Study On Residual Amount Of Aluminum Flocculant By Jar-Test

In this paper,the correlation between the dosage of aluminum salt flocculant,pH value of raw water and stirring conditions on turbidity removal rate,floc morphology,fractal dimension and residual aluminum content was studied by beaker experiment.The main conclusions are as follows :1.The content of residual total aluminum and dissolved aluminum decreased with the increase of turbidity removal rate under different dosage and different raw water pH.There is little correlation between residual particulate aluminum and turbidity removal rate.There is a significant negative correlation between residual total aluminum,dissolved aluminum content and turbidity removal rate.2.Under different stirring time and stirring speed,the increase of turbidity removal rate corresponds to the decrease of residual total aluminum and particulate aluminum content.There was little correlation between residual dissolved aluminum and turbidity removal rate.There is a certain negative correlation between residual total aluminum,particulate aluminum content and turbidity removal rate.3.Under different dosages and different pH values of raw water,the content of residual total aluminum and dissolved aluminum decreased with the increase of floc size and the number of large flocs.There is little correlation between residual particulate aluminum and floc morphology,and there is a significant negative correlation between residual total aluminum,dissolved aluminum content and floc morphology.4.Under different stirring time,the flocculation process with small floc size corresponds to a high content of residual total aluminum and particulate aluminum,and the flocculation process with large floc size,large number of large flocs and uniform particle size distribution corresponds to a low content of residual total aluminum and particulate aluminum.There is little correlation between residual dissolved aluminum and floc morphology,and there is a certain negative correlation between residual total aluminum,particulate aluminum content and floc morphology.5.Under different stirring speeds,when the floc size is small,the flocculation process corresponds to a higher residual total aluminum content,while when the floc size is large and the particle size distribution is uniform,the flocculation process corresponds to a lower residual total aluminum.There was a weak negative correlation between residual total aluminum,dissolved aluminum,particulate content and floc morphology.6.Under different dosage and different raw water pH,the fractal dimension of flocs increases and the content of residual total aluminum and dissolved aluminum decreases.The maximum fractal dimension of flocs corresponds to the minimum content of residual total aluminum and dissolved aluminum.There is little correlation between residual particulate aluminum and fractal dimension.There is a certain negative correlation between residual total aluminum,dissolved aluminum content and fractal dimension.7.Under different stirring time and different stirring speed,the residual total aluminum content of PAC and aluminum sulfate is the lowest at the maximum fractal dimension,and the residual total aluminum and granular aluminum content decrease with the increase of fractal dimension.The correlation between residual dissolved aluminum and fractal dimension is not significant.There is a weak negative correlation between residual total aluminum content,particulate aluminum content and fractal dimension.