1
|
Mohamed Hatta NS, Lau SW, Chua HB, Takeo M, Sen TK, Mubarak NM, Khalid M, Zairin DA. Parametric and kinetic studies of activated sludge dewatering by cationic chitosan-like bioflocculant BF01314 produced from Citrobacter youngae. ENVIRONMENTAL RESEARCH 2023; 224:115527. [PMID: 36822539 DOI: 10.1016/j.envres.2023.115527] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 02/18/2023] [Indexed: 06/18/2023]
Abstract
Bacterial strains belonging to Citrobacter spp. were reported to produce polysaccharides consisting of N-acetylglucosamine and glucosamine like chitosan, with high flocculation activity. In this work, the flocculation dewatering performance of activated sludge conditioned by a novel cationic chitosan-like bioflocculant (BF) named BF01314, produced from Citrobacter youngae GTC 01314, was evaluated under the influences of flocculant dosage, pH, and temperature. At BF dosage as low as 0.5 kg/t DS, the sludge dewaterability was significantly enhanced in comparison to the raw (untreated) sludge, featuring well-flocculated characteristic (reduction in CST from 22.0 s to 9.4 s) and good sludge filterability with reduced resistance (reduction in SRF by one order from 7.42 × 1011 to 9.59 × 1010 m/kg) and increased compactness of sludge (increase in CSC from 15.2 to 23.2%). Besides, the BF demonstrated comparable high sludge dewatering performance within the pH range between 2 and 8, and temperature range between 25 °C and 80 °C. Comparison between the BF, the pristine chitosan and the commercial cationic copolymer MF 7861 demonstrated equivalent performance with enhanced dewaterability at the dosage between 2.0 and 3.0 kg/t DS. Besides, the BF demonstrated strong flocculation activity (>99%) when added to the sludge suspension using moderate to high flocculation speeds (100-200 rpm) with at least 3-min mixing time. The BF's reaction in sludge flocculation was best fitted with a pseudo first-order kinetic model. Electrostatic charge patching and polymer bridging mechanisms are believed to be the dominant mechanistic phenomena during the BF's sludge conditioning process (coagulation-flocculation).
Collapse
Affiliation(s)
- Nur Syahirah Mohamed Hatta
- Department of Chemical and Energy Engineering, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia
| | - Shiew Wei Lau
- Department of Chemical and Energy Engineering, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia.
| | - Han Bing Chua
- Department of Chemical and Energy Engineering, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia
| | - Masahiro Takeo
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Tushar Kanti Sen
- Chemical Engineering Department, King Faisal University, Hofuf, Al-Ahsa 31982, Saudi Arabia
| | - Nabisab Mujawar Mubarak
- Petroleum and Chemical Engineering, Faculty of Engineering, Universiti Teknologi Brunei, Bandar Seri Begawan BE1410, Brunei Darussalam.
| | - Mohammad Khalid
- Graphene and Advanced 2D Materials Research Group (GAMRG), School of Engineering and Technology, Sunway University, No. 5, Jalan Universiti, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia; Uttaranchal University, Dehradun, 248007 Uttarakhand, India
| | - Danial Aminin Zairin
- Graphene and Advanced 2D Materials Research Group (GAMRG), School of Engineering and Technology, Sunway University, No. 5, Jalan Universiti, Bandar Sunway, 47500 Subang Jaya, Selangor, Malaysia
| |
Collapse
|
2
|
Li L, Xu L, He J, He Q, Zhang J. Effect of granular activated carbon and chloroform on chain elongation with simple substrate ethanol and acetate. ENVIRONMENTAL RESEARCH 2023; 221:115324. [PMID: 36669585 DOI: 10.1016/j.envres.2023.115324] [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: 11/01/2022] [Revised: 12/31/2022] [Accepted: 01/16/2023] [Indexed: 06/17/2023]
Abstract
Chain elongation is a promising technology for production of medium-chain fatty acids (MCFAs). Granular activated carbon (GAC) is commonly used in anaerobic fermentation. Low level CHCl3 can inhibit methanogenesis and homoacetogenesis at the same time. However, the effect of them on chain elongation performance with highly enriched consortia and simple substrate (i.e., ethanol and acetate) was still unclear. Hence, the effects of CHCl3 and on MCFAs production and the microbial community was studied here. CHCl3 displayed fatal effect on chain elongation system when its concentration was higher than 0.1% v/v. 0.05% v/v CHCl3 was enough to inhibit homoacetogens and further decreased the caproate production efficiency without altering the core bacteria tremendously. GAC was found to be adverse for chain elongation with simple substrate (i.e., ethanol and acetate) and highly enriched microbial consortia dominated by Clostridium sensu stricto, less than 20% electrons were finally distributed in caproate. It might be attributed to other electron consuming activities induced by GAC.
Collapse
Affiliation(s)
- Lin Li
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400045, China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
| | - Linji Xu
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400045, China.
| | - Junguo He
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China; School of Civil Engineering, Guangzhou University, Guangzhou, 510006, China
| | - Qiang He
- Key Laboratory of the Three Gorges Reservoir Region's Eco-environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, 400045, China
| | - Jie Zhang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China
| |
Collapse
|
3
|
Chen W, Zhang D, Luo X, Wang J, Xu Q, Lu X, Mao J, Song H, Wu X, Zan F. In-situ sulfite treatment enhanced the production of short-chain fatty acids from waste activated sludge in the side-stream anaerobic fermentation. BIORESOURCE TECHNOLOGY 2023; 370:128521. [PMID: 36565821 DOI: 10.1016/j.biortech.2022.128521] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/17/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Sulfite-based technology could enhance methane production from anaerobic sludge digestion. However, its potential for in-situ direct sludge treatment without anaerobic sludge addition in the side-stream remains unclear. This study investigated the feasibility of using in-situ sulfite treating sludge for short-chain fatty acids (SCFAs) production via anaerobic fermentation of waste activated sludge (WAS) as a side-stream treatment. In-situ sulfite direct sludge treatment enhanced SCFAs and acetic acid production by 2.03 and 4.89 times at 500 mg S/L compared to the control. With in-situ sulfite treatment, WAS hydrolysis and acidification were enhanced while methanogenesis was spontaneously hindered. The in-situ sulfite treatment inactivated pathogens and improved the sludge dewatering properties. The relative abundances of SCFAs-production microbial were stimulated, facilitating the sludge bioconversion. The produced SCFAs from in-situ sulfite side-stream treatment could be applied as an "internal carbon source" to enhance biological nutrient removal to improve economic and environmental value from sludge treatment.
Collapse
Affiliation(s)
- Wei Chen
- School of Urban Construction, Department of Water and Wastewater Engineering and Hubei Experimental Teaching Demonstration Center, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Dandan Zhang
- School of Urban Construction, Department of Water and Wastewater Engineering and Hubei Experimental Teaching Demonstration Center, Wuhan University of Science and Technology, Wuhan 430065, China; School of Environmental Science and Engineering, Low-Carbon Water Environment Technology Center (HUST-SUKE), and Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Huazhong University of Science and Technology, Wuhan, China
| | - Xi Luo
- Hubei Provincial Engineering Research Center for Comprehensive Water Environment Treatment in the Yangtze River Basin, Changjiang Institute of Survey, Planning, Design and Research Co., Ltd, Wuhan, China
| | - Jiale Wang
- School of Environmental Science and Engineering, Low-Carbon Water Environment Technology Center (HUST-SUKE), and Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Huazhong University of Science and Technology, Wuhan, China
| | - Qi Xu
- Hubei Provincial Engineering Research Center for Comprehensive Water Environment Treatment in the Yangtze River Basin, Changjiang Institute of Survey, Planning, Design and Research Co., Ltd, Wuhan, China
| | - Xiejuan Lu
- School of Environmental Science and Engineering, Low-Carbon Water Environment Technology Center (HUST-SUKE), and Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Huazhong University of Science and Technology, Wuhan, China
| | - Juan Mao
- School of Environmental Science and Engineering, Low-Carbon Water Environment Technology Center (HUST-SUKE), and Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Huazhong University of Science and Technology, Wuhan, China
| | - Hongjiao Song
- School of Urban Construction, Department of Water and Wastewater Engineering and Hubei Experimental Teaching Demonstration Center, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Xiaohui Wu
- School of Environmental Science and Engineering, Low-Carbon Water Environment Technology Center (HUST-SUKE), and Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Huazhong University of Science and Technology, Wuhan, China
| | - Feixiang Zan
- School of Environmental Science and Engineering, Low-Carbon Water Environment Technology Center (HUST-SUKE), and Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Huazhong University of Science and Technology, Wuhan, China.
| |
Collapse
|
4
|
He J, Ding W, Han W, Chen Y, Jin W, Zhou X. A bacterial strain Citrobacter W4 facilitates the bio-flocculation of wastewater cultured microalgae Chlorella pyrenoidosa. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:151336. [PMID: 34743821 DOI: 10.1016/j.scitotenv.2021.151336] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
A bacteria strain Citrobacter W4 isolated from the microalgae sewage culture system showed flocculating activity against Chlorella pyrenoidosa. In this work, operation parameters under outdoor conditions were optimized. When the bacterial-algal ratio was 4:1, G value was 26.30 s-1, and harvesting time was 6 h, the harvesting efficiency achieved 87.37 ± 2.96% without ions addition and pH adjustment. The microbial community structure analysis showed Citrobacter W4 was dominant in the harvesting process. Flocculating active substances were on the surface and metabolites of Citrobacter W4. The main component of bacteria flocculating active substances was protein. Polysaccharides and carboxylic acid also promoted flocculation. The flocculation mechanisms were mainly adsorption bridging, net catching, and sweeping, not electric neutralization. The quality of FAMEs was improved after flocculation. The cost of 1 kg dried microalgae flocculated by Citrobacter W4 was $1.35. The novel flocculating bacteria showed the potential to harvest microalgae cost-effectively and environmentally friendly.
