1、Su, Hongg University,Keywords:Water recycling system of the Lunar Palace 1Bioregenerative life support systemMembrane-biological activated carbon reactorCondensate waterSanitary & kitchen wastewaterUrine treatmentand recycling of those different types of wastewater will be of importantsignicance to
2、improve the system closure, reduce supplies from thefor the astronauts in long-term space exploration.BLSS since earlythat in order to putBLSS facilitiesrst. Therefore,have been con-series in Russiaand MELiSSAthe water recyclingdifferent technicalIn China, the investigation of BLSS was started late
3、and mainlyfocused on the key elemental technologies, the conceptual conguration* Corresponding author. School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.E-mail address: LH (H. Liu).Contents lists available at ScienceDirectActa Astronauticajournal homepag
4、e: 8 January 2017; Received in revised form 25 May 2017; Accepted 21 August 2017Available online 24 August 20170094-5765/ 2017 IAA. Published by Elsevier Ltd. All rights reserved.Acta Astronautica 140 (2017) 420426Bioregenerative life support system (BLSS) is very important to pro-vide indispensable
5、 living conditions for astronauts in the manned spaceactivities such as lunar/Mars bases or deeper space exploration, andwaterrecyclingisoneofthekeycomponentsforachievinghigherclosureof BLSS. The types of wastewater in BLSS include the condensate waterthrough the evapotranspiration of higher plants
6、and plant-cultivationsubstrate, the sanitary wastewater from tooth brushing, bathing,laundry, etc., the kitchen wastewater from food-processing and dining,and other wastewater from equipment operation and human metabolism(sweat, respiration moisture, urine, feces, etc.). The completed treatmentMany
7、developed countries have started to study1960s, and they have basically reached a consensusBLSS into practice in space, large-scale experimentalshould be built to verify the feasibility and reliabilityground-based experimental BLSSs and related test bedsstructed and investigated for decades, such as
8、 the BIOS(the Soviet Union), Bio-Plex in the USA, CEEF in Japanproject led by European Space Agency, in whichsystems have been designed and established by usingprocesses 16.1. Introduction earth, lower the operation cost, and to create better living environmentIn the bioregenerative life support sys
9、tem (BLSS), water recycling is one of the essential issues. The Lunar Palace1, a ground-based bioregenerative life support system experimental facility, has been developed by our team and a105-day closed bioregenerative life support experiment with multi-crew involved has been accomplished withinthi
10、s large-scale facility. During the 105-day experiment, activated carbon-absorption/ultra-ltration, membrane-biological activated carbon reactor and reduced pressure distillation technology have been used to purify thecondensate water, sanitary & kitchen wastewater and urine, respectively. The result
11、s demonstrated that thecombination of those technologies can achieve 100% regeneration of the water inside the Lunar Palace 1. Thepuried condensate water (the clean water) could meet the standards for drinking water quality in China(GB5749-2006). The treatment capacity of the membrane-biological act
12、ivated carbon reactor for sanitary &kitchen wastewater could reach 150 kg/d. During the 105-d experiment, the average volume loading of thebioreactor was 0.441 kgCOD/(m3d), and the average COD removal efciency was about 85.3%. The quality of thepuried sanitary & kitchen wastewater (the greywater) co
13、uld meet the standards for irrigation water quality (GB50842005). In addition, during the 105-day experiment, the total excreted urine volume of three crew memberswas 346 L and the contained water was totally treated and recovered. The removal efciency of ion from urinewas about 88.12%. Moreover, pa
14、rtial nitrogen within the urine was recovered as well and the average recoveryratio was about 20.5%. The study laid a foundation for the water recycling technologies which could be used inBLSS for lunar or Mars bases.ARTICLE INFO ABSTRACTThe water treatment and recycling in 105-dayexperiment in the
15、Lunar Palace 1Beizhen Xiea,b,c, Guorong Zhua,b,c, Bojie Liua,b, QiangGuanghui Liua,b,c, Chen Donga,b,c, Minjuan Wanga,b,caSchool of Biological Science and Medical Engineering, Beihang University, Beijing 100191, ChinabInstitute of Environmental Biology and Life Support Technology, Beihang University
16、, Beijing 100191,cInternational Joint Research Center of Aerospace Biotechnology & Medical Engineering, Beihanbioregenerative life supporta,b, Shengda Denga,b, Lige Yanga,b,Liua,b,c,*ChinaBeijing 100191, ChinaB. Xie et al. Acta Astronautica 140 (2017) 420426design and the simulation modeling of BLSS
17、, etc. 711. A large-scaleexperimental BLSS needed to be built urgently to verify and consum-mate the technologies. Therefore, in 2013, a ground-based bio-regenerative life support system experimental facility “Lunar Palace 1”(stage I) was developed by our team, which consists of one comprehen-sive c
