Effect of the Cationic Block Structure on the Characteristics of Sludge Flocs Formed by Charge Neutralization and Patching

Abstract

In this study, a template copolymer (TPAA) of (3-Acrylamidopropyl) trimethylammonium chloride (AATPAC) and acrylamide (AM) was successfully synthesized though ultrasonic-initiated template copolymerization (UTP), using sodium polyacrylate (PAAS) as a template. TPAA was characterized by an evident cationic microblock structure which was observed through the analyses of the reactivity ratio, Fourier transform infrared spectroscopy (FTIR), 1H (13C) nuclear magnetic resonance spectroscopy (1H (13C) NMR), and thermogravimetry/differential scanning calorimetry (TG/DSC). The introduction of the template could improve the monomer (AATPAC) reactivity ratio and increase the length and amount of AATPAC segments. This novel cationic microblock structure extremely enhanced the ability of charge neutralization, patching, and bridging, thus improving the activated sludge flocculation performance. The experiments of floc formation, breakage, and regrowth revealed that the cationic microblock structure in the copolymer resulted in large and compact flocs, and these flocs had a rapid regrowth when broken. Finally, the larger and more compact flocs contributed to the formation of more channels and voids, and therefore the specific resistance to filtration (SRF) reached a minimum.

Fabricating an anionic polyacrylamide (APAM) with an anionic block structure for high turbidity water separation and purification

“…According to the previous study, the proportion of the anionic microblock sequence could be calculated from the number and relative intensity of the carbonyl carbon resonance peaks by using the MestReNova soware. 19,35,37 The calculated results were displayed in Table 2 in which the peaks of e, f and g represented SAS, AAS and AAA trials, respectively, and those trials were all central around AM. In Table 2, it was more apparent that the proportion of the AAA trial increased rapidly form 37.3% in APAS to 49.7% in TPAS.…”

Pectin‐[(3‐acrylamidopropyl) trimethylammonium chloride‐co‐acrylic acid] hydrogel prepared by gamma radiation and selectively silver (Ag) metal adsorption

“…Here, hydroxyl (OH) free radicals attack pectin chain to abstract H ⋅ and to form pectin free radical . APTAC free radicals may undergo homopolymerization to form the microblock structure which results steric hindrance . Probably that is why APTAC can directly not combine to pectin to produce pectin–APTAC graft or crosslinked copolymer.…”

Bactericidal effect of cationic hydrogels prepared from hydrophilic polymers

“…Furthermore, ATR measurements were carried out to confirm the presence of cationic functional groups in hydrogels containing cationic polymers ( Figure 3). [21,22] colonies of E. coli were inoculated in liquid Luria-Bertani (LB) medium (Nippon Pharmaceutical Co., Ltd.) and incubated (37 C) for 1 day. Furthermore, a single colony of M. luteus was inoculated on LB medium for 1 day in a shaker incubator (30 C, 190 rpm).…”