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Wang Z, Liao Y, Yan L, Liao B. Biological performance and membrane fouling of a microalgal-bacterial membrane photobioreactor for wastewater treatment without external aeration and carbonation. ENVIRONMENTAL RESEARCH 2024; 247:118272. [PMID: 38246292 DOI: 10.1016/j.envres.2024.118272] [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: 11/23/2023] [Revised: 01/10/2024] [Accepted: 01/18/2024] [Indexed: 01/23/2024]
Abstract
Biological nutrient removal processes involving the use of activated sludge (AS) to treat municipal wastewater normally result in high aeration energy consumption and significant greenhouse gas (GHG) emissions. Therefore, developing cost-efficient and environmentally friendly processes for wastewater treatment is vital. In this work, a novel non-aerated microalgal-bacterial membrane photobioreactor (MB-MPBR) was proposed, and its feasibility for organic contaminant and nutrient removals was evaluated, for the first time. The effects of inoculation ratio (microalgae to bacteria (M/B)) on the biological performance and membrane fouling were systematically investigated. The results showed that 95.9% of the chemical oxygen demand (COD), 74.5% of total nitrogen (TN), 98.5% of NH4+-N and 42.0% of total phosphorus (TP) were removed at an inoculation M/B ratio of 3:2 at steady state, representing a significant improvement compared to the M/B inoculation ratio of 1:3. Additionally, the higher inoculation M/B ratio (3:2) significantly promoted the biomass production owing to the favorable mutual exchange of oxygen and carbon dioxide between microalgae and bacteria. Cake layer formation was the primary fouling mechanism owing to the absence of aeration scouring on the membrane surface. The membrane fouling rate was slightly higher at the higher inoculation ratio (M/B = 3:2) owing to the increased biomass and extracellular polymeric substances (EPS) productions, despite the larger particle size. These results demonstrated that the non-aerated MB-MPBR could achieve superior biological performance, of which the inoculation M/B ratio was of critical importance for the initiation and maintenance of microalgal-bacterial symbiotic system, yet possibly caused severer membrane fouling in the absence of external aeration and carbonation. This study provides a new perspective for further optimizing and applying non-aerated MB-MPBR to enhance municipal wastewater treatment.
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Affiliation(s)
- Zhaozhao Wang
- College of Civil and Architectural Engineering, North China University of Science and Technology, Tangshan, 063210, PR China; College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, 056038, PR China; Department of Chemical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1, Canada.
| | - Yichen Liao
- Department of Chemical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1, Canada
| | - Lina Yan
- College of Chemical Engineering, North China University of Science and Technology, Tangshan, 063210, PR China
| | - Baoqiang Liao
- Department of Chemical Engineering, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1, Canada.
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Krishnan S, Nasrullah M, Kamyab H, Suzana N, Munaim MSA, Wahid ZA, Ali IH, Salehi R, Chaiprapat S. Fouling characteristics and cleaning approach of ultrafiltration membrane during xylose reductase separation. Bioprocess Biosyst Eng 2022; 45:1125-1136. [PMID: 35469027 DOI: 10.1007/s00449-022-02726-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 04/01/2022] [Indexed: 11/28/2022]
Abstract
Many operating parameters of ultrafiltration (UF) are playing a crucial role when using a polyethersulfone membrane to separate xylose reductase (XR) enzyme from reaction mixtures during xylitol synthesis. The present study focuses on the separation of XR enzyme using a cross-flow ultrafiltration (UF) membrane. The filtration process was analyzed using the three effective variables such as filtration time, cross-flow velocity (CFV), and the transmembrane pressure (TMP), which were ranging from 0 to 100 min, 0.52 to 1.2 cm/s and 1-1.6 bar, respectively. Then, using the resistance in series model, the hydraulic resistance for alkali chemical cleaning during XR separation was estimated. During separation, increased TMP showed a positive-flux effect as a driving force, however, fouling and polarized layer were more prominent under higher TMP. Increased CFV, on the other hand, was found more efficient in fouling control. In terms of the membrane cleaning techniques, an alkaline solution containing 0.1 M sodium hydroxide was shown to be the most effective substance in removing foulants from the membrane surface in this investigation. Cleaning with an alkaline solution resulted in a maximum flux recovery of 93% for xylose reductase separation. This work may serve as a useful guide to better understand the optimization parameters during XR separation and alleviating UF membrane fouling induced during XR separation.
