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Hao X, Li H, Yuan T, Wu Y. Recovering and potentially applying of alginate like extracellular polymers from anaerobic digested sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 898:165549. [PMID: 37454849 DOI: 10.1016/j.scitotenv.2023.165549] [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: 06/30/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Extracellular polymeric substances (EPS) are biopolymers contained in both aerobic and anaerobic sludge. In EPS, alginate like extracellular polymers (ALE) is thought as a highly valued material, which have been widely studied with aerobic sludge. Nevertheless, a curiosity on ALE remains in anaerobic digested sludge (ADS). With 5 different sludge sources, anaerobic digestion of excess sludge was conducted in a batch mode, and then ADS was used to extract ALE and to analyze its physicochemical properties for potential applications. The yield of ALE extracted from ADS (ALE-ADS) ranged from 119.4 to 179.4 mg/g VSS. The compositional characteristics of ALE-ADS observed by FT-IR, 3D-EEM and UV-Vis spectroscopy revealed that there were minor differences in the composition and property of ALE-ADS but a similarity of 62 %-70 % to a commercial alginate remained in terms of chemical functional groups. Moreover, ALE-ADS composed of 1,4-linked β-d-mannuronic acid (M) and 1,4 α-l-guluronic acid (G) residues that form blocks of GG (20.8 %-33.8 %), MG (12.8 %-30.1 %) and MM (6.6 %-15.1 %), respectively. Based on the gel-forming capacity, film-forming property, adsorbility, and amphiphilicity, ALE-ADS seems potential as a water-proof coating with even a better performance than the commercial alginate, as a seed coating with an increased germination rate, and as a bio-adsorbent with a similar performance to the commercial alginate and ALE from aerobic sludge.
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Affiliation(s)
- Xiaodi Hao
- Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies, Beijing University of Civil Engineering and Architecture, Beijing 100044, PR China.
| | - Hui Li
- Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies, Beijing University of Civil Engineering and Architecture, Beijing 100044, PR China
| | - Tugui Yuan
- Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies, Beijing University of Civil Engineering and Architecture, Beijing 100044, PR China
| | - Yuanyuan Wu
- Beijing Capital Eco-Environment Protection Group Co., Ltd., Beijing 100044, PR China
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2
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Sarvajith M, Nancharaiah Y. Properties of alginate-like exopolymers recovered from flocculent and granular microbial sludges of different biological treatment systems treating real municipal wastewater. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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3
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Xue Y, Ma H, Li YY. Anammox-based granulation cycle for sustainable granular sludge biotechnology from mechanisms to strategies: A critical review. WATER RESEARCH 2023; 228:119353. [PMID: 36423549 DOI: 10.1016/j.watres.2022.119353] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 11/06/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Anaerobic ammonium oxidation (anammox) granular sludge is a promising biotechnological process for treating low-carbon nitrogenous wastewater, and is featured with low energy consumption and footprint. Previous theoretical and experimental research on anammox granular sludge processes mainly focused on granulation (flocs → granules), but pay little attention to the granulation cycle including granulation and regeneration. This work reviewed the previous studies from the perspective of anammox granules lifecycle and proposed various sustainable formation mechanisms of anammox granules. By reviewing the anaerobic, aerobic, and anammox granulation mechanisms, we summarize the mechanisms of thermodynamic theory, heterogeneous growth, extracellular polymeric substance (EPS)-based adhesion, quorum sensing (QS)-based regulation, biomineralization-based growth, and stratification of microorganisms to understand anammox granulation. In the regeneration process, the formation of precursors for re-granulation is explained by the mechanisms of physical crushing, quorum quenching and dispersion cue sensing. Based on the granulation cycle mechanism, the rebuilding of the normal regeneration process is considered essential to avoid granule floatation and the wash-out of granules. This comprehensive review indicates that future research on anammox granulation cycle should focus on the effects of filamentous bacteria in denitrification-anammox granulation cycle, the role of QS/ quorum quenching (QQ)-based autoinducers, development of diversified mechanisms to understand the cycle and the cycle mechanisms of stored granules.
