Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Article Citation - WoS: 41Citation - Scopus: 43Chloride or Sulfate? Consequences for Ozonation of Textile Wastewater(Academic Press Inc., 2019) Öktem, Yalçın Aşkın; Yüzer, Burak; Ökten, Hatice Eser; Ökten, Hatice Eser; Meriç, Süreyya; Selçuk, Hüseyin; 03.07. Department of Environmental Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyOzonation of chloride-rich textile wastewater is a common pretreatment practice in order to increase biodegradability and therefore meet the discharge limits. This study is the first to investigate ozone-chloride/bromide interactions and formation of hazardous adsorbable organic halogens (AOX) in real textile wastewater. Initially effect of ozonation on chloride-rich real textile wastewater samples were investigated for adsorbable organic halogens (AOX) formation, biodegradability and toxicity. After 15 min of ozonation, maximum levels of chlorine/bromine generation (0.3 mg/l) and AOX formation (399 mg/l) were reached. OUR and SOUR levels both increased by approximately 58%. Daphnia magna toxicity peaked at 100% for 10 min ozonated sample. Considering adverse effects of ozonation on chloride-rich textile industry effluents, we proposed replacement of NaCl with Na2SO4. Comparative ozonation experiments were carried out for both chloride and sulfate containing synthetic dyeing wastewater samples. Results showed that use of sulfate in reactive dyeing increased biodegradability and decreased acute toxicity. Although sulfate is preferred over chloride for more effective dyeing performance, the switch has been hampered due to sodium sulfate's higher unit cost. However, consideration of indirect costs such as contributions to biodegradability, toxicity, water and salt recovery shall facilitate textile industry's switch from chloride to sulfate.Master Thesis Preparation of Asymmetric Ti̇o2 Based Nano/Ultrafiltration Membranes for Wastewater Treatment(Izmir Institute of Technology, 2017) Odabaşı, İklima; Çiftçioğlu, Muhsin; Çiftçioğlu, Muhsin; 03.02. Department of Chemical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyFresh water scarcity have been the most fundamental problem in the world and is already affecting mankind and human activities. This problem forced an increasing effort in the reuse of wastewater originating from municipal, agricultural, and industrial activities. The textile industry demands large amounts of water and produces large quantities of wastewater. Adsorption, filtration, ozonation and photocatalysis techniques are currently used for wastewater treatment and safe discharge to the environment. Although membrane filtration necessitates a high initial setup cost, it has a high potential and may cause significant cost savings through the reuse of water and salts. The membrane based technologies are widely accepted to be the best method when compared with the currently available technologies for wastewater treatment. Extruded tubular alumina supports were coated by stable colloidal sols and polymeric sols prepared by using sol-gel based techniques for the formation of selective micro/ultra/nanofiltration layers in this work. Textile wastewater treatment (with and without pre-treatment) and membrane fouling analysis was conducted. The performances of the membranes were determined through the characterization of permeates by spectrophotometer. The reduction of colors (Pt-Co, m-1), turbidity and suspended solids content were about 99%, 100% and 100%, respectively. The incorporation of a coagulation stage by using Al2(SO4)3 followed by a successive filtration reduced the membrane/irreversible fouling levels in the MF/UF membranes significantly. The Pt-Co 455 values of permeates were determined to be in the 15-260 range which are below the discharge criteria bringing the possibility of the reuse of some of these permeates.