Publications by authors named "Takaki Yamashiro"

Anaerobic co-digestion of animal manure and lignocellulosic biomass is a potent approach for sustainable biomethane production. Co-digestion of dairy manure (DM) and Japanese knotweed (JK), which was collected from a riverbank, was investigated at five different DM-to-JK mixing ratios (100:0, 90:10, 80:20, 60:40, and 0:100; wet weight basis) under thermophilic condition. The results showed that the methane yields obtain from the co-digestion of DM and JK were much higher than that obtained from JK alone (104 ml/gVS), which indicates the synergistic effect and the benefits of co-digesting JK with DM.

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The objective of this study was to investigate the effect of solid-liquid separation on anaerobic digestion of dairy manure in semi-continuous stirred tank reactors. Reactors fed with liquid fraction of dairy manure (screened liquid manure) were kept in water baths at mesophilic (Run 1) and thermophilic (Run 3) temperatures, respectively, while reactors fed with water diluted manure and kept at mesophilic (Run 2) and thermophilic (Run 4) temperatures as control reactors. The performances of reactors were compared in terms of biogas and methane production, and digestate characteristics.

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This study provides a novel method for improving the anaerobic digestion (AD) of Holstein dairy manure (HDM) by the direct addition of Mineraso (MnS), a natural soil-derived supplement, to the feed of Holstein dairy cattle (HDC). MnS is chiefly composed of approximately 69.08% FeO and was supplemented at rates of 0 (F1), 25 (F2), and 50 (F3) g/head of HDC/d for two months.

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Article Synopsis
  • A study suggests a cost-effective method to enhance biogas production from dairy manure by adding waste iron powder (WIP) and iron oxide nanoparticles (INPs) directly to anaerobic digesters, eliminating the need for expensive pre- and post-treatments.
  • * The addition of WIP significantly improved methane yields by up to 56.89%, while INPs resulted in lower improvements of up to 21.11%, showing that WIP is more effective.
  • * The use of WIP not only increased methane production rates but also reduced hydrogen sulfide (HS) formation by up to 77.24%, demonstrating its potential for practical application in biogas production.
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Anaerobic digestion for biogas production is one of the most used technology for bioenergy. However, the adoption of nanoparticles still needs further studies. Therefore, this study was designed to examine the effect of metal oxide nanoparticles (MONPs) at four different concentrations in two different combinations, 20 (R1) and 100 (R2) mg/L for FeO, 100 (R3) and 500 (R4) mg/L for TiO, and a mixture of FeO and TiO at rates of 20, 500 (R5) and 100, and 500 (R6), on hydrogen sulfide (HS) mitigation, biogas, and methane (CH) yield during the anaerobic digestion of cattle manure (CM) using an anaerobic batch system.

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The introduction of biogas plants is a promising way to recycle organic wastes with renewable energy production and reducing greenhouse gas. Application of anaerobic digestate as a fertilizer reduces the consumption of chemical fertilizers. In this study, the survival of pathogenic bacteria and plant growth promoting bacteria (PGPB) in two full-scale biogas plants operated at mesophilic condition were investigated.

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Frequent use of pesticides to control soil-borne plant disease leads to environmental pollution and the development of pesticide resistance in phytopathogens. Soil amendment is considered to have the potential of suppressing plant disease because of its biological properties. However, information on anaerobic digestate is limited.

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Biogas is composed of different gases including hydrogen sulfide (HS), which is a hazardous gas that damages pipes and generators in anaerobic digestion system. The objective of this study was to control HS by waste iron powder produced by laser cutting machine in a steel and iron industry. Waste iron powder was mixed with dairy manure at a concentration between 2.

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The purpose of this study was to investigate the potential of high-solids anaerobic mono-digestion of riverbank grass under thermophilic conditions, focusing on the effects of the strength and the amount of inoculum. Ensiled grass was inoculated with three different inocula; inoculum from liquid anaerobic digester (LI), inoculum from dry anaerobic digester (DI), and mixture of LI and DI (MI), at feedstock-to-inoculum ratio (FIR) of 1, 2 and 4. The ensiling process of riverbank grass reduced moisture content (p>0.

