Introduction

Arsenic (atomic number 33) is an ubiquitous element in the ecosystem. Its toxicity has been known from ancient times. Man has lived with this element for thousands of years and will have to live with it for thousands more. However, during the last three decades, high concentrations of arsenic in groundwater have been reported in different regions of the world such as the Bengal Delta (West Bengal-India and Bangladesh), (>0.05-3,200 mg L-1), (Mandal et al. 1996; Bhattacharya et al. 1997; Chowdhury et al. 2000), Madhya Pradesh (Pandey 2000; Pandey et al. 1999, 2009), and many countries such as China, Inner Mongolia, Iran, USA, Argentina and Canada (WHO 2001; ATSDR 2007; Bhattacharya et al. 2002; Smedley and Kinniburgh 2002; Bundschuh et al. 2009).

Various techniques have been developed for arsenic removal from aqueous systems such as precipitation, adsorption, membrane processes, coagulation-filtration, ion exchange, nano filter and low cost filters such as sand filter unit, ALCAN filter, Bishuddhya filter, SORAS method, three-pitcher filter and so on. Of these, sorption from solution has received more attention due to its high efficiency. However, due to high maintenance costs the use of adsorbents and disposal by phytoremediation has been cited as a promising approach to arsenic removal.

In this study, we present an overview of: (1) environmental behaviour of arsenic in relation to plant-soil and plant-water systems, (2) arsenic compounds in plant cell interactions, focussing on the principal biological process (bioaccumulation and translocation of arsenic), (3) phytoremediation as a bio-remediation technique for arsenic removal, and (4) research carried out on plant and fungi materials useful as biosorbents. Phytoremediation techniques usually do not consider the biosorption processes of living plants and their dead and decaying parts. Combining bioaccumulation and biosorption may improve the effectiveness of arsenic remediation techniques and may reduce the disposal problem of arsenic adsorbed material. However further studies are needed for the development of the methodology and to enhance its cost effectiveness.

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