Polyaniline-derived carbons: Remarkable adsorbents to remove atrazine and diuron herbicides from water

The contamination of water resources by hazardous organic compounds is becoming severe worldwide. In this study, the adsorptive removal of atrazine (ATZ) and diuron (DUR), two widely used herbicides, from water by polyaniline-derived carbons (PDCs) was investigated for the first time, under various conditions. A selected PDC, fabricated at optimum conditions, i.e., by pyrolysis at 800 degrees C (and labeled PDC(800)), showed remarkable adsorptivity for both herbicides, that is, 7.7 and 11.3 times the maximum adsorption capacity (Q(o)) for ATZ and DUR, respectively, compared to activated carbon (AC). Or, the Q(o) values of PDC(800) for ATZ and DUR were 943 and 884 mg/g, respectively; however, the Q(o) values of AC were only 123 and 78.0 mg/g, respectively. Moreover, the optimum adsorbent PDC(800) had 4.5 and 3.1 times Q(o) that of the best adsorbent, that showed the highest performances, so far, for ATZ and DUR, respectively. Plausible adsorption mechanisms were suggested based on the porosity and the adsorption in a wide pH range. The new adsorbent was reusable via simple solvent washing. Based on its remarkable adsorption performance and facile reusability, PDC(800) can be considered a promising adsorbent to remove herbicides such as ATZ and DUR from contaminated water.