Phagotrophic algae in a wastewater stabilization pond

In the course of evolution, phagotrophic euglenoids developed before the phototrophic species. Most phagotrophic euglenoids have a robust feeding apparatus. Members of the algal genus Peranema are able to eat a wide variety of living organisms that have little or no mobility, such as other unicellular algae and live yeasts. Stabilization ponds are artificial environments rich in organic matter, nutrients and microorganisms, and are therefore suitable environments for growing species of Euglenophyta. This contribution records, through photographs and videos, the operation of the feeding apparatus of Peranema collected in a wastewater stabilization pond. The mean pheophytin content of the water was higher than the mean chlorophyll a content, which indicates a non-ideal environment for the growth of microalgae. Thus, Peranema can be used as a bioindicator of the quality of wastewater stabilization pond. The operation of the feeding apparatus of Peranema sp. and the strategy for phagocytizing plastids of Lepocinclis sp. are described

The influence of pre-oxidation with ozone and hydrogen peroxide on the performance of slow filtration with filtering medium of sand and activated granular carbon

A pesquisa apresenta a influência da pré-oxidação com ozônio, peróxido de hidrogênio e com ozônio associado ao peróxido de hidrogênio no desempenho da filtração lenta com meio filtrante de areia e carvão ativado granular, procedida por duas unidades de pré-tratamento em série, a pré-filtração dinâmica e a pré-filtração vertical ascendente. A unidade de filtração lenta foi bem operada com taxa de 3 m3/m 2.d, tendo sido realizadas seis carreiras de filtração. A eficiência da unidade foi avaliada em função de medições de cor, absorvância a 254 nm, carbono orgânico dissolvido, coliformes fecais, algas protozoários e metazoários. Na camada biológica predominaram as Classes Chlorophyceae, Bacillariophyceae sobre as Chrysophyceae, Cyanophyceae e Euglenophyceae. A aplicação de ozônio, peróxido de hidrogênio e ozônio associado ao peróxido de hidrogênio, afetou a maturação da camada biológica em relação à diversidade de espécies e densidade populacional de algas. As algas que colonizaram o meio filtrante, ao longo de sua profundidade, foram espécies das Classes Chlorophyceae e Bacillariophyceae. O meio filtrante apresentou, também, colonização de protozoários e rotíferos. Houve diferenças significativas na qualidade do efluente do filtro lento com relação à remoção de turbidez, cor verdadeira, cor aparente, absorvância a 254 nm e carbono orgânico dissolvido nas diferentes carreiras de filtração decorrente do uso de pré-oxidantes; o que não foi observado com relação à remoção de bactérias heterotróficas, coliformes totais e fecais.This dissertation presents the influence of pre-oxidation with ozone, hydrogen, peroxide and ozone associated with hydrogen peroxide on the performance of slow filtration with filtering medium of sand and actived granular carbon, preceded by two pretreatment units in series, i.e., dynamic and vertical downflow prefilters. Six runs of slow filtration units were operated with a rate of 3 m3/m2.d each. The efficiency of the filtering unit was evaluated by colour determination, absorbance at 254 nm, dissolved organic carbon, total coliforms, fecal coliforms, algae, protozoa and metazoa. Chlorophyceae and Bacilllariophyceae classes predominated over Chrysophyceae, Cryptophyceae, Cyanophyeeae and Euglenophyeeae classes in the schmutzdecke. The application of ozone, hydrogen peroxide and ozone associated with hydrogen peroxide affected the schmutzdecke maturation in relation to the species diversity and population density of algae. The algae that developed in the filtering medium along its depth were species of the Chlorophyceae and Bacillariophyceae classes. The filtering medium also presented a development of protozoa and rotifers. There were significam differences in the quality of slow filter effluent in relation to turbidity removal, true colour, apparent colour, absorbance at 254 nm and dissolved organic carbon in the different filtration runs caused by the use of pre-oxidants. Such differences were not observed in the removal of heterotrophic bacteria and, total and fecal coliforms

Evaluation of phototropic bacteria in stabilization lagoons: diversity, purification and identification

