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Xu H, Yang A, Pang Y, Pei H. Advances and challenges in the technologies for cyanobacterial cells removal in drinking water treatment. CHEMOSPHERE 2024; 359:142338. [PMID: 38754486 DOI: 10.1016/j.chemosphere.2024.142338] [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: 08/14/2023] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/18/2024]
Abstract
Harmful cyanobacteria in reservoirs pose a serious threat to drinking water safety due to the intracellular metabolites, such as toxins and unpleasant tastes & odours. Effective removal of harmful cyanobacteria with little to no cell damage is very important to ensure the safety of drinking water. This review first introduced development history of cyanobacterial removal technologies in drinking water treatment. Then, impacts of oxidation, coagulation and pre-oxidation enhanced coagulation processes on cyanobacterial removal and integrity of the cells were comprehensively evaluated and discussed. Oxidation can remove cyanobacteria, but high doses of oxidants can result in significant cell lysis and release of intracellular metabolites, especially when using chlorine or ozone. Although there is practically no cell damage during coagulation, the removal efficiency is low in many cases. Pre-oxidation may improve cyanobacterial removal by the subsequent solid-liquid separation processes, and moderate pre-oxidation with little to no cell lysis is very important. Mechanisms of interface interaction between pre-oxidants and cyanobacteria should be defined in future to ensure moderate pre-oxidation of algal cells. Fate of cyanobacterial cells in sludge is also reviewed because more and more waterworks return sludge supernatant to the inlet of plant. Damage to cyanobacterial cells in sludge depends mainly upon coagulant type and dosage, algal species, and cyanobacteria-containing sludge should be treated before cell lysis. Efficient techniques for harmless disposal of cyanobacteria-containing sludge should be developed in future. This paper will help to better understand the cyanobacterial removal processes and provide improved perspectives for future research in this field.
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Affiliation(s)
- Hangzhou Xu
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China
| | - Aonan Yang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Yiming Pang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China
| | - Haiyan Pei
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China; Shandong Provincial Engineering Center on Environmental Science and Technology, Jinan, 250061, China; Institute of Eco-Chongming (IEC), Shanghai, 202162, China.
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Wang Y, Zhu Y, Wang K, Tan Y, Bing X, Jiang J, Fang W, Chen L, Liao H. Principles and research progress of physical prevention and control technologies for algae in eutrophic water. iScience 2024; 27:109990. [PMID: 38840838 PMCID: PMC11152667 DOI: 10.1016/j.isci.2024.109990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024] Open
Abstract
The abnormal reproduction of algae in water worldwide is prominent in the context of human interference and global climate change. This study first thoroughly analyzed the effects of physical factors, such as light, temperature, hydrodynamics, and operational strategies, on algal growth and their mechanisms. Physical control techniques are safe and have great potential for preventing abnormal algal blooms in the absence of chemical reagents. The focus was on the principles and possible engineering applications of physical shading, ultrasound, micro-current, and ultraviolet (UV) technologies, in controlling abnormal algal reproduction. Physical shading can inhibit or weaken photosynthesis in algae, thereby inhibiting their growth. Ultrasound mainly affects the physiological and biochemical activities of cells by destroying the cell walls, air cells, and active enzymes. Micro-currents destroy the algal cell structure through direct and indirect oxidation, leading to algal cell death. UV irradiation can damage DNA, causing organisms to be unable to reproduce or algal cells to die directly. This article comprehensively summarizes and analyzes the advantages of physical prevention and control technologies for the abnormal reproduction of algae, providing a scientific basis for future research. In the future, attempts will be made toward appropriately and comprehensively utilizing various physical technologies to control algal blooms. The establishment of an intelligent, comprehensive physical prevention and control system to achieve environmentally friendly, economical, and effective physical prevention and control of algae, such as the South-to-North Water Diversion Project in China, is of great importance for specific waters.
