Objetivo: determinar a viabilidade da identificação do linfonodo-sentinela em pacientes com câncer invasor de colo uterino estádio Ib1. Material e Métodos: 16 pacientes consecutivas com câncer de colo uterino agendadas para histerectomia radical com linfadenectomia pélvica bilateral realizaram estudo para detecção de linfonodo-sentinela. Onze pacientes injetaram 1 mCi de tecnécio 99 (99Tc) em quatro pontos do estroma superficial do colo uterino ao redor do tumor, às 12, 3, 6 e 9 h ( 16 horas antes da cirurgia ). No dia da cirurgia, as pacientes foram submetidas ao mapeamento linfático com gamma-probe e azul patente injetado nos mesmos pontos que o 99Tc.Cinco pacientes realizaram a detecção apenas com azul patente. Resultados: foi detectado pelo menos um (1 a 3 por paciente) linfonodo-sentinela em cada uma das 15 pacientes (93,7 %) que realizaram a técnica combinada.Foi detectado pelo menos 1 linfonodo-sentinela em 4 pacientes ( 80% )com azul patente apenas. A maioria dos linfonodos-sentinela foi localizada nas regiões: obturadora (37 %), ilíaca externa (22,2 %) e inter-ilíacas (18,5 %). Seis pacientes (40 %) tiveram linfonodos-sentinela bilaterais. Dos 27 linfonodos-sentinela detectados, 11 (40,7 %) foram detectados pelo corante, 9 (33,3%) pela radioatividade e 7 (26 %) pela radioatividade e corante. O índice de detecção intra-operatória com o gamma-probe foi de 90,9 % ( 11 pacientes ). Destes, 7 linfonodos foram azul e quente (31,8 %), 6 linfonodos foram apenas azuis (27,2 %) e 9 linfonodos foram apenas quentes (40,9 %). A sensibilidade, especificidade e valor preditivo negativo para a detecção do linfonodo-sentinela foram 100%, 85,7 % e 100 % respectivamente. Conclusão: A combinação do radiofármaco 99Tc e azul patente é efetiva na detecção do linfonodosentinela em câncer de colo uterino inicial. / Objective: to establish the feasibility of sentinel lymph node identification in patients with stages Ib1 invasive cervical cancer. Material and Methods: 16 consecutive patients with cervical cancer, were scheduled for radical hysterectomy with bilateral pelvic lymphadenectomy, were submitted to sentinel lymph node detection. Eleven patients was injected 1 mCi of technetium-99 (99Tc) into four points of the superficial cervical stroma around the tumor, at the 12, 3, 6 and 9 o’clock positions (sixteen hours before surgery ). On the day of the surgery, the patients were submitted to gamma-probe-guided lymphatic mapping and patent blue dye was injected into the same points as the 99Tc. Five patients were submitted to detection with patent blue only. Results: at least one sentinel lymph node (one to three per patient) was detected in each of the 15 patients (93.7%) in whom a combination of both methods was used. At least one sentinel lymph node was detected in four patients ( 80 % ) with patent blue only. Most sentinel lymph nodes were identified in the obturator (37%), external iliac (22.2%) and interiliac (18.5%) regions. Six patients (40%) had bilateral sentinel lymph nodes. Of the 27 sentinel lymph nodes detected, 11 (40.7%) were identified by the blue-dye technique, 9 (33.3%) by radiation, and 7 (26%) by radiation and by the blue-dye technique. The intraoperative detection rate was 90.9% with gamma-probe only ( 11 patients ). Of these, 7 lymph nodes were blue-stained and hot (31.8), 6 were just blue-stained (27.2%) and 9 were just hot (40.9%). Sensitivity, specificity and the negative predictive value for sentinel lymph node detection were 100%, 85,7% and 100 % respectively. Conclusion: the combination of 99Tc and patent blue dye is effective in the detection of sentinel lymph nodes in early-stage cervical cancer.

Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2018-01-23T17:09:40Z No. of bitstreams: 1 Thaynara_Schafer_2017.pdf: 1932282 bytes, checksum: 89dd37a8b10b1470458f461465755dfc (MD5) / Made available in DSpace on 2018-01-23T17:09:40Z (GMT). No. of bitstreams: 1 Thaynara_Schafer_2017.pdf: 1932282 bytes, checksum: 89dd37a8b10b1470458f461465755dfc (MD5) Previous issue date: 2017-11-20 / The textile industries present a high polluting potential, due to the generation of large volumes of liquid waste, containing high organic load and strong coloration derived from the dyes. These effluents can be treated by physical, chemical and biological processes. Among these processes, the adsorption has been widely studied for the removal of water dyes, due to the lower costs, simplicity of operation and high efficiency. Methylene blue (AM), a dye widely used in the textile industry is responsible for the strong staining in the effluents. Even in small amounts (<5 mg Pt Co / L), just as other textile dyes are very visible and affect the appearance, transparency and solubility of the gases, damaging the environment. A material that has been applied as adsorbent for dye removal in wastewater treatment is the magnetic nanoparticle, because it has high adsorption capacity, low cost and magnetic character. The nanoparticles can be prepared by the electrochemical method, thermal decomposition, hydrothermal synthesis, microemulsion, decomposition-precipitation, coprecipitation, chemical vapor deposition and impregnation. Of the most well-known methods of preparation, the coprecipitation method is the oldest, the simplest, the most efficient, and the one that allows greater production on a large scale. In this work, the coprecipitation method was used to synthesize the iron oxide (Fe3O4) nanoparticle obtained by the stoichiometric mixture of Fe2+ and Fe3+ salts in aqueous medium. This material was characterized and applied in solutions with different concentrations of the methylene blue dye in order to study its adsorption capacity. The same procedure was performed with the nanoparticulate compound (Sigma-Aldrich), in order to compare the adsorption capacity. The nanoparticulate material was characterized by magnetization, X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), ultraviolet/ visible (UV/VIS) spectroscopy, scanning electron microscopy) and optical microscopy (MO). By magnetization it was possible to observe the movement of the dispersed particles in aqueous medium toward the magnetic field of the neodymium magnet, which is a property of the ferromagnetic materials. With the solid samples, the supported weight capacity was tested, whereas for the synthesized compound it was 85, 3 g and for the nanoparticulate compound was 105,3 g, it being possible to explain this difference by packaging the particles. The greater the packing of the particles, the greater the magnetic force exerted. By the study of the effect of the pH and temperature of the medium, it was confirmed that at pH 7 and ambient temperature, the interference of the medium does not occur by the surface charges of the adsorbents and thus favoring the dye adsorption process. By reading the absorbances of the AM solutions, it was possible to calculate the equilibrium concentrations and to determine the amount of dye adsorbed by the nanoparticles. At low concentrations (5,0 x 10-6 mol L-1 to 1,0 x 10-5 mol L-1) a linear behavior is observed due to the presence of monomers already in concentrations higher than 1,0x10-5 mol. L-1 has the alteration of the linear behavior of the adjusted line, characteristic of the formation of aggregate and alteration of the coefficient of molar absorption. Scanning and optical electron microscopy showed that the images presented different forms for the nanoparticulate and nanoparticulate nanoparticles (Sigma-Aldrich), and the nanoparticulate presented reduced size and rounded shape when compared to the synthesized compound. By the diffractograms it was inferred that the synthesized material presented in its composition the magnetite (Fe3O4) and hematite (Fe2O3), the nanoparticulate only the presence of magnetite. Through the FTIR spectra for the nanoparticle samples, the major bands corresponding to the Fe-O and O-H bonds were investigated. By means of the TGA analysis, a loss of 2,31% of mass was observed in the variation of 50 to 150ºC, attributed to the presence of water in the sample. Above 