Environ Monit Assess (2011) 183:151–195 DOI 10.1007/s10661-011-1914-0 A review on applicability of naturally available adsorbents for the removal of hazardous dyes from aqueous waste Pankaj Sharma · Harleen Kaur · Monika Sharma · Vishal Sahore Received: 29 March 2010 / Accepted: 27 January 2011 / Published online: 10 March 2011 © Springer Science+Business Media B.V. 2011 Abstract The effluent water of many industries, such as textiles, leather, paper, printing, cosmetics, etc., contains large amount of hazardous dyes. There is huge number of treatment processes as well as adsorbent which are available for the processing of this effluent water-containing dye content. The applicability of naturally available low cast and eco-friendly adsorbents, for the re- moval of hazardous dyes from aqueous waste by adsorption treatment, has been reviewed. In this review paper, we have provided a compiled list of low-cost, easily available, safe to handle, and easy-to-dispose-off adsorbents. These adsorbents P. Sharma (B ) · H. Kaur Department of Chemistry, Lovely School of Sciences, Lovely Professional University, Phagwara 144402, Punjab, India e-mail: sharmapankaj47@yahoo.com P. Sharma Energy and Environment Fusion Technology Center, Department of Environmental Engineering and Biotechnology, Myongji University, San 38-2, Nam-dong, Cheoin-Gu, Yongin-Si 449-728, Republic of Korea M. Sharma Department of Chemistry, Kurukshetra University, Kurukshetra 136119, India V. Sahore Department of Microelectronics & Photonics, University of Arkansas, Fayetteville, AR 72701, USA have been classified into five different categories on the basis of their state of availability: (1) waste materials from agriculture and industry, (2) fruit waste, (3) plant waste, (4) natural inorganic mate- rials, and (5) bioadsorbents. Some of the treated adsorbents have shown good adsorption capaci- ties for methylene blue, congo red, crystal violet, rhodamine B, basic red, etc., but this adsorption process is highly pH dependent, and the pH of the medium plays an important role in the treatment process. Thus, in this review paper, we have made some efforts to discuss the role of pH in the treatment of wastewater. Keywords Adsorption · Low-cost adsorbents · Dyes · Wastewater treatment · Column studies Introduction With the discovery of the synthetic dyes, the things began to change. Cheaper to produce, brighter, more color-fast, and easy to apply to fabric are some of the characteristic of these new dyes. Scientists have competed to formulate gorgeous new colors, and synthetic dyes had become obso- lete for most applications. No doubt, this bright- colored material has changed the world; however, the chemicals used to produce dyes are often toxic, carcinogenic, or even explosive. Among the different pollutants of aquatic ecosystem, dyes are