Estimation of Water Circulation Based on Experimental Results from Sequential Crop Cultivation, Closed Goat Breeding and Simulated Habitation Using CEEF

Closed habitation experiments are to be carried out using Closed Ecology Experiment Facilities (CEEF) from FY2005 to FY2009. The last target of duration of closed habitation is four months. Preliminary study and testing have been conducted in order to carry out the closed habitation experiments. The CEEF has three closed plantation chambers (PC-A, B and C) with artificial lighting solely having each cultivation area of 30 m² and a closed plantation chamber (PC-F) with both natural lighting and supplemental artificial lighting having a 60-m² cultivation area. A ‘stable’ period of sequential crop cultivation was maintained for four weeks in a trial experiment conducted in FY2003 using the Plantation Module (PM), in which rice, soybean and crops including rice sapling, soybean sapling, soybean, peanuts and safflower were cultivated in PC-A, PC-B, PC-C and PC-F, respectively. Amount of total clean water input to PM was 741 L day⁻¹ on the average for the period. That includes 645 L day⁻¹ of replenishing water supplied to plant cultivation beds and 96 L day⁻¹ of humidifying water. Amounts of condensate and water in harvested biomass from the PM were 681 and 8.4 L day⁻¹, respectively. In addition to them, 1311 L day⁻¹ of nutrient solution in the plant cultivation beds was exchanged. The waste nutrient solution was processed through the Reverse Osmosis membrane (RO) system.1245 L day⁻¹ of water having solute concentration of less than 5% of that of the waste nutrient solution was recovered. Both condensate sterilized through Ultra Violet ray exposure system and water processed through the RO were used for making of new nutrient solution. Amounts of water in food, drinking water and other water consumption including washing, shower and sanitary for two persons during a simulated closed habitation trial lasting five days conducted in FY2003 were 2.9, 1.0 and 112 L day⁻¹, respectively. Amount of water in rice straw as feeding, drinking water and cage washing water for two Shiba-goats each having 25-kg body weight during closed breeding experiment conducted in FY2003 were estimated as 0.1, 5.7 and 0.4 L day⁻¹, respectively. Using above data and estimation result, water flow in the CEEF material circulation system was estimated.