Research On The Activation Technology Of Sodium Persulfate

The printing and dyeing industry has developed rapidly in recent years.The large amount of water is used in the printing and dyeing process,therefore the discharge amount of waste water of printing and dyeing ranks to the front.Conventional wastewater treatment methods have been unable to satisfy the requirements of printing and dyeing wastewater treatment.Some studies have found that the sulfate radical(SO₄^-·)with high oxidation potential produced by persulfate activation under suitable conditions,can oxidize and degrade most organic pollutants.The author used methylene blue solution as model printing and dyeing organic wastewater,and degraded the wastewater using the SO₄^-·which were produced from persulfate activated by transition metal ions(Fe²⁺).The author found that the optimum activiation conditions were p H was 3.0 and the mass ratio of Na₂S₂O₈ to Fe²⁺was 8:1.The degradation effect for 10 m L 0.5000 g/L methyl blue solution was best using 2 g Na₂S₂O₈and 0.25g Fe SO₄.At the same time,the author also studied the effect of different anions on degradation of methylene blue by persulfate activiation,which showed that the influence effect of different anions was followed the order of HCO₃^-<Cl^-<NO₃^-<SO₄^2-,and the inhibitory effect of HCO₃^-on methylene blue degradation was maximum.The author prepared sustained-release tablets of catalytic activation sodium persulfate for the degradation of printing and dyeing organic wastewater.The optimum ratio was sodium persulfate 70%,Fe SO₄ 8.75%,acid system 8%,algin 6.25%,micro-silica 1%,anhydrousmagnesium sulfate 3.5%,K12 2.0%and sodium dodecylbenzenesulfonate0.5%,which was determined by orthogonal test.