Article
Environmental Sciences
Hadi Fakhri, Aiyoub Shahi, Suleyman Ovez, Sevcan Aydin
Summary: Bioaugmentation with immobilized Penicillium restrictum can significantly alter antibiotic removal efficiency and microbial community structure, reduce membrane fouling, and enhance wastewater treatment efficiency.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2021)
Article
Engineering, Environmental
Sojin Min, Hosung Lee, Dowon Chae, Jeongwon Park, Sang H. Lee, Hyun-Suk Oh, Kibaek Lee, Chung-Hak Lee, Soryong Chae, Pyung-Kyu Park
Summary: Bacterial quorum quenching (QQ) is an effective strategy for controlling biofouling in membrane bioreactors (MBRs), but the QQ efficiency is severely reduced in MBRs operated at low temperatures. BH4-L, prepared using a modified culture method, showed enhanced QQ efficiency at low temperatures. Application of BH4-L-entrapping beads to lab-scale MBRs operated at low temperatures successfully mitigated membrane biofouling.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Kibaek Lee, Yeong-Jun Park, Tahir Iqbal, Hyeona Park, Yeongyun Jung, Jae-Ho Shin, Kwang-Ho Choo
Summary: Quorum quenching (QQ) has been successful in preventing biofouling in membrane bioreactors (MBRs) using isolated QQ bacterial strains. However, the effect of QQ on the microbial population is still not fully understood. This study analyzed the microbial population in MBRs over an extended period under different conditions and found that QQ treatment did not significantly affect the structure and diversity of the microbial community. The research also provided insights into the role of bacterial QQ in reducing MBR biofouling and its underlying mechanisms.
Article
Agricultural Engineering
Fangfang Xu, Jialong Liao, Jinchen Hu, Yunshi Feng, Yanyao Huang, Xingtong Feng, Shuangfei Li
Summary: This study investigated the antibiofouling performance of a new indigenous QQ bacterium, Delftia sp. JL5, in membrane bioreactor (MBR). JL5 effectively inhibited biofilm formation of quorum-sensing bacteria, delaying MBR biofouling. Slower flux rate favored the suppression effect of JL5. Additionally, JL5 changed the microbial structure of the membrane biocake without affecting activated sludge.
BIORESOURCE TECHNOLOGY
(2023)
Article
Environmental Sciences
Hira Waheed, Ch Tahir Mehmood, Yiwei Li, Ying Du, Yeyuan Xiao
Summary: In this study, anaerobic bacteria naturally isolated were used to encode four quorum quenching (QQ) enzymes, which were then applied in immobilized and bioaugmented forms to investigate their effects on membrane foulants, microbial taxa, and biofouling control. Two anaerobic membrane bioreactors (AnMBRs) with different immobilizing media (silica-alginate and hollow fiber-alginate) were operated in two conventional and three QQ-based phases. The addition of QQ anaerobes in both free cells and immobilized form significantly extended the membrane filtration operation time in AnMBR-Si and AnMBR-Hf. Furthermore, QQ application resulted in a biocake with lower surface coverage compared to conventional phases.
Article
Engineering, Environmental
In Kim, Jun-U Jang, Hyeyeon Park, Jeongmi Park, Hyun-Suk Oh, Seonki Lee, Kwang-Ho Choo, Pyung-Kyu Park, Kibaek Lee
Summary: Biofouling of membrane surfaces remains a major challenge in membrane bioreactors (MBRs). Physical fouling issues caused by trapping of quorum quenching (QQ) media in the hollow-fiber module have hindered the widespread application of QQ-MBRs. This study successfully achieved continuous QQ feeding in MBRs without directly injecting fluidized QQ media into the membrane tank. By comparing different strains, it was found that the exo-type strain 1A1 was suitable for continuous QQ feeding. The results showed that QQ via strain 1A1 effectively reduced membrane biofouling by lowering biofilm formation and EPS production genes in microbial communities.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Biochemistry & Molecular Biology
Kibaek Lee, Syed Salman Ali Shah, Hyeona Park, Chung-Hak Lee, Kwang-Ho Choo
Summary: A double-layered membrane containing a QQ bacterium (BH4 strain) has been developed, which effectively inhibits biofilm formation, biopolymer accumulation, and signal molecule concentration on the membrane surface.
