Removal of low concentration of phosphorus from solution by free and immobilized cells of Pseudomonas stutzeri YG-24

Phosphorus (P) in wastewater is a main factor causing eutrophication, and removal of low concentrations of P (≤ 1.0 mg L− 1) is an important, but not fully studied topic. The removal of low content of P is rather difficult or expensive. To develop alternative biological methods for the removal of low concentration P, polyphosphate-accumulating bacteria in surface sediment of Taihu Lake in China were isolated and characterized. Among these bacteria, a Pseudomonas stutzeri strain YG-24 was found to be able to remove 97% to 100% of P in a synthetic wastewater with total P less than 1.0 mg L− 1. After immobilization by polyvinyl alcohol (PVA)-sodium alginate, this strain still showed high percentage of P removal, and maintained high efficiency in five sample loading cycles. In addition, the immobilized cells displayed better pH-resistance than free cells. The removal of P in overlying water sample collected from Taihu Lake was also satisfactory. These results demonstrated the potential of using immobilized cells of YG-24 to remove low concentrations of P in wastewater treatment.

► Pseudomonas stutzeri YG-24 was used to remove low concentrations of P. ► Low-concentration P removal by YG-24 has been systematically studied. ► The immobilized cells can be used for 5 cycles maintaining high removal rates.