Heavy Metal Removal from Liquid Wastes by Using Micellar-Enhanced Ultrafiltration

Abstract

Wastewaters from civil and industrial use, which contain high concentration of heavy metals, pose the problem for their correct disposal. They cannot be directly discharged in sewage systems, as metal ions represent a serious problem not only for human health but also for the environment. In this paper, the removal of nickel, cobalt, chromium, and zinc ions from synthetic liquid wastes was carried out, by using a micellarenhanced ultrafiltration (MEUF) process; an ultrafiltration (UF) membrane (a monotubular ceramic of molecular weight cutoff 210 kDa) together with sodium dodecyl sulfate (SDS) as an anionic surfactant was used, in a lab-scale experimental device. The synthetic liquid contained 10-mg/L metal ions (Cr, Zn, Co, Ni), while SDS concentration varied from values above and below critical micellar concentration (CMC). The experiments were carried out at room temperature (25°C). Results achieved showed that SDS was able to bind metal ions, resulting in a strong increase of rejection coefficient, which reached highest values in case of SDS concentration below CMC, unexpectedly.

Remediation of heavy metals using non-conventional adsorbents and biosurfactant-producing bacteria

“…as BSs can reduce the surface and interfacial tension of the medium, these get accumulated in the form of micelles on the solid/solution interface and bind the metal ions on themselves (Ayangbenro and Babalola, 2018). According to Tortora et al (2016) the metal-BS complex or metal-micelle complex can be taken out from the system using micellar enhanced microfiltration (MEMF) or micellar enhanced ultrafiltration (MEUF). The efficiency of BSs depends on their size, class type, charge and structure that facilitates or determines their interaction with the sorbed metal on the soil (solid) surfaces (Wan et al, 2017), also their translocation through soil pores on to the sorbed metal ions.…”

Reduction of Fouling and Scaling by Calcium Ions on an UF Membrane Surface for an Enhanced Water Pre-Treatment

“…Fouling can be classified as reversible fouling and irreversible fouling; it is formed due to cake formation (reversible fouling) and pore blocking (irreversible fouling). Efficient pretreatments may relieve the fouling by pre-reacting with the foulants in the feed water, such as coagulation and adsorption [15]. However, adverse effects from the pretreatment are also claimed.…”

Optimization of Enhanced Ultrafiltration Conditions for Cd with Mixed Biosurfactants Using the Box-Behnken Response Surface Methodology

“…With increasing industrialization, cadmium (Cd) has become widely used in various fields, including mining, metal working, electroplating and paint manufacturing [1]. As a persistent pollutant, Cd persists for a very long time after entering water bodies [2,3].…”

“…The common treatment methods for heavy metal ions in aqueous solutions include adsorption [6][7][8][9], bio-based methods [10][11][12], membrane separation techniques [13][14][15], electrolysis [16,17] and chemical precipitation [12,18]. Among these, micellar-enhanced ultrafiltration (MEUF), one of the membrane separation techniques, has received recent attention because it has the advantages of low energy consumption, easy operation, high permeation flux and high removal efficiency [1]. This technique removes heavy metal ions by adding surfactants to wastewater to form micelles that heavy metal ions in water adsorb or bind to, and thus enhanced ultrafiltration (MEUF), one of the membrane separation techniques, has received recent attention because it has the advantages of low energy consumption, easy operation, high permeation flux and high removal efficiency [1].…”

“…Among these, micellar-enhanced ultrafiltration (MEUF), one of the membrane separation techniques, has received recent attention because it has the advantages of low energy consumption, easy operation, high permeation flux and high removal efficiency [1]. This technique removes heavy metal ions by adding surfactants to wastewater to form micelles that heavy metal ions in water adsorb or bind to, and thus enhanced ultrafiltration (MEUF), one of the membrane separation techniques, has received recent attention because it has the advantages of low energy consumption, easy operation, high permeation flux and high removal efficiency [1]. This technique removes heavy metal ions by adding surfactants to wastewater to form micelles that heavy metal ions in water adsorb or bind to, and thus are retained by ultrafiltration membranes.…”