Removal of phenolic compounds from aqueous solutions by using treated and untreated natural and synthetic adsorbents
Küçük Resim Yok
Tarih
2002
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
ÖZET FENOLİK BİLEŞİKLERİN MUAMELE GÖRMÜŞ VE GÖRMEMİŞ DOĞAL VE SENTETİK ADSORBENTLER VASITASIYLA SULU ÇÖZELTİLERDEN UZAKLAŞTIRILMASI YILMAZ, Meriç Yüksek Lisans Tezi, Kimya Mühendisliği Bölümü Tez Yöneticisi; Doç. Dr. Saadet YAPAR Temmuz 2002, 96 sayfa Düşük konsantrasyonlarda bile toksik etkiye sahip olan fenol, sudaki organik bileşikler arasında ana kirleticidir. Bu nedenle, fenollü bileşiklerle kirletilmiş olan seyrettik sular ve endüstriyel atıklar için etkili saflaştırma işlemlerine ihtiyaç duyulmaktadır. Fenollü bileşikleri yok etmek için uygun mevcut işlemler ya yüksek sıcaklık ve basınç ya da oldukça karmaşık ekipmanlar gerektirmektedir; veya oldukça dar bir derişim aralığıyla sınırlandırılmışlardır. Dolayısıyla, uygun olarak seçilen adsorbentlerle adsorpsiyon, fenollü bileşiklerle kirlenmiş sulu çözeltilerin saflaştırılması için tüm bu zor yöntemlere önemli bir alternatif sunmaktadır. Bu çalışmada, doğal zeolit klinoptilolit (işlem görmüş veVI görmemiş), doğal kil montmorillonit (işlem görmemiş) ve sentetik hidrotalsit, HT (işlem görmemiş, kalsine ve modifıye edilmiş), aynı amaç için araştırılmıştır. Sentetik işlem görmemiş HT ve doğal işlem görmemiş zeolitin, yüzeylerinin sahip olduğu hidrofîlik özellik nedeniyle fenolü adsorplamadığı gözlenmiştir. Hidrotalsitin SDS ile modifiye edilmiş şeklinin ıslanmamasından kaynaklanan soranlar çözülürse, bu malzemenin fenol adsorpsiyonu için uygun olacağı düşünülmektedir. HT' in kalsine şeklinin, ortamın pH değerinde (9) oluşan fenolat anyonlarının tabakalar arası bölgeye yerleşmesini sağlayan karbonat yokluğu sayesinde, fenol adsorpsiyonu için uygun olduğu bulunmuştur. CTAB ile modifiye edilmek suretiyle işlem görmüş doğal zeolitin de, CTAB varlığı ile yüzeyin kazandığı hidrofobluk özelliği sayesinde fenolü adsorpladığı görülmüştür. Doğal kilin, hidrojen bağı ve/veya yük transfer kompleksleri vasıtasıyla eksi yüklü yüzeyde adsorplanan fenolü uzaklaştırmada kullanışlı olduğu gözlenmiştir. Çalışılan adsorbentler arasında, adsorpsiyon kapasitesi en yüksek olduğundan sentetik kalsine hidrotalsitin en uygun olduğu görülmüştür. Fenolü adsorpladığı gözlenen adsorbentlerden doğal kil dışındakilerin adsorpsiyon davranışlarının hem Langmuir hem de Freundlich izotermleri ile modellenebileceği sonucuna varılmıştır. Anahtar kelimeler: Sıvı faz adsorpsiyon, Katyon değişim kapasitesi, Anyon değişim kapasitesi, Anyonik killer, Modifikasyon, Hidrotalsit tipi bileşikler, Bentonit, Moleküler elek
vn ABSTRACT REMOVAL OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTIONS BY USING TREATED AND UNTREATED NATURAL AND SYNTHETIC ADSORBENTS YİLMAZ, Meriç MSc in Chemical Engineering Supervisor: Assoc. Prof. Dr. Saadet YAPAR July 2002, 96 pages Among the organic compounds in water, the main pollutant is phenol which has multiple toxic health effects and resistance to biodegradation at even very low concentrations. There is thus a need for efficient purification processes suitable for effluents of industry and diluted polluted water. The presently available processes for destroying phenolics either require high temperature and pressure (incineration, wet oxidation, supercritical fluids), complex equipment (photo- and sono- chemical processes) or they are limited to a narrow range of concentration (bioremediation).vra Adsorption with the properly selected adsorbents serves as an important alternative to these methods for the purification of aqueous solutions contaminated with the phenolics. In this research, natural zeolite clinoptilolite (both treated and untreated), natural clay montmorillonite (untreated) and synthetic hydrotalcite, HT (untreated, calcinated and modified) were investigated for the same purpose. Synthetic untreated HT and natural untreated zeolite were found not to adsorb phenol because of the