In this work, we are interested in the quaternization of poly(acrylamide-co-4-vinylpyridine) [AM7/VP10/0.1%/] by the methyl-tosylate CH$_{3}$TS. The obtained copolymer poly(acrylamide-co-(N-methyl-4-vinylpyridinium tosylate)) [AM7/VP10/0.1%/CTs] has been characterized by $^{1}$H NMR and UV-Vis spectroscopy. The macromolecular weight was determined by size exclusion chromatography as well as by viscosity. With the aim of removing turbidity by coagulation-flocculation from bentonite suspensions, the prepared copolymer was used as a flocculant. Several important parameters in the flocculation process, such as pH of water, initial turbidity, and flocculant concentration, were utilized for the optimization of wastewater treatment. Flocculation experiments were carried out in a conventional jar test where the turbidity removal was found about 90% at pH 3 with a low flocculant concentration range from 0.5 to 3 mg/L. In addition to obtaining good efficiency from using a semiindustrial pilot of flocculation, clear and clean water was produced during 2 h of treatment.