Effect of nitrate or sulfate on flocculation properties of cationic polymer flocculants

Abstract

The objective of this study was to investigate the effect of different counterions on the flocculation of cationic polymer flocculants and to obtain new high efficient flocculants by modifying polydiallyldimethylammonium chloride (PDADMAC) with different counterions. The effect of nitrate or sulfate as counterions on flocculation properties of polydiallyldimethylammonium salts (PDADMAX) was investigated in the conventional jar test procedure by using optical monitoring technique and zeta potential measurement. Moreover, in order to indicate the flocculation mechanism of PDADMAX having different counterions, the effect of counterions on the solution property and adsorption conformation of PDADMAX was studied by reduced viscosity and atomic force microscopy (AFM). The experiment results show that counterions have a significantly different effect on PDADMAX flocculation where "adsorption charge neutralization action" and "adsorption bridging action" play different parts. PDADMAX having NO 3 ! has stronger "adsorption charge neutralization action" and its turbidity removal is 98%, whereas PDADMAX having SO 4 2! has stronger "adsorption bridging action", as well as the wider optimum dosage and larger floc size. In particular, the flocculation efficiency of PDADMAX having different contents of SO 4 2! or NO 3 ! is different. The optimum content of SO 4 2! or NO 3 ! is 20%.

Dewatering Oil Sands Tailings with Degradable Polymer Flocculants

“…As the efficiency of “salting-out” for iodide is greater than for chloride ions, the counterion plays a role in determining the ease of adsorption of charged polymer onto the surface of the clay particles. Moreover, Tian et al demonstrated that larger monovalent counterions led to a higher cationic density along the polymer chain (i.e., less counterion condensation) and thus to more extended molecular chains that resulted in efficient adsorption on the clay surface without extending loops and tails . Therefore, the iodide counterion of poly­(PCL 2 ChMA) may be an advantage over polymers with chloride counterions.…”

“…Moreover, Tian et al demonstrated that larger monovalent counterions led to a higher cationic density along the polymer chain (i.e., less counterion condensation) and thus to more extended molecular chains that resulted in efficient adsorption on the clay surface without extending loops and tails. 31 Therefore, the iodide counterion of poly(PCL 2 ChMA) may be an advantage over polymers with chloride counterions.…”

Copper Precursor Salt‐Dependent Antimicrobial Activity of Graphite Oxide Composites Against Escherichia coli and Staphylococcus Aureus: Synthesis and Characterization

“…Copper salts using sulfate and nitrate counterions show that the bivalent coordinate tends to generate larger flocs compared to the monovalent coordinate. [ 74 ] Also, at 0 °C, the water solubility of Cu(NO 3 ) 2 is 4 times higher than that of CuSO 4 , which means that in the doping treatment, the counterions and copper ions are dissociated at different speeds, as are the intermolecular forces that homogenize the solvation sphere, which change depending on the counterion, leading to different interactions with the GrO material.…”

Synthesis, Characterization, and Flocculation Properties of Branched Cationic Polyacrylamide

“…International Journal of Polymer Science 9 Based on the comprehensiveness of the range analysis of Tables 4, 5, and 6, the factors and levels of the orthogonal experiment were optimized as shown in Table 7 [20]. Considering the factors affecting the primary and secondary orders, coupled with the single-factor experiment, the change rule of searching for the best levels of intrinsic viscosity and flocculation properties, the flocculation performance of the polymer was the better, the optimum condition was 1 3 2 1 , the concentration of initiators was [2] 45 [4] 50 [3] 2 : 3 [1] 7 [1] 25 [3] 55 [4] 2 : 3 [2] * The numbers indicate the relative effect order in the range analysis above. 5 × 5.6 × 10 −4 mol/L, the concentration of monomers was 45%, the reaction temperature was 50 ∘ C, and the weight ratio of AM/DAC was 2 : 3.…”

“…The object of this process is to turn small particles into larger particles through the use of chemicals called coagulants or flocculants [3]. Flocculants may be inorganic or organic, small molecules or polymers [4]. Based on their ionic nature, polymeric flocculants can be classified as anionic, nonionic, and cationic [5].…”