Collapse
Affiliation(s)
- Jiawen He
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Wanqing Ding
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Wei Han
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Yidi Chen
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China
| | - Wenbiao Jin
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
| | - Xu Zhou
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China; Shenzhen Engineering Laboratory of Microalgal Bioenergy, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
| |
Collapse
|
5
|
Saha S, Shukla SK, Singh HR, Pradhan KK, Jha SK. Production and purification of bioflocculants from newly isolated bacterial species: a comparative decolourization study of cationic and anionic textile dyes. ENVIRONMENTAL TECHNOLOGY 2021; 42:3663-3674. [PMID: 32114960 DOI: 10.1080/09593330.2020.1737737] [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: 12/23/2019] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
Bioflocculant-producing bacteria were isolated from various water reservoirs and sediments of the water treatment plant. Four promising strains were identified by standard biochemical methods and 16s rRNA gene sequencing. Bioflocculants were produced in a batch bioreactor of 3 L under optimized conditions. Fourier transformed infrared spectroscopy and scanning electron microscopy (SEM) were used to confirm the chemical and morphological nature of bioflocculants. Anionic and cationic textile dyes congo red (CR) and rhodamine-B (RB) decolourization efficiency by ethanol precipitated bioflocculants were accessed under different values of pH, temperature, dose of flocculant and presence of monovalent, divalent and trivalent cations. Bioflocculants of all the four isolates were found to be highly efficient in decolourization of dye from an aqueous medium with the removal rate up to 99.56%. The removal rate of CR and RB from aqueous medium was largely influenced by the physiochemical condition of the solution viz. pH, temperature, concentration of ions and dose of flocculants. The microbial bioflocculants are biodegradable and highly stable as well as possess abroad range of pH, temperature and ions tolerance range. So, they may be economical and can be greener substitutes for the present harsh chemical-based wastewater effluent treatment methods.
Collapse
Affiliation(s)
- Swastika Saha
- Department of Bioengineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
| | - Sushil Kumar Shukla
- Department of Transport Science and Technology, Central University of Jharkhand, Brambe, Ranchi, Jharkhand, India
| | - Hare Ram Singh
- Department of Bioengineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
| | - Kishanta Kumar Pradhan
- Department of Pharmaceutical Science and Technology, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
| | - Santosh Kumar Jha
- Department of Bioengineering, Birla Institute of Technology, Mesra, Ranchi, Jharkhand, India
| |
Collapse
|
6
|
Maruyama H, Seki H. Effect of soy protein-based flocculant on flocculation and filtration of diatomite and kaolin suspensions. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 82:1868-1876. [PMID: 33201850 DOI: 10.2166/wst.2020.461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The effect of ethylated soy protein-based bioflocculant (EtSP) as a filter aid reagent was investigated. The efficiency of EtSP as a filter aid was evaluated in terms of the specific cake resistance, α, and was compared with chitosan and polyaluminum chloride (PAC). Diatomite and kaolin were used as model particles. Total filtration resistance, R, decreased with increasing flocculant dosage (wt.%, flocculant/particle) and was almost constant in the range of 1 wt.% or more for both particles. The α value was significantly decreased from 1.01 × 1011 to 9.01 × 1010 m/kg for diatomite and from 5.11 × 1010 to 5.20 × 109 m/kg for kaolin by the addition of EtSP in the case of 1.0 wt.%. The α value for cakes formed by EtSP was much smaller than that formed by chitosan and PAC. In the case of diatomite, in the dose range of 0.5-1.0 wt.%, the α value for cakes formed by EtSP and chitosan was almost the same. However, at the excess dose of 2.0 wt.% over, the α value formed by chitosan abruptly increased. In the case of kaolin, in the dose range of 1.0-2.0 wt.%, the α values of chitosan and PAC were mostly the same, however, these values were larger by ca. nine times than that of EtSP.
Collapse
Affiliation(s)
- Hideo Maruyama
- Division of Marine Bioresources, Graduate School of Fisheries Sciences, Hokkaido University, Minato-cho 3-1-1, Hakodate 041-8611, Hokkaido, Japan E-mail:
| | - Hideshi Seki
- Division of Marine Bioresources, Graduate School of Fisheries Sciences, Hokkaido University, Minato-cho 3-1-1, Hakodate 041-8611, Hokkaido, Japan E-mail:
| |
Collapse
|
7
|
Li H, Wu S, Du C, Zhong Y, Yang C. Preparation, Performances, and Mechanisms of Microbial Flocculants for Wastewater Treatment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E1360. [PMID: 32093205 PMCID: PMC7068532 DOI: 10.3390/ijerph17041360] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/10/2020] [Accepted: 02/17/2020] [Indexed: 12/15/2022]
Abstract
In recent years, close attention has been paid to microbial flocculants because of their advantages, including safety to humans, environmental friendliness, and acceptable removal performances. In this review, the preparation methods of microbial flocculants were first reviewed. Then, the performances of bioflocculants in the removal of suspended solids, heavy metals, and other organic pollutants from various types of wastewater were described and commented, and the removal mechanisms, including adsorption bridging, charge neutralization, chemical reactions, and charge neutrality, were also discussed. The future research needs on microbial flocculants were also proposed. This review would lead to a better understanding of current status, challenges, and corresponding strategies on microbial flocculants and bioflocculation in wastewater treatment.
Collapse
Affiliation(s)
- Huiru Li
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China; (H.L.); (S.W.)
| | - Shaohua Wu
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China; (H.L.); (S.W.)
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China; (C.D.); (Y.Z.)
| | - Cheng Du
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China; (C.D.); (Y.Z.)
| | - Yuanyuan Zhong
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China; (C.D.); (Y.Z.)
| | - Chunping Yang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China; (H.L.); (S.W.)
- Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China; (C.D.); (Y.Z.)
- Hunan Provincial Environmental Protection Engineering Center for Organic Pollution Control of Urban Water and Wastewater, Changsha 410001, China
| |
Collapse
|
8
|
Mohammed JN, Wan Dagang WRZ. Implications for industrial application of bioflocculant demand alternatives to conventional media: waste as a substitute. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 80:1807-1822. [PMID: 32144213 DOI: 10.2166/wst.2020.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The biodegradability and safety of the bioflocculants make them a potential alternative to non-biodegradable chemical flocculants for wastewater treatment. However, low yield and production cost has been reported to be the limiting factor for large scale bioflocculant production. Although the utilization of cheap nutrient sources is generally appealing for large scale bioproduct production, exploration to meet the demand for them is still low. Although much progress has been achieved at laboratory scale, Industrial production and application of bioflocculant is yet to be viable due to cost of the production medium and low yield. Thus, the prospects of bioflocculant application as an alternative to chemical flocculants is linked to evaluation and utilization of cheap alternative and renewable nutrient sources. This review evaluates the latest literature on the utilization of waste/wastewater as an alternative substitute for conventional expensive nutrient sources. It focuses on the mechanisms and metabolic pathways involved in microbial flocculant synthesis, culture conditions and nutrient requirements for bioflocculant production, pre-treatment, and also optimization of waste substrate for bioflocculant synthesis and bioflocculant production from waste and their efficiencies. Utilization of wastes as a microbial nutrient source drastically reduces the cost of bioflocculant production and increases the appeal of bioflocculant as a cost-effective alternative to chemical flocculants.
