从尿液回收水是解决长期载人航天任务中水需求和再补给挑战的途径之一,尿液在收集和储存中需要控制微生物繁殖和保持化学稳定性。通过向新鲜尿液中添加过氧化氢及分析尿液储存过程中产生挥发性有机物结果表明:过氧化氢能抑制尿素水解而稳定尿液,也能减少尿液在处理过程中产生的挥发性有机物。这表明过氧化氢有可能成为航天任务中尿液回收稳定化处理的低风险化学品。 Recovering water from urine is one of the ways to solve the challenges of water demand and resupply in long-term manned space missions. It needs to control microbial reproduction and maintain chemical stability during urine collection and storage. By adding hydrogen peroxide to fresh urine and analyzing the volatile organic compounds produced in the urine storage process, the results show that hydrogen peroxide can inhibit the hydrolysis of urea and stabilize the urine, and it can also reduce the volatile organic compounds generated in the urine processing. This shows that hydrogen peroxide may become a low-risk chemical for urine recovery and treatment chemicals in long-term space missions.
从尿液回收水是解决长期载人航天任务中水需求和再补给挑战的途径之一,尿液在收集和储存中需要控制微生物繁殖和保持化学稳定性。通过向新鲜尿液中添加过氧化氢及分析尿液储存过程中产生挥发性有机物结果表明:过氧化氢能抑制尿素水解而稳定尿液,也能减少尿液在处理过程中产生的挥发性有机物。这表明过氧化氢有可能成为航天任务中尿液回收稳定化处理的低风险化学品。
过氧化氢,尿液预处理,稳定作用,挥发性有机物
Songlin Hu, Yuchen Gao, Yuan Xue, Xinxing He
China Astronaut Research and Training Center, Beijing
Received: Nov. 30th, 2020; accepted: Dec. 24th, 2020; published: Dec. 31st, 2020
Recovering water from urine is one of the ways to solve the challenges of water demand and resupply in long-term manned space missions. It needs to control microbial reproduction and maintain chemical stability during urine collection and storage. By adding hydrogen peroxide to fresh urine and analyzing the volatile organic compounds produced in the urine storage process, the results show that hydrogen peroxide can inhibit the hydrolysis of urea and stabilize the urine, and it can also reduce the volatile organic compounds generated in the urine processing. This shows that hydrogen peroxide may become a low-risk chemical for urine recovery and treatment chemicals in long-term space missions.
Keywords:Hydrogen Peroxide, Urine Pretreatment, Stabilization, Volatile Organic Compounds
Copyright © 2020 by author(s) and Hans Publishers Inc.
This work is licensed under the Creative Commons Attribution International License (CC BY 4.0).
http://creativecommons.org/licenses/by/4.0/
