Immobilization of heavy metals by modified bentonite coupled coagulation/flocculation process in the presence of a biological flocculant

Abstract

A B S T R A C TNanometer sized and sheet-like bentonites play an important role in the removal of metal ions from contaminated water. They exist everywhere in nature and can develop a good and less expensive alternative in wastewater cleanup containing heavy metals. However, their use may generate turbid suspensions difficult to settle. Therefore, a coupling of adsorption on natural material was chosen. A modified Algerian bentonite in coagulation/ flocculation processes was used with a biological flocculant obtained from waste recovery of fishery products. The results demonstrate that the modified bentonite has a very high adsorption capacity. The treatment efficiency was evaluated by measuring turbidity. The removal rate was observed around 99%.

Magnetic seeding coagulation: Effect of Al species and magnetic particles on coagulation efficiency, residual Al, and floc properties

“…In the enhanced coagulation process with ferric ions and calcite for high-arsenic water treatment, small arsenic-borne coagulants coating on the calcite surfaces increased the settling rate of the particles (Song et al, 2006). Many different types of particles have been added to aid coagulation performance, including carbon nanotubes (Simate et al, 2012), magnetic particles (MPs) (Zhang et al, 2012), zeolites (Liao et al, 2016), bentonite (Ferhat et al, 2016), silica (Xue et al, 2016), and manganese dioxide (Huangfu et al, 2017). However, these methods not only required large quantities of materials but also produced a considerable amount of sludge, increasing the costs for the subsequent disposal of potentially hazardous sludges.…”

Performance evaluation of adsorptive removal of Ni(II) by treated waste granular-activated carbon and new granular-activated carbon

“…In addition, there are high costs associated with treatment of the concentrate [12]. Traditional flocculants have a poor heavy metal removal capacity and frequently require additional modification or compounding to enhance the removal process [13]. Although adsorption is a relatively traditional processing technique, compared with other technologies, it has the greatest development space and application prospects owing to its low cost, stability, and convenience.…”