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Affiliation(s)
- Santhana Krishnan
- Department of Civil and Environmental Engineering, Faculty of Engineering, PSU Energy Systems Research Institute (PERIN), Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Mohd Nasrullah
- Faculty of Civil Engineering Technology, Universiti Malaysia Pahang, Gambang, Malaysia
| | - Hesam Kamyab
- Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100, Kuala Lumpur, Malaysia.,Department of Biomaterials, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai, 600 077, India
| | - Noor Suzana
- Faculty of Civil Engineering Technology, Universiti Malaysia Pahang, Gambang, Malaysia
| | | | - Zularisam Ab Wahid
- Faculty of Civil Engineering Technology, Universiti Malaysia Pahang, Gambang, Malaysia
| | - Ismat H Ali
- Department of Chemistry, College of Science, King Khalid University, P.O. Box 9004, Abha, 61413, Saudi Arabia
| | - Reza Salehi
- Department of Civil and Environmental Engineering, Faculty of Engineering, PSU Energy Systems Research Institute (PERIN), Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand
| | - Sumate Chaiprapat
- Department of Civil and Environmental Engineering, Faculty of Engineering, PSU Energy Systems Research Institute (PERIN), Prince of Songkla University, Hat Yai, Songkhla, 90110, Thailand.
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Hou B, Liu X, Zhang R, Li Y, Liu P, Lu J. Investigation and evaluation of membrane fouling in a microbial fuel cell-membrane bioreactor systems (MFC-MBR). THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 814:152569. [PMID: 34973325 DOI: 10.1016/j.scitotenv.2021.152569] [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: 10/06/2021] [Revised: 12/02/2021] [Accepted: 12/16/2021] [Indexed: 06/14/2023]
Abstract
Two membrane bioreactors with and without adding an electric circuit (named as MFC-MBR and C-MBR, respectively) were established to investigate the effects of micro-electric field on membrane fouling. With the aeration rate of 1.5 L/min, the synergistic effect of aeration and micro-electric field was the best in reducing membrane fouling and COD in treatment of a simulated phenol wastewater. Compared with C-MBR, the running time of MFC-MBR was extended for 16 days. Scanning electron microscope (SEM) and energy-dispersive X-ray detector (SEM-EDX) demonstrated that less foulants were attached to the membrane and the attachment was loosend in MFC-MBR. The decreased absolute value of zeta potential indicated repulsion among the negatively-charged sludge particles was reduced and flocculation of the sludge was improved, which alleviated the membrane fouling. The soluble microbial products (SMP) and loosely-bound extracellular polymeric substances (LB-EPS) were also decreased in MFC-MBR. It was found that migration and neutralization of the negatively-charged particles, and degradation of microorganisms contributed to the alleviation of membrane fouling. Moreover, the decreases of carbohydrates in LB-EPS led to higher protein/carbohydrates (PN/PS) ratio, which was a key parameter for alleviating membrane fouling. Meanwhile, the increase of tightly bound extracellular polymeric substances (TB-EPS) could also slow down membrane fouling. Because TB-EPS can be used as a binder to strengthen the flocculation of sludge particles.
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Affiliation(s)
- Bin Hou
- School of the Environment and Safety Engineering, North University of China, Taiyuan 030051, China
| | - Xiaoyu Liu
- School of the Environment and Safety Engineering, North University of China, Taiyuan 030051, China
| | - Rong Zhang
- School of the Environment and Safety Engineering, North University of China, Taiyuan 030051, China
| | - Ying Li
- School of the Environment and Safety Engineering, North University of China, Taiyuan 030051, China
| | - Pengxiao Liu
- School of the Environment and Safety Engineering, North University of China, Taiyuan 030051, China
| | - Jing Lu
- School of the Environment and Safety Engineering, North University of China, Taiyuan 030051, China.
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Wang B, Zhang Y, Fang Y, Zhang K, Field RW. Aeration pipe design for free bubbling hydrodynamic optimization of flat sheet MBRs. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2021.120222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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