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Affiliation(s)
- Yi Xue
- Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Haiyuan Ma
- College of Environment and Ecology, Chongqing University, Chongqing 40045, China
| | - Yu-You Li
- Graduate School of Environmental Studies, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan; Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
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4
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Wang H, Deng L, Qi Z, Wang W. Constructed microalgal-bacterial symbiotic (MBS) system: Classification, performance, partnerships and perspectives. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 803:150082. [PMID: 34525774 DOI: 10.1016/j.scitotenv.2021.150082] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/27/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
The microalgal-bacterial symbiotic (MBS) system shows great advantages in the synchronous implementation of wastewater treatment and nutrient recovery. To enhance the understanding of different MBS systems, this review summarizes reported MBS systems and proposes three patterns according to the living state of microalgae and bacteria. They are free microalgal-bacterial (FMB) system, attached microalgal-bacterial (AMB) system and bioflocculated microalgal-bacterial (BMB) system. Compared with the other two patterns, BMB system shows the advantages of microalgal biomass harvesting and application. To further understand the microalgal-bacterial partnerships in the bioflocculation of BMB system, this review discusses bioflocs characteristics, extracellular polymeric substances (EPS) properties and production, and the effect of microalgae/bacteria ratio and microalgal strains on the formation of bioflocculation. Microalgal biomass production and application are important for BMB system development in the future. Food processing wastewater characterized by high biodegradability and low toxicity should be conducive for microalgal cultivation. In addition, exogenous addition of functional bacteria for nutrient removal and bioflocculation formation would be a crucial research direction to facilitate the large-scale application of BMB system.
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Affiliation(s)
- Hong Wang
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; Chengdu National Agricultural Science and Technology Center, Chengdu 610213, China
| | - Liangwei Deng
- Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu 610041, China; Chengdu National Agricultural Science and Technology Center, Chengdu 610213, China
| | - Zhiyong Qi
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; Chengdu National Agricultural Science and Technology Center, Chengdu 610213, China
| | - Wenguo Wang
- Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu 610041, China; Chengdu National Agricultural Science and Technology Center, Chengdu 610213, China.
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5
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Wang S, Li H, Zhang A, Fang F, Chen Y, Yan P, Guo J, Ma T, Shen Y. Importance of exopolysaccharide branched chains in determining the aggregation ability of anammox sludge. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 734:139470. [PMID: 32464401 DOI: 10.1016/j.scitotenv.2020.139470] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 06/11/2023]
Abstract
The high aggregation ability of anammox granular sludge is an issue of wide concern; however, the mechanism needs to be further clarified. In this study, selective hydrolysis experiments were performed to determine the role of exopolysaccharide (PS) branched chains and proteins for the aggregation mechanism of anammox granular sludge. The results revealed that selective hydrolysis of proteins hardly affected the granular aggregation while the hydrolysis of PS branched chains led to a decrease in the sludge zeta potential by 17.3% (β-amylase group) and 24.1% (isoamylase group), a decrease of hydrophobicity by 11.6% (β-amylase group) and 17.7% (isoamylase group), an increase of surface free energy by 36.8% (β-amylase group) and 55.1% (isoamylase group) and the deterioration of the PS self-assembly ability. In addition, FTIR and XPS spectra analysis showed that the disruption of PS branched chains resulted in a higher proportion of hydrophilic and electronegative groups, which hindered bacterial aggregation, which was further confirmed by XDLVO theory. The key role of the PS chain structure in sludge aggregation is a critical finding of this work that provides helpful insights for the application of anammox process.
