Comparative study of floc characteristics with titanium tetrachloride against conventional coagulants: Effect of coagulant dose, solution pH, shear force and break-up period

Zhao, Yuwei; Bao, Gao; Zhang, G.Z.; Phuntsho, Sherub; Wang, Y.; Yue, Qin Yan; Li, Q.; Shon, Ho Kyong

doi:10.1016/j.cej.2013.08.017

Cited by 22 publications

(13 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results suggest that, for the coagulant doses studied, charge neutralisation is unlikely to be the sole mechanism involved in the flocculation of algae for all three coagulants otherwise zeta potential values would have been close to zero after flocculation. These results differ from previous studies on titanium coagulants [19,23,26,[49][50][51][52][53] where it was found that the predominant coagulation mechanism for both TiCl 4 and PTC was through charge neutralisation. However, most of these studies were targeting the removal of organic…”

Section: Coagulation Performance: Turbidity Removal Efficiency and Zecontrasting

confidence: 99%

Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl 4 ) and ferric chloride (FeCl 3 ) in algal turbid water

Chekli

Eripret

Park

et al. 2017

Separation and Purification Technology

Self Cite

View full text Add to dashboard Cite

Seasonal green algae blooms in freshwaters have raised attention on the need to develop novel effective treatment processes for the removal of algae in water. In the present study, the performance of newly developed polytitanium tetrachloride (PTC) coagulant for the removal of freshwater microalga Chlorella vulgaris has been investigated and compared with titanium tetrachloride (TiCl 4) coagulant and the conventional ferric chloride (FeCl 3) coagulant. The main benefit of using titaniumbased coagulants is that the sludge produced after flocculation may be recycled into a valuable product: titanium dioxide photocatalyst. Both titanium-based coagulants achieved good flocculation over a broader pH range and coagulant dose compared to conventional FeCl 3 coagulant. All three coagulants achieved comparable performance in terms of turbidity removal (i.e. turbidity removal efficiency > 97%); although TiCl 4 performed slightly better at the lower tested dose (i.e. < 9 mg/L). Zeta potential measurements indicated that charge neutralisation may not be the sole mechanism involved in the coagulation of algae for all three coagulants. Analysis of the dynamic floc size variation during floc breakage showed no regrowth after floc breakage for the three coagulants. The flocs formed by both Ti-based coagulants were larger than those formed by FeCl 3 and also grew at a faster rate. This study indicates that Ti-based coagulants are effective and promising coagulants for algae removal in water.

show abstract

Section: Coagulation Performance: Turbidity Removal Efficiency and Zecontrasting

confidence: 99%

Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl 4 ) and ferric chloride (FeCl 3 ) in algal turbid water

Chekli

Eripret

Park

et al. 2017

Separation and Purification Technology

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the present study, the initial pH of the CMWW was about 7.3, which is close to this pH range and may therefore suggest that, bridging adsorption together with charge neutralisation could be the main coagulation mechanisms using FeCl 3 coagulant [29]. With the use of TiCl 4 , several studies [30][31][32] have demonstrated that the main coagulation mechanisms was charge neutralisation. While for the PTC coagulant, a recent study by Zhao et al [18] indicated that charge neutralisation may be the predominant coagulation mechanism as the zeta potential was close to zero after flocculation.…”

Section: Floc Characterisationmentioning

confidence: 57%

Coagulation performance and floc characteristics of polytitanium tetrachloride and titanium tetrachloride compared with ferric chloride for coal mining wastewater treatment

