Tertiary treatment of dairy industry wastewater with production of Chlorella vulgaris biomass: evaluation of effluent dilution

Efluentes secundários da indústria de laticínios, quando não tratados adequadamente, podem provocar eutrofização de corpos d’água, principalmente por conter nutrientes como fósforo e nitrogênio. O tratamento terciário empregando microalgas poderia ser uma solução adequada para o estado de Minas Gerais, maior produtor brasileiro de leite, contribuindo na redução de impactos ambientais, bem como fornecendo biomassa para extração de óleos e obtenção de compostos ativos e insumos (incluindo proteínas) para nutrição animal. Neste trabalho, avaliaram-se diluições (com água destilada) do efluente secundário da indústria de laticínios para cultivo de Chlorella vulgaris em fotobiorreator tubular em escala de bancada. Os resultados encontrados indicam a viabilidade do uso de efluente de indústria de laticínios, pós tratamento secundário, para o cultivo de microalgas, apresentando crescimento similar àquele obtido em cultivos padrões (meio basal Bold). O efluente secundário sem diluição (100% efluente) foi o que apresentou melhor desempenho na produção de biomassa. Além disso, a biomassa obtida em efluentes não apresentou diferenças em relação àquela obtida em meio basal Bold (controle), no que se refere a teores de proteínas, lipídios ou perfil de ácidos graxos.Secondary wastewaters from the dairy industry may cause eutrophication of water bodies when not properly treated, mainly because they contain nutrients such as phosphorus and nitrogen. Tertiary treatment using microalgae could be an adequate solution for Minas Gerais State, the largest Brazilian milk producer, contributing to the reduction of environmental impacts, as well as providing biomass for oil extraction, and obtaining active compounds and inputs (including proteins) for animal feeding. In this work, dilutions (with distilled water) of the secondary wastewater from the dairy industry were evaluated to cultivate Chlorella vulgaris in a bench-scale tubular photobioreactor. Theresults indicate the feasibility of using wastewater from the dairy industry, after secondary treatment, to cultivate microalgae, showing cell growth like that obtained in control cultures (Bold basal medium). The secondary wastewater without dilution (100% wastewater) provided the best condition for biomass production. The biomass obtained in wastewater showed no differences from the biomass obtained in the Bold basal medium (control) in terms of protein, lipid content, or fatty acid profile

FLORAÇÕES DE CIANOBACTÉRIAS TÓXICAS EM UMA LAGOA COSTEIRA HIPEREUTRÓFICA DO RIO DE JANEIRO/RJ (BRASIL) E SUAS CONSEQUÊNCIAS PARA SAÚDE HUMANA

revista vol 13 nº 2.indd The Jacarepaguá Basin, Rio de Janeiro, Brazil has over the last four decades undergone a disordered process of urban and industrial growth with direct consequences on water quality and incidence of cyanobacterial blooms in the Jacarepaguá Lagoon Complex (JLC). The present study combines data aiming to evaluate water quality in Jacarepaguá Lagoon (JL) from monitoring of physical variables (pH, water transparency, temperature), chemical variables (salinity, dissolved oxygen, chlorophyll), the planktonic community, and the concentration of microcystins in fish from the region. The data herein presented were divided into three periods according to seasonal cycles: PI (aug/96 to sep/97), PII (jan/99 to nov/99), and PIII (feb/07 to jan/08). Dominance by cyanobacteria characterized most of the study period, interspersed with sudden peaks (e.g. during PII and PIII) of high diversity of phytoplankton. Phytoplanktonic peaks were represented by Chlorophyta, diatoms, Prasinophyta and Criptophyta. Interestingly, the events observed in 1999 repeated almost 10 years later, suggesting roughly seasonal community structure dynamism in the JLC. Disappearance of the bloom coincided with the lowest recorded water temperatures, suggesting that temperature is an important factor in the observed dynamics. The JL had a high abundance of zooplankton, yet species diversity was relatively low. Concentrations of microcystins found in muscles of fish from JL often contained values above the levels recommended by OMS for human consumption.  revista vol 13 nº 2.indd La Cuenca de Jacarepaguá (RJ/Brasil) ha sufrido, en las últimas cuatro décadas, un proceso desordenado de ocupación urbana e industrial, que se refleja en un cambio en la calidad del agua y en la incidencia de floraciones de las cianobacterias en el Complejo Lagunar Jacarepaguá (CLJ). El presente estudio reúne una serie de datos con el objeto de evaluar la calidad del Lago Jacarepaguá (LJ), a través del monitoreo físico (pH, transparencia del agua y temperatura), químico (salinidad, O.D. y clorofila a) y de la comunidad planctónica. También fue analizada la concentración de microcistinas en pescados comercializados en la región. Los datos fueron divididos en tres períodos de acuerdo con los diferentes ciclos estacionales estudiados: PI (ago/96 a sept/07), PII (ene/99 a nov/99) y PIII (feb/07 a ene/08). La dominancia de cianobacterias ocurre en la mayor parte del período de estudio, intercalada con pulsos de mayor diversidad fitoplanctónica, observada desde 1999 (PII y PIII). Dicha diversidad estuvo representada por las clorofíceas, diatomeas, prasinoficeas y criptoficeas. Cabe destacar que la dinámica observada en 1999 se repitió casi 10 años después, lo que sugiere una tendencia estacional para la estructura de la comunidad del CLJ. La desaparición de la floración coincide con épocas de bajas temperaturas sugiriendo que ésta es un factor regulador importante de la dinámica observada. El LJ presentó una elevada abundancia zooplanctónica, con baja diversidad de especies. Durante algunos meses, las concentraciones de microcistinas encontradas en los músculos de los peces estuvieron por encima de los valores recomendados por la OMS para el consumo humano.A baixada de Jacarepaguá (RJ/Brasil) vem sofrendo há pelo menos quatro décadas um processo desordenado de ocupação urbana e industrial, o que tem se refletido em mudança na qualidade da água e na incidência de florações de cianobactérias no Complexo Lagunar de Jacarepaguá (CLJ). O presente estudo reuniu uma série de dados temporais objetivando avaliar a qualidade hídrica da Lagoa de Jacarepaguá (LJ) através do monitoramento físico (pH, transparência da água e temperatura), químico (salinidade, O.D. e clorofila a) e da comunidade planctônica. Foi também analisado a concentração de microcistinas no pescado comercializado na região. Os dados foram divididos em três períodos de acordo com os diferentes ciclos sazonais estudados: PI (ago/96 a set/97), PII (jan/99 a nov/99) e PIII (fev/07 a jan/08). Dominância de cianobactérias ocorreu na maior parte do tempo, intercalada por pulsos de maior diversidade fitoplanctônica, observados a partir de 1999 (PII e III). Esta diversidade foi representada pelas clorofíceas, diatomáceas, prasinoficeas e criptoficeas. Foi interessante notar que a dinâmica observada em 1999 tenha se repetido quase 10 anos depois, o que sugere uma tendência sazonal de estruturação da comunidade no CLJ. O desaparecimento da floração coincidiu com épocas de menores temperaturas, sugerindo ser esse um importante fator regulador da dinâmica observada. A LJ apresentou uma elevada abundância zooplanctônica, com baixa diversidade de espécies. Durante alguns meses, as concentrações de microcistinas encontradas nos músculos dos peixes estiveram acima dos valores recomendados pela OMS para consumo humano

