The removal of toxic metals from liquid effluents by ion exchange resins. Part XVII: Arsenic(V)/H+/Dowex 1x8

Abstract

The performance of anionic exchange resin Dowex 1x8 in the removal of arsenic(V) from aqueous solutions was investigated. Batch experimentation was carried out under different variables, including, the stirring speed applied on the system, the pH of the aqueous solution, resin dosage and temperature. Due to the characteristic speciation of arsenic(V) in aqueous phases, the removal of this element from the solution is negligible at highly acidic or alkaline pH values, but it is possible at the aqueous pH range of 4-9, thus, both HAsO42- and H2AsO4- species are loaded onto the resin. At the above pH range, arsenic(V) uptake is exothermic. Different models are fitted to the experimental values in order to gain knowledge about this ion exchange system: rate law, kinetics and solute loading onto the resin. This loading is compared against the yielded using non-functionalized multiwalled carbon nanotubes. The elution step is investigated using acidic solutions (HCl medium) as eluent, from the eluted solutions, arsenic(V) can be efficiently stabilized as ferric or calcium arsenates.

Synthesis, Characterization and Decomposition of Potassium Jarosite for Adsorptive As(V) Removal in Contaminated Water: Preliminary Study

“…In this sense, the stability of As(V) in the recrystallized structure of jarosite could be due to the formation of ferric arsenates when As(V) is trapped by the Fe contained in the amorphous and porous FeOH structure (obtained after jarosite decomposition). The above was described by other authors; in the first case, with a pre-treatment of an As-bearing eluate from a resin, they achieved stabilization of As(V) with iron salts, forming iron (III) arsenate, and in the second case, the oxidation, adsorption, and stabilization of As was carried out using Fe hydroxides, and this last technology is capable of reaching up to 99.9% in removal efficiency [ 49 , 50 , 51 ]. In this work, unlike what was mentioned above, the use of resins and Fe-hydroxide reagents can be omitted while also achieving an adequate adsorption and stabilization of As(V) directly into the decomposed jarosite structure.…”

A Review Study of Immobilized Microbial-Nanoparticles: Techniques and Biotechnology Applications

“…Hydrolysis of lignocellulose materials by immobilized enzymes is preferred over MNPs as these nano-bio-catalysts can be easily recovered and reused which increases the life of the bio-catalyst, and reduces the cost of bio-catalytic synthesis [85]. Figure (3) shows the steps of biotransformation of lignocellulose into monosaccharides by immobilized enzymes on magmatic NPs [86].…”

“…Some of these pollutants are non-biodegradable chemical compounds frequently introduced into ecosystems from industrial discharge, petroleum production activities, agricultural, fungicides, and mining activities [2]. Traditional physicochemical processes are frequently utilized to decline the toxicity from effluents among several techniques Iraqi Journal of Oil & Gas Research such as ion exchange [3], adsorption [4], ozonization treatment [5], membrane filtration [6], and photocatalysis [7]. The traditional processes result in some drawbacks such as high cost of operation and maintenance and the production of toxic sludge.…”

Adsorption Characteristics and Mechanisms of Fe-Mn Oxide Modified Biochar for Pb(II) in Wastewater

“…Recently, ion exchange [5], chemical precipitation [6], electrocoagulation [7], and adsorption [8] have been used to remove heavy metals from wastewater. Among these, adsorption is widely used because of its advantages of simple operation, high efficiency, and environmental friendliness, especially in the deep treatment of heavy metals in wastewater [9].…”