Phosphorus release during decomposition of Tubifex residues from wastewater treatment system

Release of phosphorus(P) into effluent of activated sludge process was reported in the recent researches of sludge reduction induced by Tubifex. Decomposition of Tubifex residues is considered to be accompanied by the release of P. A series of experiments were undertaken to evaluate the influence of phosphorus which released from the Tubifex residues to the wastewater treatment system. In present study, it indicated that the release rate of PO_3-⁴-P and total phosphorus (TP) were 3.8×10^-4 mgPO_3-⁴-P / gWorm (dry weight) h and 4.2×10^-4 mgTP /gWorm (dry weight) h, respectively. Compared to the phosphorus release rate of worm´s predation on activated sludge, the phosphorus release rate of decomposition of Tubifex residues was slow. Therefore, the influence of P from Tubifex residues decomposition to wastewater treatment system might can be ignored.