Denitrifying phosphorous removal in anaerobic/anoxic SBR system with different startup operation mode

To achieve stable and efficient nitrogen and phosphorus removal and to investigate the characteristics of the A/A SBR enriched with denitrifying phosphorus removal bacteria(DPB),the whole course of startup was studied with two reactors operated in different mode.The reactor I was operated under anaerobic/settling/anoxic/settling mode,and the reactor II was operated under anaerobic/anoxic/settling mode.Differences between the two reactors in removal efficiency of COD,nitrogen and phosphorus were examined.The results indicated that efficient performance could be achieved in both reactors with different startup operation mode,while the phosphorus removal efficiency was improved sooner in reactor I than in reactor II,which suggested that reactor I would supply a more favorable condition for DPB proliferation.Meanwhile,it was observed that the amount of organic substrates consumption had a linear correlation to that of phosphorus release in anaerobic phase when DPB was accumulated in the A/A SBR denitrifying phosphorus removal system.

A Study on the Structure and Behavior of Sinter-free Material for Phosphorous Removal from Waste Water

Oyster shell and cement were taken as the major raw materials to fabricate hollow, tubular and recoverable material for phosphorous removal （P removal） from waste water without sintering. In this paper, the effects of different affecting factors on the sample P removal ratio were discussed to select optimal P removal process conditions. SEM and XRD were used to characterize the microscopic structures and composition of samples, and molybdenum blue spectrophotometry was applied to determine the P content in waste water. Results showed that at 30 ℃ for 2 d, the P removal ratio reached 93.3% when the cement content was 10 wt% and oyster shell powder was 90 wt%. SEM analysis revealed a flaky structure consisting of phosphorus-containing compound in the samples after P removal, and it piled on and maintained the porous structure. In addition, the results also suggested that raising the ambient temperature was benefit to the P removal. The P removal ratio of the material was optimal under neutral and alkali conditions.

Preparation of Iron-Pillared Bentonite/Oyster Shell Composite and Phosphate Adsorption in Water

Iron-pillared bentonite(FB)was prepared by Fe(III)modified bentonite,and then the composites(FB-OS)were prepared by iron-pillared bentonite and oyster shell powder.The composites were characterized by FTIR,SEM,TGA,and EDS,and the phosphorus removal test was carried out.The results showed that FB-OS contained a large amount of CaO.Its structure was compact,but there were gaps in it.The maximum bending stress and compressive strength were 43.7 N and 0.927 MPa,respectively.The phosphorus removal test showed that the phosphorus removal rate of FB-OS was more than 90%,and measured the maximum adsorption capacity was 48.31 mg/g.A large amount of spherical products were produced on the surface and inside of FB-OS after phos-phorus removal,it was speculated that spherical products were amorphous calcium phosphate in the paper.Ana-lysis indicated that there was chemical adsorption during phosphorus removal.The kinetic equation of phosphorus adsorption by FB-OS was qt=10:193t/1+2:574t (R^(2)=0.995).The adsorption rate was mainly controlled by outerfilm diffusion and intraparticle diffusion.