Additives in Plasticised Polyvinyl Chloride Fuel Microbial Nitrate Reduction at High pH: Implications for Nuclear Waste Disposal
Additives in Plasticised Polyvinyl Chloride Fuel Microbial Nitrate Reduction at High pH: Implications for Nuclear Waste Disposal
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增塑聚氯乙烯燃料中的添加剂在高 pH 值下微生物硝酸盐还原：对核废物处置的影响
DOI：
10.3389/fenvs.2018.00097
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发表时间：
2018
影响因子：
4.6
通讯作者：
J. Lloyd
中科院分区：
文献类型：
--
作者：
S. Nixon;B. V. van Dongen;C. Boothman;J. Small;J. Lloyd
核废料的安全处置需要彻底了解微生物对废料长期命运的作用。尽管对核废物库存有重大的体积贡献，但对地质处置库的高pH值和辐照条件下塑料的命运知之甚少。我们进行了微生物富集实验，以评估核工业中常用的增塑聚氯乙烯（PVC）片材中添加剂的潜力，以通过适应在pH 10下生长的微生物群落来促进硝酸盐还原。这些添加剂包括增塑剂和阻燃剂等。PVC粉末（无添加剂）作为无添加剂对照，两种材料的样品在超碱性条件下进行伽马辐照（1 MGy），代表调节的核废料，以评估辐照对生物利用度的影响。增塑PVC支持几乎完全的硝酸盐还原，无论是否照射，虽然照射PVC片材支持硝酸盐还原较少。尽管经过辐照的粉末支持少量的硝酸盐减少，但未经过辐照的PVC粉末没有观察到硝酸盐减少。这些结果突出了在水泥质中级核废物地质处置相关条件下，体积显著增塑PVC的生物利用度，并强调了限制对最终影响处置安全情况的生物化学过程的下游影响的迫切需要。
The safe disposal of nuclear waste necessitates a thorough understanding of the role microorganisms play on the fate of the waste materials over time. Despite significant volumetric contributions to nuclear waste inventories, little is known about the fate of plastics under the high pH and irradiating conditions of a geological repository. We conducted microbial enrichment experiments to assess the potential for additives in plasticised polyvinyl chloride (PVC) sheet, commonly used in the nuclear industry, to fuel nitrate reduction by a microbial community adapted to grow at pH 10. These additives include plasticisers and flame retardants, amongst others. PVC powder (no additives) served as an additive-free control, and samples of both materials were gamma irradiated (1 MGy) under hyperalkaline conditions, representative of conditioned nuclear waste, to assess the effect of irradiation on bioavailability. Plasticised PVC supported near-complete nitrate reduction, whether irradiated or not, although irradiated PVC sheet supported less nitrate reduction. No nitrate reduction was observed with non-irradiated PVC powder, although irradiated powder supported minor nitrate reduction. These results highlight the bioavailability of volumetrically significant plasticised PVC under conditions relevant to its geological disposal in cementitious intermediate level nuclear waste and highlight the critical need to constrain downstream effects on biogeochemical processes ultimately impacting on the safety case for disposal.
影响因子：
7
作者：
Haas, Brian J.;Gevers, Dirk;Birren, Bruce W.
通讯作者：
Birren, Bruce W.