The flocculation experiment using PAC was carried out to study the impact of the physico-chemical condition of micro-organic-polluted water and hydraulic condition on fractal dimension of aggregated floc by scanning the electron microscope photos. The results showed that the fractal dimension increases from 5.13% lower than the standard to higher 16.03% when residence time from 20.00% shorter than the reference time to longer 33.30%, the fractal dimension is the biggest when the coagulant dosage is optimal, and the fractal dimension of aggregated floc decreases by 17.06% ~31.5% and increases to 24.39%~28.13% when the coagulant dosage is short and excessive separately. The results showed that the fractal dimension has good response to the flocculation factor, and it can be used as a parameter of quantitative analysis of flocculation efficiency.
