| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 5.12 MB | Adobe PDF |
Authors
Advisor(s)
Abstract(s)
Com as necessidades energéticas e de água limpa, tanto para uso doméstico quanto
industrial, sempre a crescer, o impacto ambiental gerado e a necessidade de o reverter,
tem-se procurado alternativas que sejam ecológicas, eficientes e de baixo custo. As
microalgas podem ser uma dessas alternativas. As microalgas são microrganismos
encontrados em muitos tipos de ambientes, capazes de uma reprodução rápida; de se
adaptar ao ambiente em que se encontra e altera-lo; e são fontes de diversos compostos
de interesse, tanto para energia verde quanto para os setores alimentares e
farmacêuticos.
O presente trabalho visa analisar a aclimatação da microalga Selenastrum sp. em
efluentes industriais (têxtil e da pasta para papel), avaliar o tratamento de matéria
orgânica biodegradável e observar a acumulação de compostos de interesse na
biomassa. Para tal, realizaram-se cultivos em reatores de 1L durante 8 dias, com
controlo da intensidade luminosa (195 de µmol/m2/s, 12h/dia), temperatura (23ºC) e
fluxo de ar (0,4L/L/min) filtrado. Cada cultivo tinha uma concentração de 90% (v/v)
de efluente filtrado, além dos cultivos controlo com e sem adição de glucose para
comparação de desenvolvimento da biomassa e eliminação de matéria orgânica
respetivamente. Devido aos baixos teores de nutrientes inorgânicos nos efluentes, em
todos os cultivos foram adicionados 10mL de GoldMedium Fresh-Water Species (GMFWS). Amostras para contagem de células, análise de carência química de oxigénio
(CQO), peso seco, dimensões celulares e leituras em espectrofotómetro (200 – 800nm)
foram feitos em 4 alturas do cultivo.
Após o cultivo, obteve-se uma redução de níveis da CQO de 70%, 64,3% e 49,2% para
os cultivos com glucose, efluente da pasta para papel e efluente têxtil, respetivamente,
além de uma redução média de 31,7% nos compostos solúveis que absorvem no UVVisível. A esta atividade de bioconversão dos compostos dissolvidos correspondeu um
crescimento de 9,8 milhões de células por mL em média nos cultivos. Relativamente à
quantidade de biomassa gerada, face ao valor obtido para o cultivo controlo
(0,29mg/mL), verificou-se um incremento de 76,7% no cultivo com glucose, 62,8% no
cultivo com efluente da pasta para papel e de 46,5% no cultivo com efluente têxtil.
Estas observações permitem concluir que a Selenastrum sp. é uma eficiente alternativa
para tratamento de efluentes industriais, e devido ao seu crescimento e capacidade de
acumular biomassa apresenta um potencial suplementar como fonte de compostos
úteis.
With the energy and clean water needs, both for domestic and industrial uses, always growing, the environmental impact generated and the need to reverse them, alternatives that are ecological, efficient, and low cost have been sought. Microalgae can be one of those alternatives. Microalgae are microorganisms found in almost all types of aqueous media, capable of rapid reproduction, adapting and changing the environment and are sources of various compounds of interest, both for green energy and for the food and pharmaceutical sectors. The present work aims to analyze the acclimatization of the microalgae Selenastrum sp. in effluents from the textile and paper pulp industry, evaluate the treatment and elimination of biodegradable organic matter and observe the accumulation of compounds of interest. For this purpose, cultures were carried out in 1L reactors for 8 days, with control of light intensity (195 µmol/m2/s, 12h/day), temperature (23ºC) and filtered air flow (0,4L/L/min). Each culture had a concentration of 90% (v/v) of filtered effluent, in addition to the control and control cultures with addition of glucose for comparison of biomass development and organic matter elimination, respectively. Due to the low inorganic nutrient content in the effluents, 10mL of GoldMedium FreshWater Species (GM-FWS) were added to all cultures. Samples for cell counting, chemical oxygen demand (COD) analysis, dry weight, cell dimensions and spectrophotometer readings (200 – 800nm) were taken at 4 different times of cultivation. After cultivation, there was a reduction in COD levels of 70%, 64.3% and 49.2% for cultures with glucose, pulp effluent and textile effluent respectively, in addition to an average reduction of 31.7% in total compounds dissolved in the medium, according to UV-Visible analysis. This bioconversion activity resulted in a growth of 9.8 million cells per mL on average in the cultures. Regarding the amount of biomass accumulated, using the control culture as reference (0.29mg/mL), increment of 76.7% was observed for the cultivation with glucose, 62.8% for the pulp effluent and 46.5% for the textile effluent. These observations enable to conclude that Selenastrum sp. is an efficient alternative for the treatment of industrial effluents, and due to its growth and capacity to accumulate biomass exhibit an additional potential as source of useful compounds.
With the energy and clean water needs, both for domestic and industrial uses, always growing, the environmental impact generated and the need to reverse them, alternatives that are ecological, efficient, and low cost have been sought. Microalgae can be one of those alternatives. Microalgae are microorganisms found in almost all types of aqueous media, capable of rapid reproduction, adapting and changing the environment and are sources of various compounds of interest, both for green energy and for the food and pharmaceutical sectors. The present work aims to analyze the acclimatization of the microalgae Selenastrum sp. in effluents from the textile and paper pulp industry, evaluate the treatment and elimination of biodegradable organic matter and observe the accumulation of compounds of interest. For this purpose, cultures were carried out in 1L reactors for 8 days, with control of light intensity (195 µmol/m2/s, 12h/day), temperature (23ºC) and filtered air flow (0,4L/L/min). Each culture had a concentration of 90% (v/v) of filtered effluent, in addition to the control and control cultures with addition of glucose for comparison of biomass development and organic matter elimination, respectively. Due to the low inorganic nutrient content in the effluents, 10mL of GoldMedium FreshWater Species (GM-FWS) were added to all cultures. Samples for cell counting, chemical oxygen demand (COD) analysis, dry weight, cell dimensions and spectrophotometer readings (200 – 800nm) were taken at 4 different times of cultivation. After cultivation, there was a reduction in COD levels of 70%, 64.3% and 49.2% for cultures with glucose, pulp effluent and textile effluent respectively, in addition to an average reduction of 31.7% in total compounds dissolved in the medium, according to UV-Visible analysis. This bioconversion activity resulted in a growth of 9.8 million cells per mL on average in the cultures. Regarding the amount of biomass accumulated, using the control culture as reference (0.29mg/mL), increment of 76.7% was observed for the cultivation with glucose, 62.8% for the pulp effluent and 46.5% for the textile effluent. These observations enable to conclude that Selenastrum sp. is an efficient alternative for the treatment of industrial effluents, and due to its growth and capacity to accumulate biomass exhibit an additional potential as source of useful compounds.
Description
Keywords
Efluente da Pasta Para Papel Efluente Industrial Efluente Têxtil Microalga Selenastrum Sp. Tratamento de Efluentes