An Effective Biomass for the Adsorption of Methylene Blue Dye and Treatment of River Water

Neolamarckia cadamba leaves were used as an adsorbent for methylene blue removal as well as for the reduction in the water quality parameters of the sewage belts of Yamuna River in Allahabad, Uttar Pradesh, India. A variety of water quality parameters were assessed, including chemical oxygen demand, biological oxygen demand, total dissolved solids, conductivity, hardness, pH, and temperature. A great deal of degradation in the water quality parameters collected from three locations within the Yamuna River in Allahabad, Uttar Pradesh, India, has been observed by treating with Neolamarckia cadamba leaves. The adsorption studies were carried out by the batch method, and the effect of various parameters such as contact time, pH, initial concentration, and temperature was assessed. The maximum removal of methylene blue was obtained at pH 5 after 120 minutes of equilibrium time. In addition to fitting the Langmuir isotherm most accurately, the adsorbent also followed pseudokinetics of the second order. The maximum monolayer adsorption capacity of used biomass was 101 mg/g using 50 mg/L methylene blue solution. It is evident from the thermodynamic data that the adsorption is exothermic. Also, the spontaneity of the interaction between adsorbent and adsorbate decreases with temperature. Energy-dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy techniques were used to characterize the adsorbent. SEM images revealed that the biomass consisted of irregular spherical lumps with a porous structure, which provided effective adsorption sites. A chemical composition analysis of the biomass by EDAX shows that the chemical composition of oxygen and carbon decreases, whereas nitrogen’s chemical composition increases.