Yoshiyuki Abe

Characterization of dairy cattle manure/wallboard paper compost mixture.

The aim of this research was to evaluate the use of manufacturing wallboard paper scraps as an alternative bulking agent for dairy cattle manure composting. The characteristics of the composting process were studied based on the changes in physico-chemical parameters and final compost quality. Composting of dairy cattle manure with wallboard paper was performed in a 481-L cylindrical reactor with vacuum-type aeration. Rapid degradation of organic matter was observed during the thermophilic stage of composting due to high microbial activity. High temperature and alkaline pH conditions promoted intense ammonia emission during the early stage of composting. The number of mesophilic and thermophilic microorganisms were found to be affected by changes in temperature at different composting stages. The total nitrogen (N), phosphorus (P), potassium (K), and sodium (Na) concentrations of the mixture did not change significantly after 28days of composting. However, the presence of gypsum in the paper scraps increased the calcium content of the final compost. The wallboard paper had no phyto-inhibitory effects as shown by high germination index of final compost (GI=99%).

Transfer factor of radioactive cesium to forage corn (Zea mays L.) from soil to which contaminated farmyard manure had been applied

Abstract Radioactive cesium (Cs) deposited after the Fukushima Daiichi Nuclear Power Station accident contaminated farmyard manure (FYM) in the wide area surrounding the plant. We conducted a field trial to determine the transfer factor of radioactive Cs to forage corn (Zea mays L.) from soil to which the contaminated FYM had been applied. The main purpose of this experiment was to examine the behavior of the radioactive Cs from contaminated FYM that was incorporated in agricultural fields. Application of FYM containing 3900 Bq kg−1 dry matter (DM) of cesium-137 (137Cs) at a rate of 4.3 kg m−2 increased the 137Cs concentration in the soil by 64 Bq kg−1 dry soil, and in the forage corn by 9.2 Bq kg−1 DM. Therefore, we calculated the transfer factor to corn plants from the soil after application of contaminated FYM to be 0.14. This value is lower than that observed for soil to which uncontaminated FYM had been applied as a control, and it is within the range of reported soil-to-plant transfer factors of 0.003–0.49 listed in the recent parameter handbook by International Atomic Energy Agency. The increase in the radioactive Cs concentration in the corn plants, expressed as the sum of 137Cs and cesium-134 (134Cs), was only 3% of the 2012 provisional tolerance level for cattle roughage in Japan. Even though the application of contaminated FYM did not cause a large change in the radioactive Cs concentration in the corn plants in this trial, such application should be carefully controlled because it increased radioactive Cs concentrations in both soil and forage corn.

Binary Power Generation Using Composting Fermentation Heat as Heat Source

Abstract. This study was conducted to verify the possibility of binary power generation using composting fermentation heat recovered by a full-scale suction-type aeration composting system (SACS). SACS is different from ordinary composting system aerated by blowers. In SACS, air is sucked from the bottom of composting material by blowers, and fresh air is supplied from the surface of the material so that exhaust gas gathered at the bottom of compost contains gases as ammonia and heat in high density is generated during composting process. Binary power generation was carried out at full scale SACS (Tochigi city, Tochigi, Japan), which had a volume of 400 m 3 . The temperature of the exhaust gas in this facility is 64.2 °C on average. Water warmed by this exhaust gas was used for a high-heat source and agricultural water (16.1 °C on average) was used for a low-heat source for a binary power generator (ECOR-3-Ft; ADVANCE RIKO, Japan). Firstly, the layout of the heat exchanger for recovering exhaust gas heat was investigated. Next, we attempted to maintain a continuous power generation and clarified issues of it. As a result, using an exhaust gas heat of 5.2 GJ/day (= 60 kW), a power of more than 700 W was generated. The energy conversion efficiency in this power generation process was approximately about 5%. When the compost material was turning over, the heat of the exhaust gas temporarily decreased. Due to this, power generation stopped 1 or 0.5 days after turning over, but it remained stable during other times.