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Liang J, Tan X, Ali I, Duan Z, Huang J, Zhu R. Polystyrene microplastics enhanced the photo-degradation and -ammonification of algae-derived dissolved organic matters. JOURNAL OF HAZARDOUS MATERIALS 2024; 480:135991. [PMID: 39369677 DOI: 10.1016/j.jhazmat.2024.135991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Revised: 09/16/2024] [Accepted: 09/26/2024] [Indexed: 10/08/2024]
Abstract
Algae-derived organic matter (ADOM) is a key source of chromophoric dissolved organic matter (CDOM) in natural waters. When exposed to solar irradiation, ADOM undergoes gradual degradation and transformation. The escalating presence of microplastics (MPs) can act as a novel type of environmental photosensitizer, however its impacts on ADOM photodegradation remains largely unexplored. Thus, in this study, ADOM were extracted from four common algal species (Microcystis aeruginosa, Synechococcus sp., Chlorella pyrenoidosa and Scenedesmus obliquus) and exposed to UV irradiation with or without polystyrene (PS) MPs, namely ADOM+PS groups and ADOM groups, respectively. The results indicated that a more rapid degradation of amino acid-like substances (∼38 % vs. ∼22 %) and more ammonia products (1.86 vs. 1.21 mg L-1) were observed in the ADOM+PS groups compared to the ADOM groups after a five-day exposure. This enhanced photodegradation might be attributed to the production of environmentally persistent free radicals and reactive species during the photoaging of PS. Furthermore, PS-derived high electron transfer belt activity of ADOM led to the production of highly aromatic and humified products. These humic-like products could potentially accelerate the degradation of amino acid-like compounds by exciting the generation of excited triplet CDOM. This study underscores the role of MPs as environmental photosensitizers in promoting ADOM degradation and ammonia generation, providing insights on the transformation of ADOM mediated by emerging pollutants and its impact on aquatic carbon and nitrogen cycles.
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Affiliation(s)
- Jia Liang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Xiao Tan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Imran Ali
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China.
| | - Zhipeng Duan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Jiang Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
| | - Rui Zhu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, PR China
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Wang J, Wang Y, Li W, Wu X. Enhancement of KMnO 4 treatment on cyanobacteria laden-water via 1000 kHz ultrasound at a moderate intensity. ULTRASONICS SONOCHEMISTRY 2023; 98:106502. [PMID: 37379744 PMCID: PMC10320383 DOI: 10.1016/j.ultsonch.2023.106502] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/03/2023] [Accepted: 06/20/2023] [Indexed: 06/30/2023]
Abstract
1000 kHz high-frequency ultrasound at 0.12 and 0.39 W/mL intensity was used to enhance the inactivation of suspensions of Microcystis aeruginosa cells using KMnO4. With 10 mg/L of KMnO4, ultrasound at 0.12 W/mL intensity was found to be effective in inactivating the cyanobacteria within 10 min. A Weibull model was found to describes the inactivation well. Its concave shape shows that some cells have a certain resistance to this treatment. Cytometry and microscopic analysis confirm that the treatment damages cell integrity. Despite that the extracellular organic matter in the water was not significantly increased. The concentration of extracellular cyanobacterial toxins even decreased. The filtered suspension of inactivated cyanobacteria was used to cultivate mung beans, and the suspension did not hinder their germination. This provides a new idea for using cyanobacteria-laden wastewater. These findings suggest a technique for speeding up the oxidation of Microcystis cells using KMnO4 with ultrasound at moderate intensity, which provide new insights into the biological effects of ultrasound.
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Affiliation(s)
- JuanJuan Wang
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China; Key Laboratory of Cultivated Land Quality Monitoring and Evaluation, Ministry of Agriculture and Rural Affairs, Yangzhou 225127, China; Jiangsu Collaborative Innovation Centre for Solid Organic Waste Resource Utilization, Nanjing, Jiangsu 210095, China
| | - Yuting Wang
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Wenshu Li
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China
| | - Xiaoge Wu
- Environment Science and Engineering College, Yangzhou University, Yangzhou, Jiangsu 225009, China; Jiangsu Collaborative Innovation Centre for Solid Organic Waste Resource Utilization, Nanjing, Jiangsu 210095, China.