150°C, there was another loss of 1,20% corresponding to the mass of gaseous substances, possibly carbon dioxide (CO2) or oxygen gas (O2). / As indústrias têxteis apresentam um elevado potencial poluente, devido à geração de grandes volumes de resíduos líquidos, contendo alta carga orgânica e forte coloração derivada dos corantes. Esses efluentes podem ser tratados por processos físicos, químicos e biológicos. Dentre estes processos, a adsorção vem sendo amplamente estudada para a remoção de corantes de águas, devido os menores custos, simplicidade de operação e alta eficiência. O azul de metileno (AM), um corante amplamente utilizado na indústria têxtil é responsável pela forte coloração nos efluentes. Mesmo em pequena quantidade (< 5 mg Pt Co/L), assim como os demais corantes têxteis são bastante visíveis e afetam a aparência, a transparência e a solubilidade dos gases, prejudicando o meio ambiente. Um material que vem sendo aplicado como adsorvente para a remoção de corante no tratamento de águas residuarias é a nanopartícula magnética, pois possui alta capacidade de adsorção, baixo custo e caráter magnético. As nanopartículas podem ser preparadas pelo método eletroquímico, decomposição térmica, síntese hidrotérmica, microemulsão, decomposição-precipitação, coprecipitação, deposição química a vapor e a impregnação. Dos métodos de preparo mais conhecidos, o método da coprecipitação é o mais antigo, simples, eficiente e o que permite maior produção em larga escala. Neste trabalho, o método da coprecipitação foi utilizado para sintetizar a nanopartícula de óxido de ferro (Fe3O4), obtida pela mistura estequiométrica de sais de Fe2+ e Fe3+ em meio aquoso. Este material foi caracterizado e aplicado em soluções com diferentes concentrações do corante azul de metileno, a fim de, estudar a sua capacidade de adsorção. O mesmo procedimento foi realizado com o composto nanoparticulado (Sigma–Aldrich), com o propósito de comparar a capacidade de adsorção. O material sintetizado e o composto nanoparticulado foram caracterizados por magnetização, difração de raios-X (DRX), análise termogravimétrica (TGA), espectroscopia de infravermelho (FTIR), espectroscopia ultravioleta/visível (UV/VIS), microscopia eletrônica de varredura (MEV) e microscopia óptica (MO). Por magnetização foi possível observar o movimento das partículas dispersas em meio aquoso em direção ao campo magnético do ímã de neodímio, sendo esta uma propriedade dos materiais ferromagnéticos. Com as amostras sólidas, testou-se a capacidade de peso suportado, sendo que para o composto sintetizado foi de 85,3 g e para o composto nanoparticulado foi de 105,3 g, sendo possível explicar esta diferença pelo empacotamento das partículas. Quanto maior o empacotamento das partículas, maior a força magnética exercida. Pelo estudo do efeito do pH e temperatura do meio, confirmou-se que em pH 7 e temperatura ambiente, não ocorre a interferência do meio pelas cargas da superfície dos adsorventes e assim tem-se o favorecimento no processo de adsorção do corante. Por meio da leitura das absorbâncias das soluções de AM, foi possível calcular as concentrações no equilíbrio e determinar a quantidade de corante adsorvido pelas nanopartículas. Em baixas concentrações (5,0x10-6 mol. L-1 a 1,0x10-5 mol. L-1) tem-se um comportamento linear, devido à presença de monômeros, já em concentrações superiores a 1,0x10-5 mol. L-1 tem-se a alteração do comportamento linear da reta ajustada, característica da formação de agregado e alteração do coeficiente de absorção molar. Por microscopia eletrônica de varredura e óptica foi observado que as imagens apresentaram formas diferenciadas para a nanopartícula sintetizada e nanoparticulado (Sigma– Aldrich), sendo que o nanoparticulado apresentou tamanho reduzido e formato arredondado quando comparado ao composto sintetizado. Pelos difratogramas inferiu-se que o material sintetizado apresentou em sua composição a magnetita (Fe3O4) e hematita (Fe2O3), já o nanoparticulado somente a presença de magnetita. Através dos espectros de FTIR para as amostras das nanopartículas, averiguaram-se as principais bandas correspondentes as ligações Fe-O e O-H. Por meio da análise TGA, observou-se uma perda de 2,31% de massa na variação de 50 a 150ºC, atribuído a presença de água na amostra. Acima de 150ºC, houve outra perda de 1,20% correspondente a massa de substâncias gasosas, possivelmente dióxido de carbono (CO2) ou O2 (gás oxigênio).