Collapse
Affiliation(s)
- Jibrin Ndejiko Mohammed
- Department of Microbiology, Ibrahim Badamasi Babangida University, PMB11, Lapai, Niger State, Nigeria; Faculty of Science, Universiti Teknologi Malaysia, 81310, Johor, Malaysia E-mail:
| | | |
Collapse
|
9
|
Zhang J, Liu L, Ren Y, Chen F. Characterization of exopolysaccharides produced by microalgae with antitumor activity on human colon cancer cells. Int J Biol Macromol 2019; 128:761-767. [DOI: 10.1016/j.ijbiomac.2019.02.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/30/2019] [Accepted: 02/02/2019] [Indexed: 02/08/2023]
|
10
|
Abu Tawila ZMM, Ismail S, Abu Amr SS, Abou Elkhair EK. A novel efficient bioflocculant QZ-7 for the removal of heavy metals from industrial wastewater. RSC Adv 2019; 9:27825-27834. [PMID: 35530503 PMCID: PMC9070865 DOI: 10.1039/c9ra04683f] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 07/31/2019] [Indexed: 11/21/2022] Open
Abstract
In this study, a novel bioflocculant QZ-7 was produced from Bacillus salmalaya 139SI for industrial wastewater treatment. Biochemical analysis, FTIR, scanning electron microscopy-energy dispersive X-ray spectroscopy, and thermogravimetric analysis were performed. A synthetic wastewater sample was used to validate the performance of the prepared OZ-7 for the adsorption efficiency of As, Zn2+ Pb2+, Cu2+, and Cd2+ under optimal experimental conditions such as initial metal concentrations, pH, contact time (h) and QZ-7 adsorbent dosage (mg mL−1). The maximum removal efficiency for Zn2+ (81.3%), As (78.6%), Pb2+ (77.9%), Cu2+ (76.1%), and Cd2+ (68.7%) was achieved using an optimal bioflocculant dosage of 60 mg L−1 at 2 h shaking time, 100 rpm and pH 7. Furthermore, the obtained optimum experimental conditions were validated using real industrial wastewater and the removal efficiencies of 89.8%, 77.4% and 58.4% were obtained for As, Zn2+ and Cu2+, respectively. The results revealed that the prepared bioflocculant QZ-7 has the capability to be used for the removal of heavy metals from industrial wastewater. In this study, a novel bioflocculant was produced using Bacillus salmalaya 139SI for industrial waste water treatment.![]()
Collapse
Affiliation(s)
- Zayed M. M. Abu Tawila
- Institute of Biological Science
- Faculty of Science
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - Salmah Ismail
- Institute of Biological Science
- Faculty of Science
- University of Malaya
- Kuala Lumpur
- Malaysia
| | - Salem S. Abu Amr
- Malaysian Institute of Chemical & Bioengineering Technology
- Universiti Kuala Lumpur, (UniKL, MICET)
- Melaka
- Malaysia
| | | |
Collapse
|
11
|
Abu Tawila ZM, Ismail S, Dadrasnia A, Usman MM. Production and Characterization of a Bioflocculant Produced by Bacillus salmalaya 139SI-7 and Its Applications in Wastewater Treatment. Molecules 2018; 23:molecules23102689. [PMID: 30340415 PMCID: PMC6222882 DOI: 10.3390/molecules23102689] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 08/29/2018] [Accepted: 09/11/2018] [Indexed: 11/16/2022] Open
Abstract
The production, optimization, and characterization of the bioflocculant QZ-7 synthesized by a novel Bacillus salmalaya strain 139SI isolated from a private farm soil in Selangor, Malaysia, are reported. The flocculating activity of bioflocculant QZ-7 present in the selected strain was found to be 83.3%. The optimal culture for flocculant production was achieved after cultivation at 35.5 °C for 72 h at pH 7 ± 0.2, with an inoculum size of 5% (v/v) and sucrose and yeast extract as carbon and nitrogen sources. The maximum flocculating activity was found to be 92.6%. Chemical analysis revealed that the pure bioflocculant consisted of 79.08% carbohydrates and 15.4% proteins. The average molecular weight of the bioflocculant was calculated to be 5.13 × 10⁵ Da. Infrared spectrometric analysis showed the presence of carboxyl (COO-), hydroxyl (-OH), and amino (-NH₂) groups, polysaccharides and proteins. The bioflocculant QZ-7 exhibited a wide pH stability range from 4 to 7, with a flocculation activity of 85% at pH 7 ± 0.2. In addition, QZ-7 was thermally stable and retained more than 80% of its flocculating activity after being heated at 80 °C for 30 min. SEM analysis revealed that QZ-7 exhibited a clear crystalline brick-shaped structure. After treating wastewater, the bioflocculant QZ-7 showed significant flocculation performance with a COD removal efficiency of 93%, whereas a BOD removal efficiency of 92.4% was observed in the B. salmalaya strain 139SI. These values indicate the promising applications of the bioflocculant QZ-7 in wastewater treatment.
Collapse
Affiliation(s)
- Zayed M Abu Tawila
- Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
- Department of Biology, Faculty of Science, Al-Azhar University, Gaza, Palestine.
| | - Salmah Ismail
- Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Arezoo Dadrasnia
- Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Mohammed Maikudi Usman
- Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia.
| |
Collapse
|
12
|
Xu L, Zhou M, Ju H, Zhang Z, Zhang J, Sun C. Enterobacter aerogenes metabolites enhance Microcystis aeruginosa biomass recovery for sustainable bioflocculant and biohydrogen production. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 634:488-496. [PMID: 29635192 DOI: 10.1016/j.scitotenv.2018.03.327] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 03/25/2018] [Accepted: 03/26/2018] [Indexed: 06/08/2023]
Abstract
We report a recycling bioresource involving harvesting of Microcystis aeruginosa using the bioflocculant (MBF-32) produced by Enterobacter aerogenes followed by the recovery of the harvested M. aeruginosa as the main substrate for the sustainable production of MBF-32 and biohydrogen. The experimental results indicate that the efficiency of bioflocculation exceeded 90% under optimal conditions. The harvested M. aeruginosa was further recycled as the main substrate for the supply of necessary elements. The highest yield (3.6±0.1g/L) of MBF-32 could be obtained from 20g/L of wet biomass of M. aeruginosa with an additional 20g/L of glucose as the extra carbon source. The highest yield of biohydrogen was 35mL of H2/g (dw) algal biomass, obtained from 20g/L of wet biomass of M. aeruginosa with an additional 10g/L of glycerol. Transcriptome analyses indicated that MBF-32 was mainly composed of polysaccharide and tyrosine/tryptophan proteins. Furthermore, NADH synthase and polysaccharide export-related genes were found to be up-regulated.
Collapse
Affiliation(s)
- Liang Xu
- School of Environment, Northeast Normal University, Changchun 130117, China; Jilin Institute of Chemical Technology, Jilin, 132022, China; Key Laboratory for Vegetation Ecology, Ministry of Education, NO. 2555 Jingyue Street, Changchun 130117, China; State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, China
| | - Mo Zhou
- School of Environment, Northeast Normal University, Changchun 130117, China; Key Laboratory for Vegetation Ecology, Ministry of Education, NO. 2555 Jingyue Street, Changchun 130117, China; State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, China
| | - Hanyu Ju
- School of Environment, Northeast Normal University, Changchun 130117, China; Key Laboratory for Vegetation Ecology, Ministry of Education, NO. 2555 Jingyue Street, Changchun 130117, China; State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, China
| | - Zhenxing Zhang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, China; Key Laboratory for Vegetation Ecology, Ministry of Education, NO. 2555 Jingyue Street, Changchun 130117, China
| | - Jiquan Zhang
- School of Environment, Northeast Normal University, Changchun 130117, China; Key Laboratory for Vegetation Ecology, Ministry of Education, NO. 2555 Jingyue Street, Changchun 130117, China; State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, China.
| | - Caiyun Sun
- School of Environment, Northeast Normal University, Changchun 130117, China; Jilin Institute of Chemical Technology, Jilin, 132022, China; Key Laboratory for Vegetation Ecology, Ministry of Education, NO. 2555 Jingyue Street, Changchun 130117, China; State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Northeast Normal University, Changchun, 130024, China.
| |
Collapse
|
13
|
Agunbiade M, Pohl C, Ashafa O. Bioflocculant production from Streptomyces platensis and its potential for river and waste water treatment. Braz J Microbiol 2018; 49:731-741. [PMID: 29674102 PMCID: PMC6175721 DOI: 10.1016/j.bjm.2017.02.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 02/10/2017] [Accepted: 02/11/2017] [Indexed: 11/26/2022] Open
Abstract
A bacterium isolated from Sterkfontein dam was confirmed to produce bioflocculant with excellent flocculation activity. The 16S rDNA nucleotide sequence analyses revealed the bacteria to have 99% similarity to Streptomyces platensis strain HBUM174787 and the sequence was deposited in the Genbank as Streptomyces platensis with accession number FJ 486385.1. Culture conditions for optimal production of the bioflocculant included glucose as a sole carbon source, resulting in flocculating activity of 90%. Other optimal conditions included: peptone as nitrogen source; presence of Mg2+ as cations and inoculum size of 1.0% (v/v) at neutral pH of 7. Optimum dose of the purified bioflocculant for the clarification of 4g/L kaolin clay suspension at neutral pH was 0.2mg/mL. Energy Dispersive X-ray analysis confirmed elemental composition of the purified bioflocculant in mass proportion (%w/w): carbon (21.41), oxygen (35.59), sulphur (26.16), nitrogen (0.62) and potassium (7.48). Fourier Transform Infrared Spectroscopy (FTIR) indicated the presence of hydroxyl, carboxyl, methoxyl and amino group in the bioflocculant. The bioflocculant produced by S. platensis removed chemical oxygen demand (COD) in river water and meat processing wastewater at efficiencies of 63.1 and 46.6% respectively and reduced their turbidity by 84.3 and 75.6% respectively. The high flocculating rate and removal efficiencies displayed by S. platensis suggests its industrial application in wastewater treatment.
Collapse
Affiliation(s)
- Mayowa Agunbiade
- University of the Free State, Qwaqwa Campus, Department of Plant Sciences, Phytomedicine and Phytopharmacology Research Group, Phuthaditjhaba, South Africa; University of the Free State, Department of Microbial, Biochemical & Food Biotechnology, Bloemfontein, South Africa
| | - Carolina Pohl
- University of the Free State, Department of Microbial, Biochemical & Food Biotechnology, Bloemfontein, South Africa
| | - Omotayo Ashafa
- University of the Free State, Qwaqwa Campus, Department of Plant Sciences, Phytomedicine and Phytopharmacology Research Group, Phuthaditjhaba, South Africa.