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3
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Park YH, Park J, Choi JS, Kim HS, Choi JS, Choi YE. Ultrasonic Treatment Enhanced Astaxanthin Production of Haematococcus pluvialis. J Microbiol 2023:10.1007/s12275-023-00053-5. [PMID: 37310559 DOI: 10.1007/s12275-023-00053-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 04/17/2023] [Accepted: 04/27/2023] [Indexed: 06/14/2023]
Abstract
In this study, effects of ultrasonic treatment on Haematococcus pluvialis (H. pluvialis) were investigated. It has been confirmed that the ultrasonic stimulation acted as stress resources in the red cyst stage H. pluvialis cells containing astaxanthin, resulting in additional astaxanthin production. With the increase in production of astaxanthin, the average diameter of H. pluvialis cells increased accordingly. In addition, to determine how ultrasonic stimulation had an effect on the further biosynthesis of astaxanthin, genes related to astaxanthin synthesis and cellular ROS level were measured. As a result, it was confirmed that astaxanthin biosynthesis related genes and cellular ROS levels were increased, and thus ultrasonic stimulation acts as an oxidative stimulus. These results support the notion on the effect of the ultrasonic treatment, and we believe our novel approach based on the ultrasonic treatment would help to enhance the astaxanthin production from H. pluvialis.
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Affiliation(s)
- Yun Hwan Park
- Division of Environmental Science & Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Jaewon Park
- Division of Environmental Science & Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
- OJeong Resilience Institute, Korea University, Seoul, 02841, Republic of Korea
| | - Jeong Sik Choi
- Division of Environmental Science & Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Hyun Soo Kim
- Department of Electronic Engineering, Kwangwoon University, Seoul, 01897, Republic of Korea
| | - Jong Soon Choi
- Division of Analytical Science, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea.
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea.
| | - Yoon-E Choi
- Division of Environmental Science & Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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4
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Liu Y, Liu X, Cui Y, Yuan W. Ultrasound for microalgal cell disruption and product extraction: A review. ULTRASONICS SONOCHEMISTRY 2022; 87:106054. [PMID: 35688121 PMCID: PMC9175141 DOI: 10.1016/j.ultsonch.2022.106054] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/08/2022] [Accepted: 05/09/2022] [Indexed: 05/12/2023]
Abstract
Microalgae are a promising feedstock for the production of biofuels, nutraceuticals, pharmaceuticals and cosmetics, due to their superior capability of converting solar energy and CO2 into lipids, proteins, and other valuable bioactive compounds. To facilitate the release of these important biomolecules from microalgae, effective cell disruption is usually necessary, where the use of ultrasound has gained tremendous interests as an alternative to traditional methods. This review not only summarizes the mechanisms of and operation parameters affecting cell disruption, but also takes an insight into measuring techniques, synergistic integration with other disruption methods, and challenges of ultrasonication for microalgal biorefining. Optimal conditions including ultrasonic frequency, intensity, and duration, and liquid viscosity and sonochemical reactor are the key factors for maximizing the disruption and extraction efficiency. A combination of ultrasound with other disruption methods such as ozonation, microwave, homogenization, enzymatic lysis, and solvents facilitates cell disruption and release of target compounds, thus provides powerful solutions to commercial scale-up of ultrasound extraction for microalgal biorefining. It is concluded that ultrasonication is a sustainable "green" process, but more research and work are needed to upscale this process without sacrificing performance or consuming more energy.
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Affiliation(s)
- Ying Liu
- State Environmental Protection Key Laboratory of Drinking Water Source Management and Technology, Shenzhen Academy of Environmental Science, Shenzhen 518001, Guangdong, China
| | - Xin Liu
- Key Laboratory of Tropical Marine Ecosystem and Bioresource, Fourth Institute of Oceanography, Ministry of Natural Resources, Beihai 536000, Guangxi, China
| | - Yan Cui
- Gansu Innovation Center of Microalgae Technology, Hexi University, Zhangye 734000, Gansu, China
| | - Wenqiao Yuan
- Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695, USA.
