Thesis (Ph. D.)--Lehigh University, 2003. / Includes vita. Includes bibliographical references (leaves 164-170).

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Membrane bioreactors (MBRs) show great promise for productivity improvement and energy conservation in conventional bioprocesses for wastewater reclamation. In order to attain high productivity in a bioprocess, it is crucial to retain the microorganisms in the bioreactors by preventing wash out. This enables recycling of the microorganisms, and is consequently saving energy. The main feature of MBRs is their permeable membranes, acting as a limitative interface between the medium and the microorganisms. Permeation of nutrients and metabolites through the membranes is thus dependent on the membrane characteristics, i.e. porosity, hydrophilicity,and polarity. The present thesis introduces membranes for MBRs to be used in a continuous feeding process, designed in the form of robust, durable, and semi-hydrophilic films that constitute an effective barrier for the microorganisms, while permitting passage of nutrients and metabolites. Polyamide 46 (polytetramethylene adipamide), a robust synthetic polymer, holds the desired capabilities, with the exception of porosity and hydrophilicity. In order to achieve adequate porosity and hydrophilicity, bulk functionalization of polyamide 46 with different reagents was performed. These procedures changed the configuration from dense planar to spherical, resulting in increased porosity. Hydroxyethylation of the changed membranes increased the surface tension from 11.2 to 44.6 mJ/m2. The enhanced hydrophilicity of PA 46 resulted in high productivity of biogas formation in a compact MBR, due to diminished biofouling. Copolymerization of hydrophilized polyamide 46 with hydroxymethyl 3,4-ethylenedioxythiophene revealed electroconductivity and hydrophilic properties, adequate for use in MBRs. To find either the maximal pH stability or the surface charge of the membranes having undergone carboxymethylation, polarity and the isoelectric point (pI) of the treated membranes were studied by means of a Zeta analyzer. The hydroxylated PA 46 was finally employed in a multilayer membrane bioreactor and compared with hydrophobic polyamide and PVDF membranes. The resulting biogas production showed that the hydroxylated PA 46 membrane was, after 18 days without regeneration, fully comparable with PVDF membranes.

ABSTRACT In this paper we describe the use of electrospray-assisted pyrolysis ionization/mass spectrometry (ESA-Py/MS) to selectively ionize trace polar compounds that coexist with large amounts of nonpolar hydrocarbons in synthetic polymer, crude oil, amber, humic substances, and rubber. Samples of different origins are distinguished rapidly by their ESA-Py mass spectra without prior separation or chemical pretreatment. During ESA-Py analysis, the samples in their solid or liquid states were pyrolyzed at 590 ¢XC using a commercial Curie-point pyrolytical probe; the gaseous pyrolysates were transferred into a glass reaction cell; the polar compounds (M) in the pyrolysates were then ionized in the form of protonated molecules (MH+), through their reactions with the charged species in the ESI plum. Although the major components of the pyrolysates are nonpolar hydrocarbons, their lack of functional groups that can receive a proton in the ESA-Py source results in no hydrocarbon ion signals being produced; thus, the ions detected in ESA-Py mass spectra all result from trace polar component in the pyrolysates.

Laboratory directed evolution have enabled the discovery of numerous functional natural and synthetic macromolecules with tailor-made functions. However, approaches that use enzymes to effect the crucial translation from an information carrier molecule such as DNA or RNA to synthetic polymers are limited to producing close analogs of nucleic acids, either due to a strict requirement to hybridize with a nucleic acid template or as a consequence of the limited substrate scope of polymerase enzymes. / Chemistry and Chemical Biology

