Preparation of quaternized carboxymethyl chitosan and its capacity to flocculate COD from printing wastewater

Abstract

A bioflocculant, quaternized carboxymethyl chitosan (QCMC), was developed by the quaternization of N,O-carboxymethyl chitosan (N,O-CMC) and characterized by FTIR, 1 H-NMR, GPC, and potentiometry. The efficiency of the removal of chemical oxygen demand (COD) in printing wastewater by this flocculant was further reported. Results indicated that the capacity of QCMC to remove the COD from tested wastewater was the best one among the investigated flocculants. The pH had great influence on this capacity and the suitable pH for QCMC to treat the tested wastewater was about 5.0. The utilization of aid-flocculant, especially bentonite, could improve this capacity obviously, and the increase of mass ratio of bentonite to QCMC resulted in the increase of the capacities of complex flocculant to remove the COD from the tested wastewater. When the mass ratio of bentonite to QCMC was 40, pH of wastewater was 5.0 and amount of complex flocculant in the wastewater was from 2500 to 3142 mg L À1 , the removal ratio of COD was more than 80%.

Efficiency of chitosans for the treatment of papermaking process water by dissolved air flotation

“…Another strategy to improve the efficiency of chitosans is their low exploited combination with bentonites. The use of bentonites can improve the size and the density of the formed flocs which can result in an increase of its flocculation rate and at the same time can promote the adsorption of organics [22][23]. For a given level of contaminants' removal, the use of bentonites can help to reduce the required dosage of chitosan and thus, the treatment costs.…”

Biobased polymers and cationic microfibrillated cellulose as retention and drainage aids in papermaking: Comparison between softwood and bagasse pulps

“…. (Peniche et al, 2008;Cai et al, 2010;Sun et al, 2010;Zhang et al, 2010;Gu et al, 2011Kuutti et al, 2011Miranda-Castro et al, 2013). In papermaking, chitosan has been studied as an additive in order to enhance paper properties such as dry strength (Fatehi et al, 2010;Nicu et al, 2011;Ashori et al, 2013;Salam et al, 2013a,b), wet strength Chen et al, 2013), to improve retention and dewatering (Li et al, 2004a,b,b;Chi et al, 2007;Kuutti et al, 2011;Nicu et al, 2013) and to control the water-circuit contamination (Liu et al, , 2012.…”

“…Considering the fact that chitosan is insoluble at pH above 6.5, cationization of this polymer is a way to extend the range of its potential applications (Prado and Matulewicz, 2014). Indeed, a lot of the above cited papers investigate the use of cationized chitosan with this objective (Li et al, 2004a,b,b;Chi et al, 2007;Cai et al, 2010;Fatehi et al, 2010;Zhang et al, 2010;Miranda-Castro et al 2013).…”

Synthesis, Characterization and Antioxidant Activity of Quaternized Carboxymethyl Chitosan Oligosaccharides

“…However, the low solubility of chitosan in water has limited its application (2). In order to improve the water solubility of chitosan, much effort has been made to prepare its watersoluble derivatives, such as carboxymethyl chitosan (4,5) (6), quaternized chitosan (7), quaternized carboxymethyl chitosan (1,3,8), etc.…”