Cationic polyacrylamide (CPAM) enhanced pressurized vertical electro-osmotic dewatering of activated sludge

Cai, Meiqiang; Qian, Zhuohui; Xiong, Xingaoyuan; Dong, C.Y.; Song, Zhijun; Shi, Yuejing; Wei, Zongsu; Jin, Micong

doi:10.1016/j.scitotenv.2021.151787

Cited by 14 publications

(4 citation statements)

References 79 publications

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“…Mpofu et al studied an intermittent depletion method to measure the adsorption isotherm of APAM on kaolinite and deduced that the adsorption of APAM on kaolinite depends on hydrogen bonds. Macroscopically described effects of PAM on clay mainly include the following two aspects: − (1) PAM can be adsorbed on the clay surface through hydrogen bonding and electrostatic attraction and (2) PAM adsorbed on the clay surface can enhance the dehydration effect of clay.…”

Section: Introductionmentioning

confidence: 99%

Effect of PAM on Surface Hydrophobicity of Montmorillonite and Difference of Interface Adsorption: An Experimental and Simulation Study

Yan,

Meng,

Ammami

et al. 2024

ACS Omega

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How to realize efficient treatment of coal slime generated by a coal washing operation is an urgent problem to be solved in this industry. The presence of clay minerals, especially highly hydrophilic montmorillonite (MMT), is the key to the poor treatment effect of coal slime. Polyacrylamide (PAM) is very popular as a polymer agent to improve the treatment of coal slime. However, when it is used to treat coal slime with a high content of MMT, the selection of PAM type and the mechanism of action are still lacking. In this study, the effects of different types of PAM on the treatment of coal slime water containing MMT are considered by sedimentation and press filtration tests. The interaction mechanism of PAM on the MMT surface is studied by using ζ-potential, Brunauer–Emmett–Teller (BET) analysis, low-field nuclear magnetic resonance, density functional theory (DFT), and molecular dynamics (MD) simulations. The results show that the three PAM can improve the sedimentation and filtration effect of coal slime water, and the performance is CPAM > NPAM > APAM. The ζ-potential of the MMT (001) surface increases under the action of three PAM, and the effect of CPAM is the most significant. The adsorption of PAM on the MMT (001) surface has the ability to neutralize the surface charge of MMT. The flocculation of MMT particles under PAM results in an increase of particle size and a decrease of specific surface area. Meanwhile, the pore volume of MMT decreases, and the average pore size increases. In addition, PAM mainly removes vicinal water on the MMT surface. The active sites of the MMT surface and PAM are calculated by DFT. The adsorption of three PAM structural units on the MMT Na-001 surface and non-001 surface is nonbonding interaction, and the adsorption energy of CPAM is the largest. And the left shift of εp of the O atom on the MMT surface is conducive to the stable adsorption of CPAM. The MD results show that the concentration of water molecules on the surface of MMT Na-001 decreases after PAM is adsorbed on the MMT Na-001 surface, indicating that PAM can keep water molecules away from the surface of MMT, which means that the hydrophobicity of the MMT surface is enhanced. This study has guiding significance for the selection of PAM and the development of new flocculants in the treatment of coal slime with a high content of MMT.

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Section: Introductionmentioning

confidence: 99%

Effect of PAM on Surface Hydrophobicity of Montmorillonite and Difference of Interface Adsorption: An Experimental and Simulation Study

Yan,

Meng,

Ammami

et al. 2024

ACS Omega

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“…To improve the dewaterability of sludge and achieve a deep dewatering effect, technological processes have been extensively researched, developed, and improved. Over the last three decades, much research has been carried out on the development of the technical mechanisms of various sludge dewatering processes, such as advanced oxidation, flocculation, precipitation, and electric dewatering methods and sludge framework processes [6][7][8][9][10][11][12][13]. In most cases, prior to mechanical dewatering, disintegration techniques are necessary, such as the mechanical methods using ultrasonics, mills or homogenizers, thermal hydrolysis, and freezing and thawing, and the biological method usually performed by enzymes [2,12,14,15].…”