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Affiliation(s)
- Shuai Wang
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Hanxiang Li
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Aiyu Zhang
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Fang Fang
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
| | - Youpeng Chen
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Peng Yan
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Jinsong Guo
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Tengfei Ma
- National Base of International Science and Technology Cooperation for Intelligent Manufacturing Service, Chongqing Key Laboratory of Catalysis & New Environmental Materials, Chongqing Technology and Business University, Chongqing 400067, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing 400060, China
| | - Yu Shen
- National Base of International Science and Technology Cooperation for Intelligent Manufacturing Service, Chongqing Key Laboratory of Catalysis & New Environmental Materials, Chongqing Technology and Business University, Chongqing 400067, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing 400060, China.
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6
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Wang S, Liu L, Li H, Fang F, Yan P, Chen Y, Guo J, Ma T, Shen Y. The branched chains and branching degree of exopolysaccharides affecting the stability of anammox granular sludge. WATER RESEARCH 2020; 178:115818. [PMID: 32344269 DOI: 10.1016/j.watres.2020.115818] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/28/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
The effect of extracellular polysaccharides on the structural stability of granular sludge is widely recognized, and determining their mechanism of action on the stability of granules remains challenging. Herein, enzymatic experiments were used to systematically study the stability changes and internal mechanisms of anammox granular sludge following hydrolysis of extracellular proteins and polysaccharides (PS). The results revealed that the selective hydrolysis of the proteins hardly affected the stability of the granules, while the hydrolysis of the PS branched chains caused the granules to disintegrate. The hydrolysis of the PS chains in the EPS matrix decreased the degree of branching, width and height via nuclear magnetic resonance (NMR) spectroscopy and atomic force microscopy (AFM), and these parameters are closely related to granular stability. Moreover, scanning electron microscopy (SEM) showed a large number of pores and cracks on the granules, bacterial adhesion decreased, and the EPS adhered to the surface of the granules dissolved. The changes in the gel characteristics of the granules were studied by rheology, and the mechanical strength and viscosity of the granular sludge decreased. For the surface characteristics of granules, the zeta potential and hydrophobicity both decreased, revealing that changes in the branched-chain configuration of the PS and the degree of branching caused granular disintegration. Spectral analysis showed that the hydrolysis of the branch points and the branched glycosides of PS led to a higher proportion of hydrophilic and electronegative groups in the EPS matrix, which hindered bacterial aggregation and reduced anammox granule stability. This investigation clarifies the impact of the branched-chain configuration of the PS and their degree of branching on anammox granule stability, which will promote the further application of anammox granules.
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Affiliation(s)
- Shuai Wang
- College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Lijuan Liu
- College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Hanxiang Li
- College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Fang Fang
- College of Environment and Ecology, Chongqing University, Chongqing, 400045, China.
| | - Peng Yan
- College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Youpeng Chen
- College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Jinsong Guo
- College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Tengfei Ma
- National Base of International Science and Technology Cooperation for Intelligent Manufacturing Service, Chongqing Key Laboratory of Catalysis & New Environmental Materials, Chongqing Technology and Business University, Chongqing, 400067, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing, 400060, China
| | - Yu Shen
- National Base of International Science and Technology Cooperation for Intelligent Manufacturing Service, Chongqing Key Laboratory of Catalysis & New Environmental Materials, Chongqing Technology and Business University, Chongqing, 400067, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing, 400060, China.
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7
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Wang H, Qi B, Jiang X, Jiang Y, Yang H, Xiao Y, Jiang N, Deng L, Wang W. Microalgal interstrains differences in algal-bacterial biofloc formation during liquid digestate treatment. BIORESOURCE TECHNOLOGY 2019; 289:121741. [PMID: 31323710 DOI: 10.1016/j.biortech.2019.121741] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/28/2019] [Accepted: 06/29/2019] [Indexed: 06/10/2023]
Abstract
In this study, the effect of microalgal strains on the formation of algal-bacterial biofloc was investigated in liquid digestate pretreated by a sequencing batch reactor (SBR), which loaded much aerobic bacteria from activated sludge. Six microalgal strains resulted in three cases: no-bioflocculation (Scenedesmus obliquus and Botryococcus braunii), optimal-bioflocculation with high flocculation activity and good growth (Chlorella sp. BWY-1, Haematococcus pluvialis and Dictyosphaerium ehnenbergianum) and over-bioflocculation with high flocculation activity and bad growth (Chlorella vulgaris). Chlorella sp. BWY-1 provided a better level of flocculation activity and growth. Polysaccharides and proteins were present in EPS of algal-bacterial biofloc, and their distribution was confirmed by staining with alcian blue and fluorescein isothiocyanate (FITC).
