Synthesis of nanocomposites from cationic polyacrylamide and modified carbon black: Application as flocculants for oily sludge suspension

Abstract

Carbon black was modified using various liquid-phase oxidation methods (modified carbon black = m-CB, m = (1, 2, 3): 1, sulfuric acid/potassium permanganate method; 2, nitric acid method; 3, hydrogen peroxide method). With acetone–ethylene glycol as initiator, dimethyldiallylammonium chloride (DMDAAC) and acrylamide (AM) as monomer, cationic polyacrylamide (CPAM) was prepared by UV excitation of the monomer. The m-CB/CPAM nanocomposites were synthesized using a hydrothermal method. The factors that affected the molecular weight of CPAM were investigated, including the total monomer concentration, the dosage of the complex initiator, the mass ratio of mAM:mDMDAAC and the UV irradiation time. The chemical structures and morphologies of the samples were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental composition, X-ray diffraction and scanning electron microscopy. 1-CB/CPAM was utilized to flocculate oil sludge suspension, and the effects of 1-CB quality, 1-CB/CPAM dosage, temperature and pH value on the flocculation performance of 1-CB/CPAM were investigated. The flocculation mechanism of 1-CB/CPAM was also analyzed. The results show that 1-CB/CPAM has an outstanding flocculation effect, and it flocculates oil sludge particles by adsorption bridging and charge neutralization in acidic and alkaline conditions.