Interactive effect of oxytetracycline and lead on soil enzymatic activity and microbial biomass

Interactive effect of oxytetracyline (OTC) and lead on soil enzymatic activity and population of microbes was studied in the paper. The results showed effect of pollutants on bacteria, actinomycetes and enzymatic activity increased in the order: (OTC + Pb) > Pb > OTC, (OTC + Pb)> Pb > OTC and (OTC + Pb) > OTC > Pb, respectively. However, impact of pollutants on fungi decreased in the order: (OTC + Pb) < Pb < OTC. The analysis of X-ray photoelectron spectroscopy (XPS) showed that binding energy and atomic percentage of Al, Fe, C, O, N, Si, Mg and Ca altered after the amended with OTC or Pb. The decrease of oxygen atom density and increase of binding energy can be associated to the charge transfer, resulting from oxygen and carbon atoms coordinated with metal ions, other chemicals or partial decomposition. Thus, the findings of this study can provide a better insight into the interaction of both pollutants and their impacts on soil quality. (C) 2013 Elsevier B.V. All rights reserved.