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Lee WH, Kim JO. Optimization of turbidity removal and floc formation for ballasted flocculation using magnetite-based agents by response surface methodology. CHEMOSPHERE 2024; 363:142932. [PMID: 39067827 DOI: 10.1016/j.chemosphere.2024.142932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/21/2024] [Accepted: 07/23/2024] [Indexed: 07/30/2024]
Abstract
In this study, a static mixer was used as an alternative to the existing flash mixing method for ballasted flocculation to assess the turbidity removal and ballasted floc formation characteristics. Synthetic magnetite exhibits excellent properties, such as high specific gravity, hydrophobicity, and wear resistance, making it a suitable ballast agent (BA). The experimental design was optimized using the response surface methodology. To evaluate turbidity removal, a model based on polyaluminum chloride dosage, BA surface charge, and pH was developed. To assess the ballasted floc characteristics, the BA dosage, BA size, and G value of the static mixer were used. During ballasted flocculation, the impact of the zeta potential of the BA was minimal. Consequently, bonding primarily resulted from the viscosity of the floc caused by physical collisions rather than electrostatic forces stemming from the BA charge. The findings of this study demonstrated promising outcomes, including potential energy savings and process streamlining, by identifying crucial design elements for implementing a static mixer in the ballasted flocculation process.
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Affiliation(s)
- Won-Hee Lee
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
| | - Jong-Oh Kim
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea.
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2
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He W, Luo J, Huang J, Tang C, Yang Z. Two-stage injection of polymer and microsand during ballasted flocculation for treating kaolin waters with or without humic acid: Floc evolutional characteristics, performance and mechanisms. WATER RESEARCH 2024; 259:121846. [PMID: 38820733 DOI: 10.1016/j.watres.2024.121846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 05/26/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024]
Abstract
Ballasted flocculation is regarded as a most promising water treatment technology in aspects of retrofit and high-rate applications. To deep understand the incorporation behaviors of ballasting agent into ballasted floc growth, two distinct injection modes (namely a two-stage injection of polyacrylamide (PAM) alone, and a two-stage injection of both PAM and microsand) were developed in this study. Then, ballasted flocculation tests of kaolin and kaolin-HA (humic acid) waters were conducted at varying split ratios for fixed total dosages of both PAM and microsand. The experimental results showed that for either two-stage injection mode, the higher the second percentage of each split ratio, the greater the average size of maturated flocs at the second sub-stage of maturation. Meanwhile, the turbidity and UV254 values of settled water became lower at 30 and 180 s of sedimentation, suggesting that varying split ratios significantly affected the kinetics of ballasted floc growth. Moreover, it was suggested that the selection of either two-stage injection mode or corresponding split ratios played a more pronounced role in the HA removal than the total dosage of PAM. This suggestion was supported by SEM, FTIR and XPS analyses for surface morphological details, functional groups and chemical states of maturated flocs eventually formed in the kaolin-HA water through both two-stage injection modes. Accordingly, newly-established conceptual models of ballasted floc growth were proposed to explore the potential influencing mechanisms of varying split ratios on the ballasted flocculation performance. At each sub-stage of maturation, an appropriate dosage ratio between PAM and microsand was of great importance to effectively incorporate microsand particles into ballasted floc formation, besides the hydrolyzed produces of AS coagulant formed at the coagulation stage of ballasted flocculation. This study is expected to provide valuable insights for making ballasted flocculation more effective, economical and sustainable in water treatment engineering.
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Affiliation(s)
- Weipeng He
- Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency (Ministry of Education), College of Civil Engineering, Hunan University, Changsha 410082, PR China.
