Preparation And Application Of PMAS-CTS Compound Flocculant

In this study, inorganic polymer flocculant polymer magnesium sulfate aluminum (PMAS) was compounded with natural organic polymer flocculant chitosan (CTS), prepared a new inorganic-organic composite flocculant PMAS-CTS. This composite flocculant combines the advantages of polymer magnesium sulfate aluminum and chitosan flocculant, so that the new composite flocculant PMAS-CTS has better flocculation on wastewater, more efficient processing and more adaptable. This paper mainly discussed the best preparation conditions of PMAS-CTS composite flocculant, the changes of the matter’s structure before compound and after, the flocculation effect of the flocculant on the different types of wastewater, as well as comparison with other flocculants of their flocculation performance. Preliminary studied the flocculation mechanism of PMAS-CTS composite flocculant. The results show that:(1) The best preparation conditions of PMAS-CTS composite flocculant are:reaction temperature of30℃, reaction time was24h, the ratio of raw materials (PMAS and CTS’s volume ratio) was2:1, the pH value was3.(2) The inrared spectrum displaied that PMAS and CTS forming a hydrogen-bonded aggregate after complex reaction. The dehydration reaction occured between groups in the formation of PMAS-CTS, and lead the poly magnesium, poly aluminum into the long chain of CTS by coordination bond. The scanning electron microscopy shows:PMAS and CTS’s structure have changed after complex reaction, and response to the former PMAS, CTS monomers have essentially different. PMAS had sheet structure before reaction, the overall showing a layered, overlapping, extended three-dimensional structural characteristics; the appearance of CTS before reation was irregular, slightly curled flack. Continue to zoom in, can see CTS showed many irregular drawing shape, between layers, linearly extended to both ends; PMAS-CTS showed dendritic branches, stagger after composite reaction. The overall showing staggered, extension, three-dimensional multi-gap structure, and response to the former PMAS, CTS monomers have essentially different.(3) There are different optimal flocculation pH value on different wastewater by PMAS-CTS composite flocculant. On their own pH value of Fen river water and sewage water, PMAS-CTS composite flocculant can achieve the best flocculation effect, at this time the water pH value shows neutral or slightly acidic. Adjusted the pH of livestock wastewater and papermaking black liquor to5, PMAS-CTS composite flocculant can achieve the best flocculation effect. PMAS-CTS composite flocculant has good removal efficiency of turbidity on wastewater, the highest turbidity removal rate can reach97%and above. The highest removal efficiency of chroma in different types of wastewater can reach between80%and90%. It has good removal efficiency of COD in sewage, livestock wastewater and papermaking black liquor, the highest can reach70%and above. The removal rate of COD in livestock can reach88%, it shows that water with high background value of COD has better ability to handle.(4) Compared PMAS-CTS with PMAS, CTS, PMAS+CTS and PAC, PMAS-CTS is superior to the other four kinds of flocculants from the highest turbidity, chroma, the removal rate of COD and composite flocculant amount for livestock wastewater. PMAS-CTS is better than the other four flocculants for water turbidity, COD maximum removal rate and the flocculant dosage when reach the maximum removal rate for papermaking black liquor. It synthesizes the advantages of inorganic polymeric flocculant and natural organic polymer flocculant.(5) The flocculation mechanism of PMAS-CTS is more complex as a kind of inorganic-organic composite flocculant. There are compression of electric double layer, adsorption and charge neutralization, adsorption bridging and sediment netting sweep mainly in four. Play a role in the process of water treatment at the same time or cross, mainly in a mechanism in different water treatment cases.