Removal of Polycyclic Aromatic Hydrocarbons (PAHs) from Produced Water by Ferrate (VI) Oxidation

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are mutagenic and carcinogenic contaminants made up of fused benzene rings. Their presence has been reported in several wastewater streams, including produced water (PW), which is the wastewater obtained during oil and gas extraction from onshore or offshore installations. In this study, ferrate (VI) oxidation was used for the first time for the treatment of 15 PAHs, with the total concentration of 1249.11 μg/L in the produced water sample. The operating parameters viz., ferrate (VI) dosage, pH, and contact time were optimized for maximum removal of PAHs and chemical oxygen demand (COD). Central composite design (CCD) based on response surface methodology (RSM) was used for optimization and modeling to evaluate the optimal values of operating parameters. PAH and COD removal percentages were selected as the dependent variables. The study showed that 89.73% of PAHs and 73.41% of COD were removed from PW at the optimal conditions of independent variables, i.e., ferrate (VI) concentration (19.35 mg/L), pH (7.1), and contact time (68.34 min). The high values of the coefficient of determination (R2) for PAH (96.50%) and COD (98.05%) removals show the accuracy and the suitability of the models. The results showed that ferrate (VI) oxidation was an efficient treatment method for the successful removal of PAHs and COD from PW. The study also revealed that RSM is an effective tool for the optimization of operating variables, which could significantly help to reduce the time and cost of experimentation.

Recent Advances in Methods for the Recovery of Carbon Nanominerals and Polyaromatic Hydrocarbons from Coal Fly Ash and Their Emerging Applications

“…The vessels were then heated in a microwave extraction system at 120 • C for 30 min (Milestone, Italy). After extraction, the samples were allowed to cool down, filtered, and cleaned using silica gel as per the USEPA Method 363 • C. The extracts were concentrated to 1.0 ml with a gentle flow of molecular nitrogen [154].…”

The photocatalytic process in the treatment of polluted water

“…Whereas Hanee et al ( 2020 ) sterilized pesticide-contaminated water using photochemical reactions aided by visible light/nanobubbles, advanced photocatalysis has proven to be a successful method for inactivating bacterial spores due to its ability to convert solar energy efficiently while producing fewer byproducts. Through the intimate connection of micro/nanobubbles, a new technology for optically visible light water disinfection has been developed (MNBs).…”

Mitigation of Ship Emissions: Overview of Recent Trends

“…Alternatively, conditioning can be performed by implementing other nonmechanical approaches, such as thermal hydrolysis, ultrasound, , microwave, oxidation, chemical leaching, and focus-pulse conditioning . Also note that significant remediation of PAHs can occur simultaneously in the conditioning section when microwave, oxidation, , or ultrasound , treatments are used. Finally, in the third and last step of the dewatering process, the sludge is dried using filter presses, evaporators, or centrifugal dryers until a relatively anhydrous cake is obtained.…”