| | - Jiacheng Luo
- Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency (Ministry of Education), College of Civil Engineering, Hunan University, Changsha 410082, PR China
| | - Jinguo Huang
- Changsha Public Engineering Construction Center, Changsha 410023, PR China
| | - Chen Tang
- Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency (Ministry of Education), College of Civil Engineering, Hunan University, Changsha 410082, PR China
| | - Zhen Yang
- Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency (Ministry of Education), College of Civil Engineering, Hunan University, Changsha 410082, PR China
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3
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Blancho F, Lapointe M, Quevedo AC, Kannan K, Tufenkji N. Demonstrating scale-up of a novel water treatment process using super-bridging agents. WATER RESEARCH 2024; 254:121301. [PMID: 38417265 DOI: 10.1016/j.watres.2024.121301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/22/2024] [Accepted: 02/09/2024] [Indexed: 03/01/2024]
Abstract
Fiber-based materials have emerged as a promising option to increase the efficiency of water treatment plants while reducing their environmental impacts, notably by reducing the use of unsustainable chemicals and the size of the settling tank. Cellulose fiber-based super-bridging agents are sustainable, reusable, and versatile materials that considerably improve floc separation in conventional settling tanks or via alternative screening separation methods. In this study, the effectiveness of fiber-based materials for wastewater treatment was evaluated at lab-scale (0.25 L) and at pilot-scale (20 L) for two separation methods, namely settling and screening. For the fiber-based method, the performance of floc separation during settling was slightly affected by an 80x upscaling factor. A small decrease in turbidity removal from 93 and 86 % was observed for the jar and pilot tests, respectively. By contrast, the turbidity removal of the conventional treatment, i.e., no fibers with a settling separation, was largely affected by the upscaling with turbidity removals of 84 and 49 % for jar and pilot tests, respectively. Therefore, results are suggesting that fiber-based super-bridging agents could be implemented in full-scale water treatment plants. Moreover, the tested fibers increase the robustness of treatment by providing better floc removal than conventional treatment under several challenging conditions such as low settling time and screening with coarse screen mesh size. Furthermore, at both lab-scale and pilot-scale, the use of fiber-based materials reduced the demand for coagulant and flocculant, potentially lowering the operational costs of water treatment plants and reducing the accumulation of metal-based coagulants and synthetic polymers in sludge. Acute toxicity tests using the model organism Daphnia magna show that the cellulose fibers introduce insignificant toxicity at the optimized fiber concentration. Although dedicated mechanistic studies are required at various scales to understand in detail the influence of fibers on water treatment (coagulation/flocculation time, floc formation, floc size distribution velocity gradient, etc.), the efficacy and scalability of the fiber-based approach, along with its minimal environmental impact, position it as a viable and sustainable option for existing and future wastewater treatment plants.
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Affiliation(s)
- Florent Blancho
- Department of Chemical Engineering, McGill University, Quebec H3A 0C5, Canada
| | - Mathieu Lapointe
- Department of Construction Engineering, École de technologie supérieure - University of Québec, Québec H3C 1K3, Canada.
| | - Ana C Quevedo
- Department of Chemical Engineering, McGill University, Quebec H3A 0C5, Canada
| | - Krishnaveni Kannan
- Department of Chemical Engineering, McGill University, Quebec H3A 0C5, Canada
| | - Nathalie Tufenkji
- Department of Chemical Engineering, McGill University, Quebec H3A 0C5, Canada.
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4
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Suzuki Y, Kaku R, Takahashi K, Kanai M, Tamai S, Annaka Y, Chuganji N. Optimum conditions for high-speed solid-liquid separation by ballasted flocculation. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2023; 88:35-46. [PMID: 37452532 PMCID: wst_2023_204 DOI: 10.2166/wst.2023.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
In the ballasted flocculation, high-speed sedimentation of suspensions is achieved using a microsand as a ballast material and a polymer flocculant combined with microflocs made of polyaluminum chloride (PAC) as an inorganic coagulant. In this study, three turbid water samples containing kaolin clay (kaolin concentration: 20, 200, and 500 mg/L) were treated by coagulation-sedimentation and ballasted flocculation. The effects of pH and PAC dosage, which are the controlling parameters for coagulation, and the microsand (silica sand) and polymer dosages, which are the controlling parameters for ballasted treatment, on the treatment efficiency and floc settling velocity were examined. The floc settling velocity under the optimum conditions was 17 times higher than that of the conventional coagulation-sedimentation process using PAC. The turbidity was 0.54 turbidity unit (TU) (TU as the kaolin standard), and its removal efficiency was 99.7%. Furthermore, turbid water samples with different kaolin concentrations (20 and 500 mg/L) were treated via the ballasted flocculation. In this study, fundamental information on the optimization of each dosage condition of coagulant, ballast, and polymer and pH condition in ballasted flocculation was obtained, and the removal mechanisms under optimal, underoptimistic and overoptimistic conditions were proposed.