| |
Collapse
|
14
|
Takeo M, Kimura K, Mayilraj S, Inoue T, Tada S, Miyamoto K, Kashiwa M, Ikemoto K, Baranwal P, Kato D, Negoro S. Biosynthetic Pathway and Genes of Chitin/Chitosan-Like Bioflocculant in the Genus Citrobacter. Polymers (Basel) 2018; 10:polym10030237. [PMID: 30966272 PMCID: PMC6414854 DOI: 10.3390/polym10030237] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 02/19/2018] [Accepted: 02/22/2018] [Indexed: 11/17/2022] Open
Abstract
Chitin/chitosan, one of the most abundant polysaccharides in nature, is industrially produced as a powder or flake form from the exoskeletons of crustaceans such as crabs and shrimps. Intriguingly, many bacterial strains in the genus Citrobacter secrete a soluble chitin/chitosan-like polysaccharide into the culture medium during growth in acetate. Because this polysaccharide shows strong flocculation activity for suspended solids in water, it can be used as a bioflocculant (BF). The BF synthetic pathway of C. freundii IFO 13545 is expected from known bacterial metabolic pathways to be as follows: acetate is metabolized in the TCA cycle and the glyoxylate shunt via acetyl-CoA. Next, fructose 6-phosphate is generated from the intermediates of the TCA cycle through gluconeogenesis and enters into the hexosamine synthetic pathway to form UDP-N-acetylglucosamine, which is used as a direct precursor to extend the BF polysaccharide chain. We conducted the draft genome sequencing of IFO 13545 and identified all of the candidate genes corresponding to the enzymes in this pathway in the 5420-kb genome sequence. Disruption of the genes encoding acetyl-CoA synthetase and isocitrate lyase by homologous recombination resulted in little or no growth on acetate, indicating that the cell growth depends on acetate assimilation via the glyoxylate shunt. Disruption of the gene encoding glucosamine 6-phosphate synthase, a key enzyme for the hexosamine synthetic pathway, caused a significant decrease in flocculation activity, demonstrating that this pathway is primarily used for the BF biosynthesis. A gene cluster necessary for the polymerization and secretion of BF, named bfpABCD, was also identified for the first time. In addition, quantitative RT-PCR analysis of several key genes in the expected pathway was conducted to know their expression in acetate assimilation and BF biosynthesis. Based on the data obtained in this study, an overview of the BF synthetic pathway is discussed.
Collapse
Affiliation(s)
- Masahiro Takeo
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| | - Kazuyuki Kimura
- Hyogo Analysis Center Co., Ltd., 4-10-8 Seimondori, Hirohata, Himeji, Hyogo 671-1116, Japan.
| | - Shanmugam Mayilraj
- Microbial Type Culture Collection & Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh-160 036, India.
| | - Takuya Inoue
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| | - Shohei Tada
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| | - Kouki Miyamoto
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| | - Masami Kashiwa
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| | - Keishi Ikemoto
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| | - Priyanka Baranwal
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| | - Daiichiro Kato
- Department of Chemistry and Bioscience, Graduate School of Science and Engineering, Kagoshima 890-8580, Japan.
| | - Seiji Negoro
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
| |
Collapse
|
15
|
Guo J, Chen C. Removal of arsenite by a microbial bioflocculant produced from swine wastewater. CHEMOSPHERE 2017; 181:759-766. [PMID: 28478236 DOI: 10.1016/j.chemosphere.2017.04.119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/17/2017] [Accepted: 04/24/2017] [Indexed: 06/07/2023]
Abstract
This paper focused on the production and characteristics of a bioflocculant by using swine wastewater and its application in removing arsenite from aqueous solution. A series of experimental parameters including bioflocculant dose, calcium ions concentration, and solution pH value on arsenite uptake were evaluated. Results have demonstrated that a bioflocculant of 3.11 g L-1 was achieved as the maximum yield after 60 h fermentation, with a main backbone of polysaccharides. Maximum arsenite removal efficiency of 99.2% can be reached by adding bioflocculant in two stages: 3 × 10-3% (w/w) in the 1.0 min's rapid mixing (180 rpm) and 2 × 10-3% (w/w) after 2.0 min's slow mixing (80 rpm) with pH value fixed at 7. Negative Gibbs free energy change (ΔGo) indicated the spontaneous nature of arsenite removal. Arsenite was removed by the bioflocculant through bridging mechanisms.
Collapse
Affiliation(s)
- Junyuan Guo
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China.
| | - Cheng Chen
- College of Resources and Environment, Chengdu University of Information Technology, Chengdu, Sichuan, 610225, China
| |
Collapse
|
16
|
Production, characterization and structural modification of exopolysaccharide-based bioflocculant by Rhizobium radiobacter SZ4S7S14 and media optimization. 3 Biotech 2017; 7:179. [PMID: 28664366 DOI: 10.1007/s13205-017-0811-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 04/17/2017] [Indexed: 10/19/2022] Open
Abstract
Synthesis of the exopolysaccharide-based bioflocculant Rhizobium radiobacter SZ4S7S14 was researched and medium optimized for enhanced production of bioflocculant. D-Mannose and yeast extract were found to be best carbon and nitrogen sources for maximal yield of bioflocculant. The bioflocculant samples obtained in different media with different carbon and nitrogen sources were further analyzed by SEM-EDX and FT-IR. FT-IR spectroscopy of the bioflocculant samples, obtained in different carbon/nitrogen sources showed slight modification of the structures of biopolymers. SEM micrographs revealed that exopolysaccharide-based bioflocculant of R. radiobacter SZ4S7S14 looks like bricks, and chemical structure of it can be varied due to utilized carbon and nitrogen source.
Collapse
|
17
|
Zhao H, Zhong C, Chen H, Yao J, Tan L, Zhang Y, Zhou J. Production of bioflocculants prepared from formaldehyde wastewater for the potential removal of arsenic. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 172:71-76. [PMID: 26921567 DOI: 10.1016/j.jenvman.2016.02.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 02/08/2016] [Accepted: 02/15/2016] [Indexed: 06/05/2023]
Abstract
A novel bioflocculant (MBF-79) prepared using formaldehyde wastewater as carbon resource was investigated in the study. The optimal conditions for bioflocculant production were determined to be an inoculum size of 7.0%, initial pH of 6.0, and formaldehyde concentration of 350 mg/L. An MBF-79 of 8.97 g/L was achieved as the maximum yield. Three main elements, namely C, H, and O, were present in MBF-79 with relative weigh percentages of 39.17%, 6.74%, and 34.55%, respectively. The Gel permeation chromatography analysis indicated that the approximate molecular weight (MW) of MBF-79 was 230 kDa. MBF-79 primarily comprised polysaccharide (71.2%) and protein (27.9%). Additionally, conditions for the removal of arsenic by MBF-79 were found to be MBF-79 at 120 mg/L, an initial pH 7.0, and a contact time 60 min. Under the optimal conditions, the removal efficiencies of arsenate (0.5 mg/L) and arsenite (0.5 mg/L) were 98.9% and 84.6%, respectively. Overall, these findings indicate bioflocculation offers an effective alternative method of decreasing arsenic during water treatment.
Collapse
Affiliation(s)
- Haijuan Zhao
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China; School of Mathematics and Economics, Hubei University of Education, Wuhan 430205, China
| | - Chunying Zhong
- Hubei Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients, Chemistry and Biology Science College, Hubei University of Education, Wuhan 430205, China
| | - Honggao Chen
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Jie Yao
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Liqing Tan
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Youlang Zhang
- Department of Political Science, Texas A&M University, College Station, 77843, USA
| | - Jiangang Zhou
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
| |
Collapse
|
18
|
Marine Microalgae Tetraselmis suecica as Flocculant Agent of Bio-flocculation Method. HAYATI JOURNAL OF BIOSCIENCES 2016. [DOI: 10.1016/j.hjb.2015.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
19
|
Okaiyeto K, Nwodo UU, Okoli SA, Mabinya LV, Okoh AI. Implications for public health demands alternatives to inorganic and synthetic flocculants: bioflocculants as important candidates. Microbiologyopen 2016; 5:177-211. [PMID: 26914994 PMCID: PMC4831466 DOI: 10.1002/mbo3.334] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/05/2015] [Accepted: 11/24/2015] [Indexed: 12/11/2022] Open
Abstract
Chemical flocculants are generally used in drinking water and wastewater treatment due to their efficacy and cost effectiveness. However, the question of their toxicity to human health and environmental pollution has been a major concern. In this article, we review the application of some chemical flocculants utilized in water treatment, and bioflocculants as a potential alternative to these chemical flocculants. To the best of our knowledge, there is no report in the literature that provides an up‐to‐date review of the relevant literature on both chemical flocculants and bioflocculants in one paper. As a result, this review paper comprehensively discussed the various chemical flocculants used in water treatment, including their advantages and disadvantages. It also gave insights into bioflocculants production, challenges, various factors influencing their flocculating efficiency and their industrial applications, as well as future research directions including improvement of bioflocculants yields and flocculating activity, and production of cation‐independent bioflocculants. The molecular biology and synthesis of bioflocculants are also discussed.
Collapse
Affiliation(s)
- Kunle Okaiyeto
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa
| | - Uchechukwu U Nwodo
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa
| | - Stanley A Okoli
- GenØK - Centre for Biosafety, Science Park, University of Tromsø, Tromsø, 9291, Norway
| | - Leonard V Mabinya
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa
| | - Anthony I Okoh
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, 5700, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, 5700, South Africa
| |
Collapse
|
20
|
Fang D, Shi C. Characterization and flocculability of a novel proteoglycan produced by Talaromyces trachyspermus OU5. J Biosci Bioeng 2016; 121:52-56. [DOI: 10.1016/j.jbiosc.2015.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 04/20/2015] [Accepted: 05/06/2015] [Indexed: 10/23/2022]
|
21
|
Cao G, Zhang Y, Chen L, Liu J, Mao K, Li K, Zhou J. Production of a bioflocculant from methanol wastewater and its application in arsenite removal. CHEMOSPHERE 2015; 141:274-81. [PMID: 26291913 DOI: 10.1016/j.chemosphere.2015.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/06/2015] [Accepted: 08/06/2015] [Indexed: 05/22/2023]
Abstract
A novel bioflocculant (MBF83) prepared using methanol wastewater as nutrient resource was systematically investigated in the study. The optimal conditions for bioflocculant production were determined to be an inoculum size of 8.6%, initial pH of 7.5, and a methanol concentration of 100.8mgL(-1). An MBF83 of 4.61gL(-1) was achieved as the maximum yield. MBF83 primarily comprised polysaccharide (74.1%) and protein (24.2%). The biopolymer, which was found to be safe in zebrafish in toxicity studies, was characterized using Fourier-transform infrared spectroscopy and elemental analysis. Additionally, conditions for the removal of arsenite by MBF83 were found to be MBF83 at 500mgL(-1), an initial pH of 7.0, and a contact time of 90min. Under the optimal conditions, the removal efficiency of arsenite was 86.1%. Overall, these findings indicate bioflocculation offers an effective alternative method of decreasing arsenite during wastewater treatment.
