Heavy metal removal of chromium from aqueous solutions by Amygdalus Scoparia shells

Environmental contaminated by heavy metals caused many attentions to discharge of sewage. In recent years,several methods of treatment have been developed for treating of wastewater, reducing the volume of produced sludge and improving water quality. The adsorption is an efficient treatment method dueto easy operation and high efficiency. In this study, effectiveness of Amygdalus Scoparia shell has been investigated to remove heavy metal of chromium from real wastewater of electroplating process. The results were compared with commercial activated carbon. The experimental results showed for Amygdalus Scopariashell, maximum adsorption occurs at pH=1 and the system has reached equilibrium in 3 hours. The pollutantconcentration is between 5 to 150(mg/L). The maximum removal rate of 96.1 % occurs for a concentration of 5 (mg/L). The adsorbent dose was between 5 to 40 (g/L). These tests indicate positive effect of increasing adsorbent dose and adverse effect of increasing initial concentration in removal percentage. Removal ofchromium decreased severely with increasing pH. Removal rate in optimal conditions was 96.1% which wasmuch more effective than commercial activated carbon (92.5%).The results are adapted with Langmuir and Freundlich isotherms.

Keywords:

Adsorption , Chromium , Amygdalus Scoparia shell , heavy metals