Investigation of the Efficiency of Mwcnt-Mn3o4 Fe3o4 Ceo2 Catalyst in the Treatment of Meat Processing Plant Wastewater With Heterogeneous Electro Fenton Process
Abstract
Bu tezde, et işleme endüstrilerinde ortaya çıkan atıksulardan Heterojen Elektro Fenton (HEF) prosesi ile KOİ giderimi amaçlanmıştır. MWCNT-Mn3O4/Fe3O4/CeO2 HEF katalizörü olarak kullanılmıştır. Katalizör XRD, FT-IR, XPS, Zeta potansiyeli ve DLS, BET, SEM/EDX ve TEM analizleri ile karakterize edilmiştir. Katalizörün ortalama partikül boyutu 4.5 nm, zeta potansiyeli ise -22.84 mV olarak belirlenmiştir. Nanopartiküllerin MWCNT yüzeyine homojen dekore edildiği ancak kısmi agglomerasyonların olduğu tespit edilmiştir. FTIR ve XPS analizleri ile katalizörün kimyasal bağ yapıları ve metal oksit nanopartiküllerin valans elektron durumları doğrulanmıştır. Katalizörün BET yüzey alanı 52.80 m²/g olarak, gözenek hacmi ise 0.103653 cm³/g olarak belirlenmiştir. Proses koşullarının numerik optimizasyonu Cevap Yüzey Yöntemi (CYY) yöntemi ile sağlanarak model uygunluğu araştırılmıştır. Kuadratik modelin regresyon katsayısı (R2) 0.9894 olarak bulunmuştur. Deneysel olarak elde edilen veriler ile tahmini değerler yakın bulunmuştur. Modelin güvenilir ve anlamlı olduğu sonucuna varılmıştır (p<0.0001). Numerik olarak optimize edilmiş şartlar; pH 4.3, akım şiddeti 7.6 A, reaksiyon süresi 83 dakika ve katalizör dozu 0.56 g/L olarak belirlenmiştir. Optimum şartlar altında KOİ giderim verimi %92 olarak tespit edilmiştir. 1 Kg KOİ'nin uzaklaştırılması için gereken enerji miktarı 54.96 kW-saat olup enerji maliyeti 8.68 $ olarak bulunmuştur. Katalizör etkinliğini araştıran çalışmalarda, Adsorpsiyon, Anodik Oksidasyon (AO) ve AO-H2O2 KOİ giderme performansını sırasıyla %25, %68 ve %78 olarak göstermiştir. Katalizörün tekrar kullanılabilirlik denemelerinde 6 döngü boyunca yüksek KOİ giderim performansı sergilediği ve metal salınımının düşük olduğu görülmüştür. Altı döngü boyunca sırasıyla KOİ giderimi (%) 92, 88, 85, 82, 77 ve %74 olarak hesaplanmış ve altıncı döngü sonunda çalışma sonlandırılmıştır. Süpürücü ajan deneyleri optimum şartlar altında gerçekleştirilmiş olup, oksidasyondan sorumlu en etkili radikalin ⦁OH olduğu belirlenmiştir. Dönüşümlü voltametri (CV) tekniği kullanılarak, katalizörün stabilitesinin iyi olduğu ortaya konulmuştur.
In this thesis, it is purposed to remove COD from wastewater generated in meat processing industries with the Heterogeneous Electro Fenton process. MWCNT-Mn3O4/Fe3O4/CeO2 was used as Heterogeneous Electro Fenton catalyst. The catalyst was analyzed by XRD, FT-IR, XPS, Zeta potential and DLS, BET, SEM/EDX and TEM methods. The average particle size of the catalyst was determined as 4.5 nm and the zeta potential was determined as -22.84 mV. It was determined that the nanoparticles were decorated homogeneously on the MWCNT surface, but there were partial agglomerations. The chemical bond structures of the catalyst and valence electron states of the metal oxide nanoparticles were confirmed by FTIR and XPS analyses. The BET surface area of the catalyst was determined as 52.80 m²/g and the pore volume was determined as 0.103653 cm³/g. Numerical optimization of process conditions was achieved using the Response Surface Method (RSM) and model suitability was investigated. Regression coefficient (R2) of the quadratic model was found to be 0.9894. Actual values and predicted values were found to be close. It was concluded that the established model was reliable and meaningful (p<0.0001). Numerically optimized conditions were determined as pH 4.3, applied current 7.6 A, reaction time 83 min, and catalyst dosage 0.56 mg/L. Under optimum conditions, COD removal was found to be 92%. The energy consumption to remove 1 Kg of COD was 54.96 kW-h and the cost was found to be 8.68 $. In the studies that investigated of the catalyst effectiveness, the processes of Adsorption, Anodic Oxidation (AO) and AO-H2O2 showed the performance of COD removal as 25%, 68% and 78%, respectively. In the reusability experiments of the catalyst, it was observed that it exhibited high COD removal performance for 6 cycles and metal release was low. During six cycles, COD removal (%) was determined as 92, 88, 85, 82, 77 and 74, respectively and the experiment terminated at the end of the sixth cycle. Scavenging agent experiments were actualized under optimum conditions and ⦁OH was found to be the most effective responsible radical for oxidation. Good stability of the catalyst was determined using cyclic voltammetry technique (CV).
In this thesis, it is purposed to remove COD from wastewater generated in meat processing industries with the Heterogeneous Electro Fenton process. MWCNT-Mn3O4/Fe3O4/CeO2 was used as Heterogeneous Electro Fenton catalyst. The catalyst was analyzed by XRD, FT-IR, XPS, Zeta potential and DLS, BET, SEM/EDX and TEM methods. The average particle size of the catalyst was determined as 4.5 nm and the zeta potential was determined as -22.84 mV. It was determined that the nanoparticles were decorated homogeneously on the MWCNT surface, but there were partial agglomerations. The chemical bond structures of the catalyst and valence electron states of the metal oxide nanoparticles were confirmed by FTIR and XPS analyses. The BET surface area of the catalyst was determined as 52.80 m²/g and the pore volume was determined as 0.103653 cm³/g. Numerical optimization of process conditions was achieved using the Response Surface Method (RSM) and model suitability was investigated. Regression coefficient (R2) of the quadratic model was found to be 0.9894. Actual values and predicted values were found to be close. It was concluded that the established model was reliable and meaningful (p<0.0001). Numerically optimized conditions were determined as pH 4.3, applied current 7.6 A, reaction time 83 min, and catalyst dosage 0.56 mg/L. Under optimum conditions, COD removal was found to be 92%. The energy consumption to remove 1 Kg of COD was 54.96 kW-h and the cost was found to be 8.68 $. In the studies that investigated of the catalyst effectiveness, the processes of Adsorption, Anodic Oxidation (AO) and AO-H2O2 showed the performance of COD removal as 25%, 68% and 78%, respectively. In the reusability experiments of the catalyst, it was observed that it exhibited high COD removal performance for 6 cycles and metal release was low. During six cycles, COD removal (%) was determined as 92, 88, 85, 82, 77 and 74, respectively and the experiment terminated at the end of the sixth cycle. Scavenging agent experiments were actualized under optimum conditions and ⦁OH was found to be the most effective responsible radical for oxidation. Good stability of the catalyst was determined using cyclic voltammetry technique (CV).
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Çevre Mühendisliği, Environmental Engineering
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