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Affiliation(s)
- Yoshihiro Suzuki
- Department of Civil and Environmental Engineering, Faculty of Engineering, University of Miyazaki, Gakuen Kibanadai-Nishi 1-1, Miyazaki 889-2192, Japan E-mail:
| | - Ryosuke Kaku
- Department of Civil and Environmental Engineering, Faculty of Engineering, University of Miyazaki, Gakuen Kibanadai-Nishi 1-1, Miyazaki 889-2192, Japan
| | - Katsuya Takahashi
- Department of Civil and Environmental Engineering, Faculty of Engineering, University of Miyazaki, Gakuen Kibanadai-Nishi 1-1, Miyazaki 889-2192, Japan
| | - Miyuka Kanai
- Department of Civil and Environmental Engineering, Faculty of Engineering, University of Miyazaki, Gakuen Kibanadai-Nishi 1-1, Miyazaki 889-2192, Japan
| | - Soichiro Tamai
- Graduate School of Engineering, University of Miyazaki, Gakuen Kibanadai-Nishi 1-1, Miyazaki 889-2192, Japan
| | - Yuko Annaka
- Nishihara Environment Co., Ltd, Yokoso-Rainbow Tower, Kaigan Minato-ku, Tokyo 108-0022, Japan
| | - Nobuaki Chuganji
- Nishihara Environment Co., Ltd, Yokoso-Rainbow Tower, Kaigan Minato-ku, Tokyo 108-0022, Japan
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5
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Liu L, Lu S, An G, Yang B, Zhao X, Wu D, He H, Wang D. Historical development of Al30 highlighting the unique characteristics and application in water treatment: A review. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2022.214807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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6
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Pikuda O, Lapointe M, Alimi OS, Berk D, Tufenkji N. Fate of microfibres from single-use face masks: Release to the environment and removal during wastewater treatment. JOURNAL OF HAZARDOUS MATERIALS 2022; 438:129408. [PMID: 35820330 DOI: 10.1016/j.jhazmat.2022.129408] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Single-use face masks can release microfibres upon exposure to environmental conditions. This study investigates the number of microfibres released in the presence and absence of UV irradiation and mechanical friction and the removal of the released microfibres in a simulated conventional wastewater treatment process. UV exposure results in a four-fold increase in the number of microfibres released from new masks and used masks resulting in ~2400 microfibres/mask and ~1100 microfibres/mask, respectively. Application of mechanical friction to the UV-exposed new and used masks further increases the number of released microfibres per mask. In a simulated coagulation/flocculation process, the removals of microfibers originating from new masks and used masks are 79% and 91%, respectively. XPS analysis reveals that the silica content of the used masks is 240% higher than that of new masks, which could explain the higher removal efficiency of microfibers from used masks. FTIR analysis of the masks after UV exposure shows carbonyl indices of 0.73 ± 0.70 and 0.27 ± 0.10 for the microfibres from used and new masks, respectively. Based on available data, we estimate that 4-47 million polypropylene microfibres can be released into natural waters per day after wastewater treatment in an urban environment (for a population of 4300 persons/km2).
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Affiliation(s)
- Oluwadamilola Pikuda
- Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada
| | - Mathieu Lapointe
- Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada
| | - Olubukola S Alimi
- Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada
| | - Dimitrios Berk
- Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada
| | - Nathalie Tufenkji
- Department of Chemical Engineering, McGill University, Montreal, Quebec H3A 0C5, Canada.
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7
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Unraveling the role of ballast surface charge at floc growth behavior in ballasted flocculation. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.119507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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He C, Wang K, Fang K, Gong H, Jin Z, He Q, Wang Q. Up-concentration processes of organics for municipal wastewater treatment: New trends in separation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 787:147690. [PMID: 34004540 DOI: 10.1016/j.scitotenv.2021.147690] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/07/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
Carbon neutrality is a pressing goal for the whole society. Over 20% of municipality electrical energy on public utilities was consumed by the operation of wastewater treatment plants (WWTPs). Up-concentration of organic matters and maximum energy recovery is essential for a more sophisticated municipal wastewater management. Chemical coagulation and biological adsorption have been used to achieve efficient carbon capture, while separation is an overlooked step. It may lead to poor effluent quality, as well as consume most of the time and volume. The introduction of new driving forces, such as pressure and magnetism, significantly improved the retention rate and speed, respectively. In this paper, recent works were comprehensively reviewed and a horizontal comparison was conducted from aspects of separation speed, retention rate, concentrate characteristics and economic costs. This review also discussed the selection of technologies under different conditions. Finally, the practical application, fouling mitigation with considering the value of the concentrate, identification of unique concentrate characteristics, and the establishment of an evaluation system was suggested as core issues for future researches. This review will promote the development of an energy-efficient wastewater treatment system with up-concentration processes.
