Indicators, such as the energy balance (EB) and greenhouse gases emissions avoided (GHGEA), are frequently used to evaluate the benefits and sustainability of biofuels. Many important papers and reports have been published in recent years to demonstrate the environmental and energetic benefits of biofuels, such as ethanol from sugar cane. EB and GHGEA often include other sugar cane products, such as electricity and bagasse. The anaerobic digestion of vinasse can generate considerable amounts of biogas but is not a common practice in Brazil. This study evaluates the potential benefits to the EB and GHGEA of ethanol by the production of biogas from vinasse and its use to produce electricity or biomethane. Biomethane can be injected on the Natural Gas Grid or used as a fossil diesel oil replacement in the mill operations of harvesting and transportation of sugar cane. The results show that biogas from vinasse can represent improvement in both indicators, which ranges from 3.5% improvement in EB by electricity generation with biogas to 27.5% improvement in GHGEA by replacing diesel in the mill operations. © 2019 American Institute of Chemical Engineers Environ Prog,39:e13226, 2020

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Veterinary pharmaceuticals can reach the soil via animal excretions and cause impacts on aquatic and terrestrial ecosystems. In this work, we employed a standardized avoidance behavior test to assess the sublethal effects of antimicrobial sulfadiazine on the earthworm Eisenia andrei. Cultivation of red worms was based on an alternative substrate made of mostly household vegetable wastes and dry leaves. The bioassays were performed with tropical artificial soil spiked with the tests substance at five different concentrations ranging from 0.01 to 100 mg sulfadiazine kg -1 . The outcome resulted in avoidance response of 30% (maximum) and a nonlinear concentration-response curve, differing from classical pollutant responses and correlating with those asymmetric responses over the environment caused by some rare xenobiotics. Avoidance tests were validated with reference substance, resulting in an EC50-48h of 819 mg boric acid kg -1 (628-1066 mg boric acid kg -1 95% confidence interval). We concluded that the avoidance test with E. andrei is useful as a standardized tool for a rapid ecotoxicological screening of soil.

Resumo Formaldeído é encontrado naturalmente no ambiente e pode atingir concentrações de até 4000 mg L-1 em efluentes industriais. Embora germicida, pesquisas indicam sua possível degradação biológica em sistemas de tratamento, destacando-se os reatores com biomassa aderida e metabolismo aeróbio ou anaeróbio. Esse estudo verifica a eficiência físico-química e capacidade de redução da concentração de formaldeído adicionado a esgoto sanitário no tratamento biológico combinado (anaeróbio e aeróbio), e avalia a toxicidade aguda residual ao microcrustáceo Daphnia similis, em amostras de sistema composto por filtro anaeróbio (FA), biofiltro aerado submerso (BAS), ambos de leito fixo e fluxo ascendente, seguido de decantador secundário, nas fases: formaldeído afluente: 200 mg L-1 (F1: 7 bioensaios) e 400 mg L-1 (F2: 8 bioensaios). A eficiência de remoção de DQO e DBO foi de 93±4% e 97±2% (F1) e 93±7% e 99±1% (F2), respectivamente; a redução de formaldeído foi de 100% (F1) e 99,8±0,3% (F2). A toxicidade aguda (CE50-48h) foi de 7,22% e 3,40% (afluente), >67% e >60% (efluente FA), para F1 e F2, respectivamente. O efluente final não apresentou toxicidade aguda, comprovando a robustez do sistema combinado e a importância de tecnologias que visam à destinação adequada de resíduos e à proteção da vida aquática.

In this paper, we demonstrate in a clear procedure the application of the Anaerobic Digestion Model No. 1 (ADM1) to model a large-scale covered in-ground anaerobic reactor (Cigar), processing sugarcane vinasse from a biorefinery in Brazil. The biochemical make-up (carbohydrates, proteins, and lipids) of the substrate was analysed based on the food industry standards. Two distinct subsets of data, based on the sugarcane harvest season for bioethanol and sugar production in 2012 and 2014, were used to direct and cross validate the model, respectively. We fitted measured data by estimating two key parameters against biogas flow rate: the degradation extent (f) and the first order hydrolysis rate coefficient (k). By cross validation we show that the fitted model can be generalised to represent the behaviour of the reactor under study. Therefore, motivated by practical and industrial application of ADM1, for both different reactors types and substrates, we show aspects on the implementation of ADM1 to a specific large-scale reactor for anaerobic digestion of sugarcane vinasse.