18、abin (42 m2) for crews living, animal breeding and waste treat-ment, and one plant cabin (58 m2) for plant cultivation. Then, a 105-dayclosed bioregenerative life support experiment with multi-crew involvedwas successfully carried out in 2014 12. In this experiment, 100%regeneration of the water ins
19、ide the Lunar Palace 1 has been achievedrelying on the high efcient operation of the water recycling system. Inthis paper, the structure of the water recycling system and its perfor-mance during the 105-day BLSS experiment would be introducedspecically.2. Materials and methodsThere were three kinds
20、of wastewater needed to be puried andrecycled inside the Lunar Palace 1, including the condensate water fromthe temperature-humidity control system, the sanitary & kitchen waste-water from the daily life of the crew and the urine. Due to the differencesof the contamination level, different wastewate
21、r treatment processesshould be designed to purify the three kinds of wastewater separately tomeet the water quality standards for different usage.During the 105-day BLSS experiment, the condensate water, sanitary& kitchen wastewater and the crews urine before and after puricationwere double sampled
22、and analyzed every 7 days, in order to monitor thewater quality and the operation conditions of the wastewater treatmentfacilities involved in the water recycling system of the Lunar Palace 1.The main continuously monitored indexes of condensate water werechemical oxygen demond (CODMn), NO2C0-N, NO3
23、C0-N, conductivity, pH,total bacteria and coliform group, the monitored indexes of sanitary &kitchen wastewater were chemical oxygen demond (CODCr), total ni-trogen (TN), total phosphorus (TP), NH4N and NO3C0-N, and for theurine, the TN and conductivity were tested continuously.TheCODMn,CODCr,TN,TP,
24、NH4N,NO2C0-N,NO3C0-N,totalnumberofbacteria and coliform group were tested according to standard methods13. The conductivity and pH were tested using portable conductometer(Hanna Instruments, Inc.) and benchtop pH meter (Mettler-Toledo In-ternational Inc.), respectively.Additionally,whentheclosedBLSS
25、experimentranstably,thetreatedcondensate water was sampled and tested by a professional testingagency to verify the quality.3. Results and discussion3.1. The design of the water recycling system in Lunar Palace 1Different wastewater treatment technologies and facilities should bedesigned and constru
26、cted to purify the three kinds of wastewater sepa-rately. Moreover, for achieving completed water recycling in system, thepuried water should be reasonably distributed and utilized. Therefore,the water recycling system in Lunar Palace 1 was carefully designed andcalculated according to our previous
27、conceptual design of a BLSS 14before its construction. Based on the mass ow design of BLSS and thecontamination conditions of each kind of the wastewater, the detailedtreatment techniques were determined and the suitable capacity of thetreatment facilities could be evaluated.3.1.1. Treatment method
28、of condensate waterAs a key component, the condensate water had the largest quantity inLunar Palace 1 water recycling system, mainly from the plant transpi-ration, the plant-cultivation substrate evaporation and the metabolism ofthe crew. The puried condensate water (the clean water) was partlyuseda
29、sdrinkingwaterandsanitary&kitchenwater,so itneededtomeetthe standards for drinking water quality in China (GB5749-2006) 15.421The rest of the clean water was used for the irrigation of the plants. It hasbeen reported that the main contaminants of the condensate water inspace station included dissolv
30、ed organics, ammonia, ions, and microor-ganisms, which were in a rather high polluted level 1618. While thecontaminants in the atmosphere of Lunar Palace 1 was highly diluted bythe large amount of condensate water from plant transpiration, whichreduced the pollution level but increased the quantity
31、of the wastewater.Therefore, activated carbon adsorption combining ultraltration and UVdisinfection were considered to purify the condensate water due to thehighefciencyandlargecapacity.Theprocessdiagramandphotosof thecondensate water treatment are presented in Fig. 1. The condensatewater from tempe
32、rature-humidity control system was collected in thecondensatewatertank(equippedwithaUVdisinfectionlamp).Then,thecondensate water was pumped through the PP cotton preltration col-umn, the activated-carbon adsorption column and the ultraltrationmembrane successively, automatically controlled by the li
33、quid levelswitch inthe condensatewatertank.Thepuriedwaterwas storedin theclean water tank for the daily use of the crew members and the plantirrigation (pumped to the nutrient solution tank when needed). Thetreatment capacity of the facility was 2 L/min.3.1.2. Treatment method of sanitary & kitchen