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Affiliation(s)
- Hong Wang
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China
| | - Bufan Qi
- College of Pharmacy and Biological Engineering, Chengdu University, No. 2205, Cheng Luo Road, Chengdu 610106, PR China
| | - Xiaomei Jiang
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China
| | - Yiqi Jiang
- Environmental Science & Engineering Research Center, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, PR China
| | - Han Yang
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China
| | - Youqian Xiao
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China
| | - Na Jiang
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China
| | - Liangwei Deng
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China
| | - Wenguo Wang
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture, Chengdu 610041, PR China.
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8
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Obituary. Carbohydr Polym 2017. [DOI: 10.1016/j.carbpol.2017.03.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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9
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Li X, Luo J, Guo G, Mackey HR, Hao T, Chen G. Seawater-based wastewater accelerates development of aerobic granular sludge: A laboratory proof-of-concept. WATER RESEARCH 2017; 115:210-219. [PMID: 28282616 DOI: 10.1016/j.watres.2017.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/22/2017] [Accepted: 03/01/2017] [Indexed: 06/06/2023]
Abstract
This study aimed to develop an aerobic granular sludge process for the efficient treatment of highly saline wastewater and understand the granulation process in a seawater-based multi-ion matrix. Five identical sequencing batch airlift reactors (SBARs) are used to treat synthetic saline sewage with different proportions of real seawater (0%-100%). The results confirm that aerobic granular sludge can be successfully developed with various proportions of seawater up to 100% and show that seawater not only significantly accelerates granulation but also generates stronger granular structures than does freshwater. The increased presence of gel-forming alginate-like exopolysaccharides in the granules explains why a greater proportion of seawater leads to higher density and improves the cohesive strength of the granules. SEM-EDX analysis further revealed substantial presence of both Ca2+ and Mg2+ phosphate in the granule core as well as in the outer layers providing extra bridging forces in addition to alginate-like exopolysaccharides for accelerating the granule formation and maintaining the structure. It is hoped that this work could explore another approach for saline sewage treatment and bring some clues for the mystery of granulation mechanism.
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Affiliation(s)
- Xiling Li
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Jinghai Luo
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Gang Guo
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Hamish R Mackey
- College of Science and Engineering, Hamad bin Khalifa University, Education City, Doha, Qatar
| | - Tianwei Hao
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; Institute for Advanced Study, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Wastewater Treatment Laboratory, FYT Graduate School, The Hong Kong University of Science and Technology, Nansha, Guangzhou, China.
| | - Guanghao Chen
- Department of Civil & Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China; Water Technology Center, The Hong Kong University of Science and Technology, Hong Kong, China; Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China; Wastewater Treatment Laboratory, FYT Graduate School, The Hong Kong University of Science and Technology, Nansha, Guangzhou, China
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10
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Lin YM, Sharma PK, van Loosdrecht MCM. The chemical and mechanical differences between alginate-like exopolysaccharides isolated from aerobic flocculent sludge and aerobic granular sludge. WATER RESEARCH 2013; 47:57-65. [PMID: 23084341 DOI: 10.1016/j.watres.2012.09.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 08/21/2012] [Accepted: 09/06/2012] [Indexed: 06/01/2023]
Abstract
This study aimed to investigate differences in the gel matrix of aerobic granular sludge and normal aerobic flocculent sludge. From both types of sludge that fed with the same municipal sewage, the functional gel-forming exopolysaccharides, alginate-like exopolysaccharides, were isolated. These two exopolysaccharides were chemically fractionated, and investigated by FT-IR spectroscopy. The isolated polymers were made into a gel by calcium addition and the mechanical properties of these reconstituted gels were measured by a low load compression tester. The viscoelastic behavior of the gels was described by a generalized Maxwell model. The alginate-like exopolysaccharides derived from aerobic granules had significantly higher amount of poly(guluronic acid) blocks but lower amount of poly(guluronic acid-manuronic acid) blocks in the chemical structure, while the alginate-like exopolysaccharides derived from aerobic flocculent sludge had equal amount of poly(guluronic acid) blocks and poly(guluronic acid-manuronic acid) blocks. These differences result in a perfect gel-forming capability of alginate-like exopolysaccharides derived from aerobic granules and bestowed this exopolysaccharides gel a stronger mechanical property as compared to alginate-like exopolysaccharides derived from aerobic flocculent sludge. The different chemical and mechanical properties of these two exopolysaccharides contributed to the distinguished characteristics between aerobic granular sludge and aerobic flocculent sludge.
