Effect of under-dosing coagulant on coagulation–ultrafiltration process for treatment of humic-rich water with divalent calcium ion

Yao, Meng; Nan, Jun; Li, Qinggui; Zhan, Dechen; Chen, Ting; Wang, Zhenbei; Li, Haoyu

doi:10.1016/j.memsci.2015.08.001

Cited by 31 publications

(12 citation statements)

References 51 publications

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“…According to previous studies, the amount of particles smaller than 5 μm should be strictly controlled due to their complicated behaviors (Yao et al 2014). Our previous studies have also demonstrated that small particles would intensify membrane fouling (Yao et al 2015a(Yao et al , 2015b. Therefore, smaller particles control, in particular particles in 0-5 μm, by using hydrodynamic breakage has important advantages for the mitigation of pollution load in the following treatment process, such as filtration and ultrafiltration.…”

Section: Effect Of Hydrodynamic Breakage On Effluent Particlesmentioning

confidence: 99%

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Effect of hydrodynamic breakage on floc evolution and turbidity reduction in flocculation and sedimentation processes

et al. 2021

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Coagulation and sedimentation process is one of the most popular processes in drinking water treatment. Hydrodynamic breakage has a significant impact on the evolution of floc characteristic and the efficiency of turbidity removal. In this work, the effects of hydrodynamic breakage on floc size, fractal dimension, and floc morphology were investigated with an in-situ recognition system. The experiments were conducted in a continuous flocculation and sedimentation reactor equipped with perforated plates to provide different hydrodynamic breakage conditions. The experimental results indicated that the hydrodynamic conditions significantly influenced the floc destabilization and restructuring processes. A low hydrodynamic shear forces provided by P1 led to the increase of both bigger sized flocs but accompanied with small particles (0–10 μm). Excessive velocity gradient provided by P3 produced smaller and looser flocs. An appropriate velocity gradient (i.e., the flow velocity through the perforated plate P2 at 18.9 × 10−3m s−1) was conducive for the formation of larger and more compact structures, with higher average floc size and fractal dimension. This flocculation condition in turn resulted in effective improvements in the turbidity removal efficiency. Floc evolution models were described based on the mechanism of the breakage and restructuring process.

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Section: Effect Of Hydrodynamic Breakage On Effluent Particlesmentioning

confidence: 99%

“…Both P and A were obtained by analysis of flocs images. The value of D f shifting from 1 to 2 suggests that the aggregate's projected area converts from a linear structure to a circular structure (Yao et al 2015b). hydrodynamic breakage conditions.…”

Section: Floc Characteristicsmentioning

confidence: 99%

Effect of hydrodynamic breakage on floc evolution and turbidity reduction in flocculation and sedimentation processes

et al. 2021

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“…In water treatment plants, controlling hydraulic conditions is an indispensable part in order to improve coagulation performance (Ratnaweera and Fettig, 2015). manifested by the fact that its presence could significantly increase UV254 removal efficiency, and reduce membrane fouling (Yao, Nan et al, 2015). In addition to Ca 2+ , magnesium also displayed an important role in improving coagulation efficiency and reducing membrane fouling.…”

Section: Coagulation/flocculationmentioning

confidence: 99%

Physico‐Chemical Processes

Hua

Xiong

Zhu

et al. 2016

Water Environment Research

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“… 18 In coagulation experiments with Dismal Swamp fulvic acid (FA), calcium reduced residual FA and substantially widened the pH range of effective treatment. 19 Yao et al 20 evaluated the effects of calcium on flocs formed by PAC in HA treatment by a coagulation–ultrafiltration (UF) process and found that calcium could promote the size and strength of flocs formed from PAC. Although so many studies regarding the effect of the calcium ions on the NOM removal were reported, none of those studies referred to the influence of calcium in the coagulation with PAC-Al 30 systemically and quantitatively.…”

Section: Introductionmentioning

confidence: 99%

Humic Acid Removal from Water with PAC-Al₃₀: Effect of Calcium and Kaolin and the Action Mechanisms

Wu¹,

Zhang²,

Pang³

et al. 2020

ACS Omega

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Polyaluminum chloride with a dominant species of Al 30 (PAC-Al 30 ) was prepared in laboratory and used for humic acid (HA) removal from water. The action properties and mechanisms of PAC-Al 30 , HA, calcium, and kaolin were tested and discussed. The results showed that the existence of calcium or kaolin contributed to the HA removal when the PAC-Al 30 dosage was deficient and had no obvious effect when the amount of PAC-Al 30 was sufficient. When the PAC-Al 30 dosage was 0.01 and 0.02 mmol/L, the HA removal rate was increased by 66.59 and 42.20%, respectively, with a calcium concentration of 2.0 mmol/L, or increased by 53.31 and 40.92%, respectively, with the kaolin particle concentration of 150 mg/L. Calcium could compress the double electrical layers or complex with HA to neutralize a part of the surface negative charge of HA, but could not make the water system reach its isoelectric point. The mechanisms of calcium and kaolin’s promoting coagulation effect were adsorption neutralization and collision aggregation respectively, but these actions were much weaker than that of PAC-Al 30 with HA. The adsorption neutralization capacity of PAC-Al 30 was calculated to be nearly 60 times than that of calcium, and the higher γ value of calcium modified by the Sips equation may indicate that the adsorption or neutralization sites of calcium on HA were pickier than PAC-Al 30.

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Effect of under-dosing coagulant on coagulation–ultrafiltration process for treatment of humic-rich water with divalent calcium ion

Cited by 31 publications

References 51 publications

Effect of hydrodynamic breakage on floc evolution and turbidity reduction in flocculation and sedimentation processes

Effect of hydrodynamic breakage on floc evolution and turbidity reduction in flocculation and sedimentation processes

Physico‐Chemical Processes

Humic Acid Removal from Water with PAC-Al₃₀: Effect of Calcium and Kaolin and the Action Mechanisms

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Effect of under-dosing coagulant on coagulation–ultrafiltration process for treatment of humic-rich water with divalent calcium ion

Cited by 31 publications

References 51 publications

Effect of hydrodynamic breakage on floc evolution and turbidity reduction in flocculation and sedimentation processes

Effect of hydrodynamic breakage on floc evolution and turbidity reduction in flocculation and sedimentation processes

Physico‐Chemical Processes

Humic Acid Removal from Water with PAC-Al30: Effect of Calcium and Kaolin and the Action Mechanisms

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Product

Resources

About

Humic Acid Removal from Water with PAC-Al₃₀: Effect of Calcium and Kaolin and the Action Mechanisms