<p>In this thesis, size-exclusion chromatography (SEC) of woodpolymers dissolved in lithium chloride/N,N-dimethylacetamide(LiCl/DMAc) has been used to characterize the molar massdistributions (MMD) of wood polymers in pulp fibers afterchemical degradation.</p><p>Characterization of birch kraft pulps subjected to ozonedegradation and acid hydrolysis, respectively, rendereddifferent changes in the MMD. Ozone degradation resulted inlarge redistributions of the original MMD, observed as thedevelopment of a distinct fraction of cellulose withintermediate molar mass. Acid hydrolysis resulted in minorchanges of the original MMD compared to ozonation. Fiberssubjected to acid hydrolysis were considerably weaker thanozonated fibers. These results indicated that there aredifferences in how the two chemicals degrade the fiber.</p><p>The solubility of softwood kraft pulp fibers was enhanced byderivatization of the fiber polymers with ethyl-isocyanateduring simultaneous dissolution in LiCl/DMAc. Thederivatization made it possible to achieve reliable estimationsof the MMD, and hence molar masses, of softwood kraft pulps.The derivatization procedure made it possible to dissolve 90 %of softwood kraft pulps with kappa numbers over 50.</p><p>Severe alkaline degradation of birch and Norway spruce woodchips was studied both by varying the pulping time and byvarying the initial alkali concentration. Differences werefound in the MMD of the two fiber types, and the alkalinedegradation was found to affect polymers in the entire MMD.</p><p>Multi-angular laser light scattering (MALLS) was used as adetection technique with SEC on cellulosic samples. The MMD andaverage molar masses obtained through directstandardcalibration with commercial standards were compared with MMDand molar masses as obtained by MALLS-detection. Largediscrepancies were found, and two methods of correcting forthese discrepancies were developed.</p><p>Theoretical simulations of polymer degradation wereperformed. Random, or homogeneous degradation was used as amodel for alkaline cellulose chain scission, and a resemblancewith experimental data was observed. End-wise depolymerizationof cellulose was also simulated and the results are discussedin the light of experimentally observed MMD.</p><p><b>Keywords:</b>cellulose, kraft pulp, birch, spruce,ozonation, acid hydrolysis, degradation, MMD, sizeexclusionchromatography, light scattering, molar mass, chainscission</p>

The potential human health issues resulting from the continuous consumption of drinking water containing low concentration levels of persistent emerging pollutants has raised some concerns. The presence of emerging pollutants in surface water bodies and ground-water in Canada together with absence of proper drinking water treatment processes in remote places has created the need for an effective and simple process for removal of emerging pollutants from drinking water. Low seasonal temperatures in regions such as Saskatchewan demand a removal process that is effective at temperatures lower than room temperature. Adsorption with granular activated carbon is a well-established and effective method for removal of organic compounds from drinking water. There are a large number of reports on removal of organic compounds by activated carbon in literature however, the effectiveness of adsorption of emerging pollutants with granular activated carbon is not clear. Effectiveness of ozone treatment for oxidation of emerging pollutants is reported in literature however, effectiveness of regeneration of adsorbents saturated with emerging pollutants with ozone has not been investigated extensively. In the present work, effectiveness of adsorption with granular activated carbon for removal of emerging pollutants is investigated. Three model compounds of Ibuprofen, 2,4-dichlorophenoxyacetic acid, and Bisphenol A reported at considerable concentration levels in Saskatchewan water bodies were selected as model compounds. Bituminous coal based and coconut shell based granular activated carbons with basic point of zero charge were selected as adsorbents. Isotherm adsorption of model compounds on adsorbents was conducted at 280, 288, and 296 K. The Gibbs free energy, enthalpy, and entropy of adsorption were calculated using isotherm model parameters. Nitric acid pre-treatment was applied to reduce the point of zero charge of adsorbents. Adsorption isotherms were conducted with the acid treated adsorbents. Adsorption removal of model compounds in tap water was studied. Effectiveness of regeneration of saturated adsorbents with ozone was investigated. In terms of quality of fit to the isotherm adsorption data, Langmuir model was better than Freundlich model indicating monolayer adsorption of model compounds in all experiments. Higher Langmuir monolayer adsorption capacity (Qmax) of bituminous coal based adsorbent than coconut shell adsorbent for adsorption of model compounds was attributed to the higher porosity of bituminous coal based adsorbent. Adsorption of model compounds (i.e. IBP and BPA) present in molecular form in the pH condition of the experiments were more dependent on adsorbent surface functional groups e.g. carboxyl and carbonyl groups. The Qmax of adsorption of 2,4-D present in anionic form was proportional with the specific surface area of adsorbent. Adsorption at temperatures lower than room temperature was effective. Adsorbent with acidic point of zero charge was more effective in removal of model compounds than adsorbent with basic point of zero charge. Adsorption of BPA was higher in tap water in comparison to Millipore water due to the more neutral surface of adsorbent in tap water. Higher pH of tap water than Millipore water and the ionic interaction between the adsorbent and dissolved solids present in tap water caused the more neutral surface of adsorbent. Regeneration of adsorbents with ozone failed in restoration of adsorption capacity of adsorbents and excessive ozonation destroyed the pore structure of adsorbents.

