Nitrite is highly toxic and is found in sewage and sanitary wastes from humans and animals due to the incomplete oxidation of nitrogenous organic matter. The methodologies for removing this health hazard have environmental significance. In the present work, a low cost bio-sorbent is developed from the ash of Tridax procumbens plant leaves to remove nitrites from polluted waters using batch adsorption methods. The conditions for the maximum extraction of nitrite using the bio-sorbent are optimized by varying the physicochemical parameters such as pH, contract time, initial nitrite ion concentration and adsorbent dosage. The effect of co-ions commonly present in water on the % of removal is also studied. Freudlich as well as Langmuir isotherms are plotted and correlation coefficient (R2) value confirmed that the adsorption follows the Langmuir isotherm indicating formation of monolayer on the surface of adsorbent. Pseudo-first-order and pseudo-second-order models are applied to identify the rate and kinetics of adsorption process. The adsorption process has good correlation coefficient value with pseudo-second-order model. The procedure developed is applied to real ground water samples and found to be successful.