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Affiliation(s)
- Y M Lin
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
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11
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Seviour T, Yuan Z, van Loosdrecht MCM, Lin Y. Aerobic sludge granulation: a tale of two polysaccharides? WATER RESEARCH 2012; 46:4803-4813. [PMID: 22776210 DOI: 10.1016/j.watres.2012.06.018] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/28/2012] [Accepted: 06/09/2012] [Indexed: 06/01/2023]
Abstract
Aerobic sludge granules are suspended biofilms with the potential to reduce the cost and footprint of secondary wastewater treatment. Attempts to answer how and why they form leads to a consideration of the role of their extracellular polymeric substances (EPS) in determining their physical and microbiological properties. The exopolysaccharide components of this matrix, in particular, have received attention as putative structural, gel-forming agents. Two quite different exopolysaccharides have been proposed as the gel-forming constituents, with their gel properties clearly different from those of activated sludge EPS. This review aims to address the question of whether more than one gel-forming exopolysaccharide exist in granules. Based on the available structural data, it seems likely that they are different gel-forming polymers and their differences are not artifacts of the analytical methods used. Nonetheless, both proposed structural gel polymers are extracted and purified based on procedures selecting for anionic polar polysaccharides soluble at high pH, and both contain hexuronic acids. Granulation does not result from EPS synthesis by any single microbial population, nor from production of a single exopolysaccharide. Future studies using solvents suitable for recalcitrant polysaccharides are likely to reveal important structural roles for other polysaccharides. It is hoped that this article will serve as a guide for subsequent studies into understanding the roles of exopolysaccharides in aerobic granular sludge.
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Affiliation(s)
- Thomas Seviour
- Singapore Centre on Environmental Life Sciences Engineering-SCELSE, Nanyang Technological University, SBS-B2n-27, 60 Nanyang Drive, Singapore 637551, Singapore.
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12
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Lee KH, Choi IS, Kim YG, Yang DJ, Bae HJ. Enhanced production of bioethanol and ultrastructural characteristics of reused Saccharomyces cerevisiae immobilized calcium alginate beads. BIORESOURCE TECHNOLOGY 2011; 102:8191-8198. [PMID: 21742486 DOI: 10.1016/j.biortech.2011.06.063] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 06/04/2011] [Accepted: 06/16/2011] [Indexed: 05/31/2023]
Abstract
Yeast immobilized on alginate beads produced a higher ethanol yield more rapidly than did free yeast cells under the same batch-fermentation conditions. The optimal fermentation conditions were 30°C, pH 5.0, and 10% initial glucose concentration with 2% sodium alginate beads. The fermentation time using reused alginate beads was 10-14 h, whereas fresh beads took 24h, and free cells took 36 h. All bead samples resulted in nearly a 100% ethanol yield, whereas the free cells resulted in an 88% yield. Transmission electron microscopy (TEM) showed that the shortened time and higher yield with the reused beads was due to a higher yeast population per bead as well as a higher porosity. The ultrastructure of calcium alginate beads and the alginate matrix structure known as the "egg-box" model were observed using TEM.
