A Novel Hyperbranched Polymeric Flocculant for Waste-Water Treatment

• Published in: Journal of polymers and the environment 2018-07, Vol.26 (7), p.2782-2792
• Main Authors: Xu, Kun, Wang, Haiwei, Liang, Xuechen, Tan, Ying, Yao, Xianping, Wang, Pixin
• Format: Article
• Language: English
• Subjects: ACRYLAMIDE; CARBON 13; Cationic polymerization; Chain entanglement; Chemical synthesis; Chemistry; Chemistry and Materials Science; Coils; Configurations; COPOLYMERS; DESORPTION; Entanglement; Environmental Chemistry; Environmental Engineering/Biotechnology; Flocculants; FLOCCULATION; FOURIER TRANSFORM SPECTROMETERS; Fourier transforms; GEL PERMEATION CHROMATOGRAPHY; Hydrochlorides; HYDROGEN 1; Industrial Chemistry/Chemical Engineering; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; Ionization; Ions; Jar tests; Lasers; Liquid chromatography; Magnetic resonance spectroscopy; Mass spectrometry; MASS SPECTROSCOPY; Materials Science; Michael reaction; NMR; NUCLEAR MAGNETIC RESONANCE; Original Paper; pH effects; PH VALUE; Polymer Sciences; Polymers; Scientific imaging; Spectroscopy; TIME-OF-FLIGHT METHOD; Transmittance; Viscosity; WASTE WATER; Wastewater treatment; Water treatment; Zeta potential
• ISSN: 1566-2543; 1572-8919
• DOI: 10.1007/s10924-017-1120-4

Cationic hyperbranched oligomer poly( N -acryloyl-1,2-diaminoethane hydrochloride) (HADE) was firstly synthesized by Michael addition reaction. And then, a series of cationic flocculants poly(acrylamide/ N -acryloyl-1,2-diaminoethane hydrochlorides) (PAM-HADEs) with hyperbranched structure was prepared from HADE as macro-monomer and acrylamide (AM). The structures of PAM-HADEs were characterized by Fourier transform infrared spectrometry, 1 H and 13 C nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). And the properties were systematically evaluated by intrinsic viscosity, zeta potential and hydrodynamic radius. The mechanism of the cationic hyperbranched copolymer used in water treatment was extensively studied via a jar test in which the transmittance of the supernatant, settling time, and average floc size were used to evaluate the flocculability. Compared with the linear flocculant poly (acrylamide/liner- N -acryloyl-1,2-diaminoethane hydrochloride) (PAM-LADE), the novel hyperbranched polymeric flocculants exhibited outstanding flocculability which were reflected by shorter settlement time, high transmittance and large floc size. The primary cause that PAM-HADEs owned excellent flocculability is the more stretching configuration and less chains entanglement of PAM-HADEs in waste-water due to their hyperbranched structure compared with that of the linear PAM-LADE which exhibited curly coil configuration. On the other hand, abundant and exposed cationic terminal groups of PAM-HADEs originated from their hyperbranched structure also hint higher flocculation capacity. At optimum dosages of the polymer, the transmittance of the supernatant is less at low and high pH values, indicating that the natural pH (pH 7.29) of the suspension is the most appropriate pH for the flocculation.