As bactérias fototróficas freqüentemente apresentam florescimentos em lagoas de estabilização utilizadas no tratamento de esgoto sanitário, formando uma camada de cor púrpura na sua superfície. Portanto, o estudo das condições que propiciam tais florescimentos, a diversidade microbiana, o potencial de remoção da matéria orgânica e o estabelecimento das relações entre tais conhecimentos, permitem compreender o metabolismo do sistema. Nesse sentido, o objetivo deste trabalho foi avaliar a diversidade de bactérias (domínio Bacteria), bactérias fototróficas púrpuras e bactérias redutoras de sulfato (BRS) em lagoas de estabilização do Vale do Ribeira (Cajati, SP). Para tal, foram realizadas coletas sazonais (primavera, verão, outono e inverno) na sub-superfície, camada intermediária e interface água-sedimento, em dois horários (14:00 h e 02:00 h), nas lagoas anaeróbia e facultativa. Para analisar os diferentes grupos de microrganismos, utilizou-se a técnica de PCR/DGGE, com primers específicos. Nas análises de filogenia realizou-se o seqüenciamento parcial do gene RNAr 16S e da subunidade M do centro de reação fotossintético das bactérias fototróficas púrpuras. Análises físico-químicas, tais como sulfato, DQO, sólidos, nitrogênio e fósforo foram realizadas, além da determinação da concentração de oxigênio dissolvido, pH, temperatura e radiação solar fotossinteticamente ativa incidente. No outono observou-se maior diversidade de microrganismos do domínio Bacteria, bactérias fototróficas púrpuras e BRS, enquanto na primavera foi verificada a menor diversidade desses microrganismos para as duas lagoas. Na lagoa facultativa foi observada maior diversidade do domínio Bacteria e das BRS em relação à lagoa anaeróbia. Verificou-se maior diversidade de bactérias fototróficas púrpuras na lagoa anaeróbia, caracterizada por duas populações predominantes nas quatro estações e nas diferentes profundidades. A concentração de matéria orgânica (DQO) variou de 60,3 mg/L (inverno) a 298,0 mg/L (primavera) e a maior concentração de sulfato observada foi de 51,0 mg/L (inverno). Bacilo curvo Gram negativo, semelhante à bactéria fototrófica púrpura não sulfurosa, presente em amostra proveniente da sub-superfície da lagoa anaeróbia foi purificado e apresentou 92% de similaridade com Rhodopseudomonas palustris. Em ambas as lagoas foram identificadas bactérias semelhantes a Chromobacterium suttsuga (95%), Clostridium sp. (99%), Rhodobacter sphaeroides (99%), Rhodopseudomonas palustris (99%), Lampropedia hyalina (97%), Campylobacter fetus (99%), Desulfovibrio vulgaris (95%), Rhodospirillum rubrum (95%) e diferentes bactérias não cultivadas.The phototrophic bacteria frequently blossom in the stabilization lagoons that are used in sanitary sewer treatment, forming a purple layer on its surface. Therefore, the study of the conditions that propitiate such blooms, the microbial diversity, the removal of the organic matter and the establishment of the relations between them permit to understand the metabolism of the system. The objective of this work was to evaluate the diversity of the bacteria (Bacteria domain), purple phototrophic bacteria and sulfate reducing bacteria (SRB) in stabilization lagoons of Vale do Ribeira (Cajati - SP). For this, it was made seasonal collects (spring, summer, autumn and winter) from the sub-surface, intermediate layer and interface water-sediment, at two times (14:00 h and 02:00 h) of the anaerobic and facultative lagoons. To analyze the different groups of microorganisms it was used the PCR/DGGE technique, with specific primers; for the phylogenic analysis it was realized the DNA partial sequencing of the 16S RNAr gene and of the subunit M of the photosynthetic center of reaction of the purple photosynthetic bacteria. It was determined: the concentration of dissolved oxygen, pH, temperature and photosynthetically active incident solar radiation, and the physical-chemistry analysis as: COD, solids, nitrogen and phosphorus. In the autumn it was observed greater diversity of microorganisms of the Bacteria domain, the group of the purples phototrophic bacteria and SRB, while in the spring it was verified minor diversity of these microorganisms in the two lagoons studied. In the facultative lagoon it was observed greater diversity of the Bacteria domain and of the SRB with respect to the anaerobic lagoon. It was verified greater diversity of the purple phototrophic bacteria in the anaerobic lagoon, of what in the facultative lagoon, which was characterized by the two predominant populations in the four seasons and in the different points of collect. The concentration of the organic matter (COD) varied from 60,3 mg/L (winter) to 298,0 mg/L (spring) and the greater concentration of sulfate observed was of 51,0 mg/L (winter). Arched bacillus Gram-negative similar to purple not sulfurous bacteria, from a sample of the sub-surface of the anaerobic lagoon was purified and presented 92% of similarity with Rhodopseudomonas palustris. In both lagoons it was identified bacteria similar to Chromobacterium suttsuga (95%), Clostridium sp. (99%), Rhodobacter sphaeroides (99%), Rhodopseudomonas palustris (99%), Lampropedia hyalina (97%), Campylobacter fetus (99%), Desulfovibrio vulgaris (95%), Rhodospirillum rubrum (95%)

The influence of pre-oxidation with ozone and hydrogen peroxide on the performance of slow filtration with filtering medium of sand and activated granular carbon

