Impact of Peroxydisulfate in the Presence of Zero Valent Iron on the Oxidation of Cyclohexanoic Acid and Naphthenic Acids from Oil Sands Process-Affected Water

Abstract

Large volumes of oil sands process-affected water (OSPW) are produced during the extraction of bitumen from oil sands in Alberta, Canada. The degradation of a model naphthenic acid, cyclohexanoic acid (CHA), and real naphthenic acids (NAs) from OSPW were investigated in the presence of peroxydisulfate (S(2)O(8)(2-)) and zerovalent iron (ZVI). For the model compound CHA (50 mg/L), in the presence of ZVI and 500 mg/L S(2)O(8)(2-), the concentration decreased by 45% after 6 days of treatment at 20 °C, whereas at 40, 60, and 80 °C the concentration decreased by 20, 45 and 90%, respectively, after 2 h of treatment. The formation of chloro-CHA was observed during ZVI/S(2)O(8)(2-) treatment of CHA in the presence of chloride. For OSPW NAs, in the presence of ZVI alone, a 50% removal of NAs was observed after 6 days of exposure at 20 °C. The addition of 100 mg/L S(2)O(8)(2-) to the solution increased the removal of OSPW NAs from 50 to 90%. In absence of ZVI, a complete NAs removal from OSPW was observed in presence of 2000 mg/L S(2)O(8)(2-) at 80 °C. The addition of ZVI increased the efficiency of NAs oxidation by S(2)O(8)(2-) near room temperature. Thus, ZVI/S(2)O(8)(2-) process was found to be a viable option for accelerating the degradation of NAs present in OSPW.

Enhanced Delignification of Oil Palm Empty Fruit Bunch Fibers with in situ Fenton-oxidation

“…Even though the adsorption uptake of Fe(0) with a similar concentration of Fe(III) was comparable, the desorption performance was much less due to the in situ formation of Fe(0) particles. The penetration of Fe(III) was on the lumen, hence the introduction of reducing agent of NaBH4 as the formation of an in situ Fe(0) particle contributed more to a homogeneous distribution of the particles compared to Fe3O4 (Drzewicz et al 2012). …”

“…The oxidation process was introduced with a low concentration of Fe(III), zerovalent iron (Fe(0)), and magnetite particles (Fe3O4) as the Fenton reagents to enhance the delignification process of EFB fibers. Even though Fe(0) is expensive and unstable, it has been introduced in this study because it can generate hydroxyl radicals without the presence of hydrogen peroxide (Drzewicz et al 2012). The impact of hydrogen peroxide concentration, retention time, and weight ratio of Fenton reagents on delignification was observed to identify the efficiency of the catalyst.…”

Treatment of oil sands process-affected water with ceramic ultrafiltration membrane: Effects of operating conditions on membrane performance

“…To achieve the sustainability of the oil sands operations, OSPW needs to be treated to decrease its toxicity and to facilitate its reclamation for safe release into the receiving environment and/or for treated-OSPW recycle for reuse to minimize the volume of the fresh water uptake. Various chemical, physical, physicochemical and biological treatments have been evaluated in order to develop a performance-efficient and cost-effective strategy for OSPW remediation [5][6][7][8][9][10].…”

Metal-free catalysis of persulfate activation and organic-pollutant degradation by nitrogen-doped graphene and aminated graphene

“…The PS activation may occur either through generation of free radicals or by nonracial processes (Zhang et al, 2013). Recently, electrochemical methods or electron donors (zerovalent iron or ferrous ion (II)) also have been used for PS activation (Drzewicz et al, 2012;Ahn et al, 2013;Cai et al, 2014;Chaplin, 2014;Zhong et al, 2015). The focus has been on efficient and low-cost transition metal catalysis including Cu, Co, and others Dionysiou, 2003, 2004;Chaplin, 2014).…”