Phytoremediation of Cu and Mn from Industrially Polluted Soil: An Eco-Friendly and Sustainable Approach

Abstract

Water and soil polluted by heavy metals (HMs) are the primary problem due to rapidly increasing urbanization and industrialization. For the treatment of polluted soil, phytoremediation turns into a cost-effective and eco-friendly technique. The current research aimed to examine the load of pollution, specifically HMs, in sediment and wastewater (WW) of the GadoonAmazai Industrial Estate (GAIE), Pakistan and compare the ability of native grass species Cynodon dactylon and Digiteria sanguinalis for the phytoaccumulation of HMs. The industrially polluted soil was analysed for HMs using atomic absorption spectrophotometry (AAS) and compared with healthy soil (irrigated by freshwater), which served as a control. The HM accumulation was considerably higher in the soil irrigated with WW than in control soil samples. The most substantial metal pollutant was manganese (Mn), which accumulated up to 2491.7 mg/kg in the WW irrigated soil. For assessing the bioremoval efficiency of grass species, pot experimentation was performed for 90 days. Soil samples and grasses were collected from the pots to examine the HM removal efficiency. A significant reduction was noted in physicochemical characteristics of the soil, such as electrical conductivity, total organic matter, phosphorus, potassium, and saturation. The grasses removed up to 59.0% of the Cu and 59.9% of Mn from the soil. The highest bioconcentration factor (BCF) and translocation factor (TF) of Cu were observed for D. sanguinalis. While the highest BCF and TF of Mn were obtained for C. dactylon. The research showed that the grass significantly (p ≤ 0.05) reduced HM in soil samples. Moreover, the selected grasses found a higher capability to accumulate HM in the roots than in the shoot. The maximum Cu removal was obtained by D. sanguinalis and Mn by C. dactylon. The research study concluded that phytoremediation using D. sanguinalis and C. dactylon is an eco-friendly and cost-effective method that can be utilized for soil remediation.

Keywords

• phytoremediation
• soil
• <i>Cynodon dactylon</i>
• Digiteria sanguinalis
• heavy metals
• wastewater