Article
Engineering, Environmental
Haoliang Pang, Jinhui Huang, Xue Li, Kaixin Yi, Suzhou Li, Zhexi Liu, Wei Zhang, Chenyu Zhang, Si Liu, Yanling Gu
Summary: In this research, electrospun fiber coated hydrogel QQ beads (QQ-ECHB) were fabricated for the first time, which showed long-lasting QQ activity and stable physical washing effect. The QQ-ECHB significantly prolonged the time to reach transmembrane pressure (TMP) of 40 kPa in a membrane bioreactor (MBR) and maintained its structural strength and stability under cyclic compression and fluctuations in sewage quality.
Article
Engineering, Environmental
Tahir Iqbal, Syed Salman Ali Shah, Kibaek Lee, Kwang-Ho Choo
Summary: The new design of QQ balls showed superior stability in quorum quenching, significantly reduced biofouling, saved energy, maintained high QQ activity during long-term use, and proved to be a promising structure for sustainable MBR applications.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Environmental Sciences
I-Chieh Chien, Chiao-Yun Chu, Chien-Yu Huang
Summary: Membrane bioreactors (MBRs) are widely used in wastewater treatment due to their high-quality effluent production. However, biofilm formation on membrane surfaces remains a major limitation of this technique. Bacterial quorum quenching (QQ) has been proven successful in controlling biofouling in MBRs. This study isolated potential QQ bacteria and investigated their degradation rates against eight different AHLs. The results showed that four isolates exhibited consistent AHL removal capabilities, indicating their potential for mitigating biofilm formation on MBR membranes.
Review
Biotechnology & Applied Microbiology
Karolina Bachosz, Minh T. Vu, Long D. Nghiem, Jakub Zdarta, Luong N. Nguyen, Teofil Jesionowski
Summary: This study provides insights into biofouling and enzyme-based mitigating techniques in membrane-based water and wastewater purification. It discusses the underlying mechanisms of biofouling formation, emphasizing the roles of extracellular polymeric substances (EPS) in membrane surface interaction, biofilm stability, and diversity, and comprehensively reviews the quorum sensing (QS) process that regulates bacterial communication and biofilm formation. The study systematically describes the relationship among EPS, QS, and biofouling for the first time and critically analyzes the current enzyme-based techniques for controlling and removing biofoulants.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2022)
Article
Agricultural Engineering
Abdolvahed Noori, Hyeok Kim, Myung Hee Kim, Keumyong Kim, Kibaek Lee, Hyun-Suk Oh
Summary: This study isolated quorum quenching strains from activated sludge used to treat industrial wastewater containing toxic substances, which effectively degraded bacterial communication signals and reduced membrane biofouling in the presence of toxic compounds like TMAH.
BIORESOURCE TECHNOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Shimei Ge, Ruixue Yang, Ying Zhang, Alan Kueichieh Chang, Yaru Li, Xiaohui Chen, Xinjiao Dong
Summary: Quorum quenching (QQ) is a promising strategy for mitigating membrane biofouling in membrane bioreactors (MBRs). This study isolated and studied six QQ bacterial strains, finding that strain Y6 performed better in reducing biofouling in MBR due to the presence of extracellular QQ enzymes and rapid adaptation to the conditions within the MBR. Additionally, strain Y6 did not affect the content of various compounds in the effluent released by the MBR.
INTERNATIONAL BIODETERIORATION & BIODEGRADATION
(2023)
Review
Environmental Sciences
Parthiban Anburajan, Roent Dune Cayetano, You Mit Prohim, Nguyen Tang Thau, Sungmi Kim, Hyeok Kim, Je Hyeon Ko, Hyun-Suk Oh
Summary: This review examines the roles of quorum sensing (QS) and quorum quenching (QQ) in anaerobic digestion processes. QS signal molecule AHL can promote biofilm formation and organic degradation, thereby improving the efficiency of anaerobic digestion. QQ has been shown to effectively control membrane fouling. However, its impact on methane productivity remains unclear.
ENVIRONMENTAL RESEARCH
(2023)
Article
Environmental Sciences
Huaorng Yu, Chenyu Du, Fangshu Qu, Junguo He, Hongwei Rong
Summary: This study explored various potential bio-stimuli for quorum quenching enhancement in activated sludge, identifying compounds like gamma-caprolactone, D-xylonic acid-1,4-lactone, and urea as effective in promoting inactivating activity. Through entrapment, these bio-stimuli effectively disrupted quorum sensing in membrane bioreactors.
Article
Environmental Sciences
Turker Turken, Reyhan Sengur-Tasdemir, Gulsum Melike Urper-Bayram, Oguz Gunes, Esra Ates-Genceli, Volodymyr V. Tarabara, Ismail Koyuncu
Summary: The study found that the optimum permeability and BSA rejection were achieved when the molecular weight of the PVP was 40 kDa. However, increasing the advancing speed resulted in a thinner membrane wall, which increased the likelihood of irreversible fouling.
ENVIRONMENTAL TECHNOLOGY
(2021)
Article
Chemistry, Physical
Xunhao Wang, Reyhan Sengur-Tasdemir, Ismail Koyuncu, Volodymyr V. Tarabara
Summary: The study reveals that drying of lip balms increases surface hydrophobicity, leading to enhanced virus adhesion. Through experiments and calculations, it is found that hydrophilic colloids may attach to lip balm surfaces under conditions of saliva ionic strength.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Environmental Sciences
Borte Kose-Mutlu, Heileen Hsu-Kim, Mark R. Wiesner
Summary: Micelle enhanced ultrafiltration (MEUF) is an effective membrane separation process for separating target ions from mixed metal aqueous solutions. This study evaluates the separation efficiency of MEUF for rare earth elements (REEs) using sodium dodecyl sulfate (SDS) as the sorbent. The results show that under optimized conditions, the membrane rejection efficiency of REEs is high and SDS can be efficiently recovered using a two-step precipitation method.
ENVIRONMENTAL TECHNOLOGY
(2022)
Article
Engineering, Environmental
Borte Kose-Mutlu
Summary: This study focused on investigating the impact of membrane characteristics and applied pressure on the removal of natural organic matter and sulphate using nanofiltration membranes for drinking water production. The results revealed that membrane characteristics had a greater influence on the removal efficiency than the operating pressure. Ultimately, a removal efficiency of over 99% was achieved for natural organic matter and sulphate under optimal conditions.
WATER SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Paper & Wood
Mehmet Emin Pasaoglu, Ismail Koyuncu
Summary: The study fabricated tubular nanofiber PRO membranes using electrospinning technique, where the addition of CNCs increased the mechanical strength in PAN membranes and achieved higher PRO water flux.
