Study of Ferrate(VI) oxidation for COD removal from wastewater

Abstract

Produced water (PW) is the abundant by-product of oil and gas industries. It contains several organic pollutants and needs proper treatment before its discharge. This study investigated the effectiveness of Ferrate (VI) (Fe6+) oxidation for remediation of the organic compounds produced water. A series of batch experiments were performed by ferrate oxidation method. A glass beaker of 1000 ml as reactor covered with aluminum foil was used to protect from sunlight. Produced water sample of 300 ml and a pre-decided amount of Fe6+ was added to initiate the oxidation process. All experiments were performed at constant magnetic stirrer speed of 200 rpm at room temperature. The Fe6+ dosage of 1-25 mg/l, pH 1-7, and contact time 5-90 minutes were used to determine the effectiveness of Fe6+ for organic compounds degradation. The COD removal was increased with the increase in Fe6+ dosage and contact time. The maximum COD removal was achieved with Fe6+ dosage up to 15 mg/l; further any increase in Fe6+ dosage decreased the COD removal. The same trend was observed for pH, COD removal was increased until pH 5 beyond that COD removal was decreased. Maximum 55% of COD removal was attained under optimum conditions such as pH, Fe6+ dosage, and contact time were 5, 15mg/l and 50mins respectively. The results indicate that Ferrate (VI) oxidation is a promising method for the degradation of organic compounds in produced water.

Investigation on the application of ferrate for the treatment of aquaculture wastewater

“…This finding is consistent with the results from Tahir Haneef's study in which the highest COD removal (i.e. 55%) reached with the increase of Fe 6+ concentration to 15 mg/L and additional concentration increase reduced the COD removal [21].…”

“…The trend in the effect of pH on COD removal from this study was different from that of Hanif and Mustafa [21] while partly agreeing with the findings from Sun et al [22]. The higher removal of COD was found in the basic conditions and the optimum condition of pH was at 11.…”

“…Also, Guo et al [23] treated CODMn (from glucose) with 1 mg/L K2FeO4 at pH from 6.2 to 8.0 and also found an increase in CODMn removal when pH was increased. In contrast, Hanif and Mustafa [21] investigated COD removal in the pH range of 1 -7 and revealed the increase in COD removal until pH 5 but the higher value of pH led to a reduction of COD removal. From Table 6, the optimal ferrate dose and pH were 10.2 mg/L and 11, respectively which would provide the COD removal of 72%.…”

Optimization of Micro-Pollutants’ Removal from Wastewater Using Agricultural Waste-Derived Sustainable Adsorbent

“…These refractory organic pollutants are also present in oil and gas extraction industries' wastewater in considerable amounts [4]. The wastewater obtained from oil and gas exploration industries is known as produced water (PW) [5]. The range of PAH concentration in PW reported by various research is from 124 to 1000 µg L −1 [6][7][8][9], and these pollutants are precarious even in low concentrations (µg L −1 -mg L −1 ) [7].…”