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Silva PGP, Prescendo Júnior D, de Medeiros Burkert JF, Santos LO. Carotenoid extraction from Phaffia rhodozyma biomass: downstream strategies and economic evaluation of energy. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2022. [DOI: 10.1007/s43153-022-00225-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Xu Q, Leng H, You H, Wang S, Li H, Yu Y. A novel co-catalyzed system between persulfate and chlorite by sonolysis for removing triphenylmethane derivative. J Environ Sci (China) 2022; 112:291-306. [PMID: 34955213 DOI: 10.1016/j.jes.2021.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/09/2021] [Accepted: 05/09/2021] [Indexed: 06/14/2023]
Abstract
Triphenylmethane (tpm) derivatives (e.g. tpmCV) have threatened the safety of the aquatic environment due to the potential toxicity and carcinogenicity. In this study, the novel ultrasonic/persulfate/chlorite (US/S2O82-/ClO2-) oxidation process was developed for the effective removal of tpmCV in wastewater. The apparent non-integer kinetics (n around 1.20) of tpmCV degradation under different factors (R2Adj > 0.990) were investigated, respectively. Inhibiting effects of anions were greater than those of cations (except Fe(II/III)). The adding of micromolecule organic acids could regulate degradation towards positive direction. The double response surface methodology (RSM) was designed to optimize tpmCV removal process, and the acoustic-piezoelectric interaction was simulated to determine the propagation process of acoustic wave in the reactor. The possible degradation pathway was explored to mainly include carbonylation, carboxylation, and demethylation. The estimated effective-mean temperature at the bubble-water interface was calculated from 721 to 566 K after introducing the ClO2-, however, the adsorption or partitioning capacity of tpmCV in the reactive zone was widened from 0.0218 to 0.0982. The proposed co-catalysis of US/S2O82-/ClO2- was based on the determined active species mainly including ClO2, SO4⋅-, and ⋅OH. Compared with other US-based processes, the operating cost (3.97 $/m3) of US/S2O82-/ClO2- with the EE/O value (16.8 kWh/m3) was relatively reduced.
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Affiliation(s)
- Qihui Xu
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Haoran Leng
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hong You
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China.; School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.
| | - Shutao Wang
- School of Environment, Harbin Institute of Technology, Harbin 150090, China.
| | - Haoyang Li
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China
| | - Yibo Yu
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China
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Xu Q, Zhang H, Leng H, You H, Jia Y, Wang S. Ultrasonic role to activate persulfate/chlorite with foamed zero-valent-iron: Sonochemical applications and induced mechanisms. ULTRASONICS SONOCHEMISTRY 2021; 78:105750. [PMID: 34544014 PMCID: PMC8455865 DOI: 10.1016/j.ultsonch.2021.105750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/31/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
The novel system, consisting of composite oxidants (persulfate/chlorite, S2O82-/ClO2-) and stationary phase activator (zero-valent-iron foam, Fe0f) driven by ultrasonic (US) field, was applied to treat the triphenylmethane derivative effectively even at low temperature (≈ 289 K). By comparisons of sub-systems, the US roles to S2O82-, ClO2-, and Fe0f were seriatim analyzed. US made the reaction order of multi-component system tend to within 1 (leading to de-order reaction), and widened pH activating range of the Fe0f by sonicate-polishing during the process of ClO2- co-activating S2O82-. US and Fe0f were affected by fluid eddy on activating S2O82-/ClO2-. The Fe0f had slight effect on the temperature of US bubble-water interface but the addition of ClO2- lowered it. The partitioning capacity of the above US reactive zone increased during the reaction. US and ClO2- could enrich the kinds of degradation intermediates. The contributions of free radicals (ClOx-based radicals, sulfate radicals (SO4-), and hydroxyl radicals (OH)) and non-free radicals (ClO2, and O = FeIV/V from ionic Fe under "-O-O-" of S2O82- and cyclic adjustment reaction of ClO2-) processes by sonochemical induction were equally important by corresponding detection means. Especially, real-time and online high-resolution mass spectrum by self-developing further confirmed the chain transfers of different free radicals due to US role. The findings expanded the application of sono-persulfate-based systems and improved understanding on activation mechanism.