Orientador: Ricardo de Lima Isaac / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil / Made available in DSpace on 2018-08-05T08:38:56Z (GMT). No. of bitstreams: 1 SilvaJunior_ArchimedesPereirada_M.pdf: 2766426 bytes, checksum: c4a329b55233959c0c769a4fd9c68911 (MD5) Previous issue date: 2003 / Resumo: Os principais resíduos de ETAs são os Iodos gerados nos decantadores, a água de lavagem dos filtros e o rejeito de limpeza dos tanques de produtos químicos. Os lodos mesmo classificados como resíduos sólidos, apresentam baixíssimo teor de sólidos. Sendo o custo do transporte e disposição final bastante elevado, a redução do volume constitui-se em alternativa, economicamente, viável. Os principais processos utilizados para redução de volume do Iodo são o adensamento, o condicionamento químico e a desaguamento. A pesquisa teve por objetivo comparar a tratabilidade do Iodo do decantador do tipo convencional e do decantador de alta taxa, da SANASA, na cidade de Campinas. Foi verificada a influência dos parâmetros que caracterizam a qualidade do Iodo, no seu desaguamento; o efeito do adensamento do Iodo por gravidade, com auxílio de polímeros e o efeito do condicionamento químico com polímeros no desaguamento, por centrifuga. O lodo bruto foi pré-condicionado com polímeros sintéticos, e também se investigou a eficiência destes no condicionamento do lodo já adensado, para sua centrifugação. O adensamento mostrou que o polímero aniônico foi o melhor para ambas as ETAs. A dosagem ótima foi a mesma para ambas as épocas, para as duas ETAs, sendo de 1mg/g para ETA-3 e 3g/Kg para ETA-4. O tempo de mistura, para ETA-3, foi maior na época seca (45s) do que no período de chuvas (30s). Para ETA-4 o tempo de mistura foi o mesmo (60s) para as duas épocas. O lodo adensado foi condicionado com polímero e submetido à centrifugação. Desta, concluiu-se que, para o período de chuvas e para os dois tipos de lodo a condição ótima foi: polímero catiônico, 1g/Kg, 5s de mistura e 200rpm de rotação. Na época de estiagem e lodo da ETA-3 a condição ótima foi dada por: polímero catiônico, 1g/Kg, 60s de mistura e 200rpm de rotação. No caso da ETA-4, a condição é dada por: polímero catiônico, 2,5g/Kg, 60 s de mistura e 100 rpm / Abstract: The main residues of WTPs are sludge from thickener, filter backwash waters and solids from basins of chemicals products. The sludge even labeled as solid residues present very low solids content. Like the costs of transportation and ultimate disposal are very high, to reduce the sludge volume is an economical feasible alternative. The principal methods used to reduce the sludge volume are thickening, chemical conditioning and dewatering. The aim of this research was to compare the handling of both sludge from the conventional and high-rate thickener. It was checked the influence of the parameters that give particular characteristics to the sludge in its dewatering; the gravity thickening with polymers aid and the influence of the polymers in the sludge dewatering with centrifuge. The raw sludge was conditioned with synthetics polymers. Also was checked whether that polymers were efficient in the thickened sludge conditioning aiming its centrifugation. The best polymer to the gravity thickening for both sludge (WTPs 3 and 4) was the anionic polymer. The same polymer dose was required for the both seasons studied (wet and dry) and for the two WTPs. It was 1mg/g to the WTP-3 and it was 3g/Kg to the WTP-4. The mixing time for the WTP-3 was greater in the dry season (45s) than the wet season (30s) and the mixing time was the same (60s) in both seasons for the WTP-4. The thickened sludge was conditioned with organic synthetic polymer and subjected to centrifugation. After this, was concluded that in the wet season and for the two kinds of sludge the optimum condition s given to: cationic polymer, 1g/Kg of polymer dose, mixing time of 5s and 200 rpm of centrifuge rotation. In the dry season and residues from WTP-3 the optimum condition is given to: cationic polymer, 1g/Kg of polymer dose, mixing time of 60s and 200 rpm of centrifuge rotation. For residues from WTP-4 the optimum condition is given to: cationic polymer, 2,5g/Kg of polymer dose, mixing time of 60s and 100 rpm of centrifuge rotation / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

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