Use of Cyanobacteria and Organic Fertilizer Mixture as Soil Bioremediation

Abstract

3 Abstract: Soil pollution with heavy metals is spreading worldwide along with industrial progress. The exocellular polysaccharides of cyanobacteria had been suggested to alleviate the heavy metal toxicity by bio-sorption. This work aimed to study the effect of cyanobacteria suspension, Nostoc minutum and Anabaena spiroides, either alone or in addition to chemical or organic fertilizer on broad beans cultivated in contaminated soil with heavy metals. The obtained results showed that treatment with mixtures of cyanobacteria and organic fertilizer significantly increased dry weight of broad bean more than full chemical and organic fertilizers doses by 41% and 103%, respectively. All algal treatments caused an increase in nitrogen content in seeds more than full dose of both chemical and organic fertilizers. Mixtures of cyanobacteria and organic fertilizer reduced Pb, Cd and Ni contents in both shoot and seed more than other treatments. Soil pH, electric conductivity, Pb, Cd and Ni were highly significantly decreased by inoculation with cyanobacteria. The study recommends the use of mixture of cyanobacteria and organic fertilizers to improve the contaminated soil.