Combining Ferric Salt and Cactus Mucilage for Arsenic Removal from Water

Abstract

New methods to remediate arsenic-contaminated water continue to be studied, particularly to fill the need for accessible methods that can significantly impact developing communities. A combination of cactus mucilage and ferric (Fe(III)) salt was investigated as a flocculation-coagulation system to remove arsenic (As) from water. As(V) solutions, ferric nitrate, and mucilage suspensions were mixed and left to stand for various periods of time. Visual and SEM observations confirmed the flocculation action of the mucilage as visible flocs formed and settled to the bottom of the tubes within 3 min. The colloidal suspensions without mucilage were stable for up to 1 week. Sample aliquots were tested for dissolved and total arsenic by ICP-MS and HGAFS. Mucilage treatment improved As removal (over Fe(III)-only treatment); the system removed 75-96% As in 30 min. At neutral pH, removal was dependent on Fe(III) and mucilage concentration and the age of the Fe(III) solution. The process is fast, achieving maximum removal in 30 min, with the majority of As removed in 10-15 min. Standard jar tests with 1000 μg/L As(III) showed that arsenic removal and settling rates were pH-dependent; As removal was between 52% (high pH) and 66% (low pH).

Investigation of Self-Assembly Processes for Chitosan-Based Coagulant-Flocculant Systems: A Mini-Review

“…The literature on arsenic removal by coagulation-flocculation with chitosan is sparsely reported [27,33,34,35,36,37,38,39,40]. In general, typical examples of coagulation-flocculation studies have focused on inorganic arsenic species, either arsenate (As(V); HAsO 4 2− ) and/or arsenite (As(III); H 3 AsO 3 ) species [27].…”

“…This is advantageous since increased levels of Fe(III) in water are less aesthetically pleasing in taste and smell [39]. Baskan et al [35] used the Box–Behnken design to study optimal parameters for the coagulation of arsenate.…”

System integration of functionalized natural materials

“…38 For instance, when mucilage was added in combination with iron, >90% removal of As was attained in just 10 min. 61 When mucilage was added as a pure powder or in membrane form, up to 50% As or 18-20% As was removed, respectively. 55 , 57 Sibaja et al, 62 Vollrath et al, 14 and Truss 9 have also used natural fi bers in functional applications such as textiles and tissue scaffolds.…”

Mucilage-capped silver nanoparticles for glucose electrochemical sensing and fuel cell applications

“…Recently, its role as a natural occulant for arsenic removal has been reported. 24 Li et al reported the excellent lubrication properties of mucilage that result from the hydration layer between the polymer nanosheets in mucilage. 25 Mucilage was used as food thickener, food emulsier, and adhesive for lime and plasticizer.…”