载人航天器舱内环境由环境控制和生命支持系统维持,长期载人航天任务中从尿液回收水对生命支持系统水循环和再补给产生重大影响。尿液是航天器中水回收和管理系统的重要来源之一,尿液是包含大量的无机物和有机物组成的水溶液,其中含量较大的包括尿素、氯化钠、其他盐和各种酸,这些物质能占尿液总重的3%~4%(wt.) [
目前,在航天任务中使用的尿液预处理化学品是氧化杀菌剂和无机酸组合,氧化性杀菌剂包括六价铬(CrO3)、次氯酸钠(NaOCl)、碘化有机物和Oxone [过氧单硫酸钾(KHSO5)、硫酸氢钾(KHSO4)和硫酸钾(K2SO4)的混合物]等,而使用的无机酸包括浓硫酸、磷酸和盐酸等 [
因此,本研究开展过氧化氢处理尿液等实验,研究过氧化氢在对尿液稳定化作用,以及对过氧化氢在处理尿液过程中产生挥发性有机物的情况进行分析,以探索适合于航天飞行任务中低毒性低风险尿液预处理化学品。
本研究使用的仪器包括:多参数水质分析仪(Multi 9630 IDS,WTW,德国)、气相色谱质谱仪(GC7890/5977MSD,Agilent,美国)和气体预浓缩仪(7200,Entech,美国)。主要使用的化学试剂有三氧化铬(分析纯,阿拉丁)、浓硫酸(98%,国药集团)、过氧化氢(3%,江西草珊瑚消毒用品有限公司)。
收集新鲜尿液1 L,分成4份,每份200 ml,其中3份加入10 ml过氧化氢溶液(3%,0.88 mol/L)作为实验组,一份加入10 ml去离子水作为对照组,对加入过氧化氢的尿液,分别用60%硫酸溶液调整溶液的pH值≤4和≤2,使用多参数水质分析仪测定不同时间点的pH值、电导率和盐度。
将200 ml过氧化氢、200 ml过氧化氢(60%硫酸20 ml)和40 ml三氧化铬(2%)硫酸溶液分别放入4 L尿液收集桶,尿液在2天内收集完成,在稳定处理5天后,分别取出500 ml,放入吹洗瓶中,用适当流速的氦气将溶液中挥发性有机物吹扫出来,收集到5 L泰德拉气体采样袋中。同时吹扫500 ml新鲜尿液以收集气体到采样袋。然后,采用气体预浓缩仪–气相色谱质谱仪分析气样中的挥发性有机物成份。
不同处理方式的尿液中挥发性有机物测试条件:设置气体预浓缩的进样量200 ml,气相条件设定:色谱柱:Agilent DB-5MS,60 m × 250μm × 1μm,35℃用于6 min,然后6℃/min到140℃用于0 min,然后15℃/min到220℃用于5 min;质谱条件设定:传输线温度:250℃,电子能量:70 eV,离子源温度:230℃,四级杆温度:150℃,扫描模式:Full Scan模式。使用Agilent MassHunter Qualitative Analysis软件分析色谱总离子流图(TIC),获得各色谱峰面积,计算各色谱峰面积所占百分比。
在太空飞行中回收尿液中的水,用于饮用等目的,在尿液收集和处理过程时,需要控制微生物繁殖和尿液化学稳定性 [
图1. 过氧化氢在尿液处理中pH值、电导率和盐度随时间变化
已有的研究表明:过氧化氢能附着在微生物的细胞壁、膜和酶转运系统上,导致细胞内成份氧化,因微生物修复能力过载而导致其死亡 [
通过添加预处理化学品控制尿液在收集和储存时的微生物繁殖,防止尿素水解产生氨气,尿液在氧化性预处理剂作用下,将会引起尿液中有机物的降解和产生难闻的气体,这将导致航天器舱内空气环境恶化,引发威胁乘员生命健康的风险和增加生命支持保障系统的工作负荷。因此,在尿液预处理过程中要求产生的挥发性有机物和发泡最小化 [
通过气相色谱质谱法对新鲜尿液和储存尿液吹扫产生的气体进行分析发现:新鲜尿液中挥发性有机物较少,主要成份是甲醇、乙醇、丙酮和4-庚酮等;而储存尿液在发生腐败的过程产生了中含有大量含硫化合物,包括硫化氢、甲硫醇、二甲基硫和二甲基二硫等,以及少量酮类化合物,见表1和图2所示。这表明尿液在存储时发生微生物污染后,尿素水解会导致尿液中的化合物发生改变,除了产生氨外,还会产生多种含硫的挥发性有机物而使尿液出现恶臭气味,并形成絮状生物膜和沉淀。
类型 | 名称 | CAS | 色谱峰面积 | 色谱峰高 | 峰面积所占 百分比% |
---|---|---|---|---|---|
新鲜尿液 | Methyl Alcohol1 | 67-56-1 | 1,325,613.75 | 585,821.42 | 21.67% |
Ethanol | 64-17-5 | 332,967.71 | 116,165.81 | 5.44% | |
Acetone | 67-64-1 | 2,044,051.16 | 923,125.00 | 33.42% | |
2-Pentanone | 107-87-9 | 84,934.12 | 36,060.46 | 1.39% | |
Pyrrole | 109-97-7 | 59,583.01 | 16,874.38 | 0.97% | |
Hexanal | 66-25-1 | 75,067.97 | 30,783.54 | 1.23% | |
Ethylbenzene | 100-41-4 | 70,159.58 | 30,875.32 | 1.15% | |
4-Heptanone | 123-19-3 | 987,274.77 | 464,013.88 | 16.14% | |
Phenol | 108-95-2 | 702,984.65 | 270,522.23 | 11.49% | |
