Adsorption-characteristics-of-the-dye,-Brilliant-Green,-on-Neem-leaf-powder_2003_Dyes-and-Pigments.pdf

Adsorption characteristics of the dye, Brilliant Green, on Neem leaf powder Krishna G. Bhattacharyya*, Arunima Sarma Department of Chemistry, Gauhati University, Guwahati 781014, Assam, India Received 4 October 2002; received in revised form 15 November 2002; accepted 6 January 2003Abstract A novel adsorbent was developed from mature leaves of natural Neem trees for removing dyes from water. The adsorbent, in the form of fine powder, was found to be very effective in removing the dye, Brilliant Green, from aqu- eous solution. The adsorption process was carried out in a batch process with different concentrations of the aqueous dye solution as well as with different adsorbent doses, at a range of pH values and temperature. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherms and by computing equi- librium thermodynamic and kinetic parameters, the values of which showed the Neem leaf powder as a promising adsorbent for dyes in aqueous solution. # 2003 Elsevier Science Ltd. All rights reserved.Keywords: Neem leaf powder; Brilliant Green; Colour removal; Adsorption1. Introduction The Neem tree (Azadirachta indica) of family meliaceae is native to the Indian sub-continent, and its seeds and leaves have been in use since ancient times to treat a number of human ailments and also as a household pesticide [1–4]. The tree itself is known as an air purifier and a variety of medicinal and germicidal properties have been attributed to leaves, bark, seeds and other parts of the plant [5]. Leaves of the tree are used as anti-inflammatory, anxiolytic, anti-androgenic,anti-stress, humoral and cell-mediated immuno- stimulant, anti-hyperglycemic, liver-stimulant, anti-viral and anti-malarial activities [6]. Many industries generate coloured effluents containing various dyes and pigments and dis- charge the same to natural water bodies. Such effluents are characterized by fluctuating pH with large load of suspended solids an