Preparation Of Poly Aluminum Ferric Chloride And Compsite With Cationic Polyacrylamide Dealing With Waste Water

Flocculation technology is an economical and effective water treatment technology,which is widely used in water treatment at home and abroad.In this paper,based on the strong electrical neutralization effect of inorganic flocculant polyaluminum ferric chloride(PAFC)and the strong bridging effect of organic polymer flocculant cationic polyacrylamide(CPAM),the flocculation experiment was carried out.That is to overcome the disadvantages of unstable hydrolysis of iron-based flocculant,small floc formation and small application range,and solve the problem of weak neutralization ability of organic polymer flocculant.The introduction of organic high molecular polymer into the iron flocculant can improve the adsorption bridging effect of the iron flocculant,thereby improving its flocculation ability to small solid particles and enhancing the flocculation effect.The synthetic inorganic polymer flocculant PAFC has better water treatment effect than the traditional iron salt and aluminum salt.By compounding PAFC and CPAM,the synergistic effect of inorganic and organic components can be fully utilized to obtain better application effects than single flocculant components.The content of this paper mainly includes the following two parts:(1)The polyaluminium ferric chloride with different ratio of aluminum to iron and different alkalization degree(B)was prepared by experiment.The flocculation test of the Yellow River water was used to select the PAFC with the best ratio of aluminum to iron and alkalinity(B).Infrared spectroscopy analysis of the selected PAFC revealed that the PAFC has both a polymer of iron bridged by a hydroxyl group and a polymer of aluminum bridged by a hydroxyl group.(2)Polyacrylamide with a commercial cationic degree of 30% was selected and paired with typical watery domestic sewage and Yellow River water with high turbidity as the measurement object.The turbidity,chroma and COD of water samples were taken as the removal indexes.In the process of dosing,the first experiment was carried out on PAFC and CPAM alone,and then the flocculation experiment was carried out on the dosage of the two drugs,the order of addition,and the adjustment of the pH range of the water sample.Finally,the optimal PAFC and CPAM compounding method was selected for wastewater treatment.The flocculation stirring experiment confirmed that the flocculation performance of this kind of compound flocculant was the best at pH value of 8.The flocculation effect of the flocculant was better after increasing the ratio of cationic polyacrylamide;In addition,the flocculation characteristics are less affected by the degree of cationicity.The pH showed the COD,turbidity and chromaticity index in the range of 6~8,which were obviously superior to other intervals of pH,and the sedimentation speed was also obvious;Analysis of the addition sequence experiment shows that the content of colloidal particles in the PAFC solution is large and the sedimentation is not completed,and the solution is acidic.Therefore,after the addition of the CPAM,the colloidal particles are settled by the electrostatic adsorption,so a large amount of flocculation and sedimentation can be seen in the solution.It is worth mentioning that the cationic CPAM is no longer having flocculation activity;in the test of CPAM dropping PAFC solution,since the PAFCsolution slowly diffuses into the weakly alkaline CPAM solution at a very slow rate,This adsorption precipitation is somewhat weakened.After standing for a while,the solution precipitated part of the CPAM,which explains why there is a precipitate at the bottom of the solution,which is redispersed into the solution by shaking,so that no precipitate is observed.In contrast to the above method,it was determined that the CPAM solution was slowly added as a compounding sequence while the PAFC solution was under high speed agitation.This paper initially explored the flocculation mechanism of such complex flocculants.By comparing the flocculation effect of the prepared polyaluminum ferric chloride and cationic polyacrylamide with polyaluminum ferric chloride flocculant on domestic sewage and Yellow River water,it is concluded that the flocculation effect of the composite flocculant is significantly better than that of the polymerization alone.Aluminum iron chloride.In the experiment,the compound flocculant is more efficient in removing turbidity,decolorization and COD removal,and has a wider pH range when the total dosage is small.The comprehensive research results show that the combination of polyaluminum ferric chloride and cationic polyacrylamide is a new type of high-efficiency,inorganic-organic polymer flocculant.