Investigation of the Efficiency of Selected Bacterial and Fungal Species in the Removal of Phosphate and Sulphate from Wastewater

Abstract

The aim of this study was to ascertain the efficiency of selected bacteria (Pseudomonas, Staphylococcus, Klebsiella and Lysinibacillus species) and fungi (Aspergillus niger, Aspergillus flavus, Fusarium and Absidia species) in the removal of phosphate and sulphate compounds from wastewater. The study was carried out under shaking flasks conditions. The test wastewater was filtered, sterilised and inoculated with the respective test bacterial and fungal isolates. Just after inoculation with a test isolate and every 24 h for 96 h, aliquot wastewater sample was taken from each flask aseptically for the estimation of phosphate and sulphate concentration in the wastewater. The results revealed remarkable phosphate and sulphate removal within the first 24 h and 48 h, respectively of incubation in the presence of three of the bacterial (Pseudomonas, Staphylococcus and Klebsiella) isolates, after which increases were observed. In the presence of the fungal isolates, remarkable decreases in phosphate and sulphate levels in the wastewater were observed after the first 48 h of incubation in the presence of the Aspergillus niger and Aspergillus flavus. In the presence of the Fusarium spp., there were consistent decreases in phosphate and sulphate levels with time. No remarkable decreases in phosphate and sulphate levels were observed with time in the presence of the Lysinibacillus and Absidia species. The study was able to give an insight into the phosphate and sulphate removal ability of the test isolates under the experimental conditions.