O câncer de mama (CA de mama), com exceção do câncer de pele do tipo não melanoma, é o tumor de maior incidência dentre as mulheres, sendo que no Brasil são encontrados principalmente nas regiões Sul e Sudeste. Seu principal tratamento é o cirúrgico. A disseminação do tumor pode ocorrer por via linfática, acometendo linfonodos regionais. A biópsia do linfonodo sentinela (BLNS) é um procedimento altamente relevante, é altamente sensível na identificação de metástases. A técnica de linfocintilografia (LINCT) pré-operatória é essencial, pois permite avaliar a cadeia linfática acometida e possibilita a visualização do linfonodo sentinela (LNS) durante a cirurgia. O objetivo é descrever os padrões de drenagem linfática e avaliar a contribuição da LCINT na localização dos LNS em pacientes com CA de mama. No período de março de 2009 a agosto de 2011 foram estudados 70 casos sequenciais da rotina clínica, submetidos ao tratamento cirúrgico do CA de mama com estudo do LNS através da técnica de LCINT. Na LCINT foram aplicadas 4 injeções intradérmicas contendo 37 MBq (1,0 mCi) do FITATO-Tecnécio99m, ao redor da aréola mamária. Após a localização do LNS foi realizado marcações na pele, nas incidências anterior, oblíqua e lateral, para auxiliar o cirurgião na abordagem cirúrgica ulterior, juntamente com a sonda gama intra-operatória e corante azul patente. Dos 70 casos submetidos ao estudo, todos são do sexo feminino (100%) com faixa etária entre 28 e 77 anos, média de 54 anos. O tamanho médio do tumor encontrado nos pacientes foi de 1,4 cm. Os tipos histológicos mais incidentes foram o carcinoma ductal invasivo com 45 (64,4%) pacientes, seguido de carcinoma ductal in situ com 16 (22,8%). No exame de LCINT, todos os pacientes apresentaram drenagem linfática do radiofármaco a partir do local da injeção. Em 43 (61.5%) pacientes, observamos drenagem para 1 LNS, em 21 (30%) para 2 LNS/LNNS (linfonodo não sentinela), em 5 (7%) para 3 LNS/LNNS e em 1 (1.5%) para 4LNS/LNNS. Dos 70 pacientes, 68 (97%) apresentaram drenagem linfática ipsilateral e 2 (3%) apresentaram drenagem linfática bilateral. Em relação aos territórios de drenagem linfática dos LNS/LNNS, em 68 (97%) pacientes apresentaram drenagem para a região axilar, 1 (1,5%) para a região mamária interna e 1 (1,5%) para as regiões axilar e mamária interna. Os LNS/LNNS presentes na cadeia mamária interna não foram retirados. No intra-operatório, os cirurgiões utilizaram o corante azul patente em 35 (50%) pacientes, destes o corante identificou os LNS/LNNS em 79% dos casos. A técnica de LCINT possibilitou a visualização de todos os LNS e em alguns casos não foi possível a visualização do LNNS, o qual foi localizado e retirado com a sonda gama. Com isso, a técnica de LCINT foi eficaz em 88,5% dos casos. Dos 69 pacientes submetidos à BLNS apenas 13 (18,8%) pacientes apresentaram LNS/LNNS metastáticos, sendo estes submetidos à linfadenectomia axilar. Conclui-se que o exame pré-operatório de LCINT foi muito eficiente para o estudo da drenagem linfática, visualizando os canais linfáticos, linfonodos funcionalmente ativos e seus respectivos territórios de drenagem. Por tanto, esta técnica auxiliou o cirurgião na abordagem cirúrgica juntamente com a sonda gama intra-operatória e corante azul patente para a realização da BLNS. / With the exception of non-melanoma skin cancer, the Breast cancer (breast CA) is the most incident cancer in women. In Brazil, the breast CA is more often found in South and Southeast regions. The main treatment of breast CA is the surgery. The main pathway for the tumor spreading is the lymphatic system, which may affect the regional lymph nodes. The sentinel node biopsy (SLNB) is of considerable importance, once it has a high sensitivity in identifying metastases. The technique of preoperative lymphoscintigraphy (LINCT) is essential because it allows evaluating the lymphatic drainage chain and enables the visualization of sentinel lymph node (SLN) during surgery. We aim here to describe the lymphatic drainage patterns and to evaluate the contribution of LCINT to the location of SLN in patients with breast CA. We evaluated 70 patients sequentially selected from the clinical routine, between march 2009 and august 2011, and that underwent the surgical treatment for breast CA, including the usage of the technique of LCINT for the SLN location. The LCINT were performed by the injection of four periareolar intradermal injections containing 37 MBq (1.0 mCi) of the radiopharmaceutical PHYTATE-99m-Technetium. Based on the LCINT images, we performed skin marks in the dermal projections of the SLN in all anterior/posterior, oblique and lateral views. Additionally, the gamma probe and blue dye were used to help surgeons in the surgical location of the SLN. All of the 70 patients of our study were female, ranging from 28 to 77 years, mean 54 years. The average tumor size was 1.4 cm. The most commonly found histological types were invasive ductal carcinoma (45 patients, 64.4%), followed by the in situ ductal