Removal of lead and phosphate ions from aqueous solutions by organo-smectite

Abstract

Smectite has been modified using hexadecyltrimethyl ammonium bromide in an amount of double cationic exchange capacity. This alteration makes it possible to use organo-smectite as a sorbent to remove anionic forms. The experiment consisted of the interchangeable sorption of phosphate(V) and lead(II) by organo-smectite. Research was carried out with varying pH (2-5) and various concentrations (0.1-5 mmol/L). Organo-smectite with previously adsorbed lead ions removed more phosphate than the untreated organo-smectite. Experimental data show that lead is more likely to absorb on the organo-smectite than on the organo-smectite with previously adsorbed phosphate ions. It follows that the most effective use of the organo-smectite is through the sorption of first - Pb cations and then PO4 anions. With an increasing concentration of Pb(II) or P(V), the sorption efficiency increases. The maximum sorption efficiency of lead and phosphate ions is observed at pH 5. This enables the removal of harmful lead and phosphorus compounds from waste water and immobilizes them on the sorbent's surface. The alternating reactions of lead and phosphorus ions result in the crystallization of brompyromorphite Pb5(PO4)3Br.

Sorption of Molybdates and Tungstates on Functionalized Montmorillonites: Structural and Textural Features

“…The preparation of the final sample consisted of several stages. First, the clay-size fraction (<2 μm) was separated from bentonite by a sedimentation process [25]. XRD confirmed that the only phase occurring after the separation procedure was Ca-montmorillonite and that all impurities from the initial sediment had been removed [12].…”

Clay Soil Modification Techniques for the Adsorption of Heavy Metals in Aqueous Medium: A Review

“…The results of this work provide novel information for developing new effective adsorbents of heavy metals. Smectite was modified using hexadecyltrimethylammonium bromide which an amount to double cationic exchange capacity for the interchangeable sorption of phosphate (V) and Pb (II) (Bajda et al, 2015). Possible use of montmorillonite modified with polyethyleneimine was investigated by Goncharuk et al (2010) for the removal of Co (II) and Ni (II) metal ions from aqueous solutions.…”

Removal of Heavy Metals and Metalloids from Water Using Drinking Water Treatment Residuals as Adsorbents: A Review

“…Adsorption seems to be one of the best-suited methods, due to its high efficiency, low-cost, and ease of operation. Various adsorbents, such as carbon foam [30], activated carbon [31], zeolite [32], clay minerals [33,34], organic polymers [35], and biochar [36], and many waste materials, such as fly ash [37], reused sanding wastes [38], biomass [39], and water treatment residuals (WTRs) [40,41], have been used for the removal of heavy metals by adsorption. The most effective heavy metal adsorbents, especially for arsenic, are adsorbents based on metal oxides (Fe, Al, Mn oxides), such as WTRs, bog iron ores [42], ferrihydrite [43], goethite [44], layered double hydroxide (LDH) [45], Sn/Ti-Mn binary metal oxides [46,47], Al/Fe oxide-oxyhydroxide composite powders [48], and red mud [49].…”