Search

Novel cellulose based flocculants C-g-P (DMC) with various chain architectures are synthesized through a situ graft copolymerization. The cationic ammonium chloride group (DMC) is grafted onto cellulose by two separate inverse emulsion polymerization with γ-methacryloxypropyl trimethoxy silane (KH-570) and double bond addition reactions, which is a new and simple method to employ KH-570 as a bridge for the connection of cellulose matrix and DMC group. The effects of pH, flocculant dose, standing time on turbidity of kaolin suspensions and particle sizes have been studied systematically. In addition, the response surface methodology (RSM) study confirms that PAC and C-g-P (DMC) have synergy in turbidity removal with a higher removal efficiency of 98.32%. Moreover, C-g-P (DMC) 1 has higher removal efficiency with 96.5% at a low dosage of 0.6 mg L−1 and better floc properties than C-g-P (DMC) 2 and C-g-P (DMC) 3, suggesting that the length and quantity of cationic branch chains play a crucial role in Kaolin flocculation due to their dramatically enhanced bridging effects. Keywords: Cellulose, Cationic flocculant, Inverse emulsion polymerization, Kaolin suspension

We determined the optimum activation conditions and formation mechanism of activated clay prepared using a waste acid recycling method. The aim of this study was to determine the effect of the processes used on the quality of the activated clay. Key objectives were to optimize operating conditions and to determine the mechanism of acid treatment. Results of single-factor experiments showed the following optimum conditions: sulfuric acid concentration of 22%, liquid–solid ratio of 3.5, and 4 h reaction time at 90°C. Under these conditions, the performance of activated clay appears to be much better than that prepared using the traditional method. Compared with the traditional method, the waste acid recycling process consumed less sulfuric acid (up to 21%) and the amount of aluminum released during the activation processes was also lower. Improvement in clay quality was due to the presence of several types of sulfate residue in the waste acid, preventing further dissolution of the crystal structure of montmorillonite. This improved structure uniformity resulted in an activated clay with better performance. Moreover, the waste acid recycle method reduces the environmental impact and pollution due to acid reuse. [ABSTRACT FROM AUTHOR]