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Affiliation(s)
- Kwang Ho Lee
- Department of Wood Science and Landscape Architecture (BK21 Program), Chonnam National University, Gwangju 500-757, Republic of Korea
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Lin Y, de Kreuk M, van Loosdrecht MCM, Adin A. Characterization of alginate-like exopolysaccharides isolated from aerobic granular sludge in pilot-plant. WATER RESEARCH 2010; 44:3355-3364. [PMID: 20417539 DOI: 10.1016/j.watres.2010.03.019] [Citation(s) in RCA: 162] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 03/15/2010] [Accepted: 03/17/2010] [Indexed: 05/29/2023]
Abstract
To understand functional gel-forming exopolysaccharides in aerobic granular sludge, alginate-like exopolysaccharides were specifically extracted from aerobic granular sludge cultivated in a pilot plant treating municipal sewage. The exopolysaccharides were identified by the FAO/WHO alginate identification tests, characterized by biochemical assays, gelation with Ca(2+), blocks fractionation, spectroscopic analysis as UV-visible, FT-IR and MALDI-TOF MS, and electrophoresis. The yield of extractable alginate-like exopolysaccharides was reached 160+/-4mg/g (VSS ratio). They resembled seaweed alginate in UV-visible and MALDI-TOF MS spectra, and distinguished from it in the reactions with acid ferric sulfate, phenol-sulfuric acid and Coomassie brilliant blue G250. Characterized by their high percentage of poly guluronic acid blocks (69.07+/-8.95%), the isolated exopolysaccharides were capable to form rigid, non-deformable gels in CaCl(2). They were one of the dominant exopolysaccharides in aerobic granular sludge. We suggest that polymers play a significant role in providing aerobic granular sludge a highly hydrophobic, compact, strong and elastic structure.
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Affiliation(s)
- Yuemei Lin
- Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
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14
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Jha B, Basha S, Jaiswar S, Mishra B, Thakur MC. Biosorption of Cd(II) and Pb(II) onto brown seaweed, Lobophora variegata (Lamouroux): kinetic and equilibrium studies. Biodegradation 2009; 20:1-13. [PMID: 18427935 DOI: 10.1007/s10532-008-9194-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Accepted: 04/09/2008] [Indexed: 10/22/2022]
Abstract
The present work deals with the biosorption performance of raw and chemically modified biomass of the brown seaweed Lobophora variegata for removal of Cd(II) and Pb(II) from aqueous solution. The biosorption capacity was significantly altered by pH of the solution delineating that the higher the pH, the higher the Cd(II) and Pb(II) removal. Kinetic and isotherm experiments were carried out at the optimal pH 5.0. The metal removal rates were conspicuously rapid wherein 90% of the total sorption occurred within 90 min. Biomass treated with CaCl(2) demonstrated the highest potential for the sorption of the metal ions with the maximum uptake capacities i.e. 1.71 and 1.79 mmol g(-1) for Cd(II) and Pb(II), respectively. Kinetic data were satisfactorily manifested by a pseudo-second order chemical sorption process. The process mechanism consisting of both surface adsorption and pore diffusion was found to be complex. The sorption data have been analyzed and fitted to sorption isotherm of the Freundlich, Langmuir, and Redlich-Peterson models. The regression coefficient for both Langmuir and Redlich-Peterson isotherms were higher than those secured for Freundlich isotherm implying that the biosorption system is possibly monolayer coverage of the L. variegata surface by the cadmium and lead ions. FT-IR studies revealed that Cd(II) and Pb(II) binding to L. variegata occurred primarily through biomass carboxyl groups accompanied by momentous interactions of the biomass amino and amide groups. In this study, we have observed that L. variegata had maximum biosorption capacity for Cd(II) and Pb(II) reported so far for any marine algae.
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Affiliation(s)
- Bhavanath Jha
- Discipline of Marine Biotechnology and Ecology, Central Salt and Marine Chemicals Research Institute, Bhavnagar, 364 002, Gujarat, India.
