All issues
Volume 48 (2017)
- Issue 4 Pages 197-
- Issue 3 Pages 123-
- Issue 2 Pages 67-
- Issue 1 Pages 2-
Volume 48, Issue 1
Vol. 48, No. 1 (Ser. No. 152)
Displaying 1-5 of 5 articles from this issue
- |<
- <
- 1
- >
- >|
-
[in Japanese], [in Japanese], [in Japanese]2017 Volume 48 Issue 1 Pages 2-8
Published: 2017
Released on J-STAGE: September 07, 2023
JOURNAL OPEN ACCESSDownload PDF (1489K) -
[in Japanese]2017 Volume 48 Issue 1 Pages 9-23
Published: 2017
Released on J-STAGE: September 07, 2023
JOURNAL OPEN ACCESSDownload PDF (4483K) -
Shiho ASAKAWA, Atsuo IKEGUCHI, Takahiro YAMASHITA, Hiroshi YOKOYAMA2017 Volume 48 Issue 1 Pages 24-30
Published: 2017
Released on J-STAGE: September 07, 2023
JOURNAL OPEN ACCESSA microbial fuel cell (MFC) is a device that simultaneously generates electricity and decomposes organic matters in wastewater. Commonly-used cathodes in MFCs are made of expensive materials, and are low in mechanical strength. Scale-up of MFC reactors has been hindered by the low physical strength of the cathode. Conventional cathodes are composed of carbon cloth containing Pt catalyst, fused with or without the proton exchange membrane, Nafi on. In the present study, we report a new physically-strong cathode, made of cost-effective alternative materials, Selemion HSF membrane, stainless-steel mesh, and polydimethylsiloxane. Single-chambered MFCs (125 mL) equipped with the new cathode or conventional Nafi on cathode were operated using an artifi cial wastewater containing peptone and beef extract. Coulombic effi ciency of the MFCs with the new cathode was 23.9–27.7 %, which was signifi cantly higher than that of the MFCs with the conventional cathode (5.9–11.1 %). The power density was similar levels between the MFCs with the new cathode (114.4–125.0 W/m2) and the conventional cathode (97.6–119.1 W/m2). The new cathodes displayed similar current productivities as compared to the conventional cathodes in a polarization test using a potentiostatic device. The tensile strength of the new cathode was 9.3-fold higher than that of the conventional cathode, as measured with a tension meter. These results show that the new cathode is a cost-effective and mechanically-strong electrode with the performance of current production nearly equal to that of the conventional cathode. The new cathode is high in physical strength, and therefore, could tolerate the inner pressure of scaled-up MFC reactors in practical applications.View full abstractDownload PDF (1366K) -
Mami OHWADA, Shiho ASAKAWA, Atsuo IKEGUCHI, Takahiro YAMASHITA, Hirosh ...2017 Volume 48 Issue 1 Pages 31-37
Published: 2017
Released on J-STAGE: September 07, 2023
JOURNAL OPEN ACCESSMicrobial fuel cells (MFCs) are prospective bioreactors that simultaneously generate electricity and decompose organic matters in wastewater. In single-chambered MFCs with a proton–exchange membrane, the cathode is fused to the membrane by hot pressing, forming a membrane-electrode assembly (MEA). Nafi on membrane is commonly used in the MFCs. However, the membrane is expensive, and thus development of MEAs made of low-cost materials is required. Selemion HSF membrane is an inexpensive alternative for nafi on. Selemion HSF has been applied to twochambered MFCs but not to single-chambered MFCs, since a preparation method of the MEA containing Selemion HSF has not been analyzed. In the present study, the hot-pressing conditions for the fusion of the Selemion membrane to a carbon-cloth cathode were analyzed, and the electrochemical performances of the Selemion-HSF MEA were compared to the conventional (Nafi on) MEA. We revealed that the condition in the hot-pressing to prepare the Selemion-HSF MEA was a pressure of 780 kPa, temperature of 50 oC, and pressing time of 40 min. MFCs equipped with the Selemion-HSF MEA displayed the maximum power density of 230 mW/m2 that was 1.9-fold higher than that of MFCs equipped with the Nafi on MEA. The internal resistance of the MFCs with Selemion HSF (106 to 112 Ω) was approximately half of that of the MFCs with Nafi on. The current production of Selemion-HSF MEAs was 1.8-fold higher than that of Nafi on MEAs in a potentiostatic test. The removal percentage of chemical oxygen demand in the MFCs with Selemion-HSF MEA (84 to 87 %) was also higher than that of the MFCs with Nafi on MEA (61 to 80 %). These results demonstrated that Selemion-HSF MEA is comparable to Nafi on MEA in current production and removal of organic matters in the MFCs.View full abstractDownload PDF (1154K) -
Yoichiro KOJIMA, Koichi MUROI, Keiichi NAGATAKI, Masatsugu OKAMOTO, Ki ...2017 Volume 48 Issue 1 Pages 38-44
Published: 2017
Released on J-STAGE: September 07, 2023
JOURNAL OPEN ACCESSThis paper describes a treatment method for waste milk from dairy farming, using a coagulation reaction by acid addition to milk warmed to 45 °C. In this study, a pilot-scale treatment unit was developed and used to investigate treatment performance (experiment 1), and the composting characteristics of mixtures of cowshed litter and separated coagulum were verifi ed (experiment 2). In experiment 1, 16.8 % of raw milk was separated as a coagulum. More than 95 % of the coagulum was recovered by 5-mm sieve. More than 50 % of chemical or biochemical oxygen demand of raw milk were removed from the supernatant by the coagulation treatment, due to the removal of more than 70 % of the milk fat and protein. In experiment 2, the temperature of composting material remained high, and the organic matter decomposed more with addition of milk coagulum than without it. Mixing milk coagulum in composting material had no negative effect on the composting process, and composting satisfactorily degraded the milk coagulum.View full abstractDownload PDF (1076K)
- |<
- <
- 1
- >
- >|