Archive - Abstract

Vol.52 No.1 (March, 2021)

  • Research Paper (Japanese)
  • Investigation of Influence Factors for Decolorization of Brown Pigments in Food Biomass by Electrochemical Oxidation
  • Gen Yoshida, Zhengxuejiu Li, Ikko Ihara
  • In food manufacturing, large quantities of food biomass, including dark brown wastewater, are emitted. When reusing such food biomass, it is necessary to remove coloring components. In this study, we examined the decolorization by electrochemical oxidation. The effects of current intensity, sodium chloride concentration and initial chromaticity on decolorization performance and energy consumption were investigated for treatment of caramel and melanoidin as coloring components. As the current intensity increased, the processing speed increased and the decolorization performance improved. On the other hand, the energy consumption increased under the condition where the current intensity was large. As the concentration of sodium chloride increased, the decolorization performance improved and the energy consumption decreased. It was suggested that the decolorization process that can reduce energy consumption can be constructed by controlling the concentration of sodium chloride.

Keywords:electrochemical oxidation, decolorization, food biomass, caramel, melanoidin

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  • Notes (Japanese)
  • Field Survey of Greenhouses Damaged by Typhoon Faxai in 2019
  • Hideki Moriyama, Masahisa Ishii and Ryota Tsuchiya
  • Typhoon Faxai, the Reiwa 1 Boso Peninsula Typhoon, hit Kanto Region in 2019 caused damages more than 36 billion yen on greenhouses in Chiba prefecture. We surveyed multiple side-by-side pipe-framed greenhouses and multi-span steel frame greenhouses damaged by the Typhoon and Typhoon Phanfone to elucidate the effect of layout condition on behaviors of damaged greenhouses and on air flow pattern around greenhouses. The damage causes of greenhouses were positive pressure on windward side wall or side gable, negative pressure and re-attachment flow on roofs of leeward greenhouses, and contraction flow. For the measures against strong wind, it is important that appropriate direction of shelter net, addition of bracing on pipe-framed greenhouse, and maintenance of depth of foundations of steel greenhouse.

Keywords:pipe-framed greenhouse, steel frame greenhouse, positive pressure, negative pressure, re-attachment flow, rooting depth, measures against strong wind, Typhoon Faxai, Typhoon Phanfon

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Vol.52 No.2 (July, 2021)

  • Research Paper (Japanese)
  • Acoustic Radiation for Suppressing Mating Behavior of Whiteflies Using Acoustic Signals
  • Yasuhiko NISHIJIMA, Koichi MIZUTANI, Tadashi EBIHARA , Naoto WAKATSUKI , Kenji KUBOTA , Masahisa ISHI and Hiroyuki UGA
  • Whiteflies are major pests damaging a wide variety of crops. Whiteflies use sound for communication in their courtship process, and their acoustic communication plays an important role in their mating process. From these features, the use of acoustic radiation may disturb their mating behavior. Hence, in this paper, we examined the influence of acoustic radiation on the mating behavior of whiteflies by emitting the acoustic signal of whiteflies artificially. The obtained results suggest that the mating behaviors of whitefly can be suppressed when rms sound pressure of 28 mPa / rms vibration amplitude of 83 nm.

Keywords:Whiteflies, Bemisia tabaci, Mating behavior, Plant protection, Acoustic communication, Acoustic radiation

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  • Research Paper (Japanese)
  • Life Cycle Assessment of Manure Treatment System Utilizing Public Sewerage System at Dairy Farm in The Suburban
  • Eisuke KAWAMURA and Tatsuo HISHINUMA
  • The purpose of this study was to assess environmental impacts from livestock manure and dairy wastewater treatment systems utilizing public sewerage system at dairy farm has 150 dairy cows, using life cycle assessment. The scenario for treating solid waste was composting (Cp) system. The purification (Pf) system and feces-and-urine separate (Se) system was the scenario of using on-site purification facilities. The bedding material (Bp) processing system and the methane fermentation (Mf) system, of the on-site, were the scenarios involving a public sewage system for purifying liquid waste. The amount of manure and wastewater was estimated from 150 head dairy farm with free-stall barn and milking parlor, and lactation ability of dairy cow. The functional unit for evaluating each scenario was to treat the manure and wastewater from the dairy farm for an entire year. The system boundary included the construction and installation stage of facilities and the operation stage. We assessed the impact of global warming, acidification, and eutrophication from the results of the life cycle inventory analysis. The impact of global warming and acidification at the Pf and Bp system was the largest at the construction and installation stage, and it was two times larger than the Se system with a simple facility. At the operation stage, the global warming impact from the Mf system decreased 15 % compared with the Se system. The eutrophication impact was lower at the two scenarios, the Bp system and the Mf system, because of utilizing the public sewerage system for purifying liquid waste. The dairy manure and wastewater treatment system utilizing the public sewerage system has a potential for mitigating global warming and eutrophication impact compared with the system including on-site purification processes.

