Modelling of Adsorption Kinetic Processes—Errors, Theory and Application

Adsorption has become a competitive method in the field of wastewater and air treatment. Adsorption kinetics is one of the main factors that must be understood before the applicability of any adsorbent. In every adsorption process, linear or non-linear analysis of the kinetics is applied. The goodness of fit index (coefficient of correlation or sum of squares) is applied to access the best model. The usage of linear or non-linear from of the adsorption kinetics has an impact on the distribution of error function. Almost in every adsorption study, linear forms have been used to conclude the best kinetic model that influence the adsorption mechanism—which might be an error. Therefore, this review highlights the mistakes in the usage of linear and non-linear models. The applicability of the adsorption kinetics in wastewater treatment is also illuminated

Application Of Coagulation And Ozonation To Control Hazardous Wastes

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2002Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2002Çalışmanın öncelikli amacı, in-situ, on-site koşullar göz önünde bulundurularak , pestisit endüstrisinden kaynaklanan, zehirli etkiye sahip bir zararlı atık için uygun kontrol mekanizmasının saptanmasıdır. Söz konusu atık EPA zararlı atık listelerinde yer almaktadır. Bu atığa uygun bir yönetim mekanizması belirlemek amacıyla, kimyasal arıtma ve ozonlama prosesleri uygulanmıştır. Çalışma süresince, ozon hem atığın zehirlilik özelliğini giderebilmek hem de kimyasal arıtma üzerindeki etkilerini gözlemleyebilmek amacıyla uygulanmıştır. Çalışma süresince incelenen zararlı atık, sıvı formda, zehirli, tutuşabilir olduğu gibi suyla reaktif olabilme özelliğine de sahiptir. Atık, reaktörlerin yıkanması sonucu çıkan proses sıvıları ve çamaşırhane sularının birleşmesinden oluşmaktadır. Çalışma esnasında, farklı karakteristiklere sahip üç örnek üzerinde gözlemleme yapılmıştır. Bu gözlemleme için iki farklı deneysel akım şeması belirlenmiş ve her bir numune için uygulanarak en iyi verime hangi düzende ulaşılabildiği araştırılmıştır. Deneysel akımların ilkinde, sırasıyla kimyasal arıtma ve ozonlama işlemleri tatbik edilmiştir. Kimyasal arıtma esnasında kireç, alum ve FeCl3 koagülant olarak denenmiş ve pH ayarları NaOH ve H2SO4 ile yapılmıştır. Yeterli çökelmeyi sağlayabilmek amacıyla yardımcı kimyasal olarak non-iyonik polielektrolit kullanılmıştır. Deneysel çalışmalarda kullanılan ozon cihazının optimum çalıştığı oksijen akım hızı 5 lt/dak. dır. Cihaz ozon üretmeye çalıştırıldıktan 4 dakika sonra başlamakta ve üretilen ozon bir pompa vasıtası ile reaktör teflon boru sisteminde döndürülen atıksuya boru enjeksiyonu ile uygulanmaktadır. Ozonun detoksifikasyon özelliğini izleyebilmek amacıyla akut balık zehirlilik deneyi sürdürülmüştür. Çalışma esnasında, üzerinde araştırma yapılan numunenin zehirlilik özelliği sürdürülen standart balık zehirlilik deneyine göre değerlendirilmiştir. Böylece öldürücü konsantrasyon (LC50) ve zehirlilik seyrelme faktörü (TU(a)) değerleri saptanmıştır. LC50 değeri atıksuyun konsantrasyon yüzdesi biçiminde 17 olarak, TU(a) ise 6 olarak bulunmuştur.The main scope of the study is to determine an appropriate control system in order to reduce pollution potential of a hazardous waste generated by a pesticide industry. In order to achieve that goal, both chemical treatment and ozonation applied on this hazardous waste which has been listed in EPA hazardous waste lists. During the study, ozone has been applied for both detoxification and monitoring its impact on chemical treatment. The hazardous waste investigated during the study, is a liquid-formed toxic waste, which also has the properties of both flammability and reactivity with water. The waste is derived from the combination of both cleaning of the reactors that are used for formulation of liquid and powdered pesticides and laundry wastewater. In the study, three different characterized samples were monitored and two different experimental procedures were followed to monitor which system reached maximum removal efficiency. In the first experimental procedure, chemical treatment and ozone application processes have been performed to the samples, respectively. For chemical treatment lime, FeCl3 and alum are used as coagulants and NaOH and H2SO4 are used as helping agents. Non-ionic polyelectrolyte has also been used to achieve sufficient settling during jar tests. Ozone generator, used in the study, reaches the optimum operating efficiency by 5 lt/min oxygen flow rate. Ozone generation starts after 4-min delay time and the ozone was injected with a teflon pipe into the circulated wastewater in reactor. To monitor detoxification ability of O3, acute fish toxicity test has been run for both raw and treated wastewater. In the study, toxicity characteristic of hazardous waste derived from pesticide industry has been evaluated according to acute fish toxicity test. Screening and toxicity methodology is used to determine the lethal concentration (LC50) and toxicity unit (TU(a)). Using this method LC50 and TU(a) determined 17 as concentration percentage of the wastewater and 6, respectively.Yüksek LisansM.Sc

MICROELEMENTS IN THE LANDS OF THE AZERBAIJAN REPUBLIC

Microelements are necessary to support life. However, in larger or lower amounts, they may become more important and critical. They may be accumulated in biological systems and become a significant health hazard. The main scope of this study was to determine the amount of microelements in soil in order to evaluate the relation between microelement content of soil and its health effect in some regions in the Republic of Azerbaijan. Endemic health problems are widespread in the region. For instance, endemic goitre, a type of goitre that is associated with dietary iodine deficiency, has been seen frequently in some regions of the Azerbaijan and many researhers have been working on the relation between microelement content of soil and endemic goitre. During the study, six main regions were determined to collect soil samples and those sites were devided into sub-regions. Totally, 161 soil samples were collected and microelements such as cobalt(Co), copper(Cu), fluorine(F), manganese(Mn), molybdenum(Mo), zinc(Zn) and iodine(I) were measured and the results were compared with the samples where no endemic goitre were noticed. Measurements were also compared with the standards in order to evaluate the magnitude of the problem. Results revealed that the amount of microelements in the Republic of Azerbaijan soil samples varied in a large range even in the different parts of the same region. Especially, the amount of iodine in soil sample was measured low (average, 1.18-7.43 mg/kg) where endemic goitre was freguently seen. It is also revealed that not only the deficiency of iodine was a reason for endemic diseases but also other microelements take role in the existence of such problems in the Republic of Azerbaijan