The Experimental Study Of Magnesium Sulfate In Reactive Dye Wastewater Treatment

In the treatment of wastewater containing reactive dyes, magnesium salt and flocculant with magnesium salt are high-efficiency, free of pollution, safe, but they can’t get people’s attention in the practical engineering application.This paper based on the actual engineering wastewater as the research target, the inorganic low molecular magnesium salt and flocculant with magnesium salt agentia and preparation inorganic polymer of magnesium silicate and flocculant with magnesium salt to treat the reactive dyes dyeing wastewater, then discusse the feasibility and applicability of magnesium salt and flocculant with magnesium salt, and deeply research the coagulation decoloring mechanism. The main research contents are as follows:(1) Using MgSO4, FeSO4, Fe2(SO4)3, MgSO4+FeSO4,MgSO4+Fe2(SO4)3these five kinds of inorganic low molecular flocculant to treat wastewater, the results showed that under certain conditions, the monometal salts,MgSO4,has the best treatment effect with a decolouring ratio that reach up to85.77%, and COD removal rate to65.97%.In all the compound coagulant,the treatment effect of MgSO4+FeSO4is the best, with decoloring rate reach up to98.47%,COD removal rate reach up to76.89%. Magnesium salt shows a splendid performance in dealing with this kind of waste water,and the decoloring rate will be improved dramatically when composite ferrous salt,they two coordinate efficiency.(2) Preparation silicon polymer magnesium sulfate. silicon polymer ferric sulfate, silicon polymer ferrous sulfate, polysilicate iron magnesium,and polysilicate ferrous magnesium these five kinds of inorganic polymer flocculant to deal wastewater, the results showed that under appropriate conditions, silicon polymer magnesium sulfate and polysilicate ferrous magnesium decolor best,the decolored rate of silicon polymer magnesium sulfate can amount to97.37%, COD removal rate can amount to77.77%. Polysilicate ferrous magnesium has a better treatment effect with decolored rate99.81%and COD removal rate80.85%. All these magnesium polysilicate have shown efficient decoloring performance, but the dosing quantity of polysilicate ferrous magnesium will reduced by half compare to silicon polymer magnesium sulfate, also less dosage compare to inorganic low molecular composite of magnesium sulfate and ferrous sulfate.(3) Usage of the visible light spectrum analysis, biological microscope taking pictures,infrared spectrum,XRD,and other means to discuss the flocculation mechanism of inorganic polymer polysilicate metal salts,found that polysilicate metal containing magnesium flocculant efficiency mainly comes from its strong adsorption bridges,adhesion volume ability in wastewater. The introduction of different metal salts into activity silicic acid will cause different influence to its structure, generating a lot of complex polymer, greatly enhances the flocculant performance.Visibly, magnesium salt, either using as a low molecular metal single salt, or composite with other other metal salt composite use, or preparation into inorganic polymer polysilicic acid flocculant,it shows its excellent decoloring performance in handling bleaching and dyeing plant wastewater containing reactive dyes.