Collapse
Affiliation(s)
- Gang Cao
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Yanbo Zhang
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China; School of Chemical Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Li Chen
- Central China Normal University Library, Wuhan 430079, China
| | - Jie Liu
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Kewei Mao
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Kangju Li
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Jiangang Zhou
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
| |
Collapse
|
22
|
Bacillus toyonensis strain AEMREG6, a bacterium isolated from South African marine environment sediment samples produces a glycoprotein bioflocculant. Molecules 2015; 20:5239-59. [PMID: 25806549 PMCID: PMC6272666 DOI: 10.3390/molecules20035239] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 03/15/2015] [Accepted: 03/17/2015] [Indexed: 11/17/2022] Open
Abstract
A bioflocculant-producing bacteria, isolated from sediment samples of a marine environment in the Eastern Cape Province of South Africa demonstrated a flocculating activity above 60% for kaolin clay suspension. Analysis of the 16S ribosomal deoxyribonucleic acid (rDNA) nucleotide sequence of the isolate in the GenBank database showed 99% similarity to Bacillus toyonensis strain BCT-7112 and it was deposited in the GenBank as Bacillus toyonensis strain AEMREG6 with accession number KP406731. The bacteria produced a bioflocculant (REG-6) optimally in the presence of glucose and NH4NO3 as the sole carbon and nitrogen source, respectively, initial medium pH of 5 and Ca2+ as the cation of choice. Chemical analysis showed that purified REG-6 was a glycoprotein mainly composed of polysaccharide (77.8%) and protein (11.5%). It was thermally stable and had strong flocculating activity against kaolin suspension over a wide range of pH values (3-11) with a relatively low dosage requirement of 0.1 mg/mL in the presence of Mn2+. Fourier transform infrared spectroscopy (FTIR) revealed the presence of hydroxyl, carboxyl and amide groups preferred for flocculation. Scanning electron microscopy (SEM) revealed that bridging was the main flocculation mechanism of REG-6. The outstanding flocculating performance of REG-6 holds great potential to replace the hazardous chemical flocculants currently used in water treatment.
Collapse
|
23
|
Wang Z, Shen L, Zhuang X, Shi J, Wang Y, He N, Chang YI. Flocculation Characterization of a Bioflocculant from Bacillus licheniformis. Ind Eng Chem Res 2015. [DOI: 10.1021/ie5050204] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhi Wang
- Department
of Chemical and Biochemical Engineering, College of Chemistry and
Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Liang Shen
- Department
of Chemical and Biochemical Engineering, College of Chemistry and
Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Xiaoling Zhuang
- Department
of Chemical and Biochemical Engineering, College of Chemistry and
Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Jiangshui Shi
- Department
of Chemical and Biochemical Engineering, College of Chemistry and
Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Yuanpeng Wang
- Department
of Chemical and Biochemical Engineering, College of Chemistry and
Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - Ning He
- Department
of Chemical and Biochemical Engineering, College of Chemistry and
Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
| | - You-Im Chang
- Department
of Chemical and Material Engineering, Tunghai University, Taichung 40704, Taiwan
| |
Collapse
|
24
|
Salehizadeh H, Yan N. Recent advances in extracellular biopolymer flocculants. Biotechnol Adv 2014; 32:1506-22. [DOI: 10.1016/j.biotechadv.2014.10.004] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 10/02/2014] [Accepted: 10/07/2014] [Indexed: 10/24/2022]
|
25
|
Yin YJ, Tian ZM, Tang W, Li L, Song LY, McElmurry SP. Production and characterization of high efficiency bioflocculant isolated from Klebsiella sp. ZZ-3. BIORESOURCE TECHNOLOGY 2014; 171:336-342. [PMID: 25218206 DOI: 10.1016/j.biortech.2014.08.094] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/21/2014] [Accepted: 08/22/2014] [Indexed: 06/03/2023]
Abstract
In this study, a new bioflocculant (ZZ-3) is isolated and evaluated. This novel flocculant was derived Klebsiella, which was identified by 16S rDNA sequencing as well as biochemical and physiological analyses. The composition of ZZ-3 was found to be 84.6% polysaccharides and 6.1% protein. More specifically, the amount (moles) of the polysaccharides rhamnose, mannose, and galactose were found to be 6.48, 2.47, and 1.74 greater than glucose, respectively. Results show ZZ-3 has a relatively high molecular weight (603-1820 kDa) and contains many functional groups (hydroxyl, amide, carboxyl, and methoxyl) that likely contribute to flocculation. The results of microscopic observation, zeta potential measurements, and ZZ-3 bioflocculant structure suggested that bridging was the main mechanism for flocculation with kaolin. Based on a high flocculation efficiency, thermal stability, pH tolerance and the ability to flocculate without additional cations, ZZ-3 shows potential for industrial application.
Collapse
Affiliation(s)
- Ya-Jie Yin
- Environmental Microbiology and Ecology Research Center, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, PR China
| | - Zun-Ming Tian
- Shanghai Information Center for Life Sciences, Shanghai Institute of Biological Sciences, Chinese Academy of Science, Shanghai 200031, PR China
| | - Wei Tang
- Environmental Microbiology and Ecology Research Center, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, PR China
| | - Lei Li
- Environmental Microbiology and Ecology Research Center, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, PR China
| | - Li-Yan Song
- Environmental Microbiology and Ecology Research Center, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, PR China; Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, PR China.
| | - Shawn P McElmurry
- Department of Civil & Environmental Engineering, Wayne State University, Detroit, MI 48202, USA
| |
Collapse
|
26
|
More TT, Yadav JSS, Yan S, Tyagi RD, Surampalli RY. Extracellular polymeric substances of bacteria and their potential environmental applications. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2014; 144:1-25. [PMID: 24907407 DOI: 10.1016/j.jenvman.2014.05.010] [Citation(s) in RCA: 426] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 05/02/2014] [Accepted: 05/11/2014] [Indexed: 05/06/2023]
Abstract
Biopolymers are considered a potential alternative to conventional chemical polymers because of their ease of biodegradability, high efficiency, non-toxicity and non-secondary pollution. Recently, extracellular polymeric substances (EPS, biopolymers produced by the microorganisms) have been recognised by many researchers as a potential flocculent for their applications in various water, wastewater and sludge treatment processes. In this context, literature information on EPS is widely dispersed and is very scarce. Thus, this review marginalizes various studies conducted so far about EPS nature-production-recovery, properties, environmental applications and moreover, critically examines future research needs and advanced application prospective of the EPS. One of the most important aspect of chemical composition and structural details of different moieties of EPS in terms of carbohydrates, proteins, extracellular DNA, lipid and surfactants and humic substances are described. These chemical characteristics of EPS in relation to formation and properties of microbial aggregates as well as degradation of EPS in the matrix (biomass, flocs etc) are analyzed. The important engineering properties (based on structural characteristics) such as adsorption, biodegradability, hydrophilicity/hydrophobicity of EPS matrix are also discussed in details. Different aspects of EPS production process such as bacterial strain maintenance; inoculum and factors affecting EPS production were presented. The important factors affecting EPS production include growth phase, carbon and nitrogen sources and their ratio, role of other nutrients (phosphorus, micronutrients/trace elements, and vitamins), impact of pH, temperature, metals, aerobic versus anaerobic conditions and pure and mixed culture. The production of EPS in high concentration with high productivity is essential due to economic reasons. Therefore, the knowledge about all the aspects of EPS production (listed above) is highly essential to formulate a logical and scientific basis for the research and industrial activities. One of the very important issues in the production/application/biodegradation of EPS is how the EPS is extracted from the matrix or a culture broth. Moreover, EPS matrix available in different forms (crude, loosely bound, tightly bound, slime, capsular and purified) can be used as a bioflocculant material. Several chemical and physical methods for the extraction of EPS (crude form or purified form) from different sources have been analyzed and reported. There is ample information available in the literature about various EPS extraction methods. Flocculability, dewaterability and biosorption ability are the very attractive engineering properties of the EPS matrix. Recent information on important aspects of these properties qualitatively as well as quantitatively has been described. Recent information on the mechanism of flocculation mediated by EPS is presented. Potential role of EPS in sludge dewatering and biosorption phenomenon has been discussed in details. Different factors influencing the EPS ability to flocculate and dewaterability of different suspensions have been included. The factors considered for the discussion are cations, different forms of EPS, concentration of EPS, protein and carbohydrate content of EPS, molecular weight of EPS, pH of the suspension, temperature etc. These factors were selected for the study based upon their role in the flocculation and dewatering mechanism as well the most recent available literature findings on these factors. For example, only recently it has been demonstrated that there is an optimum EPS concentration for sludge flocculation/dewatering. High or low concentration of EPS can lead to destabilization of flocs. Role of EPS in environmental applications such as water treatment, wastewater flocculation and settling, colour removal from wastewater, sludge dewatering, metal removal and recovery, removal of toxic organic compounds, landfill leachate treatment, soil remediation and reclamation has been presented based on the most recent available information. However, data available on environmental application of EPS are very limited. Investigations are required for exploring the potential of field applications of EPS. Finally, the limitations in the knowledge gap are outlined and the research needs as well as future perspectives are highlighted.