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Affiliation(s)
- Qihui Xu
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hong Zhang
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China
| | - Haoran Leng
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Hong You
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China; School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China.
| | - Yuhong Jia
- School of Marine Science and Technology, Harbin Institute of Technology at Weihai, Weihai 264209, China
| | - Shutao Wang
- State Key Laboratory of Urban Water Resources and Environment, Harbin Institute of Technology, Harbin 150090, China
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8
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Khan MJ, Ahirwar A, Schoefs B, Pugazhendhi A, Varjani S, Rajendran K, Bhatia SK, Saratale GD, Saratale RG, Vinayak V. Insights into diatom microalgal farming for treatment of wastewater and pretreatment of algal cells by ultrasonication for value creation. ENVIRONMENTAL RESEARCH 2021; 201:111550. [PMID: 34224710 DOI: 10.1016/j.envres.2021.111550] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/01/2021] [Accepted: 06/15/2021] [Indexed: 05/16/2023]
Abstract
Wastewater management and its treatment have revolutionized the industry sector into many innovative techniques. However, the cost of recycling via chemical treatment has major issues especially in economically poor sectors. On the offset, one of the most viable and economical techniques to clean wastewater is by growing microalgae in it. Since wastewater is rich in nitrates, phosphates and other trace elements, the environment is suitable for the growth of microalgae. On the other side, the cost of harvesting microalgae for its secondary metabolites is burgeoning. While simultaneously growing of microalgae in photobioreactors requires regular feeding of the nutrients and maintenance which increases the cost of operation and hence cost of its end products. The growth of microalgae in waste waters makes the process not only economical but they also manufacture more amounts of value added products. However, harvesting of these values added products is still a cumbersome task. On the offset, it has been observed that pretreating the microalgal biomass with ultrasonication allows easy oozing of the secondary metabolites like oil, proteins, carbohydrates and methane at much lower cost than that required for their extraction. Among microalgae diatoms are more robust and have immense crude oil and are rich in various value added products. However, due to their thick silica walls they do not ooze the metabolites until the mechanical force on their walls reaches certain threshold energy. In this review recycling of wastewater using microalgae and its pretreatment via ultrasonication with special reference to diatoms is critically discussed. Perspectives on circular bioeconomy and knowledge gaps for employing microalgae to recycle wastewater have been comprehensively narrated.
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Affiliation(s)
- Mohd Jahir Khan
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. HarisinghGour Central University, Sagar, MP, 470003, India
| | - Ankesh Ahirwar
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. HarisinghGour Central University, Sagar, MP, 470003, India
| | - Benoit Schoefs
- Metabolism, Bioengineering of Microalgal Metabolism and Applications (MIMMA), Mer Molecules Santé, Le Mans University, IUML - FR 3473 CNRS, Le Mans, France
| | - Arivalagan Pugazhendhi
- Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Viet Nam
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar, Gujarat, 382 010, India.
| | - Karthik Rajendran
- Department of Environmental Science, SRM University-AP, Neerukonda, Andhra Pradesh, India
| | - Shashi Kant Bhatia
- Department of Biological Engineering, Konkuk University, Seoul, 05029, Republic of Korea
| | - Ganesh Dattatraya Saratale
- Department of Food Science and Biotechnology, Dongguk University-Seoul, Ilsandong-gu, Goyang-si, Gyeonggido, 10326, Republic of Korea
| | - Rijuta Ganesh Saratale
- Research Institute of Biotechnology and Medical Converged Science, Dongguk University-Seoul, Ilsandong-gu, Goyang-si, Gyeonggido, 10326, Republic of Korea
| | - Vandana Vinayak
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. HarisinghGour Central University, Sagar, MP, 470003, India.