hydrophilic nature surfaces of these had. If the problems arisen from nonwetting of the treated form of HT modified with SDS is overcome, it is expected to be found useful. Calcinated form of HT was found to be suitable due to absence of carbonate anions in the interlayer region, leading to insertion of phenolate anions formed at occuring pH, 9 to the places previously occupied by carbonate. Natural treated zeolite modified with CTAB was also found to adsorb phenol because of the hydrophobicity surface gained in the presence of CTAB. Finally, natural untreated clay was also found to be useful, since phenol was adsorbed on negatively charged surface through hydrogen bonding and/or charge transfer complexes. Among mentioned adsorbents, synthetic calcinated HT was found to be most suitable since adsorption capacity of mentioned adsorbent was the greatest of all. It was also concluded that the adsorption behavior of all studied adsorbents found to adsorb phenol except natural untreated clay, fitted both Langmuir and Freundlich Type Isotherms. Key words: Liquid phase adsorption, CEC, AEC, Anionic clays, Modification, Intercalation, LDH, HTlcs, Bentonite, Molecular sieve.
vn ABSTRACT REMOVAL OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTIONS BY USING TREATED AND UNTREATED NATURAL AND SYNTHETIC ADSORBENTS YİLMAZ, Meriç MSc in Chemical Engineering Supervisor: Assoc. Prof. Dr. Saadet YAPAR July 2002, 96 pages Among the organic compounds in water, the main pollutant is phenol which has multiple toxic health effects and resistance to biodegradation at even very low concentrations. There is thus a need for efficient purification processes suitable for effluents of industry and diluted polluted water. The presently available processes for destroying phenolics either require high temperature and pressure (incineration, wet oxidation, supercritical fluids), complex equipment (photo- and sono- chemical processes) or they are limited to a narrow range of concentration (bioremediation).vra Adsorption with the properly selected adsorbents serves as an important alternative to these methods for the purification of aqueous solutions contaminated with the phenolics. In this research, natural zeolite clinoptilolite (both treated and untreated), natural clay montmorillonite (untreated) and synthetic hydrotalcite, HT (untreated, calcinated and modified) were investigated for the same purpose. Synthetic untreated HT and natural untreated zeolite were found not to adsorb phenol because of the hydrophilic nature surfaces of these had. If the problems arisen from nonwetting of the treated form of HT modified with SDS is overcome, it is expected to be found useful. Calcinated form of HT was found to be suitable due to absence of carbonate anions in the interlayer region, leading to insertion of phenolate anions formed at occuring pH, 9 to the places previously occupied by carbonate. Natural treated zeolite modified with CTAB was also found to adsorb phenol because of the hydrophobicity surface gained in the presence of CTAB. Finally, natural untreated clay was also found to be useful, since phenol was adsorbed on negatively charged surface through hydrogen bonding and/or charge transfer complexes. Among mentioned adsorbents, synthetic calcinated HT was found to be most suitable since adsorption capacity of mentioned adsorbent was the greatest of all. It was also concluded that the adsorption behavior of all studied adsorbents found to adsorb phenol except natural untreated clay, fitted both Langmuir and Freundlich Type Isotherms. Key words: Liquid phase adsorption, CEC, AEC, Anionic clays, Modification, Intercalation, LDH, HTlcs, Bentonite, Molecular sieve.
Açıklama
Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.
Anahtar Kelimeler
Kimya Mühendisliği, Chemical Engineering, Adsorbentler, Adsorbents, Adsorpsiyon, Adsorption, Fenolik bileşikler, Phenolic compounds, Katyon değişimi, Cation exchange, Modifikasyon, Modification, Saflaştırma, Purification