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Affiliation(s)
- Conghui He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Kaijun Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Kuo Fang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Hui Gong
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Zhengyu Jin
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Qiuhang He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Qi Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China
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9
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Lv M, Li D, Zhang Z, Logan BE, Peter van der Hoek J, Sun M, Chen F, Feng Y. Magnetic seeding coagulation: Effect of Al species and magnetic particles on coagulation efficiency, residual Al, and floc properties. CHEMOSPHERE 2021; 268:129363. [PMID: 33360935 DOI: 10.1016/j.chemosphere.2020.129363] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/01/2020] [Accepted: 12/15/2020] [Indexed: 05/12/2023]
Abstract
Magnetic seeding coagulation (MSC) process has been used to accelerate flocs sedimentation with an applied magnetic field, offering large handling capacity and low energy consumption. The interactions of three typical Al species, aluminum chloride (AlCl3), Al13O4(OH)247+ polymer (Al13), and (AlO4)2Al28(OH)5618+ polymer (Al30), with magnetic particles (MPs) were examined to clarify the MSC process. In traditional coagulation (TC) process, the aggregation of primary Ala-dissolved organic matter (DOM) complexes with in-situ-formed polynuclear species generated a large average floc size (226 μm), which was proved to be efficient for DOC removal (52.6%). The weak connections between dissolved Ala-DOM complexes and MPs led to the negligible changes of dissolved Al after seeding with MPs in AlCl3. A significant interaction between MPs and Al13 was observed, in which the MPs-Al13-DOM complexes were proposed to be responsible for the significant improvement of DOC removal (from 47% to 52%) and residual total Al reduction (from 1.05 to 0.27 mg Al L-1) with MPs addition. Al30 produced a lower floc fractal dimension (Df = 1.88) than AlCl3 (2.08) and Al13 (1.99) in the TC process, whereas its floc strength (70.9%) and floc recovery (38.5%) were higher than the others. Although more detached fragments were produced with MPs addition, the effective sedimentation of these fragments with the applied magnetic field led to the decrease of residual turbidity and colloidal Al in Al30. The dependence of coagulation behavior to MPs and different Al species can be applied to guide the application of an effective MSC process.
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Affiliation(s)
- Miao Lv
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Dongyi Li
- School of Environmental Science and Engineering, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin, 300072, China
| | - Zhaohan Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Bruce E Logan
- Department of Civil and Environmental Engineering, Penn State University, 212 Sackett Building, University Park, PA, 16802, United States
| | - Jan Peter van der Hoek
- Department of Water Management, Delft University of Technology, PO Box 5048, 2600, GA, Delft, the Netherlands
| | - Muchen Sun
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| | - Fan Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, 710129, China
| | - Yujie Feng
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
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10
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Qasim M, Park S, Kim JO. The role of ballast specific gravity and velocity gradient in ballasted flocculation. JOURNAL OF HAZARDOUS MATERIALS 2020; 399:122970. [PMID: 32540703 DOI: 10.1016/j.jhazmat.2020.122970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 05/11/2020] [Accepted: 05/14/2020] [Indexed: 06/11/2023]
Abstract
This study investigated the concealed interaction between applied velocity gradient (G value) and ballast specific gravity (SG) in ballasted flocculation (BF). The objective was to unravel the participation of applied surface concentration (SC: 0.005 m2L-1-0.02 m2L-1) of high specific gravity ballasts (SG: 2.9-5.57) in BF aggregation phenomenon at varied velocity gradients (G value: 750s-1-1250s-1). Static mixer was used to perform the BF experiments, and aggregated flocs were characterized using charge coupled device (CCD) camera. The results revealed that conventionally adopted velocity gradient (G value: 150s-1 - 300s-1) in BF studies was insufficient for efficient floc development due to inadequate suspension of denser ballasts during mixing. This resulted in poor turbidity removal (< 40 %) and immature slow settling flocs (< 25 mh-1) despite higher ballast consumption. However, appropriate optimization of G value (1250s-1) corresponding to high specific gravity ballast (SG: 5.57) resulted in 99.5 % turbidity removal (residual turbidity: 1NTU) achieved in a shorter settling interval of 30 s consuming significantly less ballast concentration. This expeditious settling phenomenon was also evident in CCD camera observations of the ballasted flocs achieving superficial settling velocity (105mh-1). Therefore, it was concluded that appropriate optimization of the G value corresponding to the pertinent concentration of denser ballasts can exhibit rapid elimination of micropollutants, and superficial sedimentation with efficient material and energy use. This can lead to efficient BF design with a short HRT, compact footprint, and ability to handle highly turbid influent.
