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Neste trabalho analisa-se, de forma preliminar, o comportamento higrotérmico de uma biblioteca construída no século XVIII, pertencente ao núcleo histórico-arquitectónico da Universidade de Coimbra, a partir de dados registados numa campanha de medidas executadas por termo-higrómetros, durante os meses de Junho e Julho de 1993. Caracteriza-se a envolvente do edifício do ponto de vista da sua inércia térmica e simula-se o comportamento do piso superior, claramente mais sensível às solicitações climáticas exteriores, utilizando um algoritmo de cálculo apropriado. Aproveitando as características de elevada inércia do edifício, procura-se estabelecer as condições higrotérmicas interiores compatíveis com a preservação dos espécimes bibliográficos existentes, recorrendo a potências baixas e reduzidos custos de funcionamento. A preliminar analysis is presented concerning the hygrothermal behaviour of the XVIII century library of the University of Coimbra, wich is based on temperature and relative hurnidity measurements canied out during June and July 1993. A simulation is made utilysing a suitable algorithm wich takes account of the thermal inertia of the building and the tirne-evolutions of the outdoor values of temperature, relative humidity, global and diffuse solar radiation. It was possible to demonstrate that reasonable leveIs of internal temperature and relative humidity can be obtained with the use of relatively small climatisation plants and corresponding low energy costs.

Waste of Mytella falcata shell was used as low-cost adsorbent to remove the biocide Basic Green 4 (BG4) from water. Shells were collected form trash nearby the lagoon were Mytella falcata is fished. After clean, dry and crushed, the powder was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and X-ray dispersive energy spectroscopy (EDS). Both kinetic and equilibrium adsorption tests are carried out. Adsorbent regenerability was tested during adsorption/desorption cycles, using a UV photo-regeneration process. The maximum adsorption capacity reached 539.24 mg.g-1 (60 °C), which was higher than those retrieved for other materials with similar origin. The kinetic results indicated that the process followed pseudo-second order model. Equilibrium data indicate an increase in BG4 adsorption capacity with temperature and Sips model had better fit for all the investigated temperatures (30, 40, 50 and 60 °C). The regeneration/reuse test indicated that the adsorbent is able to assure a BG4 removal above 70 % during five adsorption/desorption cycles evaluated. Thermodynamic parameters suggested that adsorption is spontaneous, endothermal, governed by chemisorption and with structural changes in the solid surface upon adsorption.

This work deals with the use of Mytella falcata shells (a bivalve mollusk) as innovative biosorbent for the removal of rifampicin antibiotic from water. The material is alternatively tested as raw or after either pyrolysis or calcination, in order to improve its adsorption capacity. The calcination temperature (700 °C) was determined from the thermogravimetric analysis (TGA) of the raw shell. Preliminary adsorption tests allow individuating the calcined sample as the most performing. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray-dispersive energy spectroscopy (EDS) are used for characterization of the adsorbent. They showed the presence of residual CaCO3, mainly in the form of aragonite and calcite, and a porous structure with heterogeneous surface characterized by rounded particles. Kinetic tests showed fast adsorption phenomena, which were completed in 30−45 min. They present the best fit with pseudo-first order model and the equilibrium adsorption capacity obtained in the different tests (3.05, 4.58 e 7.00 mg.g−1) were satisfactorily predicted. Equilibrium data show that rifampicin adsorption capacity is almost independent on temperature, probably for the simultaneous increase in water desorption associated with the increase in temperature. The isotherms show a Redlich-Peterson model behavior, indicating a multilayer adsorption. The analysis of thermodynamic parameters shows that adsorption is spontaneous and slightly endothermic. Further experimental tests to simulate different water matrix indicate that a high ionic strength can increase the adsorption of rifampicin on the selected adsorbent. Finally, adsorbent regeneration by sonication shows a significant decrease in the performances after 5 adsorption/desorption cycles.