Micropollutants such as pesticides and their derivatives can be major threats causing cancer and disrupting the endocrine system. There is an urgent need for the removal of these kinds of micropollutants. Nanocellulose-based materials, classified as "green" materials," have been used very rarely in pesticide removal processes. Therefore, cellulose nanofiber immobilization was performed on poly(2-hydroxyethyl methacrylate-glycidyl methacrylate) [poly(HEMA-GMA)] polymeric structures under alkaline conditions to increase surface area, hydroxyl content, and transport kinetics in an adsorbent. The stability and structural verification of the polymeric adsorbent were assessed via Fourier transform infrared spectroscopy (FT-IR) and swelling tests. While the water-sorption capacity for plain poly(HEMA-GMA) was 16 times higher than its weight, this value increased up to 30 times after modification. The maximum adsorption of 95.76 mg/g was obtained at the plateau value of 250 mg/L atrazine concentration. Adsorption was analyzed by mathematical models, and it has been observed that interactions dominated by chemical dynamics occur homogeneously and irreversibly.