Flocculation Efficiency of Novel Amphiphilic Starch Derivatives: A Comparative Study

Abstract

Flocculation properties of amphiphilic starch derivatives of varying degrees of substitution (DS) of benzyl-and 2-hydroxypropyl-trimethylammonium moieties have been investigated in dispersions of kaolin, calcium carbonate, and silica. Moderate hydrophobic substitution leads to a decrease of efficient flocculant dose and increase of flocculation window width. Samples with high DS of hydrophobic moieties are effective only at significantly higher doses but in a broader concentration range compared to solely cationic ones of the same DS. Joint analysis of adsorption isotherms and flocculation test data has revealed that the surface coverage required to induce phase separation ranges between 10-25% and is minimal for amphiphiles, whose floc sizes are moreover less dependent on the flocculant dose.

The Influence of Salt Anions on Heavy Metal Ion Adsorption on the Example of Nickel

“…The increasing amount of sulfate ions leads to a decreasing pH-value of the water and therefore to damages and corrosion of cement in sewer and bridges for example [ 7 ]. Current physical and chemical processes for heavy metal ion as well as for oxyanion removal such as precipitation, filtration, reduction, and ion-exchange are expensive and inefficient in treating large quantities of water [ 8 , 9 , 10 ]. Adsorption is an efficient and economical process with increasing concern in research during the last years.…”

Chitosan — A Natural Sorbent for Copper Ions

“…The overwhelming majority of these processes uses polyelectrolytes to regulate the stability and flocculation properties of the disperse systems. This resulted in a great variety of synthetic and natural flocculants like chitosan and starch as natural products which are now commercially available to meet the specific demands of industrial fields, where an efficient solid-liquid separation is required [1][2][3][4][5][6][7]. The removal of inorganic components/particles has been intensively investigated during the last years.…”