Application of phytoremediation for heavy metal contaminated sites in the South Pacific: strategies, current challenges and future prospects
Ivan Diarra, K K Saji Kumar, Surendra Prasad
Abstract
Effectively dealing with hazardous and recalcitrant pollutants such as heavy metals (HMs) has become a global challenge with limited options available for reprieve. This is true for Pacific Island Countries and Territories (PICTs) which have witnessed significant economic transitions and substantial increases hazardous waste depositions. Although several physico-chemical remediation techniques exist, the economic and geographic limitations of PICTs render them impractical for the region. Phytoremediation, a plant–based remediation technology which exploits hyperaccumulator plants to extract, accumulate and/or stabilize HMs, has received significant interest as a sustainable and non–intrusive remediation option. Nonetheless, improving the application and efficiency of phytoremediation programs not only requires a better understanding of the fundamental mechanisms governing HM accumulation and tolerance in plants, but also demands fast and reliable spectroscopic techniques for in–situ analysis. This review critically examines the current practices in phytoremediation and its prospects for the treatment of HM–contaminated sites in PICTs. We also review the limitations of traditional spectroscopic techniques such as inductively coupled plasma mass spectroscopy/atomic emission spectroscopy (ICP–MS/AES) and the promise of novel techniques such as field portable X–ray fluorescence spectrometry (FP–XRF), atmospheric pressure discharge plasma (APDP) and lab on chip (LOC) in phytoremediation studies.