Orientador: Marco Aurélio Cremasco / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-20T13:54:46Z (GMT). No. of bitstreams: 1 Pacheco_JoseRicardo_M.pdf: 2421854 bytes, checksum: 0892102a47f0322520b05c0bad2a79d9 (MD5) Previous issue date: 2012 / Resumo: A gestão dos recursos hídricos, englobando uso de água para fins potáveis e processos industriais, tornou-se de vital importância e ganhou visibilidade na última década do século vinte. Dentre as tecnologias e processos de tratamento de água potável e residuária destaca-se a ozonização. Diante deste contexto a presente dissertação de mestrado visou construir e avaliar um sistema de ozonização baseado em coluna de borbulhamento. Foi construída uma célula de geração de ozônio para se estudar a eficiência de geração, com três gases de alimentação: ar úmido; ar seco e oxigênio. O ar úmido foi captado diretamente da atmosfera, o ar seco e oxigênio foram fornecidos através de um secador de ar e um concentrador de oxigênio respectivamente. O processo de fornecimento de ar seco e oxigênio foi o de "PSA" (pressure swing adsorption) no qual o ar atmosférico passou por uma coluna recheada com zeólita capaz de reter a umidade e moléculas de nitrogênio. A célula geradora de ozônio teve então as condições de descarga elétrica fixas e os três gases de alimentação foram passados pela mesma. A eficiência de geração de ozônio foi então comparada entre os três gases de alimentação. Os valores obtidos apresentaram consistência em relação aos valores de outros autores. Para avaliação da ozonização em fase líquida foi construída uma coluna de borbulhamento onde o ozônio foi borbulhado na parte inferior da coluna usando-se água destilada. Foram realizados experimentos: a) com recirculação da água da parte inferior da coluna até o topo; b) sentido contra-corrente água/gás; c) sentido co-corrente água/gás...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The management of water resources embracing the use of water for potable and industrial processes, has become of vital importance and has gained visibility in the last decade of the twentieth century. Among the technologies and processes for treatment of drinking water and wastewater, ozonation plays an important role. Considering this context the dissertation work aimed to construct and evaluate a system based on bubble column ozonation. An ozone generation cell was built to study the generation yield with three feed gases: humid air; dry air and oxygen. The humid air was captured directly from the atmosphere, dry air and oxygen were supplied by an air dryer and one oxygen concentrator respectively. The feed gas preparation process to supply dry air and oxygen is called "pressure swing adsorption", which the atmospheric air is passed through a column filled with a zeolite compound which retains moisture and nitrogen molecules. Ozone generation cell discharge electrical conditions were fixed, after the three feed gases were passed through the cell. Then ozone generation efficiency was measured and compared between the three feed gases. The values obtained were consistent with those obtained by other authors. To evaluate ozonation in the liquid phase a bubble column was constructed, where gaseous ozone was bubbled into the column bottom. Distilled water was chosen as the liquid medium. Experiments were carried out in the following conditions: a) recirculating water from the bottom to the top of the column; b) countercurrent flow directions between gas/liquid; c) concurrent flow directions between gas/liquid...Note: The complete abstract is available with the full electronic document / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16387号 / 工博第3468号 / 新制||工||1524(附属図書館) / 29018 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 清水 芳久, 教授 伊藤 禎彦 / 学位規則第4条第1項該当

The purpose of this Bachelor thesis was to establish a method for determining the chemical oxygen demand (COD) fractionation in wastewater from cruise liners. COD fractions of interest were soluble biodegradable (SS), particulate biodegradable (XS), soluble unbiodegradable (SI) and particulate unbiodegradable (XI). Three types of wastewater (gray water, black water and permeate) were analysed and a method with a physiochemical approach was established. The method was originally elaborated by Jun Wu et al in the study “Wastewater COD biodegradability fractionated by simple physical–chemical analysis” (2014) Chemical Engineering Journal[ES1] [JB2]  258, p 450-459. The method was also used for comparison reasons of the COD fractionation in permeate before and after advanced treatment with nanofiltration and ozonation. Total COD in permeate was almost half of the initial value after nanofiltration and XI was eliminated. After ozonation no significant difference was observed neither in total COD concentration or fractionation pattern. The conclusion is that this method to determine the COD fractions has potential but it needs further optimization in form of adjusting the methods matrix specifically based on wastewater from cruise liners. / NAUTEK