1,3-Cyclohexadiene, 1-methyl-4-(1-methylethyl)- | 99-86-5 | 51,095.7 | 25,892.64 | 0.84% | |
Benzene, 1-methyl-3-(1-methylethyl)- | 535-77-3 | 225,381.96 | 116,608.88 | 3.68% | |
D-Limonene | 5989-27-5 | 33,065.96 | 17,879.09 | 0.54% | |
γ.-Terpinene | 99-85-4 | 124,891.29 | 62,855.43 | 2.04% | |
峰面积合计 | 6,117,071.63 | ||||
存储尿液 (7天) | Hydrogen sulfide | 7783-06-4 | 14,590,478.51 | 1,152,317.06 | 8.61% |
Methanethiol | 74-93-1 | 4,108,146.46 | 697,466.76 | 2.43% | |
Methylamine, N,N-dimethyl- | 75-50-3 | 3,895,080.23 | 599,307.2 | 2.30% | |
Acetone | 67-64-1 | 2,673,033.29 | 243,421.8 | 1.58% | |
Dimethyl sulfide | 75-18-3 | 21,296,925.78 | 6,650,303.79 | 12.57% | |
2-Pentanone | 107-87-9 | 505,579.31 | 124,690.44 | 0.30% | |
Sulfide, allyl methyl | 10152-76-8 | 14,325,869.1 | 5,330,523.59 | 8.46% | |
Propane, 1-(methylthio)- | 3877-15-4 | 550,510.69 | 215,799.42 | 0.33% | |
1-Propene, 1-(methylthio)-, (Z)- | 52195-40-1 | 927,537.03 | 356,627.48 | 0.55% | |
Disulfide, dimethyl | 624-92-0 | 101,454,216.1 | 16,290,031.94 | 59.90% | |
4-Heptanone | 123-19-3 | 2,859,583.11 | 1,308,324.61 | 1.69% | |
2,4-Dithiapentane | 1618-26-4 | 748,630.17 | 251,029.29 | 0.44% | |
Disulfide, methyl 2-propenyl | 2179-58-0 | 455,319.47 | 198,880.26 | 0.27% | |
Dimethyl trisulfide | 3658-80-8 | 987,426.97 | 425,940.98 | 0.58% | |
峰面积合计 | 169,378,336.22 |
表1. 新鲜尿液和储存尿液(7天)吹扫气体GC-MS色谱图详细信息
图2. 新鲜尿液和储存尿液(7天)中挥发性有机物色谱质谱总离子流图
在本研究中使用三氧化铬(2%)硫酸溶液作为过氧化氢在在尿液处理时产生挥发性有机物的参照物。经分析吹扫产出的气体发现:向尿液添加三氧化铬(2%)硫酸浓酸稳定7天后的尿液中含有易挥发的含硫化合物,包括硫化氢、羰基硫、甲硫醇和二甲基二硫等,以及酮类化合物如丙酮、2-戊酮和4-庚酮等,也包括含氮化合物和烯烃等;过氧化氢在中性条件下处理尿液时产生挥发性有机物主要是含有酮类化合物如丙酮、2-戊酮和4-庚酮等,而在酸性条件处理尿液时产生主要挥发性有机物是酮类化合物和呋喃衍生物等,见表2和图3。
在酸性条件下,三氧化铬和过氧化氢都具有氧化性 [
类型 | 名称 | CAS | 色谱峰面积 | 色谱峰高 | 峰面积所占 百分比% |
---|---|---|---|---|---|
三氧化铬 (硫酸) | Hydrogen sulfide | 7783-06-4 | 393,262.73 | 334,344.27 | 0.42% |
Propene | 115-07-1 | 6,476,500.63 | 5,242,847.07 | 6.85% | |
Carbonyl sulfide | 463-58-1 | 3,783,832.55 | 3,061,539.97 | 4.00% | |
Methanethiol | 74-93-1 | 18,765,738.81 | 8,391,208.44 | 19.85% | |
Acetone | 67-64-1 | 6,165,846.36 | 2,747,602.24 | 6.52% | |
Furan | 110-00-9 | 1,182,699.73 | 589,383.47 | 1.25% | |
Allyl chloride | 107-05-1 | 330,287.31 | 157,734.93 | 0.35% | |
Propane, 1-(ethynylsulfinyl)- | 121564-27-0 | 2,970,978.51 | 999,785.47 | 3.14% | |
