تاثیر مواد افزودنی شیمیایی خاک بر میزان جذب و تجمع سرب و کادمیم در گیاهان بومی شمال ایران

Background and purpose: Using plants for cleaning up the soil contaminated with pollutants, especially heavy metals increased in the last decade. Decrease in the availability of heavy metals in soil by plants is one of the major challenges of phytoremediation. This study was conducted to determine the role of EDTA, ammonium citrate and ammonium phosphate in the mobility and availability of Pb and Cd in soil by native plants of Mazandaran Province. Materials and methods: In this study, sampling was randomly done from the soil around the highway and industrial and agricultural areas in two cities of Amol and Babol. Three native plants of northern areas in Iran, namely, Abutilon theophrasti, Amaranthus retroflexus, and Zea maize, were studied. Lead and cadmium concentration in the soil and plant samples was determined by Atomic Absorption Spectrometry (AAS) Perkin-Elmer 603. Results: In EDTA treatment, maximum concentration of lead in Zea maize, Amaranthus retroflexus and Abutilon theophrasti was 686.5, 538 and 264.5 mg/Kg, respectively, while maximum cadmium concentration (36, 43, 66) was observed in Amaranthus retroflexus, Abutilon theophrasti and Zea maize. Minimum lead concentration existed in Abutilon theophrasti (15 mg/Kg) and minimum cadmium was in Zea maize (5.5 mg/Kg) which was related to ammonium phosphate treatment in the studied plants. In EDTA and ammonium citrate treatments, mean concentration of lead in the shoots of Amaranthus retroflexus and Abutilon theophrasti were more than that of the roots (contrary to Zea maize), while cadmium concentration in roots of plants was more than shoots in all treatments. In this study, maximum lead and cadmium concentration existed in Zea maize and Amaranthus retroflexus, respectively. Conclusion: There is considerable amount of uptake of heavy metals such as lead and cadmium in the soil by non-edible plants (Amaranthus retroflexus and Abutilon theophrasti). Moreover, low concentration of heavy metals is observed in the soils around the industrial areas of the northern provinces of Iran. Therefore, phytoremediation technology is a fundamental step toward preserving the environment and promoting the health of the society.