"Green technology": Bio-stimulation by an electric field for textile reactive dye contaminated agricultural soil

Highlights: • Electro-biostimulation (EBS) process demonstrated in dye contaminated soil • In-situ formation of β-cyclodextrin enhanced the pollutant removal in the soil. • The EBS process enhanced the reduction of salinity. • The pollutants were removed by EBS process with eco-friendly technology. • Soil fertility and plant growth were enriched by EBS process. The aim of the study is to degrade pollutants as well as to increase the fertility of agricultural soil by starch enhancing electrokinetic (EKA) and electro-bio-stimulation (EBS) processes. Starch solution was used as an anolyte and voltage gradient was about 0.5 V/cm. The influence of bacterial mediated process was evaluated in real contaminated farming soil followed by pilot scale experiment. The in-situ formation of β-cyclodextrin from starch in the treatments had also influence on the significant removal of the pollutants from the farming soil. The conductivity of the soil was effectively reduced from 15.5 dS/m to 1.5 dS/m which corroborates well with the agricultural norms. The bio-stimulation was confirmed by the increase of the phosphorus content in the treated soil. Finally, phytotoxicity assays demonstrated the viability of the developed technique for soil remediation because plant germination percentage was higher in the treated soil in comparison to untreated soil.