The Impact of Metallic Coagulants on the Removal of Organic Compounds from Oil Sands Process-Affected Water

Abstract

Coagulation/flocculation (CF) by use of alum and cationic polymer polyDADMAC, was performed as a pretreatment for remediation of oil sands process-affected water (OSPW). Various factors were investigated and the process was optimized to improve efficiency of removal of organic carbon and turbidity. Destabilization of the particles occurred through charge neutralization by adsorption of hydroxide precipitates. Scanning electron microscope images revealed that the resultant flocs were compact. The CF process significantly reduced concentrations of naphthenic acids (NAs) and oxidized NAs by 37 and 86%, respectively, demonstrating the applicability of CF pretreatment to remove a persistent and toxic organic fraction from OSPW. Concentrations of vanadium and barium were decreased by 67-78% and 42-63%, respectively. Analysis of surface functional groups on flocs also confirmed the removal of the NAs compounds. Flocculation with cationic polymer compared to alum, caused toxicity toward the benthic invertebrate, Chironoums dilutus, thus application of the polymer should be limited.

Impact of ozonation pre-treatment of oil sands process-affected water on the operational performance of a GAC-fluidized bed biofilm reactor

“…Although many different treatments have been investigated for their ability to remove NAs from OSPW, most of the approaches have shown poor efficiency for removal of the most recalcitrant compounds. Additionally, the relatively high costs of many of these treatments may limit their applications in large-scale industrial treatments (Kim et al 2011;Pourrezaei et al 2011).…”

Water treatment technologies for the remediation of naphthenic acids in oil sands process-affected water

“…The combination results in charge neutralization and instability in aqueous solution. While coagulation/flocculation has often been investigated for the improved setting of dissolved fine solids in OSPW [82][83][84], in some circumstances, it has also been shown to be an effective method for NA removal [85,86].…”

“…Pourrezaei et al [85] demonstrated the removal of NAs from OSPW using a coagulation/flocculation process. The OSPW was collected from the West In Pit settling basin operated by Syncrude Canada Ltd in Fort McMurray, Alberta.…”

“…Conversely, reports of NA bioremediation often conclude that NAs of lower molecular weight, with fewer rings and branching, are more readily biodegraded by microbial cultures, leaving higher molecular weight NAs unmetabolized [64][65][66]77]. Further, coagulation/flocculation processes are often cited as significant producers of sludge [85,88,91], while fouling and poor selectivity are frequent challenges for both membrane filtration and adsorption processes [91,92]. Given the apparent limitations of these individual processes, much of the emerging research in this field is directed toward the treatment of OSPW using a combination of techniques [76,94,97,98,110,113].…”

Impact of petroleum coke characteristics on the adsorption of the organic fractions from oil sands process-affected water

“…A solid addition method was used to determine the pH of the zero surface charge (PZC) of the adsorbent. The AEF concentrations in OSPW before and after adsorption were measured using a FT-IR instrument (PerkinElmer Spectrum, 100 FT-IR Spectrometer, Waltham, USA), following the methodology explained in details elsewhere (Jivraj et al 1996;Pourrezaei et al 2011). …”