carcinoma (16 patients, 22.8%). All LCINT procedures were well succeeded in demonstrating at least one SLN in our sample of patients. We observed lymphatic drainage for only one SLN in 43 patients (61.5%), for 2 SLN/SLNN in 21 (30%) (non sentinel lymph node), for 3 SLN/SLNN in 5 (7%) and for 4 SLN/SLNN in one patient (1.5%). From the 70 patients, 68 (97%) exhibited ipsilateral and 2 (3%) exhibited bilateral lymphatic drainage. Concerning the lymphatic territories, 68 patients (97%) exhibited drainage to SLN/SLNN in the axillary region, 1 patient (1.5%) in the internal mammary region and another patient (1.5%) in both axillary and internal mammary regions. The two SLN/SLNN found in the internal mammary chain were not removed. Complimentary to the LCINT, the surgeons used blue dye in 35 patients (50%), which enabled them to identify the SLN/SLNN in 79% of cases. On the other hand, LCINT allowed the visualization of all SLN (100%). In some cases, in which was not possible to visualize the SLNN, these ones were found by the use of the gamma probe. Thus, the LCINT technique was effective to localize the SLN in 88.5% of cases. From the 69 patients who underwent SLN biopsy, only 13 patients (18.8%) exhibited metastatic infiltration of the SLN/ SLNN. All these patients were submitted to the axillary dissection. We conclude that the preoperative LCINT was very effective for the study of lymphatic drainage, enabling the visualization of the lymphatic channels, functionally active nodes and their drainage areas. Therefore, this technique helped surgeons in the surgical approach with intraoperative gamma probe and patent blue dye for SLNB.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Organic and inorganic materials have been used as adsorbent materials of aquatic pollutants due to their both good adsorption capacities and physical and chemical stabilities. In this work, the ligand 3-aminopropytrimethoxysilane was immobilized on silica gel surface, with consecutive reactions with glutaraldehyde and chitosan. All materials were characterized by TG/DTG, DSC, FTIR, DRX and MEV, where the presence of the silica-immobilized chitosan was evidenced. The adsorption kinetics of the anionic dye remazol blue (AR) on the cross linked silica/chitosan (Sil-Quit-R) was studied in the temperature range of 25 - 55 ºC and initial dye concentration of 23 - 800 mg L-1. The results were best fitted to both the pseudo second-order Ho and McKay and the Avrami models. The AR dye adsorption at chemical equilibrium were best described using the three-parameter Redlich-Peterson I, Sips, Tóth, Baudu I and five-parameter Fritz-Schlunder IV models. From these results, the heterogeneity of the Sil-Quit-R adsorption sites was evidenced. The adsorption enthalpies (ΔadsH) were all endothermic and increased with the increasing of adsorption temperature. The negative values for ΔadsG have indicated that the adsorption processes are spontaneous. The adsorption entropies (ΔadsS) were all positive and increased with the increasing of adsorption temperature. From the thermodynamic viewpoint, the positive ΔadsS values were the adsorption driving force. The adsorption capacity of Sil-Quit-R was good, mainly related to the adsorption results at low dye concentrations in solution. / Matrizes orgânicas e inorgânicas têm sido utilizadas como materiais para remoção de poluentes aquáticos, dada às suas boas capacidades de adsorção e estabilidades físicas e químicas. Neste trabalho, foi sintetizado e caracterizado o material híbrido orgânico/inorgânico Sílica/Quitosana Reticulado (Sil-Quit-R) através da formação de ligações cruzadas, sendo caracterizados por TG/DTG, DSC, FTIR, DRX e MEV e avaliada as suas interações com o corante Azul de Remazol (AR). Na avaliação da cinética de interação do corante (AR) na (Sil-Quit-R), foi feita entre 25 e 55ºC, nas concentrações do corante entre 23 a 800 mg.L-1. Os modelos de Difusão Intrapartícula e de Avrami mostraram os melhores ajustes. Evidenciaram-se também várias etapas cinéticas de difusão em relação ao tempo de contato. As adsorções nos equilíbrios químicos foram mais bem descritas pelos modelos de três parâmetros ajustáveis de Redlich-Peterson I, Sips, Tóth, Baudu I e para o modelo de cinco parâmetros ajustáveis de Fritz-Schlunder IV. Esses resultados evidenciaram a heterogeneidade dos sítios de adsorção da Sil-Quit-R. Os valores das entalpias de adsorção (ΔadsH) foram maiores que zero indicando processos endotérmicos e aumentaram com o aumento da temperatura de adsorção. Os valores negativos de ΔadsG indicaram a espontaneidade dos processos de adsorção. As entropias das adsorções (ΔadsS) foram positivas e aumentaram com o aumento da temperatura de adsorção, sendo, termodinamicamente, a força motriz dos processos de adsorção. As capacidades de adsorção máximas do material podem ser consideradas bem evidenciadas com um qemax em todas as concentrações e temperaturas, principalmente quando o corante Azul de Remazol estava presente em baixas concentrações em solução.

