N-nitrosomorpholine in potable reuse

WATER RESEARCH

卷:148

Article

Glover, Caitlin M.¹  Verdugo, Edgard M.¹  Trenholm, Rebecca A.¹  Dickenson, Eric R. V.¹ 

[1] Southern Nevada Water Author, Water Qual Res & Dev Div, POB 99954, Las Vegas, NV 89193 USA

关键词: N-nitrosomorpholine;    Potable reuse;    Advanced treatment;    Ozonation;    Biological activated carbon;    Granular activated carbon;    Reverse osmosis;    UV photolysis;   

DOI  :  10.1016/j.watres.2018.10.010

来源: Elsevier

【 摘 要 】

As potable reuse guidelines and regulations continue to develop, the presence of N-nitrosamines is a primary concern because of their associated health concerns. In this study, bench-, pilot-, and full-scale tests were conducted to focus on the occurrence and treatment of N-nitrosomorpholine (NMOR) in United States (U.S.) potable reuse systems. Out of twelve U.S. wastewater effluents collected, ambient NMOR was detected in eleven (average = 20 +/- 18 ng/L); in contrast, only two of the thirteen surface water and stormwater samples had NMOR. Across all of these samples maximum formation potential by chloramination produced an average increase of 3.6 +/- 1.8 ng/L. This result underscores the need to understand the sources of NMOR as it is not likely a disinfection byproduct and it is not known to be commercially produced within the U.S. At the pilot-scale, three potable reuse systems were evaluated for ambient NMOR with oxidation (i.e., chlorination and ozonation), biofiltration, and granular activated carbon (GAC). Both pre-oxidation and biofiltration were ineffective at mitigating NMOR during long-term pilot plant operation (at least eight-months). GAC adsorbers were the only pilot-scale treatment to remove NMOR; however, complete breakthrough occurred rapidly from <2000 to 10,000 bed volumes. For comparison, a full-scale reverse osmosis (RO) potable reuse system was monitored for a year and confirmed that RO effectively removes NMOR. Systematic bench-scale UV-advanced oxidation experiments were undertaken to assess the mitigation potential for NMOR. At a fluence dose of 325 +/- 10 mJ/cm(2), UV alone degraded 90% of the NMOR present. The addition of 5 mg/L hydrogen peroxide did not significantly decrease the UV dose required for one-log removal. These data illustrate that efficient NMOR removal from potable reuse systems is limited to RO or UV treatment. (C) 2018 The Authors. Published by Elsevier Ltd.

【 授权许可】

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