African Journal of Agricultural Research Vol. 6(24), pp. 5391-5397, 26 October, 2011 Available online at http://www.academicjournals.org/AJAR DOI: 10.5897/AJAR10.818 ISSN 1991-637X ©2011 Academic Journals Full Length Research Paper Mercury and arsenic accumulation by three species of aquatic plants in Dezful, Iran Alishir Afrous 1 *, Mohammad Manshouri², Abdolmajid Liaghat³, Ebrahim Pazira² and Hossein Sedghi² 1 Department of Water Sciences and Engineering, Science and Research Branch, Islamic Azad University (IAU), Tehran, Iran. 2 Department of Water Sciences and Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. 3 Department of Irrigation and Reclamation Engineering, University of Tehran, Karaj, Iran. Accepted 23 May, 2011 Heavy metals can be absorbed by living organisms, such as aquatic plants or non-living biomass. Aquatic plants can be used for removing heavy metals and nutrients from industrial and municipal wastewaters. This paper investigates the capability of Phragmites australis, Typha latifolia and Scirpus (Bulrush) to uptake arsenic and mercury from industrial wastewater. The accumulation capacities of these aquatic plants in three treatments consisting of 50, 100 and 200 mg/kg As and Hg in soil were studied under the semi-arid conditions of Dezful, Southwest Iran. Data observed from the treatments 60 days after growth indicated that each three species were capable to uptake As and Hg from the solution. Results showed significant statistical differences in accumulation of As in the below-ground tissues of three plants where the highest As accumulation (measuring 119.55 mg/kg) was observed for P. australis in the treatment of 200 mg/kg As in soil, followed by 65.25 and 47.86 mg/kg for Bulrush (Scirpus) and T. latifolia, respectively. Maximum accumulation for Hg in below-ground tissues was observed in P. australis measuring 6.23 mg/kg in 200 mg/kg Hg in soil treatment, followed by Bulrush (Scirpus) and T. latifolia measuring 2.23 and 1.45 mg/kg, respectively. The results indicated that As and Hg accumulations in below-ground tissues were higher than those for the above-ground tissues for all plants. The results also indicated highest below-ground to above-ground tissues rations (BG/AG) for As and Hg in P. australis and Bulrush (Scirpus) ranging 85.3 to 108.8 and 19.7 to 39, respectively. Data obtained from this research conformed well to the exponential association model. The overall conclusion being that the three aquatic plants selected in this study can be used as effective catalysts for removing heavy metals from the industrial wastewater under arid and semi-arid conditions. Key words: Accumulation, arsenic, mercury and Phragmites australis. INTRODUCTION Contamination of water and wastewater with heavy metals is emerging as a global environmental challenge caused by this phenomenon. One approach is to treat the contaminated wastewater in order to remove their heavy metals contents and reuse the out product for agricultural *Corresponding author. E-mail: ali.afrous@gmail.com. Abbreviations: BG, Below-ground; AG, above-ground; ICPMS, inductively coupled plasma mass spectroscopy. that has attracted the attention of the researchers and decision-makers on methods to overcome the problems production. The aquatic plants can reportedly be used as the natural catalysts to absorb and accumulate heavy metals in their tissues from wastewater (Vymazal, 2008). Various researches have been conducted on the harmful effects of the heavy metals of the wastewater such as arsenic, nickel and mercury and the way in which these aquatic plants are able to absorb and accumulate these hazardous metals from the wastewater and therefore to mitigate their harmful consequences (Ma et al., 2001; Robinson et al., 2003; Taggrat et al., 2005; Skinner et al.,