A pesquisa apresenta a influência da pré-oxidação com ozônio, peróxido de hidrogênio e com ozônio associado ao peróxido de hidrogênio no desempenho da filtração lenta com meio filtrante de areia e carvão ativado granular, procedida por duas unidades de pré-tratamento em série, a pré-filtração dinâmica e a pré-filtração vertical ascendente. A unidade de filtração lenta foi bem operada com taxa de 3 m3/m 2.d, tendo sido realizadas seis carreiras de filtração. A eficiência da unidade foi avaliada em função de medições de cor, absorvância a 254 nm, carbono orgânico dissolvido, coliformes fecais, algas protozoários e metazoários. Na camada biológica predominaram as Classes Chlorophyceae, Bacillariophyceae sobre as Chrysophyceae, Cyanophyceae e Euglenophyceae. A aplicação de ozônio, peróxido de hidrogênio e ozônio associado ao peróxido de hidrogênio, afetou a maturação da camada biológica em relação à diversidade de espécies e densidade populacional de algas. As algas que colonizaram o meio filtrante, ao longo de sua profundidade, foram espécies das Classes Chlorophyceae e Bacillariophyceae. O meio filtrante apresentou, também, colonização de protozoários e rotíferos. Houve diferenças significativas na qualidade do efluente do filtro lento com relação à remoção de turbidez, cor verdadeira, cor aparente, absorvância a 254 nm e carbono orgânico dissolvido nas diferentes carreiras de filtração decorrente do uso de pré-oxidantes; o que não foi observado com relação à remoção de bactérias heterotróficas, coliformes totais e fecais.This dissertation presents the influence of pre-oxidation with ozone, hydrogen, peroxide and ozone associated with hydrogen peroxide on the performance of slow filtration with filtering medium of sand and actived granular carbon, preceded by two pretreatment units in series, i.e., dynamic and vertical downflow prefilters. Six runs of slow filtration units were operated with a rate of 3 m3/m2.d each. The efficiency of the filtering unit was evaluated by colour determination, absorbance at 254 nm, dissolved organic carbon, total coliforms, fecal coliforms, algae, protozoa and metazoa. Chlorophyceae and Bacilllariophyceae classes predominated over Chrysophyceae, Cryptophyceae, Cyanophyeeae and Euglenophyeeae classes in the schmutzdecke. The application of ozone, hydrogen peroxide and ozone associated with hydrogen peroxide affected the schmutzdecke maturation in relation to the species diversity and population density of algae. The algae that developed in the filtering medium along its depth were species of the Chlorophyceae and Bacillariophyceae classes. The filtering medium also presented a development of protozoa and rotifers. There were significam differences in the quality of slow filter effluent in relation to turbidity removal, true colour, apparent colour, absorbance at 254 nm and dissolved organic carbon in the different filtration runs caused by the use of pre-oxidants. Such differences were not observed in the removal of heterotrophic bacteria and, total and fecal coliforms

Decay process of free residual chlorine concentration affected by travel time in water distribution systems

Chlorination is the most widely used method for disinfecting water for human consumption. While the chlorinated water travels through a distribution system, the concentration of free residual chlorine (FRC) declines depending on the natural water characteristics. This study investigated FRC decay in two types of water sources - ground and surface water - with varied concentrations of organic compounds. The travel time variable depended on water consumption patterns of both distribution systems which attend low density populations and their initial project needs. Based on mathematical simulation techniques of water quality models, the study also investigated the effects of water temperature and total organic carbon (TOC) on the kinetic constants (kb) of chlorine decay. Results show that travel time in the most critical locations in the water networks and the minimum disinfectant concentrations required at the entry points were 40 hours and 0.27-0.28 mg L-1 at Vale dos Pássaros housing complex, and 144 hours and 0.30-0.36 mg L-1 at Terras Alphaville housing complex

Application of molecular techniques to evaluate the methanogenic archaea and anaerobic bacteria in the presence of oxygen with different COD : sulfate ratios in a UASB reactor

In this paper, the microbial characteristics of the granular sludge in the presence of oxygen (3.0 +/- 0.7 mg O-2 1(-1)) were analyzed using molecular biology techniques. The granules were provided by an upflow anaerobic sludge blanket (UASB) operated over 469 days and fed with synthetic substrate. Ethanol and sulfate were added to obtain different COD/SO42- ratios (3.0, 2.0, and 1.6). The results of fluorescent in situ hybridization (FISH) analyses showed that archaeal cells, detected by the ARC915 probe, accounted for 77%, 84%, and 75% in the COD/SO42- ratios (3.0, 2.0, and 1.6, respectively). Methanosaeta sp. was the predominant acetoclastic archaea observed by optical microscopy and FISH analyses, and confirmed by sequencing of the excised bands of the DGGE gel with a similarity of 96%. The sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris (similarity of 99%) was verified by sequencing of the DGGE band. Others identified microorganism were similar to Shewanella sp. and Desulfitobacterium hafniense, with similarities of 95% and 99%, respectively. These results confirmed that the presence of oxygen did not severely affect the metabolism of microorganisms that are commonly considered strictly anaerobic. We obtained mean efficiencies of organic matter conversion and sulfate reducing higher than 74%. (C) 2008 Elsevier Ltd. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2002/12985-7]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2001/05489-0