ABSTRACT The membrane separation capacity allows the retention of the remaining organic matter that could not be removed by the biological process, increasing the treatment efficiency. The aim of this study was to evaluate the microfiltration (MF) process in a tertiary treatment system for landfill leachate from the Rincão das Flores, Caxias do Sul/RS/Brazil. The microfiltration system of commercial hollow fiber membrane poly(etherimide) was tested in oder to promote leachate treatment. The tests carried out were leachate permeation, concentration factor, determination of fouling and obtention of the values of the resitance to the flux. The resistance due to fouling and flux decline were evaluated to determine the best operating conditions. The potential for fouling was 53% and was evaluated by comparing the pure water permeability before and after the leachate filtration. It was observed that the resistance due to fouling express 32% of the total resistance. The results showed that the MF process allows the elimination of up to 43% of the organic matter measured as chemical oxygen demand (COD) and 63% of that measured as biological oxygen demand (BOD5).

Neste trabalho, realizou-se a caracterização de compósitos confeccionados com polietileno de alta densidade "virgem" (v-HDPE) e diferentes tipos de serragem gerados na indústria moveleira. Os compósitos foram produzidos por extrusão, utilizando-se uma extrusora monorrosca de 35 mm e temperaturas de 160 ºC, 170 ºC e 180 ºC nas zonas 1, 2 e 3, respectivamente. Foram utilizados resíduos de madeira de pinus (Pinus taeda), de aglomerado, de chapa de fibra de média densidade (MDF) e madeira de eucalipto (Eucalyptus grandis), que foram incorporados ao HDPE "virgem", juntamente com um agente de acoplamento à base de anidrido maléico. Para caracterização física dos compósitos, foram realizadas análises por calorimetria diferencial de varredura (DSC) e por microscopia eletrônica de varredura (SEM). Foram também analisadas as propriedades mecânicas de resistência à tração, flexão estática e resistência ao impacto, conforme as normas ASTM D638, D790 e D256. Verificou-se que todos os tipos de serragem agiram como agentes nucleantes, pois os compósitos apresentaram índices de cristalinidade maiores que o v-HDPE puro, e houve influência do tipo de serragem usada na dispersão das fibras na matriz polimérica. Os ensaios mecânicos indicaram diferenças nas propriedades dos compósitos confeccionados com diferentes tipos de serragem. De maneira geral, a inclusão de serragem de aglomerado e de eucalipto proporcionaram compósitos com maior resistência à flexão e ao impacto que aqueles fabricados com MDF e pinus.

This work aimed to carry out a characterization of composites made of high density polyethylene (HDPE) and different types of furniture industry-derived sawdust. The composites were produced by extrusion, using a 35 mm single-screw extruder, at temperatures of 160ºC, 170ºC and 180ºC in zones 1, 2 and 3, respectively. Particleboard residues from Pinus taeda sawdust, Medium Density Fiberboard (MDF) and Eucalyptus grandis wood were used and incorporated into 'virgin' HDPE along with a coupling agent of maleic anhydride. Differential Scanning Calorimetry (DSC) and Scanning Electronic Microscopy (SEM) were used to carry out a physical characterization of the composites. Mechanical properties, such as tensile strength, static bending and impact were also analyzed, according to the ASTM. It was verified that all types of sawdust acted as nucleant agents because the composites presented greater crystallization index than the pure v-HDPE, and that the type of sawdust used influenced fiber dispersion in the polymeric matrix. The mechanical tests showed differences in the properties of the composites made from different types of sawdust. Overall, the inclusion of particleboard and Eucalyptus sp. wood produced composites with higher resistance to static bending and impact than those made with MDF and Pinus sp.