Section: Introductionmentioning

confidence: 99%

“…Over the last three decades, much research has been carried out on the development of the technical mechanisms of various sludge dewatering processes, such as advanced oxidation, flocculation, precipitation, and electric dewatering methods and sludge framework processes [6][7][8][9][10][11][12][13]. In most cases, prior to mechanical dewatering, disintegration techniques are necessary, such as the mechanical methods using ultrasonics, mills or homogenizers, thermal hydrolysis, and freezing and thawing, and the biological method usually performed by enzymes [2,12,14,15]. Generally, despite conditioning, the moisture content of the cake remains very high, usually higher than 80% after dewatering by centrifugation and vacuum filter, which cannot meet the requirement of economical drying or incineration of the filter cake.…”

Section: Introductionmentioning

confidence: 99%

The Influence of the Addition of Cement and Zeolite on the Increase in the Efficiency of Sewage Sludge Dewatering in the Pressure Filtration Process

Kowalczyk

2024

Energies

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The process of removing water from sewage sludge is particularly important due to its high content in the raw sludge. This translates into problems with the transport and storage of sediments. Additionally, high water content reduces the calorific value of the sludge. The methods for selecting the appropriate parameters for sewage sludge conditioning and filtration, based on the experimental data presented in this work, may allow for the optimization of sludge dewatering lines in small and large sewage treatment plants. The optimization of the dewatering process has a significant impact on the environmental and economic benefits, which consequently results in a decrease in the power costs of the devices used, flocculants, and sludge processing, and, above all, it contributes to the reduction in the negative impact on the environment. The use of mineral substances in the preparation of sewage sludge improves the effects of its dewatering in the pressure filtration process, as expressed in the obtained values of the final hydration and process efficiency. The use of polyelectrolytes alone significantly improves the effects of sewage sludge dewatering. In this work, the polyelectrolytes were supported by the addition of cement or zeolite. The conditioning of sewage sludge in combined methods using C-494 polyelectrolyte and minerals made it possible to reduce the compressibility coefficient to the range of 0.24–0.47 and, at the same time, to achieve the best results of sludge dewatering in the filtration process. The lowest hydration of 74.9% was achieved when polyelectrolyte and cement were added to the sludge, and this hydration was 6.5 percentage points lower compared to that of the non-filtered sludge.

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“…There are certain disadvantages due to physical, chemical, and microbial conditioning alone, and combined conditioning technology has become a research focus in recent years [ 15 ]. Combined conditioning can reduce the compressibility, the amount of chemicals added, and the cost of conditioning, and improve the dewatering performance of the sludge [ 16 ]. The research and development of efficient, low-consumption, safe and stable flocculants is the direction and goal of flocculant research in view of the currently increasing water pollution and ever stricter environmental regulations.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Dewatering of Activated Sludge by Skeleton-Assisted Flocculation Process

Xia¹,

Rao²,

Ji³

et al. 2022

IJERPH

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Sludge dewatering is the fundamental process of sludge treatment. Environmentally friendly and efficient sludge conditioning methods are the premises of sludge to achieve dehydration reduction and resource utilization. In response to sewage plant sludge dehydration, fly ash (FA), polymerized aluminum chloride (PAC), and polymer sulfate (PFS) were studied separately to determine their sludge dehydration performance, and the effects of these three conditioner composite regulations on sludge dehydration properties were studied. Compared to the sludge treated only with conditioner, the average particle size of floc increased and the organic matter content in the filtrate decreased. The sludge dewatering efficiency after the conditioning effect is better than that after conditioning a single conditioner. After PFS conditioning with fly ash, the water content and specific resistance (SRF) of the sludge cake can be reduced to 76.39% and 6.63 × 1010 m/kg, respectively. The moisture content and specific resistance (SRF) of the sludge cake can be reduced to 76.10% and 6.91 × 1010 m/kg, respectively. The pH of the sludge and filtrate changed slightly after PAC conditioning with fly ash coupling. These results indicate that fly-ash coupled with PAC and fly-ash coupled with PFS are expected to become a novel and effective environmental protection combined conditioning method for sludge dewatering.

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Cationic polyacrylamide (CPAM) enhanced pressurized vertical electro-osmotic dewatering of activated sludge

Cited by 14 publications

References 79 publications

Effect of PAM on Surface Hydrophobicity of Montmorillonite and Difference of Interface Adsorption: An Experimental and Simulation Study

Effect of PAM on Surface Hydrophobicity of Montmorillonite and Difference of Interface Adsorption: An Experimental and Simulation Study

The Influence of the Addition of Cement and Zeolite on the Increase in the Efficiency of Sewage Sludge Dewatering in the Pressure Filtration Process

Enhanced Dewatering of Activated Sludge by Skeleton-Assisted Flocculation Process

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