Preparation of a novel flocculant and its performance for treating acidic oily wastewater

In this study, a series of copolymers of methyl methacrylate (MMA), methacrylic acid (MAA) and chitosan (CS), named P(MMA-MAA-CS), were prepared via emulsion copolymerization (CS content in monomer mass was less than 3 wt%). The copolymer was characterized by infrared spectroscopy, X-ray powder diffraction, thermogravimetry and differential scanning calorimetry. The surface tensions and flocculation performances of different copolymers for treating acidic oily wastewater were also investigated. Interestingly, it was found that P(MMA-MAA-CS) has pH-sensitive surface activity and excellent flocculation performance. The effects of dosage, temperature, stirring speed and stirring time on the treatment of P(MMA-MAA-CS) were studied and the highest oil removal reached was 96%. This copolymer may have potential applications in treating acidic oily wastewater produced from oil well acidizing.