Novel Adsorption Method for Contaminated Water by Wild Endemic Almond: Amygdalus scoparia

Abstract

Many of the water systems keep ecosystems thriving and feed a growing human population have become stressed. Water pollution especially heavy metal contamination is a major global problem and it is leading to deaths and diseases. In this study the potential of wild endemic almond: Amygdalus scoparia shell was assessed for adsorption of heavy metal ions such as Pb 2+ , Ni 2+ , Cr 6+ and Cr 3+ from aqueous solution. A. Scoparia fruits were collected in July 2014 from Sirmand Mountains near Hadji-Abad County, Hormozgan province and the mountains in Gnow protected area, Bandar-Abbas, Hormozgan province in Iran, respectively. Analyzing of Pb, Ni and Cr (III) and Cr (VI) concentrations performed using Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). Adsorption capacity of Cr (VI), Cr(III), Pb and Ni onto modified almond shells by phosphoric acid was investigated in a batch system by considering the effects of various parameters like contact time, initial concentrations, pH , temperature, absorbent dose and particle size. The adsorption was pH solution dependent and the maximum adsorption was observed at solution pH of 3.23. Moreover, contents of different heavy metals in the contaminated water showed significant (p <0.05) and positive correlation with contents of Pb (r = +82 to r = +96), Cr 6+ (r = +74 to r = +94), Cr 3+ (r = +84 to r = +98), Ni (r = +33 to r = +42) in the wastewater and A. Scoparia modified shell, respectively. The amounts of Cr (VI) adsorbed increased significantly with increase in dose of A. scoparia adsorbent (p<0.05) and their contact time (p<0.05). The results of this study revealed that A. scoparia can accumulate high level of lead, Chrome (VI) and (III) in a short time and their uptake rate by plant is significantly affected by their concentrations in the contaminated water (p<0.005). A contact time of 48 hours by almond shell was found to be optimum and 87.1% Cr (VI), 89.8% Cr(III), 84.4% Pb and 48.1% Ni was removed. Experimental results showed that low cost bio-sorbent was effective for the removal of pollutants from aqueous solution.