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Affiliation(s)
- Yuyao Wang
- State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
| | - Yuanrong Zhu
- State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Kuo Wang
- State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Yidan Tan
- State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xiaojie Bing
- State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Juan Jiang
- State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
- College of Environment, Hohai University, Nanjing 210098, China
| | - Wen Fang
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Liang Chen
- School of Water Conservancy and Environment, University of Jinan, Jinan 250022, China
| | - Haiqing Liao
- State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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Giannuzzi L, Bacciadone J, Salerno GL. A Promising Use of Trimethyl Chitosan for Removing Microcystis aeruginosa in Water Treatment Processes. Microorganisms 2022; 10:microorganisms10102052. [PMID: 36296328 PMCID: PMC9610100 DOI: 10.3390/microorganisms10102052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/12/2022] [Accepted: 10/12/2022] [Indexed: 11/16/2022] Open
Abstract
The increase in cyanobacterial blooms linked to climate change and the eutrophication of water bodies is a global concern. The harmful cyanobacterium Microcystis aeruginosa is one of the most common bloom-forming species whose removal from fresh water and, in particular, from that used for water treatment processes, remains a crucial goal. Different biodegradable and environmentally friendly coagulants/flocculants have been assayed, with chitosan showing a very good performance. However, chitosan in its original form is of limited applicability since it is only soluble in acid solution. The objective of this work was therefore to test the coagulant/flocculant capacity of trimethylchitosan (TMC), a chitosan derivative produced from residues of the fishing industry. TMC has a constitutively net positive charge enabling it to remain in solution regardless of the pH. Results show that even at alkaline pHs, common during cyanobacterial blooms, TMC is effective in removing buoyant cyanobacteria from the water column, both in test tube and Jar-Test experiments. Cell integrity was confirmed by fluorescent stain and electron microscopy. Our findings lead us to conclude that the use of TMC to remove bloom cells early in the treatment of drinking water is both feasible and promising.
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Affiliation(s)
- Leda Giannuzzi
- Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CIDCA-CONICET), La Plata 1900, Argentina
- Correspondence:
| | - Julián Bacciadone
- Fundación Para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, Mar del Plata 7600, Argentina
| | - Graciela L. Salerno
- Fundación Para Investigaciones Biológicas Aplicadas (FIBA), Vieytes 3103, Mar del Plata 7600, Argentina
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Almomani F. Algal cells harvesting using cost-effective magnetic nano-particles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137621. [PMID: 32146403 DOI: 10.1016/j.scitotenv.2020.137621] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Revised: 02/27/2020] [Accepted: 02/27/2020] [Indexed: 06/10/2023]
Abstract
Innovative iron-based nanoparticles were synthesized, characterized and tested for the first time for harvesting single and mixed algal culture from real wastewater. The tailor-made magnetic nanoparticles (MNPs; Fe-MNP-I and Fe-MNP-II) achieved a percentage algae harvesting efficiency (%AHE) higher than 95% using a concentration of MNPs (CMNP) of 25 ± 0.3 (std. dev = 0.08) mg.L-1, mixing speed (Mspeed) of 120 ± 2 (std. dev = 0.10) rpm, short contact time (Ct) of 7 ± 0.1 (std. dev = 0.05) min and separation time (SPt) of 3 ± 0.1 (std. dev = 0.09) min. The optimum operational conditions for harvesting of Chlorella vulgaris (C.v) were determined at (CMNP = 40 ± 0.4 (std. dev = 0.5) gMNPs.L-1, SPt = 2.5 ± 0.4 (std. dev = 0.1) min, Mspeed = 145 ± 3 (std. dev = 1.50) rpm and Ct = 5 ± 0.3 (std. dev = 0.10) min using surface response methodology. Langmuir model describes better the adsorption behavior of algae-Fe-MNP-I system, while both Langmuir and Freundlich fit well the adsorption behavior of algae-Fe-MNP-II. The maximum adsorption capacity of Spirulina platensis (SP.PL) (18.27 ± 0.07 (std. dev = 0.19) mgDWC.mgparticles-1) was higher than that for Chlorella vulgaris (C.v) (11.52 ± 0.01 (std. dev = 0.34) mgDWC.mgparticles-1) and mixed algal culture (M.X) (17.20 ± 0.07 (std. dev = 0.54) mgDWC.mgparticles-1) over Fe-MNP-I. Zeta potential measurements revealed that the adsorption mechanism between MNPs and algal strains is controlled by electrostatic interaction. The synthesized MNPs were recycled 10 times using alkaline-ultrasonic regeneration procedure.
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Affiliation(s)
- Fares Almomani
- Department of Chemical Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar.
