Environmental Engineering / Çevre Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/4321

Browse

Filters

2021 - 20225

Settings

Institution Author: search.filters.institutionAuthor.Küçüker, Mehmet Ali

Search Results

Now showing 1 - 5 of 5
  • Article
    Fabrication of Superhydrophilic Teos-Lactic Acid Composite Films and Investigation of Biofouling Behaviour
    (Yıldız Teknik Üniversitesi, 2022) Ervan, Tuğçe; Küçüker, Mehmet Ali; Cengiz, Uğur
    Phytoplankton and diatom microalgae species cause biofouling by adhering to the surfaces, especially in closed cultivation systems such as tubular photobioreactors. This biofilm formation blocks the sunlight; after harvesting, it is necessary to clean the reactor. This cleaning process causes loss not only for time and finance but also in terms of environmental pollution due to using toxic chemicals and excess water usage. This study aimed to investigate the reduction of the microorganism cell adhesion on the hybrid surface. To succeed in this, the composite surface of tetraethoxysilane (TEOS) and lactic acid (LA) was prepared by the sol-gel process. Then the hybrid surfaces were coated on glass slides by the dip coating method. The wettability performance of the TEOS-LA hybrid surface was investigated using contact angle measurement and light transmittance. The wettability result showed that the superhydrophilic surface having 54 mJ/m2 of surface free energy values was obtained. An increase in the lactic acid content of the composite films increased the surface free energy (SFE) values decreasing the water contact angle. A pencil hardness test characterized the mechanical strength of the surfaces, and it was determined that the hardness of the composite films was decreased by increasing the LA content of the composite films. Resultantly, it is found that the TEOS-LA superhydrophilic composite film reduces the adhesion of microalgae.
  • Article
    Cyanobacterial Communities in Mucilage Collected From Çanakkale Strait (dardanelles): Metagenomic Approach
    (Çanakkale Onsekiz Mart Üniversitesi, 2022) Yılmaz, Sevdan; Kahraman Yılmaz, Dilek; Çelik, Ekrem Şanver; Küçüker, Mehmet Ali
    In this study, cyanobacterial communities in mucilage samples collected from three stations in the Dardanelles Strait were analyzed with a metagenomic approach. Mucilage samples were collected at the beginning of June 2021 from three points of the Dardanelles (Station 1: 40°6'42.78"N, 26°23'57.00"E; Station 2: 40°9'8.09"N, 26°24'16.19"E; Station 3: 40°6 '21.62"N, 26°22'41.25"E). The dominant cyanobacteria were Prochlorococcus marinus (39.17%), Synechococcus sp. (20.85%), Lyngbya sp. (12.00%), Trichodesmium erythraeum (7.33%), Aphanocapsa sp. (4.33%) and Leptolyngbya sp. (3.33%), which constituted 87.00 % of the total number of sequences. In this study, cyanobacteria species that can cause harmful algal blooms and have toxic effects on the mucilage structure have been determined. The Marmara Sea and the Dardanelles Strait, which have been affected by serious disturbances, including industrial activities, anthropogenic impacts, tourism and artificial lighting, will never be fully restored to their former ecological state. In addition, cyanobacteria species in the mucilage may cause harmful algal blooms and have toxic effects that threaten the future well-being of coastal populations and ecosystem stability. Thus, the government and local authorities should pay more attention to combating the mucilage.
  • Book Part
    Citation - Scopus: 3
    Biogas Production From Aquatic Biomass
    (Elsevier, 2022) Wieczorek, Nils; Kosheleva, Arina; Kuchta, Kerstin; Önen Çınar, Senem; Küçüker, Mehmet Ali
    The use of aquatic biomass such as algae, macrophytes, or submerged macrophytes as raw material for biogas production has numerous technical and biological advantages. In addition, synergy effects can be exploited taking into account the implementation of biogas systems in urban areas, and coupling between the production of aquatic biomass, biogas production, and urban material flows can be established. Aquatic biomass, which can be the residue of downstream processes or collected from water bodies in cities, represents an excellent opportunity for both material and energy needs. Anaerobic digestion is a widely implemented technology that is already proven for the treatment of various biomasses. Several studies showed that aquatic biomass is a valuable substrate with its high methane yield, especially codigestion processes. This chapter represents the main idea of the anaerobic digestion process while focusing on the features of the aquatic biomass applications in this process.
