The Study On Phosphorus Discharge Capability Of High Phosphatic Sludge And Phosphorus Recycle Potency

The traditionally biological phosphorus removal system uses the excess phosphorus absorption of PAOs and high phosphatic sludge discharged of mode in order to realize phosphorus removal during wastewater. treatment. the system usually has relatively shorter SRT and lower MLSS, especially the phenomenon is more obvious under the condition of low COD. Short SRT and low MLSS are a great disadvantage for the system to remove nitrogen, so the system can't achieve the optimal phosphorus and nitrogen removal synchronously. The study advances to use the technology of external recycle of high phosphatic sludge and the mode of high phosphatic sewage discharged in order to realize effective phosphorus removal in the system. The system's SRT is decided by nitration and denitrification, so the SRT doesn't influence phosphorus removal.The SBR system with phosphorus and nitrogen removal is researchful object in the system. The results show that the SBR system using external recycle of sludge has more better phosphorus and nitrogen removal than traditional SBR system, and the removal rate of COD,N and P is 95.3%,99% and 98.9% respectively, moreover, when PO43-=8～11mg/l and TN=45～50 mg/l in influent, the system still ensures PO43-＜0.25mg/l and NH3≤1mg/l in effluent. The anaerobic phosphorus discharge experiment of high phosphatic sludge shows that PAOs absorbs 1mol HAc and discharges 1mol phosphate at one time, namely, 2.03mg HAc-COD absorbed is the concomitants of 1mgp discharged; and orthogonal test shows that both HAc-COD and the quantity of recyclable sludge(QRS) remarkably influence the total discharge quantity of phosphorus of externally recyclable sludge(MP), but the alternant item of QRS and HAc-COD doesn't remarkably influence MP, the relation of QRS,HAc-COD and MP is MP =0.02＋12.56Z1＋0.25Z2, moreover, the experiment still shows that when phosphorus discharge process isn't restricted by HAc-COD, the relation of the concentration of PO43- and time is P=6.54X·t0.24+P0. The results show that chemic phosphorus removal of high phosphatic sewage in SBR system doesn't remarkably increase the charge for wastewater treatment, because the process markedly enhance the using rate of chemic medicament, and the enhancive charge of lime method,Fe3+ method and Al3+method is 0.01,0.065 and 0.11￥ per ton respectively, moreover, the chemic sludge with highphosphorus is in favor of the recycle of phosphorus and the recyclable rate of phosphorus reaches 69% of the total quantity of phosphorus in influent.Using simple wastewater treatment method and especial recyclable technology in system not only achieve good wastewater treatment effect but also realize the recycle of phosphorus in municipal wastewater. It is anticipated that wastewater treatment technology with sustaining development will be have widespread foreground.