Temperature Effect on Exploitation and Interference Competition among Microcystis aeruginosa, Planktothrix agardhii and, Cyclotella meneghiniana

We studied the effect of temperature (18 and 30°C) on growth and on the exploitation and interference competition of three species: Microcystis aeruginosa (MIJAC), Planktothrix agardhii (PAT), and Cyclotella meneghiniana (CCAP). Coculturing the organisms in batch systems allowed for the examination of both competitive interactions, while the interference competition was studied in cross-cultures. The experiments were done during 10–12 days, and samples were taken for chlorophyll-a analysis, using PHYTO-PAM. The temperature did not influence exploitation competition between MIJAC and other competitors and it was the best competitor in both temperatures. PAT presented higher growth rates than CCAP in competition at 18 and 30°C. The temperature influenced the interference competition. The growth of MIJAC was favored in strains exudates at 30°C, while CCAP was favored at 18°C, revealing that the optimum growth temperature was important to establish the competitive superiority. Therefore, we can propose two hypotheses: (i) different temperatures may results in production of distinct compounds that influence the competition among phytoplankton species and (ii) the target species may have different vulnerability to these compounds depending on the temperature. At last, we suggest that both the sensitivity and the physiological status of competing species can determine their lasting coexistence

Warming and eutrophication effects on the phytoplankton communities of two tropical water systems of different trophic states : An experimental approach

Both global warming and eutrophication are predicted to promote cyanobacterial blooms. At the same time, how tropical phytoplankton communities exhibiting different trophic state systems will respond to temperature variations is less clear. To investigate the effects of temperature changes and nutrient additions on phytoplankton communities, and gain insights regarding possible resistance to these effects, the present study focused on testing the hypothesis that temperature variations and nutrient additions will have a stronger effect on cyanobacteria dominance in eutrophic water system than in oligo-mesotrophic water systems. Experiments were conducted with phytoplankton communities from two aquatic ecosystems exhibiting different trophic states. To this end, water samples from a eutrophic and oligo-mesotrophic system were collected and incubated at 25 and 30ºC. Samples receiving additional surplus nitrogen (N) and phosphorus (P) inputs were included to serve as eutrophication treatments. The study results indicated that temperature variations alone did not promote cyanobacteria in water from either the oligo-mesotrophic or eutrophic water system. However, nutrient enrichment of the water from the eutrophic system significantly boosted the cyanobacteria, with the biomass increasing by factor of 10 for both the 25°C and 30°C treatments. In contrast, eutrophication of the water from the oligo-mesotrophic system did not change the relative contribution of phytoplankton groups, with the response ratios being much lower than those for the water from the eutrophic system. Although based on a simple experimental design, the results of the present study suggest that cyanobacteria dominance is favoured by further nutrient additions for eutrophic water systems, independently of any direct temperature effects, and that more pristine environments possess some resistance against eutrophication effects. Since global warming is assumed to indirectly intensify eutrophication symptoms, the results of the present study underscore the importance of nutrient control.</p

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora