| This sdudy adopted the method of regulating the basicity of the aluminum nitrate with aluminum powder in order to impel aluminum nitrate to hydrolyze and polymerize gradually.Two hydrated polyaluminum nitrate products were prepared through controlling the ratio of raw material,reaction temperature and crystallization conditions. And their chemical compositions and structures were characterized by using chemistry analysis,XRD and TG-DTA.The results showed that productâ… and productâ…¡were 5Al(NO3)3·8Al(OH)3·30.5H2O,the mixture of 90.79%5Al(NO3)3·8Al(OH)3·30.5H2O and 9.21%Al(NO3)3·9H2O respectively.Both of them had high water-solubility.In addition,productâ…¢was 6Al(NO3)3·29Al(OH)3·38H2O with low water-solubility. 5Al(NO3)3·8Al(OH)3·30.5H2O and 6Al(NO3)3·29Al(OH)3·38H2O were considered to be firstly synthesized with high purity.The aluminum species of productâ… and productâ…¡were studied with Al-Ferron timed complex colorimetric method.The Ala,Alb and Alc content of the productâ… were 22.50%,41.15%and 35.50%respectively.The Ala,Alb and Alc content of the productâ…¡were 42.56%,35.19%and 21.05%respectively.Flocculation test that was done by using Kaoline simulated suspending water indicated the productâ… and productâ…¡had good flocculation performance.In this experiment,alumen ustum was rapidly generated,flcos particles were large,the rate of settlement was high,removal efficiencies was good,the influence on the effluent pH value was little,and residual aluminum was low.The flocculants of new synthesized 5Al(NO3)3·8Al(OH)3·30.5H2O was more efficient than saled PAC and traditional flocculants AlCl3·6H2O.And it was very similar to M-Al13, whose flocculation performance was very good.
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