Synthesis of activated biochar incorporated PVA-silica composite and its application in the adsorption of polycyclic aromatic hydrocarbons from wastewater

Abstract

Polycyclic Aromatic Hydrocarbons (PAH) are pervasive pollutants exposed in the environment primarily due to the incomplete combustion of carbonaceous fossil fuels such as coal, crude oil derivatives, and other organic materials such as wood, paper, garbage, tobacco, etc. Secondarily other important industries such as aluminium production, catalytic cracking towers, and motor vehicle emissions also cause huge emissions. Naphthalene is one of the most available PAH, which has several negative impacts on living health. To eliminate naphthalene from wastewater, some physicochemical approaches are being taken in which adsorption is the most established one. In our present study, a novel membrane-like composite was prepared with PVA (Poly Vinyl Alcohol) and Silica nanoparticles which were modified by incorporating activated banana biochar to increase its efficiency. Characterizations like FT-IR, SEM, and EDX were performed to depict various characteristic features of the composite. The removal of naphthalene due to the adsorption process was studied experimentally by a batch study in different varying parametric conditions like different adsorbent dosages, contact time, pollutant concentration, temperature, pH, and agitation speed. From the results, the highest removal percentage was observed as 99.549 % with conditions like an adsorbent dose of 2 g/L, 160 rpm agitation speed, 20 mg/L initial naphthalene concentration, and 303 K temperature after 2 hrs. Mathematical modelling was done to evaluate the adsorption isotherm with the help of Langmuir and Freundlich models. Low cost, biodegradability, availability, and high removal efficiency have made the composite an effective adsorbent for wastewater treatment.