A Research on the Effect of Worm Predation on Phosphorus Release from Actived Sludge

The sludge reduction in the process of using worms, worms would destroy the sludge extracellular polymer institutions and bacteria, the soluble organic matter, nitrogen, phosphorus and other substances released into the water phase from sludge. By worms on sequencing batch experiments, this study is designed to investigate the sludge of phosphorus migration transformation process, reveals the effect of predation on the effect of phosphorus release in the sludge with worms. The research results that the sludge contains large amounts of phosphorus particles at the beginning, and after 24 hours, the phosphorus particles decomposed to the supernatant. At First, the upper supernatant phosphorus concentration reduced from 17.68 mg/L to 0.53 mg/L, with the nitrate nitrogen concentration reduced significantly, speculated that the denitrifying phosphorus absorption occured in the worms bed at the beginning, as worms prey on phosphorus content in the supernatant and then gradually increased to 42.19 mg/L; the phosphorus concentration of cell declined from 28.02 mg/gMLSS to 16.15 mg/gMLSS, which is 14.36% higher than the phosphorus concentration of the blank bed; the metal ions (K+, Ca2+, Mg2+) concentration in the worms bed is a total of 66.89 mg/L, about 48% higher than blank bed, speculated that the worm predation promoted the extracellular polymer metal ion release, thus promote the phosphorus release. With comprehensive analysis of the worms bed, resulted that the worms feeding effect significantly promoted the release of phosphorus in sewage sludge.