Phosphorus removal by marine bacterium enhanced with iron in the presence of silicon

BACKGROUND: Seeking efficient phosphorus (P) removal methods is of great significance in both aspects of environmental protection and resource conservation. Silicon (Si) is always present in marine sediments and it contributes significantly to P removal by iron (Fe(III)) oxides. Marine microbes play the major role in marine biomineralization. The aim of this study was to investigate P removal performance by marine bacterium enhanced with Fe (III) in the presence of Si and the role Si played in the system. RESULTS: The optimal Fe/Si/P molar ratio for P removal was 1: 1.5: 1. P removal efficiency was 47.79%, 96.02%, and 97.87% in systems of pure bacterial cultures, bacteriawith Fe (III), and bacteria with Fe (III) and Si, respectively, at P of 30 mg L-1. Flocs and micro-precipitates were formed around cells in P removal systems containing Fe (III) or Si. Moreover, the amount and size of flocs in systems containing Si were larger than those without Si. CONCLUSION: P removal by marine bacterium enhanced with Fe (III) had good performance through precipitation and adsorption. Si was able to strengthen P removal ability and sludge settleability. This study can provide us with new insights into bacterial induced metal phosphate precipitate and into themarine P cycle. (c) 2017 Society of Chemical Industry