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Huang Y, Ding S, Li L, Liao Q, Chu W, Li H. Ultrasound-enhanced coagulation for Microcystis aeruginosa removal and disinfection by-product control during subsequent chlorination. WATER RESEARCH 2021; 201:117334. [PMID: 34161875 DOI: 10.1016/j.watres.2021.117334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/08/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
Ultrasound techniques have gained increased interest in environmental remediation because of their promising performance and reagent-free nature. This study investigated the effects of ultrasound-coagulation on Microcystis aeruginosa removal, disinfection by-product (DBP) formation during subsequent chlorination, and acute toxicity and DBP-associated toxicity variations in chlorinated effluents. Compared with coagulation using polymeric aluminum chloride (5 mg-Al/L) alone, ultrasound-coagulation showed significantly enhanced turbidity removal, with the removal ratio increasing from 51% to 87%-96%. Although the addition of ultrasound may not substantially improve and even deteriorate the coagulation removal of DOC following the leakage of intracellular organic matter, the significantly improved DBP control was achieved as the cells dominated DBP formation. With the addition of ultrasound, the chlorine demand, aggregate DBP concentration and total organic halogen concentration reductions in the chlorinated M. aeruginosa solution increased from 15%, 47% and 52% (coagulation alone), respectively, to 56%-78%, 56%-80% and 68%-89%. The enhanced DBP mitigation was mainly attributed to the enhanced algal removal. Similarly, the acute toxicity and DBP-associated toxicity of chlorinated effluents further decreased from 100% and 0.0092 (coagulation alone) to 30%-88% and 0.0029-0.0060. Therefore, ultrasound-enhanced coagulation is a promising strategy for urgent algal removal, DBP mitigation and toxicity abatement.
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Affiliation(s)
- Yangrui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Shunke Ding
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Lei Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Qingying Liao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China.
| | - Huaizheng Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China.
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Continuous Ultrasound-Assisted Esterification and Transesterification of Palm Fatty Acid Distillate for Ethyl Ester Production. Processes (Basel) 2021. [DOI: 10.3390/pr9030449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ethyl ester production from palm fatty acid distillate (PFAD) with ethanol in the presence of sulfuric acid and potassium hydroxide was performed in a continuous three-step process using the ultrasound clamps and an ultrasonic probe. The ultimate goal was to produce biodiesel from the PFAD. In the first and second esterification steps, 16 units of a 400 W ultrasound clamp (20 kHz) were attached 100-m apart along each tubular reactor. In the third transesterification step, a 1000-W ultrasonic homogenizer (18 kHz) was used in a 100-mL continuous reactor. A composite central design of experiments and the response surface methodology (RSM) were used to develop predictive models and identify the optimal conditions of each step based on the purities of ethyl ester. The optimal conditions in the first step were 46.1 vol.% ethanol, 1.4 vol.% sulfuric acid, and purity 66.68 wt.% ethyl ester. In the second step, the optimized conditions were 57 vol.% ethanol, and 2.1 vol.% sulfuric acid, purity 95.32 wt.% ethyl ester. The final transesterification step was carried out with 14.6 vol.% ethanol and 3.9 gKOH L−1. As a result, a final ethyl ester purity of 98.15 wt.% was achieved in the biodiesel using the three-step process.
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11
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Tan X, Duan Z, Duan P, Parajuli K, Newman J, Shu X, Zhang D, Gao L, Li M. Flocculation of Microcystis unicells induced by pH regulation: Mechanism and potential application. CHEMOSPHERE 2021; 263:127708. [PMID: 33296998 DOI: 10.1016/j.chemosphere.2020.127708] [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: 01/20/2020] [Revised: 07/01/2020] [Accepted: 07/11/2020] [Indexed: 06/12/2023]
Abstract
In water treatment process, Microcystis colonies can be effectively removed by coagulants. However, the use of popular coagulants could cause adverse health effects in humans or increase the amount of sludge. Meanwhile, Microcystis unicells are much more difficult to remove than colonies, due to their small size and dispersed distribution. This study proposed and analyzed the flocculation of Microcystis unicells induced by pH regulation. The particle size, zeta potential, cell viability and integrity, cytochemical changes, and cell-to-cell connections were recorded during pH regulation. Results showed that when pH was adjusted in the range of 2.5 to 2 by HCl (1.2 M), Microcystis unicells aggregated to form flocs as large as 28 μm, which are easy to remove by filtration or sedimentation. The overwhelming majority of cells were intact and inactivated in the optimal pH range (2.5-2). Thus, pH regulation is an environment-friendly and cost-effective method to remove Microcystis unicells, which can be potentially applied to water treatment.