Galloux

Chekli

Phuntsho

et al. 2015

Separation and Purification Technology

Self Cite

View full text Add to dashboard Cite

19 20The production and discharge of large volumes of wastewater during coal mining activities are one of 21 the major environmental issues in Australia. Therefore, it is crucial to develop and optimise effective 22 treatment processes for the safe disposal of coal mining wastewater (CMWW). In this study, we 23 investigated the performance of a recently developed polytitanium tetrachloride (PTC) coagulant and 24 compared with the performance of titanium tetrachloride (TiCl 4 ) and the commonly used ferric 25 chloride (FeCl 3 ) coagulant for the treatment of CMWW from one of the coal mining sites in Australia. 26The use of Ti-based coagulants is particularly attractive for the CMWW treatment due to the 27 advantage of being able to recycle the sludge to produce functional titanium dioxide (TiO 2 ) 28 photocatalyst; unlike the flocs formed using conventional coagulants, which need to be disposed in 29 landfill sites. The results showed that both PTC and TiCl 4 performed better than FeCl 3 in terms of 30 turbidity, UV 254 and inorganic compounds (e.g. aluminium, copper or zinc) removal, however, PTC 31 performed poorly in terms of dissolved organic carbon removal (i.e. less than 10%). While charge 32 neutralisation and bridging adsorption were the main coagulation mechanisms identified for TiCl 4 33 treatment ; sweep coagulation and bridging adsorption seemed to play a more important role for both 34 PTC and FeCl 3 treatments. The flocs formed by PTC coagulation achieved the largest floc size of 35 around 900 µm with the highest floc growth rate. Both Ti-based coagulants (i.e., PTC and TiCl 4 ) 36 2 showed higher strength factor than FeCl 3 , while TiCl 4 coagulant yielded the flocs with the highest 37 recovery factor. This study indicates that Ti-based coagulants are effective and promising coagulants 38 for the treatment of CMWW. 39

show abstract

“…The influence of pH on the coagulation efficiency of three coagulants was examined in the pH range of 4.5–10.5 based on previous studies [ 42 , 43 ].The coagulant dosage in this experiment was fixed at 20 mg Fe 2 O 3 /l.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Coagulation-Flocculation Performance of Iron-Based Coagulants: Effects of PO43- and SiO32- Modifiers

Chen

Zheng

Teng³

et al. 2015

PLoS ONE

View full text Add to dashboard Cite

PO4 3- and SiO3 2- are often used as modifier to improve stability and aggregating ability of the iron-base coagulants, however, there are few reports about their detailed comparison between the coagulation performance and mechanisms. In this study, three coagulants—polyferric phosphoric sulfate (PFPS), polysilicon ferric sulfate (PFSS), and polyferric sulfate (PFS) were synthesized; their structure and morphology were characterized by Fourier transformed infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Scanning electron microscope (SEM). Alkali titration and Ferron species analysis were employed to investigate the hydrolysis performance and species distribution. Jar test was conducted to measure their coagulation behaviors at different dosage, pH, and temperatures in which the flocs properties were measured. The results showed that a number of new compounds were formed due to the presence of PO4 3- and SiO3 2-. Moreover, PFPS and PFSS had similar level in Fea as well as Feb. Among them, PFPS produced more multi-core iron atoms polymer and content of Feb, and the formed flocs were larger and denser. It exhibited superior coagulation performance in terms of turbidity reduction, UV254 removal and residual ferric concentration. Jar test and floc breakage/regrowth experiments indicated other than charge neutrality, the dominated mechanism involved in PFSS was the adsorption between polysilicic acid and solution particle, while PFPS was sweeping, entrapment/adsorption resulting from larger polymer colloid of Fe-P chemistry bond.

show abstract

Comparative study of floc characteristics with titanium tetrachloride against conventional coagulants: Effect of coagulant dose, solution pH, shear force and break-up period

Cited by 22 publications

References 34 publications

Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl 4 ) and ferric chloride (FeCl 3 ) in algal turbid water

Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl 4 ) and ferric chloride (FeCl 3 ) in algal turbid water

Coagulation performance and floc characteristics of polytitanium tetrachloride and titanium tetrachloride compared with ferric chloride for coal mining wastewater treatment

Enhanced Coagulation-Flocculation Performance of Iron-Based Coagulants: Effects of PO43- and SiO32- Modifiers

Contact Info

Product

Resources

About