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Affiliation(s)
- Muhammad Qasim
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
| | - Seongjun Park
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
| | - Jong-Oh Kim
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
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11
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Lapointe M, Farner JM, Hernandez LM, Tufenkji N. Understanding and Improving Microplastic Removal during Water Treatment: Impact of Coagulation and Flocculation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:8719-8727. [PMID: 32543204 DOI: 10.1021/acs.est.0c00712] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The efficacy of plastic particle removal by municipal water treatment plants is currently uncertain, and the mechanisms involved in microplastic (MP) coagulation and flocculation have only been superficially investigated. The removal of pristine versus weathered plastic debris and the impact of plastic particle size on removal remain largely unexplored. In this study, coagulation, flocculation, and settling performances were investigated using pristine and weathered MPs (polyethylene (PE) and polystyrene (PS) microspheres, and polyester (PEST) fibers). Weathering processes that changed the surface chemistry and roughness of MPs impacted MP affinity for coagulants and flocculants. A quartz crystal microbalance with dissipation monitoring was used to identify the mechanisms involved during MP coagulation and flocculation. Measured deposition rates confirmed the relatively low affinity between plastic surfaces and aluminum-based coagulants compared to cationic polyacrylamide (PAM). In every case examined, coagulant efficiency increased when the plastic surface was weathered. Removals of 97 and 99% were measured for PEST and weathered PE, respectively. Larger pristine PE MPs were the most resistant to coagulation and flocculation, with 82% removal observed even under enhanced coagulation conditions. By understanding the interaction mechanisms, the removal of weathered MPs was optimized. Finally, this study explored the use of settled water turbidity as a possible indicator of MP removal.
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Affiliation(s)
- Mathieu Lapointe
- Department of Chemical Engineering, McGill University, Wong Building, 3610 University, Montréal, Québec, H3A 0C5 Canada
| | - Jeffrey M Farner
- Department of Chemical Engineering, McGill University, Wong Building, 3610 University, Montréal, Québec, H3A 0C5 Canada
| | - Laura M Hernandez
- Department of Chemical Engineering, McGill University, Wong Building, 3610 University, Montréal, Québec, H3A 0C5 Canada
| | - Nathalie Tufenkji
- Department of Chemical Engineering, McGill University, Wong Building, 3610 University, Montréal, Québec, H3A 0C5 Canada
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12
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Murujew O, Geoffroy J, Fournie E, Socionovo Gioacchini E, Wilson A, Vale P, Jefferson B, Pidou M. The impact of polymer selection and dose on the incorporation of ballasting agents onto wastewater aggregates. WATER RESEARCH 2020; 170:115346. [PMID: 31801097 DOI: 10.1016/j.watres.2019.115346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 11/17/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Ballasted flocculation is an efficient high-rate sedimentation process getting more attention as an advanced P removal technology for levels below 0.1 mg/L. The process is well-known yet only very few studies have investigated the interactions, within the matrix of wastewater, of coagulant, polymer and ballast, especially when it comes to polymer doses and types which are, in the industry, rather based on recommendations than scientific evidence. In this work, the impact of anionic and cationic polymers has been investigated on P removal and floc properties. Anionic polymers showed to be superior to cationic ones when it comes to P removal and doses even as low as 0.01 mg/L yield better results than coagulant alone. There appears to be a "best-case" floc size with which very good P removal (>90%) can be achieved and flocs of sufficient strength can be generated.
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Affiliation(s)
- Olga Murujew
- Cranfield University, College Road, Cranfield, Bedfordshire, MK43 0AL, UK
| | - Jordan Geoffroy
- Cranfield University, College Road, Cranfield, Bedfordshire, MK43 0AL, UK
| | - Emeline Fournie
- Cranfield University, College Road, Cranfield, Bedfordshire, MK43 0AL, UK
| | | | - Andrea Wilson
- Severn Trent Water, 2 St Johns Street, Coventry, CV1 2LZ, UK; Atkins Global, Woodcote Grove, Epsom, Surrey, KT18 5BW, UK
| | - Peter Vale
- Severn Trent Water, 2 St Johns Street, Coventry, CV1 2LZ, UK
| | - Bruce Jefferson
- Cranfield University, College Road, Cranfield, Bedfordshire, MK43 0AL, UK
| | - Marc Pidou
- Cranfield University, College Road, Cranfield, Bedfordshire, MK43 0AL, UK.
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13
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Lapointe M, Barbeau B. Understanding the roles and characterizing the intrinsic properties of synthetic vs. natural polymers to improve clarification through interparticle Bridging: A review. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2019.115893] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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