TY - JOUR
T1 - Coagulation behavior and floc characteristics of a novel composite poly-ferric aluminum chloride-polydimethyl diallylammonium chloride coagulant with different OH/(Fe3+ + Al3+) molar ratios
AU - Sun, Cuizhen
AU - Qiu, Jinwei
AU - Zhang, Zhibin
AU - Marhaba, Taha F.
AU - Zhang, Yanhao
N1 - Publisher Copyright:
© IWA Publishing 2016.
PY - 2016/10
Y1 - 2016/10
N2 - In this paper, flocculating performance and mechanisms of a new composite coagulant, poly-ferric aluminum chloride-polydimethyl diallylammonium chloride (PFAC-PD) with different OH-/(Fe3+ + Al3+) molar ratios, were investigated for humic acid (HA)-kaolin synthetic wastewater treatment. The impact of OH-/(Fe3+ + Al3+) molar ratios on the removal efficiencies of turbidity and dissolved organic carbon, specific UV absorbance, coagulation mechanisms and dynamics was explored during the coagulation process using composite coagulants. The coagulation experimental results revealed that the composite coagulants with lower OH-/(Fe3+ + Al3+) molar ratio exhibited better coagulation efficiency. When OH-/(Fe3+ + Al3+) molar ratio of the composite coagulant was 1.5, adsorptionbridging played a dominant role in coagulating HA-kaolin synthetic wastewater. The floc growth rate and floc size, increased with increasing OH-/(Fe3+ + Al3+) molar ratio and the highest peak height of the size distribution was obtained by PFAC-PD with OH-/(Fe3+ + Al3+) =1.5. Also, the composite coagulants with higher OH-/(Fe3+ + Al3+) molar ratio formed more compact flocs, as reflected by the higher fractal dimension value. The flocs coagulated by PFAC-PD with basicity value of 1.0 gave strong strength and good recoverability.
AB - In this paper, flocculating performance and mechanisms of a new composite coagulant, poly-ferric aluminum chloride-polydimethyl diallylammonium chloride (PFAC-PD) with different OH-/(Fe3+ + Al3+) molar ratios, were investigated for humic acid (HA)-kaolin synthetic wastewater treatment. The impact of OH-/(Fe3+ + Al3+) molar ratios on the removal efficiencies of turbidity and dissolved organic carbon, specific UV absorbance, coagulation mechanisms and dynamics was explored during the coagulation process using composite coagulants. The coagulation experimental results revealed that the composite coagulants with lower OH-/(Fe3+ + Al3+) molar ratio exhibited better coagulation efficiency. When OH-/(Fe3+ + Al3+) molar ratio of the composite coagulant was 1.5, adsorptionbridging played a dominant role in coagulating HA-kaolin synthetic wastewater. The floc growth rate and floc size, increased with increasing OH-/(Fe3+ + Al3+) molar ratio and the highest peak height of the size distribution was obtained by PFAC-PD with OH-/(Fe3+ + Al3+) =1.5. Also, the composite coagulants with higher OH-/(Fe3+ + Al3+) molar ratio formed more compact flocs, as reflected by the higher fractal dimension value. The flocs coagulated by PFAC-PD with basicity value of 1.0 gave strong strength and good recoverability.
KW - Basicity
KW - Composite coagulant
KW - Floc breakage and regrowth
KW - Floc strength and recoverability
KW - Fractal dimension
UR - http://www.scopus.com/inward/record.url?scp=84992145758&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84992145758&partnerID=8YFLogxK
U2 - 10.2166/wst.2016.290
DO - 10.2166/wst.2016.290
M3 - Article
C2 - 27763344
AN - SCOPUS:84992145758
SN - 0273-1223
VL - 74
SP - 1636
EP - 1643
JO - Water Science and Technology
JF - Water Science and Technology
IS - 7
ER -