Insights on phytoremediation of chromium from tannery wastewater contaminated soil

Abstract

The study was conducted to evaluate the phytoremediation response of <i>Arundo donax</i> and vetiver grasses irrigated by different levels (0%, 10%, 25%, 50%, 75%, and 100%) of treated tannery wastewater. After 60 days, matured plants were harvested, sorted into root, leaf, stem and shoot, dried and digested using standard procedures and analyzed for Cr(VI) and total Cr using atomic absorption and UV-Visible spectrophotometer, respectively. Corresponding results revealed height growth of <i>Arundo donax</i> and vetiver grasses was greatly affected by the irrigation level of tannery wastewater. Roots of vetiver grasses accumulate the highest amount of Cr(VI) (2.76 mg/kg) compared to the shoots Cr(VI) 1.72 mg/kg. Lowering concentration of tannery wastewater used for irrigation to 10% boosted the accumulation capacity (3.99 mg/kg) of the root of <i>Arundo donax</i> grasses for Cr(VI). The translocation values (TF > 1) demonstrated favourability of <i>Arundo donax</i> grasses for phytoextraction of Cr(VI) to plant tissues above ground level. However, the bioaccumulation values (BAF > 1) of the root of vetiver grasses proved suitability for the phytostabilisation of Cr(VI). <i>Arundo donax and vetiver</i> grasses have demonstrated a substantial reduction in Cr contamination of soils from tanneries, and therefore, phytoremediation is potentially feasible for the decontamination of Cr-polluted environments.