  • Article
    Shotgun Metagenomic Analysis for Mucilage in the Surface Waters of the Çanakkale Strait (dardanelles): Metabolic Diversity, Microbial Community Structure and Antibiotic Resistance Genes
    (2021) Yılmaz, Sevdan; Kahraman, Dilek; Çelik, Ekrem Şanver; Küçüker, Mehmet Ali
    In this study, we used shotgun metagenome sequencing to examine the metabolic diversity, microbial community structure and diverse antimicrobial resistance genes of mucilage in the surface waters of the Çanakkale Strait (Dardanelles). Mucilage samples were collected in April 2021 from the three different stations of the Dardanelles. The dominant microbial communities at the phylum level were Bacteroidetes (20.06%), Proteobacteria (13.68%), Verrucomicrobia (6.25%), Planctomycetes (3.02%) and Cyanobacteria (2.5%). Metabolic pathway analysis using KEGG (Kyoto Encyclopedia of Genes and Genomes) revealed that most of the genes of mucilage samples were involved in unclassified (73.86%) followed by metabolism (14.45%), genetic information processing (4.16%), environmental information processing (2.57%), cellular processing (1.88%), human diseases (1.61%), and organismal systems (1.47%). The dfrA3 gene was the most prevalent (20.36%) followed by CRP (18.17%), PmrE (14.92%), rpoB2 (11.17%), SoxR (7.49%), AbeS (6.83%), baeR (5.22%), PmrF (3.70%), dfrA22 (2.20%), dfrA26 (1.76%), dfrA20 (1.63%), golS (1.26%), CAT (1.03%), mtrA (1.01%), TMB-1 (0.64%), novA (0.64%), dfrK (0.59%), vanXB (0.48%), dfrG (0.39%), FosC2 (0.31%), and MexA (0.20%) genes. Antibiotic resistance gene (ARG) types mainly included the resistance genes of multidrug (40.19%), trimethoprim (26.93%), polymyxin (18.62%), rifamycin (11.17%), chloramphenicol (1.03%), aminocoumarin (0.64%), beta-lactamase (0.64%), fosfomycin (0.31%), and vancomycin (0.48%). Antibiotic-resistant bacteria in mucilage can adhere to human skin during swimming, fishing, water sports etc., enter the body through the nose and mouth, and transfer genetic information to the bacteria in contact areas in the human body. Therefore, this situation is risky in public health, and necessary precautions should be taken. In the light of these findings, it has been observed that there is a need for more detailed studies in the future.
  • Article
    Metagenomic Characterization of Planktonic Communities During a Mucilage Event in the Çanakkale Strait (dardanelles), Turkey
    (2021) Yılmaz, Sevdan; Küçüker, Mehmet Ali; Kahraman, Dilek
    The present study investigates the planktonic communities through metagenomics sequencing during a mucilage event in the Çanakkale Strait (Dardanelles), Turkey. Mucilage samples were collected in May 2021 during an intense period of mucilage formation in three different stations of Dardanelles (Station 1: 40°9'8.09"N, 26°24'16.19"E; Station 2: 40°6'21.62"N, 26°22'41.25"E; Station 3: 40°6'42.78"N, 26°23'57.00"E). The dominant planktonic eukaryotes, at the phylum level, were Dinoflagellata (38.57%), Protalveolata (15.03%), Diatomea (12.41%), Nematozoa (8.44%), Apicomplexa (6.79%) and Chlorophyta (5.43%), which constituted 86.68 % of the total number of sequences. The most dominant OTUs (>10%), were Alexandrium and Syndiniales Group II. other dominant OTUs (>2%) were Viscosia sp., Lankesteria, Arcocellulus, Thalassiosira and Nannochloris. This study has clarified the situation of planktonic communities during a mucilage event in the Çanakkale Strait (Dardanelles), Turkey. As a result, the most dominant genus was Alexandrium, which has been known to produce mucilage. Some Alexandrium species can produce toxins, cause severe impacts on human health, and lead to bivalve, shrimp, and fish mortality. Therefore, a more detailed study is needed to determine the Alexandrium toxins in the mucilage structure. In addition, the heavy metal content of the obtained mucilage was investigated, and the concentrations of the As and Cr are above the disposal limits in the landfill sites. Therefore, collected mucilage from the sea surface should be checked before sending it to landfill sites in terms of the heavy metal content.