Plants Role in Reducing Heavy Metals from Polluted Soil Leachate

Aims In the past few decades, more attention has been paid to clean up soils pollutedwith heavy metals by plants. A serious problem in this way is the amount of heavy metalsuptake by plants. This study was conducted to evaluate the effectiveness of 3 local plants ofMazandaran province, Iran, in reducing and controlling the soil’s heavy metals.Instrument & Methods The removal amount of three heavy metals (lead, zinc and cadmium)by native plants (maize, velvetleaf and wild amaranth) was investigated in alkaline (pH=8)and acidic (pH=5) soils and also using three substances such as EDTA, ammonium citrate andphosphate. The concentrations of these metals in leachate were measured by using atomicabsorption spectrometry method.Findings Lead, cadmium and zinc levels in leachate in treatments with plants were less thanunplanted ones. The concentrations of these metals in the produced leachate of treatmentswith acidic soils were higher than those with alkaline soils. In the treatments of soil pollutedwith additives, treatments containing ammonium phosphate and EDTA had the lowest andhighest concentrations of heavy metals, respectively. Concentrations of these metals intreatments without plants were higher than those with plants.Conclusion Increasing of soil pH is effective on stabilization of heavy metals in soil.Ammonium phosphate plays an important role in stabilizing and EDTA and ammoniumcitrate increase the mobility of lead, zinc and cadmium in soil and groundwater

کلیدواژه ها:

Metals ، Heavy ، Soil ، Plants ، Water Pollutants ، Chemical