RESUMO A avaliação de ciclo de vida (ACV) é uma técnica de estimativa de impactos ambientais, como emissão de gases de efeito estufa (CO2eq), para geração de produto ou realização de processo. O objetivo deste estudo foi estabelecer a pegada de carbono para a produção da margarina e da manteiga com uso das normas ISO e PAS aplicadas a uma empresa de alimentos localizada na região Sul do Brasil desde a etapa do campo até a sua forma embalada com unidade funcional de 500 g para distribuição. Três cenários foram abordados para a margarina (óleos de soja provenientes do Sul e do Centro-Oeste com e sem desmatamento por queimada) e dois para manteiga (com alocação por massa e econômica). A modelagem foi realizada com dados primários de produção agrícola e da empresa e secundários do ecoinvent ® . A pegada da manteiga com alocação econômica (2,91 kg de CO2eq) foi maior do que a da margarina produzida com soja da mesma região (1,32 kg de CO2eq). Entretanto, esse coproduto autônomo da indústria de laticínio requer alocação mássica para evitar supervalorização, sendo de fato a menor pegada (0,63 kg de CO2eq). A utilização de grãos de soja do Centro-Oeste aumentou a pegada da margarina (1,58 kg de CO2eq), tendo sido muito intensificado quando empregado desmatamento por queimada (2,69 kg de CO2eq). A produção de leite foi o fator deletério preponderante para a manteiga. Para a margarina, houve duas situações distintas, sua fabricação quando se usa soja da mesma região ou a produção do grão quando este for proveniente de região distante desmatada por queimada.

ABSTRACT Life Cycle Assessment is a technique for estimating environmental impacts, such as the emission of greenhouse gases (CO2eq), for manufacturing product or process realization. The objective of this study was to establish the carbon footprint for the production of margarine and butter using ISO and PAS standards applied to a food company, located in the southern region of Brazil, from the field stage to its packed form with a functional unit of 500 g for distribution. Three scenarios were addressed for margarine (soybean oil from the South and the Midwest with and without burned deforestation) and two for butter (with mass and economic allocation). The modeling was performed with primary data from the agricultural and industrial production, and secondary data from ecoinvent ® . The economically allocated butter footprint (2.91 kg CO2eq) was higher than that of margarine produced with soybeans from the same region (1.32 kg CO2eq). However, this autonomous co-product of the dairy industry requires mass allocation to avoid overvaluation, being in fact the smallest footprint (0.63 kg CO2eq). The use of soybeans from the Midwest increased margarine’ footprint (1.58 kg CO2eq) and was greatly intensified with burned deforestation (2.69 kg CO2eq). Milk production was the predominant deleterious factor for butter. For margarine there were two other distinct occasions, which were the manufacture when soy from the same region is used or the production with soybeans from a distant region deforested by burning.

ABSTRACT: This study aimed to evaluate the effect of variations in organic load (hydraulic retention times - HRTs: from 2 to 0.5 day) and in alkalinity (NaHCO3 from 4,000 to 1,000 mg.L−1) on methane production. Biomass of sewage sludge was inoculated and stabilized on 1" polypropylene rings. The rings were immersed in the liquid phase (8.41 L) of an upflow anaerobic filter reactor (12.22 L). A solution of 5 g of whole milk powder per liter was used to simulate effluent from the dairy industry. Process effectiveness was measured by chemical oxygen demand reduction, biogas production, and biogas methane content. Biogas production started at a 2-day HRT and synthetic effluent alkalinization with 4,000 mg.L−1 NaHCO3. The best operation condition was at 1-day HRT and with the addition of 4,000 mg.L−1 NaHCO3. Biogas production reached 1.5 NL of biogas per L of reactor liquid phase, with 68% of methane and a concomitant reduction in COD of 57%.