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Cui H, Huang X, Yu Z, Chen P, Cao X. Application progress of enhanced coagulation in water treatment. RSC Adv 2020; 10:20231-20244. [PMID: 35520422 PMCID: PMC9059168 DOI: 10.1039/d0ra02979c] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 05/19/2020] [Indexed: 11/30/2022] Open
Abstract
Water industries worldwide consider coagulation/flocculation to be one of the major treatment methods for improving the overall efficiency and cost effectiveness of water and wastewater treatment. Enhancing the coagulation process is currently a popular research topic. In this review article, the latest developments in enhanced coagulation are summarized. In addition, the mechanisms of enhanced coagulation and the effect of process parameters on processing efficiency are discussed from the perspective of ballast-enhanced coagulation, preoxidation, ultrasound, and composite coagulants. Finally, improvements and new directions for enhanced coagulation are proposed. This review summarizes the current situation of enhanced coagulation and looks forward to future development.![]()
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Affiliation(s)
- Hongmei Cui
- School of Civil Engineering and Architecture
- Northeast Petroleum University
- China
- Key Laboratory of Disaster Prevention and Mitigation
- Projective Engineering of Heilongjiang Province
| | - Xing Huang
- School of Civil Engineering and Architecture
- Northeast Petroleum University
- China
| | - Zhongchen Yu
- School of Civil Engineering and Architecture
- Northeast Petroleum University
- China
- Key Laboratory of Disaster Prevention and Mitigation
- Projective Engineering of Heilongjiang Province
| | - Ping Chen
- School of Civil Engineering and Architecture
- Northeast Petroleum University
- China
- Key Laboratory of Disaster Prevention and Mitigation
- Projective Engineering of Heilongjiang Province
| | - Xiaoling Cao
- School of Civil Engineering and Architecture
- Northeast Petroleum University
- China
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Removal of Algae, and Taste and Odor Compounds by a Combination of Plant-Mineral Composite (PMC) Coagulant with UV-AOPs: Laboratory and Pilot Scale Studies. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8091502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The seasonal occurrence of algae blooms in surface waters remains a common problem, such as taste and odor (T&Os), the risk of disinfection by-products (DBPs), and disturbance to water treatment systems. The coagulation efficiency of plant-mineral composite (PMC) coagulant followed by UV-based advanced oxidation processes (UV-AOPs; UV/H2O2 and UV/Cl2) was evaluated for removal of algae, turbidity, dissolved organic matters, and taste and odor compounds in lab-scale and pilot-scale tests. In the lab-scale test, coagulation process with 20 mg/L of PMC shows high removal efficiency of turbidity (94%) and algae (99%) and moderate removal efficiency of UV254 (51%) and geosmin (46%). The pilot test results also show good removal efficiency of turbidity (64%), chlorophyll-a (96%). After PMC coagulation process, the major water factors, which affected the performance of UV-AOPs (i.e., UV transmittance (85–94%), and scavenging factor (64,998–28,516 s−1)), were notably improved, and further degradation of geosmin and 2-methylisoborneol (2-MIB) was achieved in both lab-and pilot-scale tests of the UV-AOPs. The UV/H2O2 process shows higher removal efficiency of geosmin and 2-MIB than the UV/Cl2 process because of the pH effect. The results confirmed that the PMC-based coagulation followed by UV/H2O2 process could be an effective process for the removal of algae, geosmin, and 2-MIB.
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Barrado-Moreno M, Beltrán-Heredia J, Martín-Gallardo J. Degradation of microalgae from freshwater by UV radiation. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2016.12.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Farooq W, Moon M, Ryu BG, Suh WI, Shrivastav A, Park MS, Mishra SK, Yang JW. Effect of harvesting methods on the reusability of water for cultivation of Chlorella vulgaris, its lipid productivity and biodiesel quality. ALGAL RES 2015. [DOI: 10.1016/j.algal.2014.12.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Krivograd Klemenčič A, Griessler Bulc T. The use of vertical constructed wetland and ultrasound in aquaponic systems. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:1420-1430. [PMID: 25146120 DOI: 10.1007/s11356-014-3463-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 08/14/2014] [Indexed: 06/03/2023]
Abstract
Treatment performance, fish production, crop plant biomass production, water consumption, and water use efficiency of a pilot aquaponic system for small-scale land-based cyprinid fish farms were evaluated. The system consisted of a 36 m(3) Pond A with an initial carp load of 0.6 kg/m(3); of a treatment chain with a lamellar settler, a roughing filter, a vertical constructed wetland filled with expanded clay and planted with tomatoes; and of a low power ultrasound unit installed in the corner of the pond. The average circulation of the water in the system was 1.2 times per day. Pond A was compared with Pond B of the same dimensions and fish load but with no treatment chain or ultrasound. The treatment chain was efficient in mass removal of total suspended solids , biochemical oxygen demand, chemical oxygen demand, NH4-N, total nitrogen, and total phosphorous (57, 49, 35, 42, 31, and 25 %, respectively). Negative removal of NO3-N, NO2-N, and PO4-P indicated the need for the introduction of additional hydroponic beds in the system. Pond A had markedly lower nutrient concentrations compared with Pond B. Fish body weight increase and specific growth rate in Pond A were higher than in Pond B (102.6 %, 72.1 %; 0.19 %/day, 0.14 %/day, respectively) indicating better rearing conditions in Pond A. Tomato biomass production was high. Water use efficiency was higher in Pond A compared with Pond B (0.31 kg of produced fish/m(3) inflow water and 0.22 kg of produced fish/m(3) inflow water, respectively). The presented aquaponic system could be useful for semi-natural fish farming with fish loads up to 2 kg/m(3).
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Affiliation(s)
- A Krivograd Klemenčič
- Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, SI-1000, Ljubljana, Slovenia,
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11
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Li P, Song Y, Yu S. Removal of Microcystis aeruginosa using hydrodynamic cavitation: performance and mechanisms. WATER RESEARCH 2014; 62:241-8. [PMID: 24960124 DOI: 10.1016/j.watres.2014.05.052] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 05/27/2014] [Accepted: 05/28/2014] [Indexed: 05/23/2023]
Abstract
Algal blooms are a seasonal problem in eutrophic water bodies, and novel approaches to algal removal are required. The effect of hydrodynamic cavitation (HC) on the removal of Microcystis aeruginosa was investigated using a laboratory scale device. Samples treated by HC were subsequently grown under illuminated culture conditions. The results demonstrated that a short treatment with HC could effectively settle naturally growing M. aeruginosa without breaking cells. Algal cell density and chlorophyll-a of a sample treated for 10 min were significantly decreased by 88% andv 94%, respectively, after 3 days culture. Various HC operating parameters were investigated, showing that inhibition of M. aeruginosa growth mainly depended on treatment time and pump pressure. Electron microscopy confirmed that sedimentation of algae was attributable to the disruption of intracellular gas vesicles. Damage to the photosynthetic apparatus also contributed to the inhibition of algal growth. Free radicals produced by the cavitation process could be as an indirect indicator of the intensity of HC treatment, although they inflicted minimal damage on the algae. In conclusion, we suggest that HC represents a potentially highly effective and sustainable approach to the removal of algae from water systems.
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Affiliation(s)
- Pan Li
- School of Environmental Science and Engineering, State Key Laboratory of Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai, PR China; The Collaborative Innovation Center of Advanced Technology and Equipment for Water Pollution Control and the Collaborative Innovation Center for Regional Environmental Quality, 1239 Siping Road, Shanghai, PR China.
| | - Yuan Song
- School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, PR China
| | - Shuili Yu
- School of Environmental Science and Engineering, State Key Laboratory of Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai, PR China; The Collaborative Innovation Center of Advanced Technology and Equipment for Water Pollution Control and the Collaborative Innovation Center for Regional Environmental Quality, 1239 Siping Road, Shanghai, PR China.
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12
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Wang M, Yuan W, Jiang X, Jing Y, Wang Z. Disruption of microalgal cells using high-frequency focused ultrasound. BIORESOURCE TECHNOLOGY 2014; 153:315-321. [PMID: 24374364 DOI: 10.1016/j.biortech.2013.11.054] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 11/14/2013] [Accepted: 11/20/2013] [Indexed: 06/03/2023]
Abstract
The objective of this study was to evaluate the effectiveness of high-frequency focused ultrasound (HFFU) in microalgal cell disruption. Two microalgal species including Scenedesmus dimorphus and Nannochloropsis oculata were treated by a 3.2-MHz, 40-W focused ultrasound and a 100-W, low-frequency (20kHz) non-focused ultrasound (LFNFU). The results demonstrated that HFFU was effective in the disruption of microalgal cells, indicated by significantly increased lipid fluorescence density, the decrease of cell sizes, and the increase of chlorophyll a fluorescence density after treatments. Compared with LFNFU, HFFU treatment was more energy efficient. The combination of high and low frequency treatments was found to be even more effective than single frequency treatment at the same processing time, indicating that frequency played a critical role in cell disruption. In both HFFU and LFNFU treatments, the effectiveness of cell disruption was found to be dependent on the cell treated.
