This book is about study of adsorption of heavy metals and dyes. Adsorption technique is well known for various applications, for which activated carbon is the popular answer. Activated carbon needs effective and economical alternative which we have given in this research. It includes synthesis of low cost adsorbents and its application to remove heavy metals and dyes from aqueous solutions. The adsorbents were prepared from various fruit shell wastes. The adsorbents were characterized with modern techniques to examine and confirm the adsorption. The study was extended by applying well known isotherm models and the rate of adsorption was determined with kinetic models. The nature of adsorption was investigated with thermodynamic study. The results were compared with reported adsorbents which concluded that these adsorbents had better adsorption capacity.