Inactivation kinetics and mechanisms of viral and bacterial pathogen surrogates during urine nitrification
Inactivation kinetics and mechanisms of viral and bacterial pathogen surrogates during urine nitrification
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DOI：
10.1039/c4ew00065j
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发表时间：
2015-01-01
影响因子：
5
通讯作者：
Kohn, Tamar
中科院分区：
文献类型：
--
作者：
Bischel, Heather N.;Schertenleib, Ariane;Kohn, Tamar
本文评估了使用细菌和噬菌体作为人类病原体的替代物在尿硝化反应器中的灭活性能和机制。两个平行的连续流移动床生物膜反应器（MBBR）运行了两个月的时间。使用一个MBBR用噬菌体MS 2进行连续加标实验。第二个反应器提供了一系列分批实验的基质，这些实验是为了研究鼠伤寒沙门氏菌，肠球菌属，MS2、Q β和Phi X174在尿硝化过程中。评价了曝气、生物活性和溶液组成在灭活中的作用。尽管噬菌体FX174和MS2在尿硝化后仍具有感染性，但观察到噬菌体Q β的部分失活。Q β失活主要归因于曝气和生物过程的潜在叠加效应，即，可归因于其他微生物存在的过程，如生物质吸附、捕食或酶活性。Q β失活的拖尾到一个平台表明，在曝气硝化反应器中的溶液组分的保护作用。与噬菌体相比，S.鼠伤寒沙门氏菌和肠球菌属主要受生物过程的影响：它们在生物活性硝化反应器中失活，而在化学等效的过滤控制中保持稳定。例如，测试的细菌可以被其他微生物群落竞争或吸附到反应器中的生物质上。微生物群落不适应灭活噬菌体MS 2（例如，通过增加病毒捕食者的流行），在流通式MBBR中连续输入51天期间没有观察到MS2的失活。这些结果的汇编表明，生物硝化作为一种肥料生产过程仍然不足以作为一个独立的技术消毒源分离的尿液。
This paper assesses the inactivation performance and mechanisms in urine nitrification reactors using bacteria and bacteriophages as surrogates for human pathogens. Two parallel continuous-flow moving bed biofilm reactors (MBBRs) were operated over a two-month period. One MBBR was used to conduct a continuous spike experiment with bacteriophage MS2. The second reactor provided the matrix for a series of batch experiments conducted to investigate the inactivation of Salmonella typhimurium, Enterococcus spp., MS2, Q beta, and Phi X174 during urine nitrification. The roles of aeration, biological activity, and solution composition in inactivation were evaluated. Whereas bacteriophages FX174 and MS2 remained infective following urine nitrification, partial inactivation of bacteriophage Q beta was observed. Q beta inactivation was attributed primarily to aeration with a potential additive effect of biological processes, i.e., processes that are attributable to the presence of other microorganisms such as sorption to biomass, predation or enzymatic activity. Tailing of Q beta inactivation to a plateau indicated a protective effect of the solution components in aerated nitrification reactors. In contrast to the bacteriophages, S. typhimurium and Enterococcus spp. were mainly affected by biological processes: they were inactivated in biologically active nitrification reactors while remaining stable in chemically equivalent filtered controls. The tested bacteria could, for example, be out-competed by other microbial communities or sorbed to biomass in the reactor. Microbial communities did not adapt to inactivate bacteriophage MS2 (e.g., via increased prevalence of virus predators) in the experimental time-scale evaluated, with no observed inactivation of MS2 during continuous input for 51 days in the flow-through MBBR. The compilation of these results suggests that biological nitrification as a fertilizer production process remains insufficient as a stand-alone technology for the sanitization of source-separated urine.