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Affiliation(s)
- Meng Wang
- Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Wenqiao Yuan
- Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695, United States.
| | - Xiaoning Jiang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Yun Jing
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Zhuochen Wang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, United States
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Pantelić D, Svirčev Z, Simeunović J, Vidović M, Trajković I. Cyanotoxins: characteristics, production and degradation routes in drinking water treatment with reference to the situation in Serbia. CHEMOSPHERE 2013; 91:421-441. [PMID: 23391374 DOI: 10.1016/j.chemosphere.2013.01.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 12/26/2012] [Accepted: 01/02/2013] [Indexed: 06/01/2023]
Abstract
Cyanobacteria are members of phytoplankton of the surface freshwaters. The accelerated eutrophication of freshwaters, especially reservoirs for drinking water, by human activity has increased the occurrence and intensity of cyanobacterial blooms. They are of concern due to their ability to produce taste and odors compounds, a wide range of toxins, which have a hepatotoxic, neurotoxic, cytotoxic and dermatotoxic behavior, being dangerous to animal and human health. Therefore, the removal of cyanobacteria, without cell lysis, and releasing of intracellular metabolites, would significantly reduce the concentration of these metabolites in the finished drinking water, as a specific aim of the water treatment processes. This review summarizes the existing data on characteristics of the cyanotoxins, their productions in environment and effective treatment processes to remove these toxins from drinking water.
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Affiliation(s)
- Dijana Pantelić
- University of Novi Sad, Department of Biology and Ecology, Faculty of Sciences, Trg Dositeja Obradovića 2, 21000 Novi Sad, Serbia.
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Inexpensive non-toxic flocculation of microalgae contradicts theories; overcoming a major hurdle to bulk algal production. Biotechnol Adv 2012; 30:1023-30. [DOI: 10.1016/j.biotechadv.2012.01.011] [Citation(s) in RCA: 181] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 01/16/2012] [Accepted: 01/19/2012] [Indexed: 11/22/2022]
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15
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Xu L, Guo C, Wang F, Zheng S, Liu CZ. A simple and rapid harvesting method for microalgae by in situ magnetic separation. BIORESOURCE TECHNOLOGY 2011; 102:10047-51. [PMID: 21890346 DOI: 10.1016/j.biortech.2011.08.021] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 08/01/2011] [Accepted: 08/03/2011] [Indexed: 05/13/2023]
Abstract
A simple and rapid harvesting method by in situ magnetic separation with naked Fe(3)O(4) nanoparticles has been developed for the microalgal recovery of Botryococcus braunii and Chlorella ellipsoidea. After adding the magnetic particles to the microalgal culture broth, the microalgal cells were adsorbed and then separated by an external magnetic field. The maximal recovery efficiency reached more than 98% for both microalgae at a stirring speed of 120 r/min within 1 min, and the maximal adsorption capacity of these Fe(3)O(4) nanoparticles reached 55.9 mg-dry biomass/mg-particles for B. braunii and 5.83 mg-dry biomass/mg-particles for C. ellipsoidea. Appropriate pH value and high nanoparticle dose were favorable to the microalgae recovery, and the adsorption mechanism between the naked Fe(3)O(4) nanoparticles and the microalgal cells was mainly due to the electrostatic attraction. The developed in situ magnetic separation technology provides a great potential for saving time and energy associated with improving microalgal harvesting.
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Affiliation(s)
- Ling Xu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
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16
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Zhang G, Zhang P, Fan M. Ultrasound-enhanced coagulation for Microcystis aeruginosa removal. ULTRASONICS SONOCHEMISTRY 2009; 16:334-338. [PMID: 19083255 DOI: 10.1016/j.ultsonch.2008.10.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2008] [Revised: 10/11/2008] [Accepted: 10/31/2008] [Indexed: 05/27/2023]
Abstract
Source water eutrophication has caused serious problems in drinking water supplies, with enhanced coagulation widely used to remove the resulting algae. This paper investigates the use of sonication to improve the removal by coagulation of Microcystis aeruginosa, a common species of toxic algae. The results show that sonication significantly enhances the reduction of algae cells, solution UV254, and chlorophyll a without increasing the concentration of aqueous microcystins. The main mechanism involved the destruction during ultrasonic irradiation of gas vacuoles inside algae cells that acted as 'nuclei' for acoustic cavitation and collapse during the "bubble crush" period, resulting in the settlement of cyanobacteria. Coagulation efficiency depended strongly on the coagulant dose and sonication conditions. When the coagulant dose was 0.5mg/l, 5s of ultrasonic irradiation increased algae removal efficiency from 35% to 67%. As further sonication enhanced the coagulation efficiency only slightly due to better mixing, optimal sonication time was 5s. The most effective sonication intensity was 47.2W/cm2, and the highest removal ratio of M. aeruginosa was 93.5% by the sonication-coagulation method. Experiments with reservoir water showed that this method could be successfully applied to natural water containing multiple species of algae.
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Affiliation(s)
- Guangming Zhang
- State Key Lab of Urban Water Resource Environment, Harbin Institute of Technology, 202 Haihe Road, Harbin, Helongjiang 150090, China.
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