeation of a 0.20 mg/L urea solution through the urease-immobilized-fiber-packed bed with a diameter of 5.5 mm and a height of 27 mm in the residence time range of 12-180 s. The activity of immobilized urease did not deteriorate after repeated use of the fiber, i.e., during reaction and storage. © 2013 The Society of Chemical Engineers, Japan.

Ikeda K.,Chiba University | Umeno D.,Chiba University | Saito K.,Chiba University | Koide F.,Nippon Rensui Co. | And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2011

By using electron-beam-induced graft polymerization, an epoxy-group-containing monomer, glycidyl methacrylate (GMA), was appended onto a 6-nylon fiber; subsequently, N-methylglucamine as a chelate-forming moiety was added to the epoxy group. The chelating group density of the resultant chelating fiber was 2.0 mmol/g, which was 74% of that of a commercially available chelating bead containing the same functionality. A 150 mg-B/L boron solution was forced to flow through the chelating-fiber-packed bed at the space velocity range from 10 to 100 h-1, defined by dividing flow rate by bed volume (0.3 mL). At a space velocity of 20 h-1, the dynamic binding capacity of the chelating-fiber-packed bed was 2.5-fold higher than that of the chelating-bead-packed bed. © 2011 American Chemical Society.

Yamashita T.,National Institute of Livestock and Grassland ScienceIbaraki | Yamamoto-Ikemoto R.,Kanazawa UniversityIshikawa | Sakurai E.,Spring Field LtdIshikawa | Aikawa K.,Kanazawa UniversityIshikawa | Kaneko E.,Nippon Rensui Co.
Sustainable Environment Research | Year: 2010

An anaerobic-anoxic-oxic biological filter reactor was applied to sewage treatment for nutrient removal. Average concentrations of total organic carbon (TOC), suspended solids (SS), total N (TN) and total P (TP) in the influent of the reactor were 46, 46, 37 and 5.8 mg L-1, respectively. Effluent TOC was consistently about 5 mg L-1 and the average concentration of SS was 11 mg L-1. Although the average removal efficiency of TN was 52%, it increased to over 70% when most of ammonium was nitrified to nitrate in the oxic bed under the conditions of hydraulic residence time > 1.5 h and dissolved oxygen > 2 mg L-1. Average removal efficiency of TP was 50%. In the anaerobic bed, 80% of sulfate decreased and 59% of dissolved organic carbon (DOC) was removed. The decrease in DOC tended to correlate with a decrease in sulfate. Although the excess sludge produced in the oxic bed was put into the anaerobic bed, the effluent water quality did not become poor. These results suggested that sulfate-reducing prokaryotes played an important role in organic removal and excess sludge reduction in the anaerobic bed. Subsequently, the microbial community of sulfate-reducing prokaryotes in the anaerobic biofilm was examined by the dissimilatory (bi)sulfite reductase gene-targeting nested PCR-DGGE, and the sequences of ten excised bands from DGGE profiles were determined. © 2010, Chinese Institute of Environmental Engineering. All rights reserved.

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