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Affiliation(s)
- Xiao Tan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
| | - Zhipeng Duan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Pengfei Duan
- Collaborative Innovation Center of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project, Nanyang, 473061, China
| | - Keshab Parajuli
- School of Population and Global Health, Faculty of Medicine, Denistry and Health Sciences, The University of Melbourne, VIC, 3010, Australia
| | - Jeffrey Newman
- School of Civil Environment & Mining Engineering, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Xiaoqian Shu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Danfeng Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Li Gao
- South East Water, 101 Wells Street, Frankston, VIC, 3199, Australia
| | - Ming Li
- Collaborative Innovation Center of Water Security for Water Source Region of Mid-line of South-to-North Diversion Project, Nanyang, 473061, China; College of Resources and Environment, Northwest A & F University, Yangling, 712100, China.
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12
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Huang YR, Li L, Wei XM, Li HZ, Zeng JY, Kuang R. An investigation of mechanisms for the enhanced coagulation removal of Microcystis aeruginosa by low-frequency ultrasound under different ultrasound energy densities. ULTRASONICS SONOCHEMISTRY 2020; 69:105278. [PMID: 32738454 DOI: 10.1016/j.ultsonch.2020.105278] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 07/11/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
There is a lack of studies elaborating the differences in mechanisms of low-frequency ultrasound-enhanced coagulation for algae removal among different ultrasound energy densities, which are essential to optimizing the economy of the ultrasound technology for practical application. The performance and mechanisms of low-frequency ultrasound (29.4 kHz, horn type, maximum output amplitude = 10 μm) -coagulation process in removing a typical species of cyanobacteria, Microcystis aeruginosa, at different ultrasound energy densities were studied based on a set of comprehensive characterization approaches. The turbidity removal ratio of coagulation (with polymeric aluminum salt coagulant at a dosage of 4 mg Al/L) was considerably increased from 44.1% to 59.7%, 67.0%, and 74.9% with 30 s of ultrasonic pretreatment at energy densities of 0.6, 1.11, and 2.22 J/mL, respectively, indicating that low-frequency ultrasound-coagulation is a potential alternative to effectively control unexpected blooms of M. aeruginosa. However, the energy density of ultrasound should be deliberately considered because a high energy density (≥18 J/mL) results in a significant release of algal organic matter, which may threaten water quality security. The specific mechanisms for the enhanced coagulation removal by low-frequency ultrasonic pretreatment under different energy densities can be summarized as the reduction of cell activity (energy density ≥ 0.6 J/mL), the slight release of negatively charged algal organic matter from cells (energy density ≥ 1.11 J/mL), and the aggregation of M. aeruginosa cells (energy density ≥ 1.11 J/mL). This study provides new insights for the ongoing study of ultrasonic pretreatment for the removal of algae via coagulation.
