Arsenic and fluoride removal by potato peel and rice husk (PPRH) ash in aqueous environments

Finding appropriate adsorbent may improve the quality of drinking water in those regions where arsenic (As) and fluoride (F(-)) are present in geological formations. In this study, we evaluated the efficiency of potato peel and rice husk ash (PPRH-ash) derived adsorbent for the removal of arsenic and fluoride from contaminated water. Evaluation was done in batch adsorption experiments and the effect of pH, initial adsorbate concentration, contact time and adsorbent dose were studied. The characterization of adsorbents were done using scanning electron micropcope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Both the Langmuir and Freundlich isotherm models fitted well for F(-) and As sorption process. The maximum adsorption capacity of adsorbent for As and F(-) were 2.17 μg g(-1) and 2.91 mg g(-1) respectively. The optimum As and F(-) removal was observed between pH 7 and 9. The sorption process was well explained with pseudo-second order kinetic model. The As adsorption was not decreased in the presence of carbonate and sulfate. Results from this study demonstrated potential utility of this agricultural biowaste which could be developed into a viable filtration technology for As and F(-) removal in As- and F-contaminated water streams.