Determination of thermodynamic and transport parameters of naphthenic acids and organic process chemicals in oil sand tailings pond water

Abstract

Oil sand tailings pond water contains naphthenic acids and process chemicals (e.g., alkyl sulphates, quaternary ammonium compounds, and alkylphenol ethoxylates). These chemicals are toxic and can seep through the foundation of the tailings pond to the subsurface, potentially affecting the quality of groundwater. As a result, it is important to measure the thermodynamic and transport parameters of these chemicals in order to study the transport behavior of contaminants through the foundation as well as underground. In this study, batch adsorption studies and column experiments were performed. It was found that the transport parameters of these chemicals are related to their molecular structures and other properties. The computer program (CXTFIT) was used to further evaluate the transport process in the column experiments. The results from this study show that the transport of naphthenic acids in a glass column is an equilibrium process while the transport of process chemicals seems to be a non-equilibrium process. At the end of this paper we present a real-world case study in which the transport of the contaminants through the foundation of an external tailings pond is calculated using the lab-measured data. The results show that long-term groundwater monitoring of contaminant transport at the oil sand mining site may be necessary to avoid chemicals from reaching any nearby receptors.

Removal of organic acids from water using biochar and petroleum coke

“…MCA has similar -COOH functionality, but is connected to a toluene molecule ( Figure 4B) (Wang and Kasperski, 2010). These two low molecular weight organic acids have differing functionalities, and are highly soluble compared to most OAs found in OSPW (Wang and Kasperski, 2010;Wang et al, 2013). We studied these two compounds to investigate differences in the adsorption of small straight-chain versus cyclic organics and low molecular OAs in OSPW.…”

“…Typical mass spectrometer conditions were as follows: source temperature 500°C, curtain gas 15 psi, nebulizer gas (GS1) 40 psi, auxiliary gas (GS2) 40 psi, interface heater (ihe) ON, collisionactivated dissociation (CAD) gas high, ion spray voltage (IS) -4500 V, declustering potential (DP) -50 V, entrance potential (EP) -10 V, collision energy (CE) -10 V, collision cell exit potential (CXP) -3 V. The system was controlled by Analyst 1.5.1 software (ABSciex) (Wang et al 2013). …”