Article
Environmental Sciences
Ayse Yuksekdag, Borte Kose-Mutlu, Bihter Zeytuncu-Gokoglu, Mustafa Kumral, Mark R. Wiesner, Ismail Koyuncu
Summary: The passage discusses how e-waste from discarded electrical and electronic devices is a potential source of rare earth elements, with China dominating global REE production. It also introduces methods for efficient REE recovery from secondary sources like e-waste through improvements in pre-treatment and acidic leaching processes.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Azmat Fatima Siddiqui, Ayse Yuksekdag, Gizem Tuncay, Borte Kose-Mutlu, Mark Wiesner, Ismail Koyuncu
Summary: Rare earth elements (REEs) are essential for modern industries, especially Ce, La, Nd, and Y. This study focused on extracting REEs from iron mining sludge in Turkey using innovative techniques of nanofiltration and SLM. The optimal conditions for REE recovery were determined, showcasing the potential for extracting REEs from secondary resources.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Environmental Sciences
Ayse Yuksekdag, Borte Kose-Mutlu, Beril Tanc Kaya, Mustafa Kumral, Mark R. Wiesner, Ismail Koyuncu
Summary: This paper reviews the potential and types of rare earth elements in 32 different secondary sources in Turkey. It was found that combustion residues and e-waste contain the highest concentrations of rare earth elements among all types of waste/wastewater.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
H. Ozgun, B. Cicekalan, Y. Akdag, I Koyuncu, I Ozturk
Summary: This study analyzed the real capital and operation and maintenance expenditures of 16 full-scale WWTPs in Istanbul to calculate unit capital and operation and maintenance costs, and investigated the impacts of treatment level and capacity on costs. The results demonstrated that the level of treatment considerably affected the costs of WWTPs.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Review
Environmental Sciences
Ayse Yuksekdag, Borte Kose-Mutlu, Azmat Fatima Siddiqui, Mark R. Wiesner, Ismail Koyuncu
Summary: This review presents six steps to close the loop and recover rare earth elements, and summarizes studies on environmentally friendly, economic, and efficient recovery processes. The obstacles to closing the REE loop in a circular economy and the reasons why secondary sources are not preferred over primary sources are also discussed.
Article
Engineering, Environmental
Ayse Yuksekdag, Borte Kose-Mutlu, Mark R. Wiesner, Ismail Koyuncu
Summary: The pre-concentration and separation processes of Rare Earth Elements (REEs) were investigated in this study. The nitric acid leachate of e-waste was pretreated to improve its quality before concentration. Nanofiltration was used for pre-concentration, resulting in a triplication of REEs concentration under optimum conditions. A flat sheet supported liquid membrane process was successfully utilized to extract REEs from the pre-treated leachate, with bis-2-ethylhexyl phosphoric acid (D2EHPA) showing higher separation efficiency compared to di-2,4,4,-trimethylpentyl phosphinic acid (Cyanex 272). The processes of direct membrane solvent extraction and MSX with pre-concentration were optimized, and the pre-concentration step was found to increase the efficiency of the MSX process and enable acid recovery. A more environmentally friendly and economical process scheme involving acid recovery from both nanofiltration permeate and post-MSX leaching residue was proposed.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Engineering, Chemical
Vahid Vatanpour, Borte Kose-Mutlu, Ismail Koyuncu
Summary: Electrospraying and electrospinning are cost-effective techniques for fabricating particles or fibers at micro- and nano-sizes. This review provides a comprehensive review and discussion on the potential of electrospraying technique in the fabrication of different types of membranes. It highlights the key factors that affect the electrospraying process and emphasizes the high performance of membranes fabricated by electrospraying.
Article
Environmental Sciences
Gulmire Ilyasoglu, Borte Kose-Mutlu, Oyku Mutlu-Salmanli, Ismail Koyuncu
Summary: This review provides a comprehensive overview of the application of nanosorbents such as carbon nanotubes, graphene oxides, and metallic organic frameworks in water and wastewater treatment. It discusses the recent advances in the fabrication of adsorptive membranes and their basic principles, highlighting the potential environmental applications of these nanosorbents.
Article
Chemistry, Multidisciplinary
Elifnur Gezmis-Yavuz, Tulay Ergon-Can, C. Elif Cansoy, Derya Y. Koseoglu-Imer
Summary: With increasing importance due to decreasing indoor air quality and increased indoor time, the development of new materials for bacteria and viruses has become crucial, especially in the context of the COVID-19 pandemic. This study successfully fabricated HNT-embedded composite nanofiber filters using the electrospinning method, with the incorporation of TiO2 and ZnO nanoparticles. The results showed that the combination of HNTs and photocatalysts improved the filtration efficiency, mechanical properties, and antibacterial properties, making the nanofibers suitable for face masks and air filter materials.