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Hydrogen sulfide (H2S) emission from liquid manure in the process preceding field application is an important issue in fertigation systems. Given that H2S poses a significant health risk, it is important to determine the effects of different handling parameters on H2S emissions to prevent health risks to farmers. In this study, the effects of total solids (TS; 3, 5, 7, 9, and 11%) and mixing speed (100, 200, 300, and 400 rpm), duration (5, 15, 30, and 60 min), and frequency (one, two, three, and four times a day) on H2S emissions from two different dairy manures were investigated.

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Anaerobic co-digestion of cow manure (CM) and waste milk (WM), produced by sick cows during treatment with antibiotics, was evaluated in two-stage process under thermophilic condition (55 °C) to determine the effect of WM addition on hydrogen (H2) and methane (CH4) production potentials, volatile solids (VS) removal, and energy recovery. Six CM to WM VS ratios of 100:0, 90:10, 70:30, 50:50, 30:70, and 10:90 were examined using 1-L batch digesters. The WM VS ratio of 30 % was found to be the minimum limit for significant increases in specific H2 and CH4 yields, and VS removal as compared to digestion of manure alone (P < 0.

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Anaerobic digestion is considered as a promising method to manage animal waste with antibiotic-resistant bacteria. Current research was conducted to investigate the survival of multidrug-resistant bacteria (MDRB) resistant to three groups of antibiotics: (i) cefazolin, neomycin, vancomycin, kanamycin (group 1); (ii) penicillin, oxytetracycline, ampicillin, streptomycin (group 2); and (iii) cefazolin, neomycin, vancomycin, kanamycin, penicillin, oxytetracycline, ampicillin, streptomycin (group 3), in anaerobic digestion of dairy manure and co-digestion of dairy manure and waste milk at 37°C and 55°C for 22 days, respectively. The population densities of three groups of MDRB on peptone, tryptone, yeast and glucose agar plates incubated at 30°C for 7 days before and after digestion showed 100% destruction in both digestates at thermophilic temperature.

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The use of cefazolin to treat mastitic cows leads to cefazolin residues in milk and manure. This is responsible for the high occurrence of cefazolin resistant bacteria (CRB) in waste and the environment. Anaerobic digestion is considered to have the potential to reduce antibiotic-resistant bacteria present in waste that results from concentrated animal feeding operations.

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The individual and combined effect of cefazolin (CFZ) and oxytetracycline (OTC) on thermophilic anaerobic digestion (55°C) of dairy manure in batch digesters was investigated. Methane productions from the concentrations tested (30, 60 and 90 mg L(-1)) were compared with no-antibiotic control. CFZ concentrations showed no inhibition (P>0.

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Biohydrogen production from co-digestion of cow manure (M) and waste milk (WM), milk from mastitis cows treated with cefazolin, was evaluated in a 3×5 factorial design. Organic loading of 20, 40 and 60g volatile solid (VS)L(-1) were tested at temperature of 55°C using M:WM (VS/VS) 70:30, 50:50, 30:70, 10:90 and 0:100. Hydrogen production increased with organic loading and M:WM to a maximum of 59.

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The paper deals with the hygienic advantages of sanitation to treat dairy manure in full-scale biogas plants. The slurry samples were collected from two thermophilic biogas plants (55°C) and two mesophilic biogas plants (38°C) in Hokkaido Japan. A detectable number of Coli-aerogenes group and Enterococcus in the slurries after anaerobic digestion (AD) could not be found in either thermophilic biogas plants.

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The magnetic activated sludge (MAS) process is a modification of the conventional activated sludge process to improve the solid-liquid separation characteristics. It was developed to reduce the production of excess sludge and the time required for the conventional activated sludge process. In this study, actual milking parlor wastewater was treated with a MAS process and no sludge was removed.

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