The potential of heterogeneous photocatalysis using TiO2 immobilized in alginate beads was evaluated for the degradation of tartrazine yellow azo dye. The treatment was performed under the action of a high-pressure mercury vapor lamp of 125 W and the degradation performance was investigated with the absorbance supplied by a photocolorimeter. Alginate beads with TiO2 were prepared and the catalyst was quantified by thermogravimetric analysis (TG) and characterized by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) and specific area analysis (BET). The immobilization was performed as a very simple and reproductible technique. The bead diameter was approximately 1 mm and its surface presented a homogeneous dispersion of catalytic sites containing about 1-2% (w/w) of TiO2. The TiO2/alginate beads presented low density and can be easier separated than the TiO2 dispersed from the reacting medium, remaining available to be reused in another batch. The dye degradation reached 30% after 120 minutes of irradiation, for the following conditions: alcaline pH (pH=9.0), 3 g of TiO2/alginate beads and 20 mol L-1 dye concentration.

A polpa celulósica da madeira deve ser branqueada e alvejada para atingir elevado valor comercial. O cloro é muito eficiente no branqueamento da polpa obtida por processo químico, mas também produz subprodutos altamente poluentes e tóxicos. Outros produtos químicos de branqueamento têm sido propostos para reduzir a toxicidade, mas são mais caros e menos versáteis. A fotodegradação catalítica com o uso de radiação ultravioleta (UV) foi feita para avaliar o potencial de redução do teor de poluentes encontrados em um efluente de branqueamento de celulose com o uso de cloro. A polpa celulósica de Pinus taeda foi produzida e branqueada em laboratório. Três litros de efluente receberam 3 g de dióxido de titânio (TiO2) e foram submetidos à radiação UV. Essa radiação foi produzida com o uso da ampola de lâmpada de vapor de mercúrio de alta pressão de 250 W (12.500 Lm) durante 240 min. A fotodegradação a 25 ºC por 240 min com UV reduziu em cerca de 43% a cor, 40% a DBO5, 50% a DQO, 40% de material calcinável e 45% do carbono orgânico total, além de baixar a toxicidade LC50 para o efluente tratado. O bioindicador Artemia salina apresentou o tempo de sobrevida maior do que 1.000% para o efluente tratado. A distribuição dos pontos experimentais de 0 a 240 min sugere que a fotodegradação deveria ser estendida. Assim, a redução de poluentes observada sugere que esse processo oxidativo avançado (POA), com fotocatálise com o uso de UV e TiO2, pode ser conveniente para o tratamento de efluentes clorados de branqueamento. Isso pode viabilizar o uso seguro de branqueamento com cloro.

The wood cellulose pulp must be bleached to reach a high commercial value. Chlorine is very effective in bleaching for pulp obtained by chemical process, but it also produces highly polluting and toxic byproducts. Other bleaching chemicals have been proposed to reduce toxicity, but they are more expensive and less versatile. Catalytic photodegradation using ultraviolet radiation (UV) was performed to assess the potential for reducing the content of pollutants in an effluent from bleaching cellulose pulp by using chlorine. The Pinus taeda cellulose pulp was produced and bleached in laboratory. Three liters of effluent received 3g of titanium dioxide (TiO2) and were submitted to UV radiation. UV was produced with the use of a mercury-vapor bulb in high-pressure of 250 W (12,500 Lm) for 240 min. Photodegradation to 25 ºC for 240 min with UV decreased about 43% of the color, 40% of the BOD5 (biochemical oxygen demand), 50% of the COD (chemical oxygen demand), 40% of calcinable material and 45% of TOC (total organic carbon), in addition to decreasing the toxicity LC50 (lethal concentration - 50%) for the treated effluent. The bioindicator Artemia salina showed the survival time greater than 1,000% for the treated effluent. The experimental points distribution from 0 to 240 min suggests that the photodegradation must be extended. Thus, the reduction of pollutants observed suggests that advanced oxidation process (AOP), using UV-TiO2 photocatalytic oxidation may be convenient to treat chlorinated bleaching effluents. This can enable the safe use of chlorine bleaching.