Keywords:Dairy cow, Manure treatment, Public sewerage system, LCA, Environmental impact

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Vol.52 No.3 (September, 2021)

  • Research Paper (Japanese)
  • Classification of Whitefly Species and Biotypes Using Deep Learning
  • Hirotaka SATO , Hiroki NAKABAYASHI , Tadashi EBIHARA , Koichi MIZUTANI, Naoto WAKATSUKI and Kenji KUBOTA
  • Whiteflies are agricultural pests causing damage to valuable crops such as tomatoes and cucumbers, and the pesticide tolerance of whiteflies differs depending on their species and biotypes. Previously, a whitefly species and biotype identification scheme using the acoustic signatures of whiteflies was proposed, focusing on the fact that whiteflies emit a tiny acoustic signal for communication that varies depending on their species and biotypes. However, only two biotypes have been reported to have been classified so far. In this paper, we propose an advanced acoustic-based classifier to classify multiple species and biotypes [Trialeurodes vaporariorum and Bemisia tabaci (biotypes B, Q1 and Q2)] by focusing on the sound spectrogram of whiteflies. We developed a deep learning model that can classify the spectrograms of whiteflies, and we conducted experiments in an anechoic chamber. As a result, we found that the proposed classifier can classify T. vaporariorum and B. tabaci (biotypes B, Q1 and Q2) with an F-value of 96.8–100 % (mean 98.7 %) while the existing acoustic classifier can only classify them with an F value of 32.7–70.5 % (mean 60.3 %). We confirmed that the proposed classifier can classify the species and biotypes of whiteflies with almost the same accuracy as a DNA-based method.

Keywords:whitefly, classification, deep learning, spectrogram

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  • Technical Paper (English)
  • Improvement in the Operational Stability of Biogas Plants Utilizing Dairy Cow Manure and the Development of a Simple Operational Status Monitoring Index
  • Shiho ISHIKAWA , Kazunori IWABUCHI , Keiji TAKAHASHI , Takashi SUZUKI , Ryoichi HARA , Hiroyuki KITA and Shinji HOSHIBA
  • We examined the operational problems that arose at Rakuno Gakuen University’s biogas plant (BGP) during the period between fiscal year 2000 and fiscal year 2010 and identified adjustments necessary to attain stable operation. In the BGP, there are shutdowns due to mechanical failure of the system itself and from software failure, and we found both of these can occur even in the first year of operation. BGP operation is improved when the composition of raw organic waste (quality and volume) is stabilized because changes in condition can lead to system failure and plant shutdown. This in turn can lead to deterioration in the function and/or performance of multiple plant facilities. We found that stabilization was optimized when the use of high loading wastewater including manure and waste milk was used. It was possible to stabilize the volume of raw material in the range of 8–11 m3 /d and produce a methane gas concentration of 50–57 % (daily average, 53 %). Furthermore, we proposed an effective method for determining the operational status of the BGP. Using methane production volume and BGP power consumption, which can both be easily measured, we calculated the volume of methane gas used for on-site consumption. Deviations from this value provided a simple and effective means of monitoring BGP operational status. This monitoring method can evaluate the operating condition by analyzing the mutual influence of multiple measurements. In addition, the effectiveness of the proposed monitoring method was confirmed at Rakuno Gakuen University BGP through analysis of actual measurement data combined with operational problem data.

Keywords:biogas plant, operational problems, stabilization, methane gas, on-site consumption, monitoring, dairy cow manure

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Vol.52 No.4 (December, 2021)

  • Research Paper (Japanese)
  • Anaerobic Co-Digestion of Food Biomass Using Vegetable Waste as a Base Substrate
  • Gen Yoshida，Ikko Ihara
  • Vegetable wastes accounts high percentage of plant residues in food industry wastes, and they are expected to be converted to biogas due to its high water content and large amount of waste. Since vegetable wastes have a low VS concentration, it is assumed that it will be used as a base raw material in anaerobic digestion, and additional materials are required to increase the amount of biogas production. In this study, we investigated the possibility of vegetable wastes as a base raw material by co-digestion of food biomass. A biogas potential test was conducted using five types of vegetable and boiled pasta as the main substrates, and cheese and chocolate as co-substrates. When 60% of cheese or chocolate was added to the organic load of vegetable wastes, the amount of biogas production increased from 3.37 m3/m3 to 4.76 m3/m3 and 5.89 m3/m3, respectively. The biogas yield also improved slightly. The effect of the mixing ratio of vegetable wastes and chocolate was investigated under the condition of constant organic load. Mixing 20-50% of chocolate compared to mono-digestion of vegetables waste increased biogas production and biogas yield. From these results, it was shown that vegetable wastes and cheese and chocolate can be anaerobically co-digested, and that vegetable wastes can be used as a base substrate for co-digestion of food biomass.

Keywords:anaerobic digestion，co-digestion，vegetable waste，base substrate

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  • Technical Paper (Japanese)
  • Estimation of the Bulk Density of Supplementary Materials for Livestock Manure Composting
  • Takeki MAEDA, Masaki SAITO, Yoichiro KOJIMA, Yoshiyuki ABE
  • The mass and bulk density of supplementary materials for livestock manure composting in the pile state were estimated from the amount of subsidence in the small volume load test. Estimating the mass when piled up 2 meters high, it was about 60 % of the previous value for sawdust, and for rice husks it was about 80 %. Although the moisture content of returned swine manure compost was different, its mass was about twice the previous value. The value obtained with returned dairy manure compost was less than 40 % that of returned swine manure compost. It was estimated that the bulk density value increased as the deposition height increased even for the same material. This change was the smallest in rice husks, larger in sawdust and returned dairy manure compost than in rice husks, and the largest was returned swine manure compost. Therefore, if rice husks are used as supplementary material for composting mixture, it is considered that the lower part is not easily affected by the load on the upper part, even if the sedimentation height is high. On the other hand, returned swine manure compost had a high bulk density and was easily affected by load. Although it has a function of adjusting moisture when used as supplementary material, it is expected that it is unlikely to lead to a decrease in bulk density, that is, an increase in air space.

Keywords:bulk density, supplementary material, heap, composting, livestock manure

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Journal

J-STAGE