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / For centuries the contamination of surface water has been problematic, especially in third world countries whereby socio-economic issues are prevalent. With the development of various technologies for surface water rehabilitation, adsorption has been found to be the most viable due to its lower cost implications. As such the development of innovative adsorbents which are synergistic to the low cost method have been sought. Herein, the use of fossil coral limestone from Mauritius as adsorbents for the removal of Pb(II), Cr(VI) and methylene blue is presented. The pristine material (PCLS) was thermally treated by calcination to temperatures 800°C (CLS-800) and 900°C (CLS-900) and chemically treated by using an acid HCl (ACL) and base NaOH (BCL). The optimum conditions found for chemical and thermal treatment of the pristine material were used for the one pot synthesis of magnetite and maghemite calcium carbonate based nanocomposites. The pristine fossil coral limestones were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDS), X-ray fluorescence XRF), X-ray diffractometer (XRD), Brunauer, Emmett and Teller (BET) and Fourier transformed infrared (FTIR) spectroscopy, UV visible spectrophotometer (UV/vis) and Photolumiscent spectroscopy (PL). Surface morphology of the material was found to contain an interconnected framework of pores, with a surface area of 20.45 m2/g and pore with of 4.04 nm. Thermal treatment of the material was found to increase the surface area of the materials to 64.10 and 63.28 m2/g for CLS-800 and CLS-900. The surface morphology of the calcined materials compared to the pristine were fibrous like and irregularly shaped for CLS-800 and CLS-900 respectively. The FTIR revealed the dominant surface groups to be (-C-O) and (-C=O) asymmetric stretch of the in and out of plane bend of carbonate (-CO32-), with the composition of the material being 91.76 % (-CaO) and 3.32% SrO. The thermally treated materials also exhibited vibrations of asymmetric stretch, which are characteristics of the carbonates as with the pristine material. However, EDS of the pristine compared to that of the calcined materials show a decline in the carbon and oxygen content, due to calcination. The XRD analysis confirmed the orthorhombic structure of aragonite, while CLS-800 was rhombohedral calcite with newly developed (-CaO) peaks. CLS-900 showed complete removal of CaCO3 polymorphs with more (-CaO) peaks. The surface morphology of the chemically modified samples show irregularly shaped surface. The XRD analysis confirmed that chemical treatment did convert the materials to a different polymorph. The FTIR of the chemically modified materials compared to the pristine, were found to reveal a removal of the vibrations of the asymmetric stretch associated with carbonates. However, vibrations associated with (-CaO) were observed. The SEM of the nanocomposites was observed to deviate from sphericity with variable size distribution. The materials were both red and blue shifted due to their variable sizes. Their UV/vis revealed absorption bands in the visible region. The adsorption analysis was done by varying parameters such as time, pH, concentration and temperature. The data was such that the highest capacity for the pristine material was found to be 37.24, 39.26 and 69.42 mg/g for MB, Pb(II) and Cr(VI) respectively. The removal of MB and Pb(II) pollutants were due to physical adsorption, as observed from the good fitting to pseudo first order model (PFOM). The removal of Cr(VI) was due chemisorption and the good fit on pseudo second order model (PSOM). The adsorption process was supported on a heterogeneous surface whereby multilayer adsorption could occur. Adsorption was spontaneous and feasible, exothermic for MB and Pb(II) and endothermic for Cr(VI) at all the studied temperatures as observed from thermodynamics. The adsorption of methylene blue was found to be more favourable on adsorption compared to photo-degradation Chemical modification was observed to increase adsorption and the maximum removal capacities for PCLS, ACL and BCL for Cr(VI) ions were 69.42, 65.04, 64.88 mg/g, Pb(II) ions 39.36, 74.11, 78.34 mg/g and methylene blue 37.24, 46.28, 46.39 mg/g, respectively. Uptake of Cr(VI) and methylene blue on ACL and BCL was feasible on a heterogeneous surface whereby multilayer adsorption took place. Monolayer adsorption on a homogenous surface of ACL and BCL was observed for Pb(II) uptake. The uptake of Pb(II) was exothermic on PCLS and ACL while methylene blue only on PCLS. The