Phytoremediation Using Bamboo to Reduce the Risk of Chromium Exposure from a Contaminated Tannery Site in Kenya

Abstract

Background. This study examines an intervention strategy to reduce the risk of chromium (Cr) exposure. It follows a previous Cr exposure investigation, which revealed that large volumes of Cr-contaminated waste were burnt on site. The study site had a long history of land-based waste disposal since 1994. Objective. The potential for phytoremediation using bamboo species to restore Cr-contaminated soil was evaluated. Methods. Chromium levels and physico-chemical properties of the tannery and control soils were analyzed before transplanting six different bamboo species. Translocation, bio-concentration and bioaccumulation factors of the species were assessed for phytoremediation capabilities. Results. Chromium levels in the tannery soils ranged from 1337.0 to 3398.0 mg/kg dw. The chromium levels were significantly higher (P 0.05). However, Cr levels in the tannery differed significantly (P 1 and translocation factor (TF) 1, indicating potential for phytoextraction, while D. birmanicus showed no potential for phytoextraction or phytostabilization. Conclusions. The present study identified D. asper, B. vulgaris, D. membranaceus and B. blumeana as suitable for restoration of Cr-contaminated tannery sites. Close monitoring of toxic metals is necessary during application of these species. Further studies are also recommended using a wide variety of bamboo species to optimize their application in phytoremediation. Competing Interests. The authors declare no competing financial interests

Keywords

• phytoremediation
• chromium exposure
• tannery waste
• bamboo species
• land-based disposal