Preparation of Aminolignin from Paper Mill Sludge and Its Discolouring Flocculant Performance

Lignin was extracted from paper mill sludge by the process of alkali dissolving and acid precipitating. Then a new kind of aminolignin discolouring flocculant was prepared with the lignin and dimethylamine epoxypropylamine (named as epoxy amimes monomer) as the raw materials and NaOH as the catalyst. The influencing factors such as the ratio of reactants, activation time, reaction temperature and reaction time on the preparation of aminolignin were investigated so as to optimize the reaction conditions. The products were characterized by using Fourier transform infrared spectroscopy. The possibility of aminolignin as a flocculant was examined by using simulated waste water of several dyes and the results show that it has a satisfactory decolourizing ability, which can afford a new method of effectively utilizing lignin and tackling paper mill sludge.