The effect of application of electrokinetic and chelating agents on substrate induced respiration and bacterial and fungal populations in a multi-metal contaminated soil

Application of combination of electrokinetic and chelating agents as a method of soil decontamination is an emerging technique recently. However there is not enough study about their effects on soil microbial activity. The current study investigated the effects of this new method on soil microbial activity to brighten its biological aspects. A multiple metal contaminated soil was treated by EDTA as a chemical chelator, cow manure extract (CME) and poultry manure extract (PME) as organic chelators (2 g kg-1) after 30 days irrigation in pots. Two weeks later the soils were treated by four oriented center electrical fields in each pot (0, 10 and 30 volts) for an hour per day during 14 days. Soil bacterial and fungal populations and substrate induced respiration (SIR) were analyzed at the end of the experiment in the soils around the cathodes and anodes separately. Result indicated that application of electrical fields had harmful effects on the bacterial and fungal populations and reduced SIR in both cathodic and anodic soils. Increasing the intensity of electrical field could increase its negative impacts. Application of EDTA catastrophically affected the analyzed indices in both cathodic and anodic soils. But utilization of PME or CME was a friendlier option in soil remediation techniques.