Polytitanium salt has attracted more and more attention recently, yet there is not much research on combining polytitanium salt with polymer flocculant. This study focused on the application of polydimethyl-diallylammonium chloride (PDMDAAC) as coagulant aid with polytitanium sulfate (PTS) in fulvic acid (FA) water treatment. Effect of dosing sequence (PTS dosed first donated as PTS + PDMDAAC; PDMDAAC dosed first donated as PDMDAAC + PTS), dose and solution pH was investigated. Coagulation sludge of dual-coagulants was also reused to produce TiO2. Results showed that compared with use of PTS alone, turbidity and FA removal were both enhanced by dual-coagulants. In addition, this study revealed that floc size and floc growth rate of PTS + PDMDAAC were also significantly improved and floc strength and recovery ability were also increased by PTS + PDMDAAC. AS for PDMDAAC + PTS, floc size, growth rate, strength and recovery ability were similar to those of PTS. Floc fractal dimension of these three coagulants was in an order of PDMDAAC + PTS > PTS > PTS + PDMDAAC. Furthermore, TiO2 produced by dual-coagulants sludge showed higher photocatalytic activity than that produced by VI'S sludge. (C) 2015 Elsevier B.V. All rights reserved.