文档介绍：Analysis of the impacts of ulation modes
and coagulant dose on dissolved air flotation
Yuheng Wang, Xiuyan Zhou, Shengguang Zhuo Qishan, Wang
Department of Environmental Science and Engineering, College of Environmental Science and Engineering,
Northeastern University at Qinhuangdao, Nankai University,
Qinhuangdao, China Tianjin, China
E-mail: sun_wangyh@

Abstract— Polyaluminium chloride (PAC) was adopted as moreover, it can impact on treatment cost and residue of
coagulant to treat the high algae-laden water containing lots of chemical agents in the purified water. ulation modes
cells of Microcysits aeruginosa (MA) by jar test of applied in C/F/DAF process includes the single-step constant
cogulation/ulation/dissovled air flotation (C/F/DAF) ulation and the multi-step tapered ulation.
process. The constant ulation and the tapered ulation
with two steps were used in C/F stage. Two-dimension fractal
The purpose of this study was to discuss the impacts of
dimension (D2) and strength factor (SF) were respectively
introduced to characterize the floc form and strength. The ulation mode and coagulant dose on C/F/DAF process,
impacts of ulation mode and coagulant dose on C/F/DAF and the causes of these impacts were analyzed by
were analysed by studying the floc structure, size and strength. investigating floc shapes and strengths formed under various
The impacts of ulation mode and coagulant dose on conditions.
C/F/DAF process were discussed, and the causes of these
impacts were analyzed by investigating floc sizes, structures II. MATERIALS AND METHODS
and strengths formed in different conditions. The experimental
results showed that at the PAC dose of ~ mg Al2O3/L, the A. Coagulant and Raw Water
flocs formed under bridging ulation had larger size and
highly branched structure, and they were more easily removed The coagulant tested was PAC (Polyaluminium chloride),
by flotation. Comparing the tapered ulati