adsorption of Cr(VI) ions onto PCLS, ACL and BCL and methylene blue dye onto ACL and BCL were endothermic in nature. The adsorption process was spontaneous and feasible at all the studied temperatures. Thermal modification further increased the adsorption uptake of the pollutants. The recorded uptake for Cr(VI) and Pb(II) were 99.12 and 98.42 mg/g onto CLS-800 and CLS-900, respectively. The adsorption process was found to be physisorption, due to the good fit on PFOM. In addition, the adsorption occurred on a heterogeneous surface whereby multilayer adsorption was possible. The removal of Cr(VI) was found to be exothermic for both the materials and Pb(II) was found to be endothermic. The materials were tested for their reusability to up to four cycles, whereby the removal on the fourth cycle were 16.87, 63.60, 73.13 mg/g for Cr(VI), 9.87, 64.19 and 70.95 mg/g for Pb(II) on PCLS, CLS-800 and CLS-900. While the leaching test for PCLS, CLS-800 and CLS-900 for the release of Ca2+ into solution was found to be within the permissible limits of world health organisation (WHO). The as synthesized nanocomposites increase adsorption of the pollutants. Maximum capacities were found to be 345.34, 388.31, 377.92 and 375.35 mg/g for Pb(II) onto magnetite-PCLS, magnetite-CLS, maghemite-PCLS and maghemite-CLS, respectively and 308.01, 335.3, 335.29 and 335.27 mg/g for Cr(VI) onto magnetite-PCLS, magnetite-CLS, maghemite-PCLS and maghemite-CLS, respectively. From the data it was observed that the maghemite samples were much more favourable for the removal of the pollutants. The removal was due to chemical adsorption, as observed from the good fit onto PSOM and intraparticle diffusion (IPD), whereby surface adsorption was the rate limiting step. The adsorption process was heterogeneous and multilayer, while thermodynamic data reveal that adsorption was spontaneous and favourable at the studied temperature.

PhD (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Water is a basic resource to mankind. The environment is deteriorating daily due to industrial pollution of water resources. Industrial effluents containing organic pollutants such as dyes are undesirable even at low concentrations in the environment. Natural biomaterials have been applied as adsorbents for dye removal from water systems, however, their application has been limited by their low adsorption capacity. Much attention has been focused on the chemical modification of natural biomass via grafting processes. The modification of natural polymers by graft copolymerization is a promising technique since it functionalizes a biopolymer thus imparting desirable properties. The purpose of the study was to prepare and optimize the working conditions for the pine-magnetite bionanocomposites (PMC) as adsorbents and as photocatalysts modifiers. First, this work focuses on the synthesis and optimization of reaction variables in the preparation of PMC for the removal of methylene blue (MB). The thesis also explores the synthesis of acrylamide and acrylic acid-grafted PMC, resulting in the formation of acrylamide-grafted PMC (GACA) and acrylic acid-grafted pine-magnetite bionanocomposites (GAA), respectively. The grafting of functional groups such as –CO, –NH2 onto cellulose from acrylamides is also explored in detail. The adsorption conditions optimized were used to investigate the adsorption efficiency of GAA and GACA on MB. Finally, the application of PMC and GAA as modifiers for amorphous TiO2 and N-doped TiO2was carried out. The photocatalytic bionanocomposites from PMC (namely PMC–a-C,TiO2 and PMC–a-C,NTiO2) and those from GAA (labeled GAA–a-C,TiO2 and GAA–a-C,NTiO2) are compared by their photocatalytic efficiency on the degradative removal of an alkaline dye mixture formed from Reactive red 120 (RR 120) and Rhodamine B (Rh B). The synthesis procedure for PMC involved treating pinecone biomass with 0.15 M NaOH solution to remove unwanted plant extracts and the subsequent coating of the treated pinecone with iron oxide magnetic particles through a co-precipitation method. The variables used for the experiments were volume of NH4OH (5 to 40 cm3), reaction temperature (40 to 100 °C), effect of time (15 to 60 min) and mass (1.0 to 3.5 g). The PMC and acrylic acid grafted pine-magnetite composite (GAA) were probed for structural morphology and surface properties using various surface characterization instrumental techniques. Strong chemical interactions between pinecone magnetite and acrylic acid were demonstrated by thermogravimetric (TGA), differential thermal analysis (DTA) and X-ray