Department of Environmental Engineering, Graduate School ofEngineering, Hokkaido University, Kita-13 Nishi-8, Kita-Ku, Sapporo 060-8628, Japan.
Environ Technol. 2011 Jul;32(9-10):953-70. doi: 10.1080/09593330.2010.521954.
The parameters of a model of the transport of water from a wet cloth sheet to the air, developed for deionized water, to establish design procedures of an on-site volume reduction system, were identified for high salt concentrations present in synthetic urine. The results showed that the water penetration was affected neither by the salts, urea or creatinine present in the synthetic urine nor by the salts accumulated on the surface of the vertical gauze sheet. However, the saturated vapour pressure decreased, leading to reduction in the evaporation rate, which occurred as a result of the salts accumulating on the surface of the vertical gauze sheet. Furthermore, a steady-state evaporation condition was established, illustrating salts falling back to the tank from the vertical gauze sheet. Accordingly, the existing design procedure was amended by incorporating the calculation procedure for the saturated vapour pressure using Raoult's law. Subsequently, the effective evaporation area of the vertical gauze sheet was estimated using the amended deign procedures to assess feasibility. This estimation showed that the arid, tropical, temperate and cold climates are suitable for the operation of this system, which require requires a small place at household level for 80% volume reduction of 10 L of urine per day for 12 hours' operation in the daytime.
为建立现场减容系统的设计程序，针对合成尿中存在的高盐浓度，确定了从湿布片向空气输送水的模型的传输参数。结果表明，水的渗透既不受合成尿中存在的盐、尿素或肌酸的影响，也不受垂直纱布表面上积累的盐的影响。然而，饱和蒸气压降低，导致蒸发速率降低，这是由于垂直纱布表面上积累的盐造成的。此外，建立了一个稳定的蒸发状态，表明盐分从垂直纱布片上回落回水箱。因此，通过采用劳尔定律计算饱和蒸气压的计算程序对现有设计程序进行了修正。随后，使用修正后的设计程序估算了垂直纱布片的有效蒸发面积，以评估其可行性。该估算表明，干旱、热带、温带和寒冷气候适合该系统运行，该系统需要在家庭层面上占用较小的空间，每天运行 12 小时，可将 10 升尿液的体积减少 80%。