Diplomová práce je zaměřena na studium degradace kontrastních látek pro magnetickou rezonanci. Tyto látky se dnes ve velké míře používají v oblastech s rozvinutým zdravotnictvím. Můžeme je najít v odtocích z čistíren odpadních vod, což svědčí o tom, že běžné stupně čištění odpadních vod nejsou dostatečně efektivní pro jejich odstranění. O degradaci kontrastních látek na bázi gadolinia je jen málo informací. Fotokatalytický rozklad za pomoci oxidu titaničitého a také ozonace vybrané kontrastní látky gadobutrolu, byl sledován pomocí měření celkového organického uhlíku, mikroskopie termálních čoček a spektrofotometrie.

Due to eutrophication of aquatic environment, massive growth of algae and cyanobacteria occurs and the seasonal algal bloom is formed. Drinking water treatment plants have to deal with the increased amount of cells as well as organic compounds produced by algae and cyanobacteria (so-called AOM). Moreover, the presence of AOM causes a reduction in the efficiency of coagulation, which is an essential process in drinking water treatment. To increase coagulation efficiency, supportive methods, such as ozone oxidation, are added usually prior to coagulation. While many studies focused on the ozonation of algal and cyanobacterial cells, little is known about the effect of ozonation on AOM. This diploma thesis focused on the evaluation of the effect of ozonation in combination with coagulation on the removal of cellular organic compounds (COM) produced by cyanobacteria Microcystis aeruginosa. The effect of ozonation before or after coagulation on COM removal was investigated. The degradation of microcystins, which are naturally contained in the COM sample, was also monitored. Various ozone doses (1 - 10 mg/L) were tested at three pH values - 5, 7 and 9. Two coagulants were utilized - aluminium sulphate and ferric sulphate. Ozonation removed COM negligibly. However, eliminated microcystins, the degradation...

This research work discusses the removal of organic pollutants specifically diclofenac and acid blue-25 using chalcogenide semiconductors. Semiconductors are materials that absorb light of specific energy and potentially degrade these organic pollutants into smaller compounds that are not toxic such as carbon dioxide and water. / Civil and Chemical Engineering

Antibiotics are substances that inhibit the growth of microorganisms and are widely used in modern medicine. High consumption of antibiotics correlates with their elevated occurence in sewage systems, from where they are further released into the environment. The threat of their occurrence in the environment is in triggering the formation and spread of antibiotic resistance. This thesis focuses on the removal of selected antibiotics and partly on the antibiotic resistance from wastewater by advanced oxidation processes (AOPs). AOPs are based on the creation of highly reactive hydroxyl radicals, which are able to oxidize even highly persistent substances. The thesis focuses on the purification of effluents from municipal wastewater treatment plants (WWTP), which are identified as the main source of pharmaceutical pollution in the environment, by AOPs mainly based on ozonation. These processes were tested under laboratory conditions on model water as well as under real conditions as the tertiary stage of the treatment at Brno-Modřice WWTP under various operating states. As the results of the performed experiments show, it could be concluded that the studied AOPs are capable of effective degradation of studied antibiotics from the treated medium. Under real conditions, the antibiotics sulfamethoxazole, trimethoprim, azithromycin and clarithromycin were monitored. Output concentrations in each operational state were achieved to be below the limit of detection for all four antibiotics. The application of AOPs based on ozonation as the tertiary step of the treatment also had a positive effect on the reduction of microbial contamination and antibiotic resistance. Within the pilot plant experiments, a reduction of up to 4 orders of magnitude of E.coli, coliform microorganisms and a reduction of their resistant strains in the range of 1.4 - 4.0 logs were observed, compared to the effluent from the WWTP.

Diploma thesis will be dealt with the utilization of ozone wastewater treatment. Experimental part will be focused on study of ozone utilization in two different reactors (bubble column, jet loop reactor). Reactors will be compared by overall mass transfer coefficient and saturation concentration. Ozonization will be applied because of biological resistent and toxic compound 2-mercaptobenzothiazole disposal. Changes of biological decomposition will be measured and assessed by respirometric measurements.