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Affiliation(s)
- Yang-Rui Huang
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China.
| | - Lei Li
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China.
| | - Xin-Min Wei
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Huai-Zheng Li
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Juan-Yan Zeng
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Rui Kuang
- College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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Duan Z, Tan X, Zhang D, Parajuli K. Development of thermal treatment for the extraction of extracellular polymeric substances from Microcystis: Evaluating extraction efficiency and cell integrity. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101879] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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14
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Li Y, Shi X, Zhang Z, Peng Y. Enhanced coagulation by high-frequency ultrasound in Microcystis aeruginosa-laden water: Strategies and mechanisms. ULTRASONICS SONOCHEMISTRY 2019; 55:232-242. [PMID: 30712852 DOI: 10.1016/j.ultsonch.2019.01.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 01/03/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Ultrasonic treatment has attracted much attention because of its physical and chemical effects that are distinct from those of chemical agents. In particularly, high-frequency ultrasound is known as an effective method because the theoretical resonance frequency of the gas vesicles in Microcystis aeruginosa is in the high frequency range (>100 kHz), which causes gas vesicles collapse and changes the settleability of the algal cells. In this work, the effects of the ultrasonic frequency, acoustic power density and duration on enhancing coagulation to remove turbidity in algae-laden water were studied. In order to explain the mechanism, the morphology of algae cells, the changes in extracellular organic substances, the zeta potential and the formation of hydroxyl radicals were analyzed systematically. Finally, Zeta potentials and flocs morphology after adding PAC were investigated to verify the mechanism. The results showed that the frequency exhibited fewer effects than power and duration on coagulation. SEM images showed that there were more severe cellular damages at 430 and 740 kHz than other frequencies. Sonication could cause the collapse of gas vesicle inside the cell, which was due to the instantaneous high pressure generated by the ultrasonic cavitation instead of the resonance. Furthermore, sonication would result in an increase in proteins in extracellular organic matter (EOM) with continuous ultrasonic irradiation, indicating that a small amount of proteins could promote coagulation and that the accumulation of proteins would inhibit coagulation. Free radical content testing showed that the production of excessive free radicals was often accompanied by a deterioration of the coagulation. The proper mechanical effects were the main mechanism of ultrasonic enhanced coagulation. Thus, it was recommended that the appropriate ultrasonic condition was the one that resulted in a small amount of protein leakage and little generation of free radicals, which occurred at 740 kHz and 0.02 W/mL in approximately 5 min, and would significantly enhance the turbidity removal rate in algae-containing water from approximately 80-90%.
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Affiliation(s)
- Yitao Li
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; Faculty of Urban Construction and Environment Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing 400045, China
| | - Xingdong Shi
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; Faculty of Urban Construction and Environment Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing 400045, China
| | - Zhi Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; Faculty of Urban Construction and Environment Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing 400045, China.
| | - Yazhou Peng
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; Faculty of Urban Construction and Environment Engineering, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing 400045, China
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Tan X, Shu X, Guo J, Parajuli K, Zhang X, Duan Z. Effects of Low-Frequency Ultrasound on Microcystis aeruginosa from Cell Inactivation to Disruption. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 101:117-123. [PMID: 29744520 DOI: 10.1007/s00128-018-2348-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
Ultrasound can be used to induce cell resonance and cavitation to inhibit cyanobacterial growth, but it can also lead to increase in dissolved nutrients because of cell disruption. This study investigated the process from cell inactivation to disruption of Microcystis aeruginosa. Algal cells were sonicated (at 35 kHz) under various intensities and durations. Results showed that chlorophyll a content and Fv/Fm values decreased slightly within the first 5 min. Superoxide dismutase activity was stimulated and its peak value appeared at the fifth minute. After 20 min, considerable number of ruptured cells were observed and the concentrations of dissolved nitrogen and phosphorus increased rapidly. Finally, ammonia and nitrate merely composed a small portion of dissolved nitrogen. This study demonstrated that excessive ultrasound treatment can significantly rupture algal cells and lead to the release of cellular inclusions, which may cause ecological issues or public health problems. Based on our findings, ultrasonic intensity controlled at 0.035 W/mL and applied for a duration of 20 min delivers the optimal result in effectively inhibiting physiological activities of Microcystis aeruginosa without marked cell disruption. This will ultimately help to achieve algal control, while conserving energy and preserving the environment and human health.
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Affiliation(s)
- Xiao Tan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Xiaoqian Shu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Jiujia Guo
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | | | - Xidong Zhang
- Nanjing Foreign Language School, Nanjing, 210008, China
| | - Zhipeng Duan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
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