Petroleomic analysis of the treatment of naphthenic organics in oil sands process-affected water with buoyant photocatalysts

Abstract

The persistence of toxicity associated with the soluble naphthenic organic compounds (NOCs) of oil sands process-affected water (OSPW) implies that a treatment solution may be necessary to enable safe return of this water to the environment. Due to recent advances in high-resolution mass spectrometry (HRMS), the majority of the toxicity of OSPW is currently understood to derive from a subset of toxic classes, comprising only a minority of the total NOCs. Herein, oxidative treatment of OSPW with buoyant photocatalysts was evaluated under a petroleomics paradigm: chemical changes across acid-, base- and neutral-extractable organic fractions were tracked throughout the treatment with both positive and negative ion mode electrospray ionization (ESI) Orbitrap MS. Elimination of detected OS and NO classes of concern in the earliest stages of the treatment, along with preferential degradation of high carbon-numbered O acids, suggest that photocatalysis may detoxify OSPW with higher efficiency than previously thought. Application of petroleomic level analysis offers unprecedented insights into the treatment of petroleum impacted water, allowing reaction trends to be followed across multiple fractions and thousands of compounds simultaneously.

Photocatalytic treatment of organoselenium in synthetic mine-impacted effluents

“…The photocatalytic treatment experiment was performed in a synthetic mine-impacted water (SMIW) solution based on the matrix provided in literature 34 , spiked with 96 ± 12 µg/L selenomethionine (US Pharmacopeia Reference Standard, Sigma-Aldrich) (Table S1). The SMIW experiment was performed in a 2 L glass cylindrical closed-cell photocatalytic reactor (Figure S1) (interior cross-sectional area of 0.0133 m 2 ) using a dose of 0.58 kg/m 2 of buoyant photocatalyst (BPC) particles (TiO2 coated hollow glass beads, similar to those described previously, 36,37 provided by H2nanO). A PTFE-coated magnetic stir bar was added to the reactor (radius = 19.05 mm) and set to mix the solution at 200 rpm, (Re ≈ 1510).…”

“…Among these, heterogeneous photocatalysis is especially promising for organoselenium treatment as it combines advantages of both adsorption and oxidation, self-regenerating adsorbents (i.e., Langmuir-Hinshelwood mechanism). Further, buoyant photocatalysts provide a passive advanced oxidation process (P-AOP), proven for trace organic contaminants [30][31][32][33] , that allows for synergistic operation with current passive biological selenium treatment process (wetlands and submerged rock flow). Well-suited for insitu treatment applications with limited oxidative treatment alternatives, a passive buoyant photocatalysis process can harness naturally occurring ultraviolet (UV) solar radiation to drive the oxidation process without additional energy or chemical inputs.…”

Mild Photocatalysis Removes Microbial Inhibition and Enables Effective Biological Treatment of Naphthenic Acids

“…Specifically, 250 mL was pelleted and grown in synthetic OSPW brine (18.9 mg/L NH4Cl; 36.7 mg/L CaCl2•2H2O; 83.6 mg/L MgCl2•6H2O, 28.6 mg/L KCl, 755.4 mg/L NaHCO3, 6.6 mg/L NaF, 1.1 g/L NaCl, and 443.6 mg/L Na2SO4) and 40 mg/L of pre-oxidized NAs (COD0 ~ 100 mg/L). The OSPW brine ionic composition was selected based on the average literature characterization of OSPW [8,10,32]. NAs (2.5 g/L) were pre-oxidized using 2 mM H2O2 under UVc light (intensity ~ 3.5 ± 0.1 mW/cm 2 ) for 90 minutes, where radicals were subsequently quenched using excess Na2S2O3.…”

“…Buoyant photocatalysts (BPCs) are hollow glass microspheres coated with TiO2 nanoparticle photocatalysts, enabling catalyst localization at waters' surfaces where they can be activated by solar light [7][8][9][10]. TiO2 activation creates internal valence band holes that react with water and generate hydroxyl radicals, a potent oxidant [8].…”

Técnica De Inspeção Ultrassônica Para O Monitoramento Do Mecanismo De Dano Em Dutos De Transporte De Petróleo

“…A PLC pode ser usada para otimizar a quantidade do solvente e a fase estacionária, ter maior controle do fluxo e pressão.Devido à complexidade do petróleo, para se obter a composição detalhada dos compostos ácidos faz-se necessário a realização de muitas etapas de separação para a elucidação deste grupo de compostos. Os ácidos naftênicos apresentam baixa volatilidade, são quimicamente estáveis, podem agir como surfactantes das emulsões, provocam a corrosão nos equipamentos de refinaria, além de contribuir para a toxicidade de vários organismos causando problemas ao ambiente marinho(Meihan et al, 2008;LESHUK ET AL, 2018). Geralmente, a análise desses ácidos envolve extrações com fases estacionárias de troca aniônica como SAX (amina quaternária) e…”