Green synthesis and toxicity assessment of nano zerovalent iron against chromium contaminated surface water

Parthenium hysterophorus an annual herbaceous weed is known for its vigorous growth and as a causative agent for contact dermatitis, hay fever and diarrhea in humans and systemic toxicity in livestock. However, in spite of all the problems associated with this weed, some beneficial activities also reported. The objective of this study is to evaluate the potential of Parthenium hysterophorus leaf extracts for the synthesis of nanoscale zerovalent iron (nZVI) and their chromium remediation property. Due its high toxicity and mobility, hexavalent chromium is considered to be a high priority pollutant. In addition this work was executed to carry out toxicity appraisal in a water sample collected from Puliyanthangal Lake, Tamilnadu, India using nZVI. The water samples were examined before and after the nZVI application by means of microbial cultivation tests, phospholipid fatty acid analysis (PLFA) and toxicological tests. The present experimental results revealed that Cr (VI) is considerably adsorbed on nZVI nanoparticles and it could be a cost effective method for the in situ remediation of Cr (VI). In addition, standard plate count assay showed the dose dependent decrease in the bacterial cell viability in lake water sample after the addition of nZVI.