Tratamento da manipueira por processo de flotação sem uso de agentes químicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Painéis alternativos produzidos a partir de resíduos termoplásticos e da pupunheira (Bactris gasipaes Kunth)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tratamento a plasma de polímeros comerciais transparentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Degradação de blendas poliméricas por microrganismos de solo e de chorume

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biotratamento de sacolas plásticas de supermercado

Supermarket plastic bags are produced by high density polyethylene (HDPE) and low density polyethylene (LDPE) resins. In Brazil, are produced annually around 150 plastic bags per capita. Disposed in landfills, the supermarket plastic bags prevent the passage of water by slowing the breakdown of biodegradable materials and hindering compaction of waste, according to their low degradability. This work investigated the biodegradation of PE bags containing additive oxo-biodegradable and bags without additives: buried in soil columns, exposed in a controlled environment and exposed to air. The analysis methods used to assess the changes brought in the bags with respect to microbial action and exposure time were weight loss, thickness measurement, infrared (FTIR), scanning electron microscopy (SEM) and contact angle. The results showed that the use of prodegradant agents such as oxobiodegradable additives in polyethylene bags, buried in soil for 270 days, was not efficient to accelerate the biodegradation by microorganisms. It seems that these additives have been more efficient to degrade the colored pigmentation of printed bags, under the influence of light and heat.

Utilização de bacteriófagos ambientais no controle de biofilmes de Salmonella spp. em superfícies utilizadas na indústria de processamento e comercialização de frango de corte e derivados

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of the degradation on the stress cracking values of high density polyethylene (HDPE) geomembranes after different exposures

This paper presents results from stress cracking (SC) tests performed in both fresh and exposed high density polyethylene (HDPE) geomembranes (GM). The HDPE GMs were exposed to ultraviolet radiation, thermal aging (air oven) and tested for chemical compatibility with sodium hydroxide. Stress cracking tests in both fresh and degraded samples were performed in accordance to ASTM D5397: Notched Constant Tensile Load Test (NCTL) and Single Point-Notched Constant Tensile Load Test (SP-NCTL). The results of the NCTL showed that the geomembrane degradation process can be considered to be a catalyst for the phenomenon of SC because it caused a 50% to 60% reduction in stress crack resistance. The most resistance reduction was observed for the sample under chemical compatibility with sodium hydroxide. For the SP-NCTL, the results showed that the samples maintain the same trend verified in the NCTL. The largest resistance reduction was evidenced in samples undergoing ultraviolet degradation. © 2012 ejge.

Construction and demolition waste as a source of PVC for recycling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

SURFACE MODIFICATION of SUGARCANE BAGASSE CELLULOSE and ITS EFFECT on MECHANICAL and WATER ABSORPTION PROPERTIES of SUGARCANE BAGASSE CELLULOSE HDPE COMPOSITES

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

UV exposure of polymeric geomembranes

The break of polymer chemical bonds may occur due to penetration of sun short wavelengths. In sanitary landfills for instance, ultraviolet radiation affects uncovered materials and can be dangerous during the installation of the liner and before the placement of the waste. Only the ultraviolet part of the light is harmful to the geosynthetic materials, moreover, each material is sensitive to a particular wavelength. This article evaluates the effects of UV degradation and condensation in black HDPE (1.0 and 1.5 mm) and white HDPE (textured - 1.0 mm) geomembrane that were tested in laboratory during 6 months. The tests were performed using a weatherometer assembled at EESC-USP in accordance to ASTM G154. The results have shown variations in punction and tear resistance after each period of exposure.

Evaluation of geomembrane UV degradation using melt flow index and oxidative induction time tests

Many factors such as the sunlight, intensity of radiation, temperature, and moisture may influence the degradation process of geosynthetics. UV stabilizers are used especially in polyolefin geomembrane to prevent the degradation process. In these geomembranes the service lifetime is initially governed by the consumption of antioxidants. Tests like MFI and OIT are a alternative to detect the oxidative degradation in polyolefins. This article evaluates HDPE geomembrane degradation after UV exposure through the results of MFI and OIT tests. Two kinds of geomembranes were evaluated: a black and smooth (0.8, 1.0, 1.5, 2.5 mm) and a white and textured (1.0 mm). MFI test showed some levels of superficial degradation (crosslink) in HDPE geomembrane.

Biotreatment effects in films and blends of PVC/PCL previously treated with heat

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biodegradation of blend films PVA/PVC, PVA/PCL in soil and soil with landfill leachate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The influence of soil and landfill leachate microorganisms in the degradation of PVC/PCL films cast from DMF

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immobilized cells of Acidithiobacillus ferrooxidans in PVC strands and sultite removal in a pilot-scale bioreactor

The biooxidation of ferrous ion into ferric ion by Acidithiobacillus ferrooxidans can be potentially used for the removal of H2S from industrial gases. In this work, Fe3+ ions were obtained through the oxidation of Fe2+ using the LR strain of At. ferrooxidans immobilized in PVC stands in a pilot-scale bioreactor, while H2S was removed in an absorption tower equipped with Rasching rings. At. ferrooxidans LR strain cells were immobilized by inoculating the bacterium in a Fe2+-mineral medium and percolating it through the support. After complete Fe2+ oxidation, which took around 90 h, the reactor was washed several times with sulfuric acid (pH 1.7) before a new cycle was started. Four additional cycles using fresh Fe2+ mineral medium were then run. During these colonization cycles, the time required for complete iron oxidation decreased, dropping to about 60 h in the last cycle. The batch experiments in the H2S gas removal trials resulted in a gas removal rate of about 98-99% under the operational conditions employed. In the continuous experiments with the bioreactor coupled to the gas absorption column, a gas removal efficiency of almost 100% was reached after 500 min. Precipitate containing mainly sulfur formed during the experimental trial was identified by EDX. (c) 2005 Elsevier B.V. All rights reserved.