Collapse
Affiliation(s)
- T T More
- Institut national de la recherche scientifique, Centre Eau, Terre & Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9, Canada.
| | - J S S Yadav
- Institut national de la recherche scientifique, Centre Eau, Terre & Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9, Canada
| | - S Yan
- Institut national de la recherche scientifique, Centre Eau, Terre & Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9, Canada
| | - R D Tyagi
- Institut national de la recherche scientifique, Centre Eau, Terre & Environnement, Université du Québec, 490 de la Couronne, Québec, QC G1K 9A9, Canada.
| | - R Y Surampalli
- U. S. Environmental Protection Agency, P.O. Box 17-2141, Kansas City, KS 66117, USA
| |
Collapse
|
27
|
Zhong C, Xu A, Chen L, Yang X, Yang B, Hong W, Mao K, Wang B, Zhou J. Production of a bioflocculant from chromotropic acid waste water and its application in steroid estrogen removal. Colloids Surf B Biointerfaces 2014; 122:729-737. [DOI: 10.1016/j.colsurfb.2014.08.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 08/03/2014] [Accepted: 08/10/2014] [Indexed: 10/24/2022]
|
28
|
Subudhi S, Batta N, Pathak M, Bisht V, Devi A, Lal B, Al khulifah B. Bioflocculant production and biosorption of zinc and lead by a novel bacterial species, Achromobacter sp. TERI-IASST N, isolated from oil refinery waste. CHEMOSPHERE 2014; 113:116-124. [PMID: 25065798 DOI: 10.1016/j.chemosphere.2014.04.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 04/12/2014] [Accepted: 04/16/2014] [Indexed: 06/03/2023]
Abstract
A bioflocculant-producing bacterial isolate designated as 'TERI-IASST N' was isolated from activated sludge samples collected from an oil refinery. This isolate demonstrated maximum bioflocculation activity (74%) from glucose among 15 different bioflocculant-producing bacterial strains isolated from the sludge samples and identified as Achromobacter sp. based on 16S rRNA gene sequence. Optimization of pH and supplementation of urea as nitrogen source in the production medium enhanced the flocculation activity of strain TERI-IASST N to 84% (at pH 6). This strain revealed maximum flocculation activity (90%) from sucrose compared to the flocculation activity observed from other carbon sources as investigated (glucose, lactose, fructose, maltose and starch). Ca(2+) served as the suitable divalent cation for maximum bioflocculation activity of TERI-IASST strain N. Maximum flocculation activity was observed at optimum C/N ratio of 1. Flocculation activity of this strain decreased to 75% in the presence of heavy metals; Zn, Pb, Ni, Cu and Cd. In addition strain N revealed considerable biosorption of Zn (430mgL(-1)) and Pb (30mgL(-1)). Bioflocculant yield of strain N was 10.5gL(-1). Fourier transform infrared spectrum indicated the presence of carboxyl, hydroxyl, and amino groups, typical of glycoprotein. Spectroscopic analysis of bioflocculant by nuclear magnetic resonance revealed that it is a glycoprotein, consisting of 57% total sugar and 13% protein.
Collapse
Affiliation(s)
- Sanjukta Subudhi
- Environmental and Industrial Biotechnology Division, The Energy and Resources Institute, Lodi Road, New Delhi, India.
| | - Neha Batta
- Environmental and Industrial Biotechnology Division, The Energy and Resources Institute, Lodi Road, New Delhi, India
| | - Mihirjyoti Pathak
- Resource Management and Environment Section, Life Science Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam, India
| | - Varsha Bisht
- Environmental and Industrial Biotechnology Division, The Energy and Resources Institute, Lodi Road, New Delhi, India
| | - Arundhuti Devi
- Resource Management and Environment Section, Life Science Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam, India
| | - Banwari Lal
- Environmental and Industrial Biotechnology Division, The Energy and Resources Institute, Lodi Road, New Delhi, India.
| | - Bader Al khulifah
- Kuwait International Law School, Kuwait International Legal Research Center, Doha City, Kuwait
| |
Collapse
|
29
|
Zhong C, Xu A, Wang B, Yang X, Hong W, Yang B, Chen C, Liu H, Zhou J. Production of a value added compound from the H-acid waste water-Bioflocculants by Klebsiella pneumoniae. Colloids Surf B Biointerfaces 2014; 122:583-590. [PMID: 25127749 DOI: 10.1016/j.colsurfb.2014.07.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/20/2014] [Accepted: 07/22/2014] [Indexed: 11/25/2022]
Abstract
A novel strain (designated as ZCY-7) which could convert H-acid into bioflocculants was isolated from H-acid wastewater sludge. Conditions for bioflocculants production were optimized by response surface methodology (RSM) and determined to be inoculum size 9.65%, initial pH 7.0, and CODCr of the H-acid wastewater 520mg/L. The highest flocculating efficiency achieved for kaolin suspension was 95.1%, after 60h cultivation. The yielded bioflocculant was mainly composed of polysaccharide (82.4%) and protein (14.2%), and maintained its flocculating activity in 0.4% (w/w) kaolin suspensions over pH 2-8 and 20-80°C. Fourier transform infrared (FTIR) spectra showed that amino, amide and hydroxyl groups were present in the bioflocculant molecules. A viable alternative treatment technology of H-acid wastewater using this novel strain is suggested, which could largely reduce bioflocculants costs. In addition, flocculating mechanism investigation reveals that the bioflocculant could cause kaolin suspension instability by means of charge neutralization firstly and then promoted the aggregation of suspension particles by adsorption and bridge. It is evident from the results that H-acid wastewater could be used as a source to manufacture bioflocculants.
Collapse
Affiliation(s)
- Chunying Zhong
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China; School of Chemistry and Life Science, Hubei University of Education, Wuhan 430205, China
| | - Aihua Xu
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Buyun Wang
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Xianghui Yang
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Wentao Hong
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Baokun Yang
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Changhong Chen
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Hongtao Liu
- School of Materials Science and Engineering, Wuhan Textile University, Wuhan 430073, China
| | - Jiangang Zhou
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
| |
Collapse
|
30
|
Nwodo UU, Okoh AI. Mixed culture fermentation and media optimization by response surface model: Streptomyces and Brachybacterium species in bioflocculant production. Molecules 2014; 19:11131-44. [PMID: 25076145 PMCID: PMC6271801 DOI: 10.3390/molecules190811131] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/14/2014] [Accepted: 07/21/2014] [Indexed: 12/02/2022] Open
Abstract
The biofloculant production potential of a consortium of Streptomyces and Brachybacterium species were evaluated. Optimum bioflocculant yields (g/L) and flocculation activities (%) were observed for the following preferred nutritional sources: glucose (56%; 2.78 ± 0.15 g/L), (NH4)2NO3 (53%; 2.81 ± 0.37 g/L) and CaSO4·H2O (47%; 2.19 ± 0.13 g/L). A Plackett-Burman design revealed the critical fermentation media components. The concentrations of these components were optimized [glucose; 16.0, (NH4)2NO3; 0.5 and CaSO4·H2O; 1.2 (g/L)] through a central composite design with optimum bioflocculant yield of 3.02 g/L and flocculation activity of 63.7%. The regression coefficient (R2 = 0.6569) indicates a weak estimation of the model’s adequacy and a high lack-of-fit value (34.1%). Lack of synergy in the consortium may have been responsible for the model inadequacy observed. FTIR spectrometry showed the bioflocculant to be a heteropolysaccharide, while SEM imaging revealed an amorphous loosely arranged fluffy structure with interstial spacing of less than 1 µm.
Collapse
Affiliation(s)
- Uchechukwu U Nwodo
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.
| | - Anthony I Okoh
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Private Bag X1314, Alice 5700, South Africa.
| |
Collapse
|
31
|
Peng L, Yang C, Zeng G, Wang L, Dai C, Long Z, Liu H, Zhong Y. Characterization and application of bioflocculant prepared by Rhodococcus erythropolis using sludge and livestock wastewater as cheap culture media. Appl Microbiol Biotechnol 2014; 98:6847-58. [PMID: 24781698 DOI: 10.1007/s00253-014-5725-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/22/2014] [Accepted: 03/25/2014] [Indexed: 12/22/2022]
Abstract
A new bioflocculant was produced by culturing Rhodococcus erythropolis in a cheap medium. When culture pH was 7.0, inoculum size was 2 % (v/v), Na2HPO4 concentration was 0.5 g L(-1), and the ratio of sludge/livestock wastewater was 7:1 (v/v), a maximum flocculating rate of 87.6 % could be achieved. Among 13 different kinds of pretreatments for sludge, the optimal one was the thermal-alkaline pretreatment. Different from a bioflocculant produced in a standard medium, this bioflocculant was effective over a wide pH range from 2 to 12 with flocculating rates higher than 98 %. Approximately, 1.6 g L(-1) of crude bioflocculant could be harvested using cold ethanol for extraction. This bioflocculant showed color removal rates up to 80 % when applied to direct and disperse dye solutions, but only 23.0 % for reactive dye solutions. Infrared spectrum showed that the bioflocculant contained functional groups such as -OH, -NH2, and -CONH2. Components in the bioflocculant consisted of 91.2 % of polysaccharides, 7.6 % of proteins, and 1.2 % of DNA. When the bioflocculant and copper sulfate (CuSO4) were used together for decolorization in actual dye wastewater, the optimum decolorization conditions were specified by the response surface methodology as pH 11, bioflocculant dosage of 40 mg/L, and CuSO4 80 mg/L, under which a decolorization rate of 93.9 % could be reached.
Collapse
Affiliation(s)
- Lanyan Peng
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, Hunan, China
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Bioflocculant production by a consortium of Streptomyces and Cellulomonas species and media optimization via surface response model. Colloids Surf B Biointerfaces 2014; 116:257-64. [DOI: 10.1016/j.colsurfb.2014.01.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 12/20/2013] [Accepted: 01/06/2014] [Indexed: 11/18/2022]
|
33
|
Wang L, Lee DJ, Ma F, Wang A, Ren N. Bioflocculants from isolated strain or mixed culture: Role of phosphate salts and Ca2+ ions. J Taiwan Inst Chem Eng 2014. [DOI: 10.1016/j.jtice.2013.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
34
|
Okaiyeto K, Nwodo UU, Mabinya LV, Okoh AI. Characterization of a bioflocculant produced by a consortium of Halomonas sp. Okoh and Micrococcus sp. Leo. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:5097-110. [PMID: 24135818 PMCID: PMC3823338 DOI: 10.3390/ijerph10105097] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/25/2013] [Accepted: 10/01/2013] [Indexed: 11/16/2022]
Abstract
The physicochemical and flocculating properties of a bioflocculant produced by a bacterial consortium composed of Halomonas sp. Okoh and Micrococcus sp. Leo were investigated. The purified bioflocculant was cation and pH dependent, and optimally flocculated kaolin clay suspension at a dosage of 0.1 mg/mL. The flocculating activity of the bioflocculant was stimulated in the presence of Ca2+, Mn2+, Al3+ and had a wide pH range of 2–10, with the highest flocculating activity of 86% at pH 8. The bioflocculant was thermostable and retained more than 70% of its flocculating activity after being heated at 80 °C for 30 min. Thermogravimetric analyses revealed a partial thermal decomposition of the biofloculant at 400 °C. The infrared spectrum showed the presence of hydroxyl, carboxyl and amino moieties as functional groups. The bioflocculant produced by the bacterial consortium appears to hold promising alternative to inorganic and synthetic organic flocculants that are widely used in wastewater treatment.
Collapse
Affiliation(s)
- Kunle Okaiyeto
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice 5700, South Africa.
| | | | | | | |
Collapse
|
35
|
Nwodo U, Okoh A. Characterization and flocculation properties of biopolymeric flocculant (glycosaminoglycan) produced by Cellulomonas
sp. Okoh. J Appl Microbiol 2013; 114:1325-37. [DOI: 10.1111/jam.12095] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 11/27/2012] [Accepted: 11/28/2012] [Indexed: 11/26/2022]
Affiliation(s)
- U.U. Nwodo
- Department of Biochemistry and Microbiology; Applied and Environmental Microbiology Research Group (AEMREG), University of Fort Hare; Alice South Africa
| | - A.I. Okoh
- Department of Biochemistry and Microbiology; Applied and Environmental Microbiology Research Group (AEMREG), University of Fort Hare; Alice South Africa
| |
Collapse
|
36
|
Distribution of chitin/chitosan-like bioflocculant-producing potential in the genus Citrobacter. Appl Microbiol Biotechnol 2013; 97:9569-77. [PMID: 23321910 DOI: 10.1007/s00253-012-4668-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 12/11/2012] [Accepted: 12/18/2012] [Indexed: 10/27/2022]
Abstract
Some strains belonging to the genera Citrobacter and Enterobacter have been reported to produce chitin/chitosan-like bioflocculants (BFs) from acetate. In this study, to investigate the distribution of the BF-producing potential in the genus Citrobacter and to screen stably and highly BF-producing strains, we obtained 36 Citrobacter strains from different culture collection centers, which were distributed among seven species in the genus, and tested for the flocculating activities of their culture supernatants using a kaolin suspension method. As a result, 21 strains belonging to C. freundii (17 strains in 23 strains tested), C. braakii (two in two), C. youngae (one in one), and C. werkmanii (one in two) showed flocculating activity, but this ability was limited to cells grown on acetate. Gas chromatography/mass spectrometry (GC/MS) analysis of the hydrolysates from the BFs of five selected strains indicated that they consisted of glucosamine and/or N-acetylglucosamine, such as the chitin/chitosan-like BF (BF04) produced by Citrobacter sp. TKF04 (Fujita et al. J Biosci Bioeng 89: 40-46, 2000). Gel filtration chromatography using a high-performance liquid chromatography system revealed that the molecular weight ranges of these BFs varied, but the average sizes were all above 1.66 × 10⁶Da.
Collapse
|
37
|
Aljuboori AHR, Idris A, Abdullah N, Mohamad R. Production and characterization of a bioflocculant produced by Aspergillus flavus. BIORESOURCE TECHNOLOGY 2013; 127:489-93. [PMID: 23159465 DOI: 10.1016/j.biortech.2012.09.016] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 07/28/2012] [Accepted: 09/07/2012] [Indexed: 05/12/2023]
Abstract
The production and characterization of a bioflocculant, IH-7, by Aspergillus flavus was investigated. About 0.4 g of purified bioflocculant with an average molecular weight of 2.574 × 10(4)Da could be obtained from 1L of fermentation medium. The bioflocculant mainly consisted of protein (28.5%) and sugar (69.7%), including 40% of neutral sugar, 2.48% of uronic acid and 1.8% amino sugar. The neutral sugar components are sucrose, lactose, glucose, xylose, galactose, mannose and fructose at a molar ratio of 2.4:4.4:4.1:5.8:9.9:0.8:3.1. Fourier-transform infrared spectroscopy analysis revealed that purified IH-7 contained hydroxyl, amide, carboxyl and methoxyl groups. The elemental analysis of purified IH-7 showed that the weight fractions of the elements C, H, O, N and S were 29.9%, 4.8%, 34.7%, 3.3%, and 2.0%, respectively. IH-7 had good flocculating rate in kaolin suspension without cation addition and stable over wide range of pH and temperature.
Collapse
Affiliation(s)
- Ahmad H Rajab Aljuboori
- Department of Chemical and Environmental Engineering, University Putra Malaysia, Sri Serdang 43400, Selangor, Malaysia.
| | | | | | | |
Collapse
|
38
|
Abstract
Bioflocculant-producing bacteria were isolated from activated sludge of a wastewater treatment plant located in Durban, South Africa, and identified using standard biochemical tests as well as the analysis of their 16S rRNA gene sequences. The bioflocculants produced by these organisms were ethanol precipitated, purified using 2% (w/v) cetylpyridinium chloride solution and evaluated for removal of wastewater dyes under different pH, temperature and nutritional conditions. Bioflocculants from these indigenous bacteria were very effective for decolourizing the different dyes tested in this study, with a removal rate of up to 97.04%. The decolourization efficiency was largely influenced by the type of dye, pH, temperature, and flocculant concentration. A pH of 7 was found to be optimum for the removal of both whale and mediblue dyes, while the optimum pH for fawn and mixed dye removal was found to be between 9 and 10. Optimum temperature for whale and mediblue dye removal was 35 °C, and that for fawn and mixed dye varied between 40–45 °C and 35–40 °C, respectively. These bacterial bioflocculants may provide an economical and cleaner alternative to replace or supplement present treatment processes for the removal of dyes from wastewater effluents, since they are biodegradable and easily sustainable.
Collapse
|
39
|
Zulkeflee Z, Aris AZ, Shamsuddin ZH, Yusoff MK. Cation dependence, pH tolerance, and dosage requirement of a bioflocculant produced by Bacillus spp. UPMB13: flocculation performance optimization through kaolin assays. ScientificWorldJournal 2012; 2012:495659. [PMID: 22997497 PMCID: PMC3444838 DOI: 10.1100/2012/495659] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Accepted: 08/09/2012] [Indexed: 11/23/2022] Open
Abstract
A bioflocculant-producing bacterial strain with highly mucoid and ropy colony morphological characteristics identified as Bacillus spp. UPMB13 was found to be a potential bioflocculant-producing bacterium. The effect of cation dependency, pH tolerance and dosage requirement on flocculating ability of the strain was determined by flocculation assay with kaolin as the suspended particle. The flocculating activity was measured as optical density and by flocs formation. A synergistic effect was observed with the addition of monovalent and divalent cations, namely, Na+, Ca2+, and Mg2+, while Fe2+ and Al3+ produced inhibiting effects on flocculating activity. Divalent cations were conclusively demonstrated as the best cation source to enhance flocculation. The bioflocculant works in a wide pH range, from 4.0 to 8.0 with significantly different performances (P < 0.05), respectively. It best performs at pH 5.0 and pH 6.0 with flocculating performance of above 90%. A much lower or higher pH would inhibit flocculation. Low dosage requirements were needed for both the cation and bioflocculant, with only an input of 50 mL/L for 0.1% (w/v) CaCl2 and 5 mL/L for culture broth, respectively. These results are comparable to other bioflocculants produced by various microorganisms with higher dosage requirements.
