Search

This study was conducted to investigate the effect of initial pH, current density, and electrolysis time on process performance in terms of decolorization and chemical oxygen demand (COD) removal from disperse dyebath wastewater (DDW) by mono-polar parallel laboratory scale electrocoagulation (EC) process. COD reduction of 51.3% and decolorization of 92.8% were obtained with operating cost of 0.19 €/m treated wastewater for Al-Al electrode pair, while 90.5% of decol-orization and 49.2% of COD reduction were obtained with operating cost of 0.203 €/m treated wastewater for an Fe-Fe electrode pair. The amount of sludge production were highly related to type of the electrode materials. At the3 optimum conditions, the amount of sludge produced were 0.18 kg/m and 0.28 kg/m for Al-Al and Fe-Fe electrode pairs, respec-tively. High decolorization can be explained by the hydrophobic nature of the disperse dye, while limited COD removal3 3 was observed due to the high dissolved organic matter of the DDW based on auxiliary chemicals. Energy, electrode, and chemical consumptions and sludge handling were considered as major cost items to find a cost-effective and sustainable solution for EC. The contribution of each cost items on operating cost were determined as 10.0%, 51.1%, 30.5% and 8.4% for Al-Al, and they were also determined as 9.0%, 38.0%, 40.5% and 12.5% for Fe-Fe, respectively. COD reduction and decolorization were fitted to first-order kinetic rule.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013, Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2013, Bu çalışma kapsamında, yerel bir tekstil endüstrisinin üretim proseslerinde kullanılan yardımcı kimyasalları içeren ayrık atık su akımlarının, biyolojik ayrışabilirlik ve toksisitesi incelenmiştir. Bu bağlamda, öncelikle laboratuvar ortamında sentetik olarak iki farklı non-iyonik yüzey aktif madde ile hazırlanmış tekstil banyosu deşarj sularının toksisiteleri Vibrio fischeri üzerinde araştırılmıştır. Numuneler, reaksiyon koşullarını optimize edebilmek amaçlı bazik, nötral ve asidik olmak üzere farklı pH değerlerinde hazırlanmış ve her biri için ayrı toksisite deneyi yapılmıştır. Toksisite deneyi sonuçlarına göre, toksik ve/veya biyolojik olarak dirençli organik kirleticilerin gideriminde önemli bir alternatif oluşturan ileri oksidasyon proseslerinden UV-C prosesi seçilerek, her bir ham numuneye uygulanmıştır. Reaktörden belirli zaman aralıklarında alınan çıkış numunelerine de toksisite deneyi yapılarak, UV-C prosesinin toksisite üzerindeki etkileri saptanmıştır. Hazırlanan ham sentetik atık suların ve UV-C reaktöründen belirli zaman aralıklarında alınan numunelerin toplam organik karbon (TOK) içerikleri ve hidrojen peroksit (H2O2) düzeyleri tayin edilmiştir. Numunelerin karakterizasyonu yapılırken, inert KOİ için, daha önce yapılmış çalışmaların verileri kullanılmıştır. Kirliliği kaynakta önlemek amacı ile tekstil üretim proseslerinde kullanılan yardımcı kimyasalların olumsuz etkilerini, onları taşıyan ayrık atık su akımlarına uygulanabilecek arıtma prosesleri ile azaltılabileceği ortaya konmuştur., Within the scope of this study, the biodegradability and toxicity of segregated effluents containing auxiliary chemicals used in the production processes of a local textile industry were investigated. In this context, first of all the toxicity of textile bath discharges prepared synthetically in laboratory with two different non-ionic surfactants were investigated on Vibrio fischeri. The samples were prepared with different pH values as alkaline, neutral and acidic to be able to optimize the reaction conditions and toxicity tests were performed to sample groups for each condition. Depending on the results of toxicity analyses, UV-C process, which is one of the further oxidation processes constituting an important alternative for removal of persistent toxic and/or organic pollutants, was selected and applied to each raw sample. Toxicity analyses were also performed in output samples taken from the reactor in certain time intervals to determine the effects of UV-C process on toxicity. Total organic carbon (TOC) content and hydrogen peroxide (H2O2) levels were determined in the samples taken from prepared raw synthetic wastewaters and UV-C reactor in certain time intervals. The data obtained from previous studies were used for inert COD during the characterization of the samples. It was concluded that, for preventing the pollution in source, the negative impacts of auxiliary chemicals used in textile production processes could be reduced by treatment processes applied on the segregated effluents carrying the chemicals., Yüksek Lisans, M.Sc.