Adsorption of Aqueous Solution of NO2 by Certain Waste Materials

Nitrogen oxides are formed during high temperature combustion processes from the oxidation of nitrogen in the air or fuel. The principal source of nitrogen oxides - nitric oxide (NO) and nitrogen dioxide (NO₂), collectively known as NO_x - is road traffic. NO and NO₂ concentrations are therefore greatest in urban areas where traffic is heaviest. Other important sources are power stations, heating plants and industrial processes. Long-term exposure to nitrogen dioxide may affect lung function and that exposure to nitrogen dioxide enhances the response to allergens in sensitized individuals. The feasibility of using waste materials as adsorbent for air pollutant NO_x was evaluated in the present study. The experiments were carried out in laboratory on certain waste materials like Neem wood, brick powder, Coal and paper pulp. The experimental investigations were carried out by traditional adsorption studies and it showed that all substances have certain capacity to adsorb the NO_x from aqueous solution of NO_x. The adsorption of NO_x due to Neem dust is 100%. The adsorption due to paper pulp is in the range of 85-100%. The adsorption by brick powder is about 85%. At lower concentration the adsorption is more compared to higher concentration. It is found that the adsorption increases with increase in surface area.