photoelectron spectroscopy (XPS) for these unique bionanocomposites as such suggesting high chemical stability. Grafting acrylic acid was shown by XPS to form polyacrylic acid on the surface of the bionanocomposites and thus capping the surface groups. Significant differences in size were shown by transmission electron spectroscopy (TEM) and scanning electron microscopy (SEM); i.e., smaller particle sizes (Ave = 13.0 nm) for GAA and slightly larger for PMC (Ave = 14.0 nm). Brunauer Emmett Teller (BET) surface analysis demonstrated a larger surface area, pore volume and pore diameter (59.9 m2.g-1, 0.2254 cm3.g-1 and 28.14) for GAA compared to PMC. These characteristics coupled with the point of zero charge for GAA (pHpzc = 6.8) were critical in enhancing the efficiency of GAA adsorption of MB at pH 12 and further enable GAA to have a higher desorption efficiency of up to 99.7% after four cycles of washing with 0.10 M HCl. The adsorption kinetics and isotherm studies indicated that the adsorption process follows the pseudo second order kinetics and Langmuir isotherm respectively. The adsorbent also showed improvement in the adsorption capacity and reusability promising to be used for the removal of dyes in a prototype scale. GAA and MB adsorption mechanism was confirmed to be through intra particle diffusion. The overall performance of the GAA bionanocomposites is hinged on the formation of polyacrylic acid on the surface, its structural morphology, and the enhanced surface properties. Most importantly, the plant-based materials (lignin and cellulose) provide an environment that is rich with surface (–COOH and –OH) groups for the attachment of the magnetite nanoparticles while the polyacrylic acid stabilizes the magnetite onto the pinecone nanoparticles while reducing the point of zero charge for increased adsorption of cationic species. The photocatalytic bionanocomposites were fabricated from the adsorptive bionanocomposites using a simple solgel process in which ~10 wt.% of PMC and GAA, respectively, were used as a starting agent. Titanium butoxide was used as a precursor, acetylacetone as a dispersant and ethylene diamine as a nitrogen source. Using this procedure, amorphous carbon-doped titania (a-C,TiO2) and amorphous carbon and nitrogen co-doped titania (a-C,NTiO2) were fabricated except that the biopolymer was not added. Two sets of amorphous titania bionanocomposites were fabricated. One set was the nitrogen doped forms that had been modified with PMC and GAA (PMC–a-C,TiO2 and GAA–a-C,NTiO2). The other set of photocatalytic bionanocomposites produced in this work were without nitrogen (PMC–a-C,TiO2 and GAA–a-C,TiO2). TEM and SEM micrographs showed that all the photocatalysts consisted of globular, smooth aggregates of nanosized a-CTiO2 and a-C,NTiO2 which decreased in size with N-doping and the incorporation of GAA and PMC to as low as <30 nm. Surface chemical analysis through FTIR, XPS and EDS confirmed the presence of C, O, Ti and N (for the N-doped photocatalysts). In addition, it was demonstrated that N-doping into TiO2 had taken place, albeit with most of the N incorporated as organic nitrogen. It was further demonstrated that because of the absence of high temperature calcination, the process chemicals played a significant role in doping the photocatalysts with carbon resulting in the promotion of photocatalytic activity for a-C,TiO2 to the point of surpassing that of, a-C,NTiO2 and all the PMC-modified photocatalytic bionanocomposites. a-C,TiO2 had an overall 94% removal of the dyes, Rhodamine B (RhB) and Reactive red 120(RR 120), under UV illumination. The benefit of co-doping a-TiO2 with C, N and the biopolymers was realized with the incorporation of GAA as a modifier. The result was 97% removal of the dyes by GAA–a-CTiO2 and 99% for GAA–a-C,NTiO2. It was further observed that the degradation of the binary mixture of the dyes (RhB and RR 120) proceeded through the zero order kinetics for the a-C,TiO2 based photocatalysts and first order kinetics for the N-doped photocatalysts. The work, has, therefore demonstrated the applicability of plant-based biopolymers in the fabrication of nanoadsorbents and nanophotocatalysts. While the photocatalytic degradations were carried out under UV-light, there still remains a number of possible avenues that researchers can build on to improve the visible light-driven photocatalytic bionanocomposites. The research work has proven the effectiveness of novel pinecone magnetic nanoparticle materials and TiO2-based photocatalyst for the degradation of undesirable dyes from wastewater.