Application of surrogates, indicators, and high-resolution mass spectrometry to evaluate the efficacy of UV processes for attenuation of emerging contaminants in water

Abstract

In response to water scarcity, strategies relying on multiple processes to turn wastewater effluent into potable water are being increasingly considered by many cities. In such context, the occurrence of contaminants as well as their fate during treatment processes is a major concern. Three analytical approaches where used to characterize the efficacy of UV and UV/H2O2 processes on a secondary wastewater effluent. The first analytical approach assessed bulk organic parameters or surrogates before and after treatment, while the second analytical approach measured the removal of specific indicator compounds. Sixteen trace organic contaminants were selected due to their relative high concentration and detection frequency over eight monitoring campaigns. While their removal rate ranges from approximately 10 to >90%, some of these compounds can be used to gauge process efficacy (or failure). The third analytical approach assessed the fate of unknown contaminants through high-resolution time-of-flight (TOF) mass spectrometry with advanced data processing and demonstrated the occurrence of several thousand organic compounds in the water. A heat map clearly evidenced compounds as recalcitrant or transformed by the UV processes applied. In addition, those chemicals with similar fate were able to be grouped together into clusters to identify new indicator compounds. In this manuscript, each approach is evaluated with advantages and disadvantages compared.

Evaluation of the transport parameters and physiochemical properties of forward osmosis membranes after treatment of produced water

“…It can be assumed that carbohydrates in the feed were attributed to guar gum, which is commonly used as a viscosity enhancer to suspend proppants during hydraulic fracturing [30]. Separation for LC/Q-TOF analysis was performed on a Zorbax C18 column using a water/acetonitrile gradient with formic acid as modifier at a flow of 0.4 mL/min [31]. For each run, 10 µL sample was injected in triplicate.…”

Predicting trace organic compound attenuation with spectroscopic parameters in powdered activated carbon processes

“…The use of indicator compounds that mimic the behavior of wider groups of chemicals is now prevalent (Merel et al, 2015). However, measuring TOrCs still requires sophisticated analytical equipment, highly trained technicians, and often requires days to weeks to receive results.…”

Rapid direct injection LC-MS/MS method for analysis of prioritized indicator compounds in wastewater effluent

“…These lists can be based on available occurrence data, detection frequency, risk assessment, impact of environmental conditions and treatment efficacy. [14][15][16][17][18] In the past, analysis of these indicator compounds at trace levels has required an extraction and concentration step that is laborious, and detrimental to reproducibility of results due to several human-manipulation steps involved. 19 Further, this is time-consuming and results in longer analysis times which can cause changes in analyte concentrations while delaying potential remedial action to the water source if required.…”

“…: pharmaceutical; S/H: Steroid/Hormone. a Literature cited 1,17,21,25,. Environmental Science: Water Research & Technology Paper Open Access Article.…”