Melamine-nitrogenated mesoporous biochar derived from palm kernel shells for diuron adsorption in contaminated water

The extensive use of the herbicide diuron is leading to serious water pollution problems. As biomass-derived carbon is an environmentally friendly and cost-effective adsorption material, it presents a feasible option for removing diuron. In this paper, we investigated the adsorption capabilities of palm kernel shell-derived biochar combined with melamine (PKS-BM) as an affordable adsorbent for diuron removal from polluted water. Various techniques, including Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), Brunauer Emmett and Teller (BET) surface area analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), were used for the assessment of the properties of biochar synthesised after infusion with melamine. The results showed that the altered ionizable functional groups biochar achieved a removal rate of 82.5% under different adsorption conditions. Findings revealed that maximum removal of diuron from water was achieved with 30 mg of adsorbent at an initial diuron concentration of 100 mg/L, pH 6.7, and an adsorption time of 180 min at 40 degrees C. Maximum diuron adsorption was 675 mg/g under the given conditions. Kinetic data was effectively captured by both pseudo-second-order and Elovich kinetic models. Additionally, the Langmuir isotherm model exhibited a significant correlation with equilibrium data and reflected diuron adsorption onto PKS-BM, attributed to monolayer formation. Thermodynamic observations showed that the adsorption process of diuron on PKS-BM occurred spontaneously and exhibited an endothermic nature. The present study enhanced our comprehension of the practical application of PKS-BM as a potential sorbent for diuron removal from wastewater.