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Davis TA, Volesky B, Mucci A. A review of the biochemistry of heavy metal biosorption by brown algae. WATER RESEARCH 2003; 37:4311-30. [PMID: 14511701 DOI: 10.1016/s0043-1354(03)00293-8] [Citation(s) in RCA: 952] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The passive removal of toxic heavy metals such as Cd(2+), Cu(2+), Zn(2+), Pb(2+), Cr(3+), and Hg(2+) by inexpensive biomaterials, termed biosorption, requires that the substrate displays high metal uptake and selectivity, as well as suitable mechanical properties for applied remediation scenarios. In recent years, many low-cost sorbents have been investigated, but the brown algae have since proven to be the most effective and promising substrates. It is their basic biochemical constitution that is responsible for this enhanced performance among biomaterials. More specifically, it is the properties of cell wall constituents, such as alginate and fucoidan, which are chiefly responsible for heavy metal chelation. In this comprehensive review, the emphasis is on outlining the biochemical properties of the brown algae that set them apart from other algal biosorbents. A detailed description of the macromolecular conformation of the alginate biopolymer is offered in order to explain the heavy metal selectivity displayed by the brown algae. The role of cellular structure, storage polysaccharides, cell wall and extracellular polysaccharides is evaluated in terms of their potential for metal sequestration. Binding mechanisms are discussed, including the key functional groups involved and the ion-exchange process. Quantification of metal-biomass interactions is fundamental to the evaluation of potential implementation strategies, hence sorption isotherms, ion-exchange constants, as well as models used to characterize algal biosorption are reviewed. The sorption behavior (i.e., capacity, affinity) of brown algae with various heavy metals is summarized and their relative performance is evaluated.
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Affiliation(s)
- Thomas A Davis
- Department of Chemical Engineering, McGill University, 3610 University Street, Que. H3A 2B2, Montreal, Canada
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Davis TA, Llanes F, Volesky B, Mucci A. Metal selectivity of Sargassum spp. and their alginates in relation to their alpha-L-guluronic acid content and conformation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2003; 37:261-7. [PMID: 12564896 DOI: 10.1021/es025781d] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The discovery of a consistent and unusual enrichment in homopolymeric alpha-L-guluronic acid G-blocks in alginates extracted from a suite of Sargassum brown algae is described in this study. 1H NMR spectroscopy was used to characterize these alginates which display homopolymeric guluronic acid block (G-block) frequency values (F(GG)) between 0.37 and 0.81. The presence of these G-blocks results in an enhanced selectivity for cadmium or calcium relative to monovalent ions such as sodium and the proton as well as smaller divalent ions such as magnesium. Results of competitive exchange experiments for the Cd-Ca-alginate system yield selectivity coefficient, K*(Cd)Ca, values between 0.43 +/- 0.10 and 1.32 +/- 0.02 for a range in F(GG) of 0.23 to 0.81. In contrast to the Cd-Ca-alginate system, the Mg-Ca-alginate and Mg-Cd-alginate systems yielded maximum values of K*(Mg)Ca (18.0 +/- 1.4) and K*(Mg)Cd (16.0 +/- 0.9) for the alginates extracted from Sargassum fluitans (F(GG) = 0.81; Cuba) and Sargassum thunbergii (F(GG) = 0.75; Korea), respectively. Selectivity studies with mixed-metal pair alginate systems highlight the importance of the specific macromolecular conformation of the alginate polymer in determining metal binding behavior in multiple-metal systems. Furthermore, they demonstrate the importance of the conformation of the alginate as it occurs within the tissue of Sargassum in determining the metal binding behavior of this algal biosorbent. The unique composition of the alginates present in species of Sargassum may represent a distinct advantage over other brown algal species when considering their implementation for the strategic removal of toxic heavy metals from contaminated and industrial wastewaters.
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Affiliation(s)
- Thomas A Davis
- Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, Quebec, Canada H3A 2B2
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