基于MBR耦合多级膜分离的生活用水供应系统在CELSS中的运行试验

Performance of Water Supply Sub-system based on MBR Coupled with Multistep Membrane in CELSS

目的针对受控生态生保系统对卫生用水和饮用水的需求,构建以膜生物反应器(membrane bio-reactor,MBR)为核心,并辅以膜分离和离子交换工艺的生活用水供应系统。方法基于受控生态生保系统(Controlled Ecological Life Support System,CELSS)试验平台,以冷凝水为水源,探讨生活用水供应系统在连续180 d试验周期内的运行效果,重点考察系统的卫生用水和饮用水出水水质。结果生活用水供应系统在180 d内有效控制了水质感官性状,使卫生用水和饮用水出水p H分别在6.5~8.9和5.8~7.4范围内,平均出水电导率达到5.8和13.3μS/cm,平均出水浊度达到1.6和0.7 NTU,满足试验医学标准。同时,该系统具有高效的污染物去除能力,MBR是TOC和NH_4^+ -N的主要去除单元,可使去除率均达到97%以上;NF和RO是TOC和NH_4^+ -N保障去除单元,使出水浓度均降低至检测限以下。但MBR对NO_x^- -N去除有限,NF和RO是其主要去除单元,可使NO_x^- -N去除率达到95%。结论以MBR为工艺核心的生活用水供应系统,可连续稳定运行180 d以上,并在运行期间不间断保质足量供给4名乘员卫生用水及饮用水。

Objective A modified MBR system with membrane separation and ion exchange process was established as the water supply sub-system for the CELSS to satisfy the sanitary and drinking water demands. Methods Based on the Controlled Ecological Life Support System（ CELSS） platform,the condensate water was used as the raw water and the performance of the water supply sub-system for 180 d experiments was investigated,especially the effluent quality of sanitary water and drinking water was surveyed. Results The long-term results indicated that the modified MBR system could efficiently control the sensory index of reclaimed water,the p H were around 6. 5 ~ 8. 9 and 5. 8 ~ 7. 4,the averaged value of electrical conductivity was around 5. 8 and 13. 3μS/cm,and the averaged turbidity were 1. 6 and 0. 7 NTU,respectively,which satisfied the medical standards of the reclaimed water. In addition,such sub-system showed a good performance in pollutant removal.TOC and NH_4~＋ -N were majorly removed by the MBR units with a removal rate higher than 97%,and they were guaranteed to be lower than the limit of detection by the NF and RO. By contrast,the NO_x^- -N was slightly removed by the MBR,but was majorly separated by the NF and RO units with removal rate higher than95%,satisfying the medical standards of reclaimed water for astronaut＇s hygiene water and drinking water.Conclusion The coupled MBR process used in the water supply sub-system demonstrated a steady-state performance for 180 d and could supply water with good quality and enough quantity for 4 crewmembers.