Furan, 2-methyl- | 534-22-5 | 496,718.48 | 240,158.37 | 0.53% | |
Propyl mercaptan | 107-03-9 | 255,761.37 | 106,457.63 | 0.27% | |
2-Butanone, 3-methyl- | 563-80-4 | 268,365.97 | 109,498.87 | 0.28% | |
2-Pentanone | 107-87-9 | 2,980,904.78 | 1,285,210.7 | 3.15% | |
Methyl Isobutyl Ketone | 108-10-1 | 406,312.18 | 179,675.09 | 0.43% | |
Disulfide, dimethyl | 624-92-0 | 10,251,405.8 | 4,348,237.43 | 10.85% | |
2-Pentanone, 3-methyl- | 565-61-7 | 305,625.59 | 123,918.72 | 0.32% | |
3-Hexanone | 589-38-8 | 442,418 | 203,492 | 0.47% | |
Furan, 2-ethyl-5-methyl- | 1703-52-2 | 374,239.89 | 240,578.26 | 0.40% | |
Hexanal | 66-25-1 | 1,291,131.47 | 533,090.62 | 1.37% | |
3-Pentanone, 2,2-dimethyl- | 564-04-5 | 337,151.42 | 150,340.87 | 0.36% | |
2-Hexanone, 3-methyl- | 2550-21-2 | 535,140.55 | 207,481.95 | 0.57% | |
4-Heptanone | 123-19-3 | 21,595,965.91 | 8,632,324.01 | 22.85% | |
Allyl Isothiocyanate | 57-06-7 | 462,469.26 | 226,530.5 | 0.49% | |
Disulfide, methyl 2-propenyl | 2179-58-0 | 265,239.01 | 116,125.76 | 0.28% | |
2H-Pyran,2-ethenyltetrahydro-2,6,6 trimethyl- | 7392-19-0 | 2,463,241.4 | 924,413.1 | 2.61% | |
1,3-Cyclohexadiene,1-methyl-4-(1-methylethyl)- | 99-86-5 | 2,814,841.49 | 1,386,869.03 | 2.98% | |
Benzene, 1-methyl-3-(1-methylethyl)- | 535-77-3 | 3,352,128.25 | 1,768,625.8 | 3.55% | |
D-Limonene | 5989-27-5 | 368,906.5 | 211,601.95 | 0.39% | |
3-Carene | 13466-78-9 | 245,223.71 | 143,539.63 | 0.26% | |
γ.-Terpinene | 99-85-4 | 3,470,476.15 | 2,097,754.45 | 3.67% |
三氧化铬 (硫酸) | Cyclohexene,1-methyl-4-(1-methylethylidene)- | 586-62-9 | 631,244.7 | 392,681.37 | 0.67% |
---|---|---|---|---|---|
Ionone | 8013-90-9 | 834,753.68 | 481,176.15 | 0.88% | |
峰面积合计 | 94,518,812.19 | ||||
过氧化氢 | Methyl Alcohol | 67-56-1 | 1,160,110.07 | 557,366.61 | 3.10% |
Acetone | 67-64-1 | 11,166,420.45 | 4,199,217.16 | 29.88% | |
2-Butanone | 78-93-3 | 214,161.13 | 93,888.67 | 0.57% | |
Furan, 2-methyl- | 534-22-5 | 110,577.49 | 49,327.12 | 0.30% | |
2-Pentanone | 107-87-9 | 815,983.46 | 350,258.83 | 2.18% | |
Pentanal | 110-62-3 | 114,135.23 | 49,369.8 | 0.31% | |
Furan, 2-ethyl- | 3208-16-0 | 64,294.38 | 28,794.37 | 0.17% | |
1H-Pyrrole, 1-methyl- | 96-54-8 | 180,920 | 71,211.28 | 0.48% | |
Pyrrole | 109-97-7 | 180,513.58 | 68,238.04 | 0.48% | |
