ABSTRACT A life-cycle assessment was conducted during semi-intensive and super-intensive commercial cultivation of marine shrimp from December 2011 to June 2012, considering all phases from the preparation of the nursery to harvesting of the shrimp, to determine the carbon footprints of each process. Inputs and outputs associated to the production of 1 kg of shrimp were evaluated using the CML-1A baseline method, V3.01 EU25, with Software SimaPro® 8.0.2, to identify the factors of impact that are most relevant to the category global warming, measured in kg of CO2 eq. The grow-out phase contributed the most to the final results in super-intensive culture, which had a higher carbon footprint, 47.9967 kg of CO2 eq., which was 1.0042 kg of CO2 eq. in the semi-intensive culture. The most important impacting factor is the use of electrical energy, which is required to maintain dissolved oxygen and the biofloc particles in suspension in the super-intensive culture and for movement of large volumes of water in the semi-intensive system.
Nesse estudo procederam-se testes de atividade metanogênica específica (AME) para lodo de indústria têxtil e lodo de indústria alimentícia. O lodo têxtil (aeróbio), proveniente de um sistema de lodos ativados, foi coletado na entrada do decantador biológico secundário e o lodo alimentício (anaeróbio) foi coletado em um reator UASB. Uma vez coletados, os lodos foram caracterizados e submetidos a ensaios de AME. Constatou-se que os microrganismos presentes no lodo alimentício apresentaram AME de 0,17 gDQO-CH4 gSSV.d-1 e produção de metano de 337,05 mL, enquanto que os microrganismos do lodo têxtil apresentaram 0,10 gDQO-CH4 gSSV.d-1 de AME e 3,04 mL de produção de metano. Deste modo, o lodo têxtil apresentou menor atividade metanogênica e produção de metano, quando comparado ao lodo alimentício, indicando não ser viável seu uso como inóculo para a partida de um reator UASB.
In this study, specific methanogenic activity (SMA) tests were performed on textile sludge and food industry sludge. The textile sludge from an activated sludge was collected at the entrance of the secondary biologic clarifier and the food sludge was collected in a UASB reactor. Once collected, the sludges were characterized and tested for SMA. It was found that the microrganisms present in the food sludge had SMA of 0.17 gCOD-CH4 gSSV.d-1 and 337.05 mL of methane production, while the microrganisms of the textile sludge presented 0.10 gCOD-CH4 gSSV.d-1 of SMA and 3.04 mL of methane production. Therefore, the food sludge was more suitable to be used as a starting inoculum in UASB.