Iron removal by precipitate flotation

Abstract

The water from several artesian wells in the metropolitan area of Recife presents high iron content, preventing its use in some industrial processes. The possibility of removing the iron by the use of precipitate flotation using sodium dodecyl sulphate (SDS) as collector was studied. The tests were carried out in a glass column 65 cm high, fed by a constant airflow. At pH 8, where the isoelectric point of colloidal iron hydroxide [Fe(OH)3] was observed, the size of the precipitate increases with conditioning time and facilitates the removal of iron ions by flotation. The results showed that an increase in conditioning time, from 5 to 20 minutes, resulted in a reduction of the residual concentration of iron from 13.2 to 0.2 ppm. The decrease in precipitate specific surface area rendered a decrease in the collector consumption possible. The iron ion removal process by flotation using SDS as collector was shown to be quite efficient. A removal of 99% of Fe3+ contained in the original solution was obtained.

Mechanisms of Reaction Between Co(II) Complexes and Peroxymonosulfate

“…Homolytic dissociation of the OÀ O bond in Co II (SO 5 )(H 2 O) is possible according to the following thermoneutral reaction (7):…”

“…Thus reaction ( 6) is followed by reaction (9), i. e., another SO 5 2À anion is coordinated to the central Co II ion, though the homolytic cleavage of OÀ O bond according to reaction (7) or reaction (8) can also occur in parallel. This time the most stable configuration is a configuration in which the second SO 5 2À anion is bound through the À OOS group, the structure is given in Figure 1b.…”

“…In environmental applications, i. e. in advanced oxidation technologies, cobalt is often the transition metal of choice, [5,6] as Fe III usually tends to precipitate as the hydroxide. [7] The increase in the application of HSO 5…”

Fe toxicity in plants: Impacts and remediation

“…Among these, ion exchange and adsorption are the most preferred methods for alleviating metal toxicity (Naushad, 2014). During the past decades, methods such as chemical precipitation (Hove et al, 2008), ion exchange (Keller, 2004), liquid–liquid extraction (Saji & Reddy, 2001), electrochemical (Ahn, 2018), oxidation infiltration (Khadse et al, 2015), electrodialysis (Ben Sik Ali et al, 2013), adsorption (Al‐Khaldi et al, 2015; Shahat et al, 2015; Sharma & Naushad, 2020; Sheibani et al, 2012), precipitate floatation (Morosini et al, 2014), filtration (Hale et al, 1916), sorption via zeolite (Ozdemir et al, 2019; Shaheen et al, 2012; Wingenfelder et al, 2005), organic amendments (Becker & Asch, 2005; Sahrawat, 2010), phytoremediation (Raza et al, 2020; Yang et al, 2018), and biological strategies (Bali et al, 2019; Sharma et al, 2005) have been employed to remove heavy metals especially Fe from large volumes of aqueous solution. Best demonstrated available approaches for remediation of Fe contaminated sites are nutrient amendment, phytoremediation, microbe‐assisted remediation, plant growth‐promoting rhizobacteria (PGPRs), chemical, organic amendments, and molecular breeding and genetic engineering (Jinal et al, 2019; Sikirou et al, 2015).…”