34、wastewaterSanitary & kitchen wastewater from bathing, laundry, food-makingand dining was second in quantity to the condensate water but muchmore polluted, and the main contaminants were high-concentrationorganic compounds and salts, such as nitrate and sulphate 16,19.Inthis experiment, the puried sa
35、nitary & kitchen wastewater (greywater)was used to prepare the nutrient solution for the plants. Thus, the grey-water should meet the standards for irrigation water quality (GB5084-2005) 20.Efcient membrane-biological activated carbon reactor wasconsidered to treat this kind of wastewater. In order
36、to prevent the mi-crobial contamination, the bioreactor didnt inoculate any microorgan-isms from outside the Lunar Palace 1, but naturally inoculated from theatmosphereand thesanitary&kitchen wastewater inside thesystem as itcontinuously operated. In addition, ultraltration and UV disinfectionwere a
37、dded after the bioreactor to prevent the growing microorganismsfrom polluting the nutrient solution. The process diagram and photos ofthe sanitary & kitchen wastewater treatment are shown in Fig. 2. Themaximum treatment capacity of the membrane-biological activatedcarbon reactor was designed to be 1
38、50 kg/d to fulll the requirement for4 crew members.In order to maintain the persistent disinfection effect during theexperiment, all the UV lamps equipped in the water recycling systemwere kept on 24 h/d.3.1.3. Treatment method of urineThe treatment and recovery of the crews urine are the most difcu
39、ltand critical issues among the water recycling system due to the highconcentrations of the salts, urea, ammonia and organics in urine. Manyresearches have been focusing on the water recycling technologies of theurine for space life support system, including physical/chemical andbiological methods 2
40、123. In this experiment, reduced-pressure distil-lation method was considered to treat the urine. Part of the nitrogenwould be distilled together with the water vapor, while most of the saltswere concentrated, dried and stored. The condensate water from urine(containing ammonia) would be mixed with
41、sanitary & kitchen waste-water and treated by the membrane-biological activated carbon reactor.Finally, the processes mentioned above were integrated to form thewaterrecyclingsystemin theLunarPalace1,anda generalschemeof thewater recovery procedures during the 105-day experiment was pre-sented 12.3.
42、2. The performance and analysis of the water recycling system during theexperimentDuring the 105-day BLSS experiment, the monitoring systemB. Xie et al. Acta Astronautica 140 (2017) 420426automaticallyrecorded the changes of the liquid levels of the clean watertank, the greywater tank and the nutrie
43、nt solution tank, and the crewFig. 1. The process diagram and photos of the condensatemeasured and recorded the daily use of the water for living in detailbased on different purposes and the excreted urine as well, which couldbe used to calculate the daily water consumption and regeneration. Theresu
44、lts showed that the daily water consumption was about 317.04 kg,including 47.24 kg for crew and 269.8 kg for the plant irrigation. Thepuried condensate water was 270.4 kg/d, and the puried urine andsanitary & kitchen wastewater were 3.01 kg/d and 43.34 kg/d, respec-tively, which indicated that 100%
45、of water regeneration was achieved12. In this part, the performances of the three subsystems for watertreatment and recycling were introduced and analyzed.3.2.1. The performance of the condensate wastewater treatment subsystemThe average values of the continuously monitored indexes ofcondensate wate
46、r before and after purication (the clean water) duringthe experiment are listed in Table 1. The organic contents (CODMn) werereduced from 3.01 mg/L, which was slightly beyond the concentrationlimit in drinking water (3 mg/L), to 2.35 mg/L. The treatment efciencywas about 24.2%. The concentrations of
47、 NO3C0-N, NO2C0-N and NH4Ninboth the condensate water and the clean water were far below the limits.In addition, to further verify the water quality, the clean water wassampled and tested by a professional testing agency during the experi-ment. Typical indexes were selected considering the standards
48、 fordrinking water, the original input (tap water) and the characteristics ofthe whole system (made of stainless steel). The test results (Table 2)showed that the clean water was transparent and without odor and taste.The toxic compounds such as arsenide, cyanide, volatilized phenol, totalCr, Pb, Al
49、 and Cu were not detected, except CHCl3and CCl4, the con-centrations of which were also far below the limits. The existed CHCl3and CCl4were considered from the tap water we used for setting up thesystem, which were common by-products produced by the drinkingwater chlorination. The undetected Fe and total Cr indicated that the422whole water subsystem mainly made of stainless steel was maintainedwell and no corrosion happened.water treatment subsystem in the Lunar Palace 1.However, the average pH values of condensate water and clean waterwere 5.83 and 5.90, respectively, which were lower than t
