Study On Phosphorus Recovery From The Wastewater Containing Phosphorus Using Struvite Precipitation Proeess

In recent years, circulation economy is expanding by leaps and bounds in our country. But the phosphate fertilizer needs is in escalation. Since especially in the late years, human develop bioenergy energetically on the international, which have increased the need to grain, thereby play moving phosphate fertilizer need increasing. The phosphorus biochemistry cycles are different from the nitrogen completeness, that one-way is mobile, being difficult to regenerates, Be one kind of the resource being difficult to regenerate as a result. The economy consuming large amount of resource sources of energy, producing grave environmental pollution, carrying out circulation in whose procedure of production is especially necessary. In whose procedure of production, large amount of resource sources of energy is consumed, that leads to greatly the environmental pollution. Since guanite (MAP) method of precipitation being able to dislodge the phosphorus, the nitrogen and reclaim at the same time, the two kind elements moreover is one kind of high-effect postpones fertilizer. Slow Buddhism chemical fertilizer can cut down greatly environmental pollution. Struvite Precipitation process be able to improve the water works at operational state, improve foul water factory living things escaping from nitrogen effect except the phosphorus, reduce out the water nitrogen and phosphorus thickness, at the same time fairly decrease the sludge amounts and sludge handle operation cost, realize the improvement wave environment and reach the purpose that water resource circulation.The thesis takes that the simulation contains phosphorus waste water as reaction raw water, priority controls a factor mainly in the process having inspected guanite precipitation, the concentration having discussed reaction system pH, reaction contact time, initial ammonium-nitrogen affects factor experiment to guanite precipitation reaction as well as Precipitation on outcome is constitutive. Design the orthogonality experiment impact of mole of match ratio and reactive pH having discussed three kinds crystal structure over guanite precipitation on reaction phosphorus coefficient of recovery (PRE). Finally, the change of PRE and the component of the product were reviewed in different Ca2+ concentrations.The results indicated that reaction PH was maintained in the range of 9.5-10.0, that was good for struvite precipitation, and PRE could reach 60%in this situation; reacted time had less effect on the precipitation reaction, three constituted irons formed nuclear and precipitate drapidly in five minutes, then their moval rate of these three on stituted irons changed a little, which maintained stead in esstill reacted time was 30 minute; initial ammonium concentration influenced PRE and the component of the Precipitate, XRD analysis showed:the precipitate was mainly composed of Mg3(PO4)2·22H2O when the NH4+:PO43-, molar rations were 1:1,1.2:1 or 1.4:1.However, the Precipitate became the mixture of Mg3(PO4)2·22H2O and MgNH4PO4;·6H2O; when the NH4+:PO43-; molar ration as 2:1.Further more, the precipitate was mainly MgNH4PO4;·6H2O when the NH4+:PO43-molar ratios were 3:1, PRE increased from 22%to 84%with increase of NH4+:PO43- molar ratio from 1:1 to 3:l:higher initial ammonium-nitrogen increased purity of the precipitate and further elevate PRE; the results of the test showed that:by maintaining the same conditions of molar ratio of Mg/N/P as 1.4:2:1, reaction PH as 9.5, and reacted time as 30 minutes, PRE reached 94.0%, and increasing Mg/P Properly was good for PRE improvement:the diffraction diagram indicated:there was no remarkable change in PRE after adding to Ca2+, the component of precipitates was still struvite when Mg/Ca changed from 1:0.2 to 1:0.5, but when Mg/Ca reached 1:0.8, the Precipitate showed the character of amorphous substance.