Collapse
Affiliation(s)
- Zufarzaana Zulkeflee
- Department of Environmental Sciences, Faculty of Environmental Studies, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | | | | | | |
Collapse
|
40
|
|
41
|
From wastewater to bioenergy and biochemicals via two-stage bioconversion processes: a future paradigm. Biotechnol Adv 2011; 29:972-82. [PMID: 21884782 DOI: 10.1016/j.biotechadv.2011.08.012] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 08/06/2011] [Accepted: 08/14/2011] [Indexed: 11/22/2022]
Abstract
Recovery of bioenergy and biochemicals from wastewater has attracted growing and widespread interests. In this respect, two-stage bioconversion process (TSBP) offers an appealing avenue to achieve stepwise and directional substrate conversion in separated stages. Such a biosystem not only enables enhanced degradation of organics, but also favors a high product yield and quality. Various TSBRs have been developed for the production of methane, hydrogen, electricity, bioplastics, bioflocculants, biopesticides, biosurfactants and other value-added products, demonstrating marked advantages over the conventional one-stage processes. It represents a promising, and likely the sole viable, paradigm for future application. However, there are also many remaining challenges. This paper provides an overview of the various TSBPs, introduces the recent advances, and discusses the major challenges and the future perspectives for practical application.
Collapse
|
42
|
Assessment of bioflocculant production by Bacillus sp. Gilbert, a marine bacterium isolated from the bottom sediment of Algoa Bay. Mar Drugs 2011; 9:1232-1242. [PMID: 21822413 PMCID: PMC3148500 DOI: 10.3390/md9071232] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 06/28/2011] [Accepted: 07/05/2011] [Indexed: 11/18/2022] Open
Abstract
The bioflocculant-producing potentials of a marine bacteria isolated from the bottom sediment of Algoa Bay was investigated using standard methods. The 16S rDNA sequence analysis revealed 98% similarity to that of Bacillus sp. HXG-C1 and the nucleotide sequence was deposited in GenBank as Bacillus sp. Gilbert with accession number HQ537128. Bioflocculant was optimally produced when sucrose (72% flocculating activity) and ammonium chloride (91% flocculating activity) were used as sole sources of carbon and nitrogen, respectively; an initial pH 6.2 of the production medium; and Mg2+ as cation. Chemical analysis of the purified bioflocculant revealed the compound to be a polysaccharide.
Collapse
|
43
|
Wang L, Ma F, Qu Y, Sun D, Li A, Guo J, Yu B. Characterization of a compound bioflocculant produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6. World J Microbiol Biotechnol 2011. [DOI: 10.1007/s11274-011-0726-2] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
44
|
Buthelezi SP, Olaniran AO, Pillay B. Production and characterization of bioflocculants from bacteria isolated from wastewater treatment plant in South Africa. BIOTECHNOL BIOPROC E 2010. [DOI: 10.1007/s12257-009-3002-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
45
|
Patil SV, Patil CD, Salunke BK, Salunkhe RB, Bathe GA, Patil DM. Studies on Characterization of Bioflocculant Exopolysaccharide of Azotobacter indicus and Its Potential for Wastewater Treatment. Appl Biochem Biotechnol 2010; 163:463-72. [DOI: 10.1007/s12010-010-9054-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 08/02/2010] [Indexed: 11/29/2022]
|
46
|
Lee AK, Lewis DM, Ashman PJ. Energy requirements and economic analysis of a full-scale microbial flocculation system for microalgal harvesting. Chem Eng Res Des 2010. [DOI: 10.1016/j.cherd.2010.01.036] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
47
|
Fed-batch production of a bioflocculant from Corynebacterium glutamicum. J Ind Microbiol Biotechnol 2010; 37:1203-9. [PMID: 20589412 DOI: 10.1007/s10295-010-0767-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Accepted: 06/14/2010] [Indexed: 10/19/2022]
Abstract
The constant-rate fed-batch production of the polygalacturonic acid bioflocculant REA-11 was studied. A controlled sucrose-feeding strategy resulted in a slight improvement in biomass and a 7% reduction in flocculating activity compared with the batch process. When fed with a 3 g l(-1) urea solution, the flocculating activity was enhanced to 720 U ml(-1) in 36 h. High cell density (2.12 g l(-1)) and flocculating activity (820 U ml(-1)) were obtained in a 10-l fermentor by feeding with a sucrose-urea solution, with values of nearly two times and 50% higher than those of the batch process, respectively. Moreover, the residual sucrose declined to 2.4 g l(-1), and residual urea decreased to 0.03 g l(-1). Even higher flocculating activity of 920 U ml(-1) and biomass of 3.26 g l(-1) were obtained by feeding with a sucrose-urea solution in a pilot scale fermentation process, indicating the potential industrial utility of this constant-rate feeding strategy in bioflocculant production by Corynebacterium glutamicum.
Collapse
|
48
|
Bioflocculant exopolysaccharide production by Azotobacter indicus using flower extract of Madhuca latifolia L. Appl Biochem Biotechnol 2009; 162:1095-108. [PMID: 19921493 DOI: 10.1007/s12010-009-8820-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 10/11/2009] [Indexed: 10/20/2022]
Abstract
Efficacy of Azotobacter indicus ATCC 9540 strain for production exopolysaccharide (EPS) bioflocculant was investigated. Mahua flower extract (Madhuca latifolia L), a natural substrate at the concentration of 20 g L(-1), gave maximum recovery of EPS followed by sucrose and mannitol as compared to other carbon sources after 172 h. Yeast extract was found to be the most effective nitrogen source as compared to beef extract, sodium nitrate, ammonium sulfate, casein hydrolysate, and urea for the production of EPS. EPS production was increased in presence of nitrogen (5.51 g L(-1)) as compared to nitrogen-free medium (3.51 g L(-1)), and fermentation time was also reduced by 28 h. Maximum EPS production (6.10 g L(-1)) was found in the presence of 20 g L(-1) flower extract and 0.5 g L(-1) yeast extract containing Ashby's media with 180 rpm at 30 degrees C at 144 h, under controlled conditions in 2.5 L fermenter using optimized medium. The isolated EPS showed cation-dependent flocculating activity. Concentration of EPS played an important role in bioflocculating activity which increased in a concentration-dependent manner up to a certain limit, with the maximum flocculation of 72% at 500 mg L(-1) concentration but remained almost static after this concentration. Extracted polymer was characterized by different chemical tests, FT-IR spectroscopy, and TLC which showed presence of uronic acids, O-acetyl groups, and Orcinol with suggestive indication of alginate like polymer. This study suggests that use of M. latifolia L. flowers can be a potential alternative bioresource for production of exopolysaccharide.
Collapse
|
49
|
Gao Q, Zhu XH, Mu J, Zhang Y, Dong XW. Using Ruditapes philippinarum conglutination mud to produce bioflocculant and its applications in wastewater treatment. BIORESOURCE TECHNOLOGY 2009; 100:4996-5001. [PMID: 19535246 DOI: 10.1016/j.biortech.2009.05.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Revised: 05/08/2009] [Accepted: 05/17/2009] [Indexed: 05/27/2023]
Abstract
A novel bioflocculant-producing bacterium, ZHT4-13, was isolated from Ruditapes philippinarum conglutination mud. By biomicroscope morphological observation, 16S rDNA sequence identification and physiological and biochemical characteristics, strain ZHT4-13 was identified as Rothia sp. The bioflocculant MBF4-13 produced by strain ZHT4-13 had a flocculating efficiency of 86.22% for 5 g L(-1) Kaolin clay suspension when the initial pH was 9 and the temperature was 20 degrees C. It had flocculating effect in a wide range, pH 1-13 and temperature 4-100 degrees C. Analysis of MBF4-13 by UV-Vis spectrophotometer, Fourier-transform infrared spectrophotometer (FT-IR) and (1)H nuclear magnetic resonance (NMR) indicated that the main component of MBF4-13 is polysaccharide. The culture conditions to produce strain ZHT4-13 were optimized with orthogonal design of experiments. MBF4-13 had high efficiency in decolorizing dye solutions, had some abilities to remove heavy metal ions (Cr(2)O(7)(2-), Ni(2+)) and improve performance of activated sludge.
Collapse
Affiliation(s)
- Qi Gao
- School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, China
| | | | | | | | | |
Collapse
|
50
|
Liu W, Yuan H, Yang J, Li B. Characterization of bioflocculants from biologically aerated filter backwashed sludge and its application in dying wastewater treatment. BIORESOURCE TECHNOLOGY 2009; 100:2629-2632. [PMID: 19153041 DOI: 10.1016/j.biortech.2008.12.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2008] [Revised: 12/08/2008] [Accepted: 12/08/2008] [Indexed: 05/27/2023]
Abstract
In this study, the feasibility of bioflocculant extraction from backwashing sludge to reduce its production costs was investigated. Results showed that ultrasound and base treatment could significantly enhance bioflocculant extraction efficiency, however, flocculating activity was affected. It was observed that bioflocculants extracted from sludge of pH 11.0 had no flocculating activity. In contrast, bioflocculants extracted from sludge of pH 5.0, named as M-1, had good flocculating activity. To further study the flocculating activity of M-1, factors such as bioflocculant dosage, temperature and pH of the reaction solution were tested. The optimal conditions were 6.0mg/l bioflocculant dosage and pH 5.0, at a temperature of 10 degrees C. Under these conditions, the flocculating rate of kaolin clay was 92.67%. The effectiveness of such bioflocculants in the decolorization of synthetically dyed wastewater was then examined. In flocculating methylene blue and fast blue in aqueous solutions, decolorization efficiency levels were 82.9% and 77.8%, respectively.
Collapse
Affiliation(s)
- WeiJie Liu
- State Key Lab for Agrobiotechnology, Center of Biomass Engineering, Key Laboratory of Agro-Microbial Resource and Application, Ministry of Agriculture, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | | | | | | |
Collapse
|