Cyclohexanol, 3,3-dimethyl- | 767-12-4 | 378,006.9 | 114,876.27 | 1.01% | |
4-Heptanone | 123-19-3 | 17,491,758.17 | 7,175,836.31 | 46.81% | |
2,4-Nonadienal, (E,E)- | 5910-87-2 | 703,358.7 | 155,604.85 | 1.88% | |
Benzene, pentyl- | 538-68-1 | 481,235.28 | 266,600.67 | 1.29% | |
峰面积合计 | 33,061,474.84 | ||||
过氧化氢(硫酸) | Propene | 115-07-1 | 6,515,241.39 | 5,436,438.74 | 9.37% |
Methyl Alcohol | 67-56-1 | 1,008,868.85 | 544,989.03 | 1.45% | |
Acetone | 67-64-1 | 19,897,553.86 | 6,618,751.05 | 28.60% | |
Furan | 110-00-9 | 717,681.19 | 308,948.11 | 1.03% | |
2-Butanone | 78-93-3 | 741,527.1 | 334,308.94 | 1.07% | |
Furan, 2-methyl- | 534-22-5 | 2,852,961.62 | 1,183,397.26 | 4.10% | |
2-Pentanone | 107-87-9 | 5,532,642.08 | 2,333,707.24 | 7.95% | |
Pentanal | 110-62-3 | 290,882.46 | 135,236.52 | 0.42% | |
Furan, 2-ethyl- | 3208-16-0 | 499,015.94 | 236,972.34 | 0.72% | |
Furan, 2,5-dimethyl- | 625-86-5 | 603,064.28 | 294,221.73 | 0.87% | |
Methyl Isobutyl Ketone | 108-10-1 | 334,359.9 | 140,780.2 | 0.48% | |
2-Pentanone, 3-methyl- | 565-61-7 | 257,831.9 | 111,776.99 | 0.37% | |
3-Hexanone | 589-38-8 | 483,810.78 | 221,705.03 | 0.70% | |
Furan, 2-ethyl-5-methyl- | 1703-52-2 | 2,389,682.82 | 887,701.08 | 3.44% | |
2-Hexanone, 3-methyl- | 2550-21-2 | 336,334.78 | 120,177.66 | 0.48% | |
4-Heptanone | 123-19-3 | 18,623,119.39 | 7,830,059.76 | 26.77% | |
Phenol | 108-95-2 | 5,390,207.69 | 1,977,820.44 | 7.75% | |
Furan, 2-pentyl- | 3777-69-3 | 842,574.82 | 480,200.34 | 1.21% | |
o-Cymene | 527-84-4 | 1,473,654.02 | 848,144.25 | 2.12% | |
γ.-Terpinene | 99-85-4 | 773,853.7 | 482,517.9 | 1.11% | |
峰面积合计 | 69,564,868.57 |
表2. 三种尿液预处理过程中吹扫气体GC-MS色谱图详细信息
图3. 不同预处理剂尿液中挥发性有机物色谱质谱总离子流图
通过上述实验揭示:向尿液加入过氧化氢能够抑制尿素水解,并在尿液处理过程中不会产物挥发性含硫化合物。尽管尿液含有有机物种类多,化学成份复杂,通过过氧化氢处理,可以将其中的无机物和有机物氧化并消除气味,降低毒性并提高可降解性,以及控制微生物生长等作用,使用时不存在像其他氧化剂存在化学残留物等问题 [
这项研究提供的数据表明:0.014%过氧化氢可以抑制尿素水解,从而稳定尿液,在酸性条件下,过氧化氢对尿液的稳定作用会增强。向尿液添加过氧化氢能降低尿液在存储处理过程中产生的挥发性有机物,特别是含硫化合物,降低了恶臭气味。因此,可以得出结论:过氧化氢可以在中性或酸性条件下稳定尿液,并能够减少尿液在存储过程中产生的挥发性有机物,是一种符合低风险低毒性的尿液预处理化学品。
感谢实验室各位老师及同事辛勤地付出。
本研究课题受到SYFDZZ18000041项目资助。
胡松林,高郁晨,薛 源,何新星. 过氧化氢对尿液处理的稳定作用研究Research on Stabilization of Urine Treatment by Hydrogen Peroxide[J]. 国际航空航天科学, 2020, 08(04): 114-124. https://doi.org/10.12677/JAST.2020.84015