Microaerated UASB reactor treating textile wastewater: The core microbiome and removal of azo dye Direct Black 22.

Sequential anaerobic and aerobic processes have been recommended to treat textile wastewater reliably. In this work, the focus was on finding an energetically more competitive system to remove tetra-azo dye Direct Black 22 (DB22). We operated two upflow anaerobic sludge blanket (UASB) reactors (R1 and R2) in three phases (PI, PII, and PIII). R1 was operated as a conventional UASB, while R2 was microaerated in the upper part (0.18 ±â€¯0.05 mg O2. L-1), aiming to remove DB22 simultaneously with the aromatic amine byproducts. PI consisted of feeding reactors with synthetic textile wastewater (STW), PII had higher salinity in the STW, and PIII was the same as PII, plus sulfate. The results showed that color and COD removal efficiencies were similar for both reactors (67-72% for R1 and 59-78% for R2) without a substantial influence of oxygen in R2. However, microaeration played a crucial role in R2 by removing the anaerobically formed aromatic amines; during PIII, the effluent was 16 times less toxic than that of R1. The microbial community that developed in the sludge bed of both reactors was quite similar, with the core microbiome represented by Trichococcus, Syntrophus and Methanosaeta genera. The increase in salinity in PII and PIII promoted a shift in the microbial community, excluding salty-sensitive genera from the core microbiome. The putative genera Brevundimonas and Ornatilinea were associated to aromatic amine microaerobic removal. Therefore, there is a potential application of a compact microaerated anaerobic system for textile wastewater treatment.

Hydraulic retention time influence on azo dye and sulfate removal during the sequential anaerobic-aerobic treatment of real textile wastewater.

In the present study, we evaluate the behavior of real textile wastewater treatment using a system composed of two sequential pilot-scale reactors (anaerobic followed by aerobic) during 622 days. The work focused on the competition between color and sulfate removal processes, when the hydraulic retention time (HRT) was increased in the anaerobic/aerobic reactors from 16/12 hours in phase I (PI) to 4/3 days in phase II (PII). The organic matter was successfully removed in both phases through the system, and the highest efficiency (75%) was achieved in PII. The increase in the HRT did not improve azo dye degradation under anaerobic conditions. Instead, it favored sulfate reduction, which removal efficiency increased from 26% in PI to 75% in PII. Aromatic amines were detected in the anaerobic reactor effluent and removed in the aerobic reactor.

Structure and dynamics of the phytoplankton community within a maturation pond in a semiarid region.

In northeastern Brazil, stabilization ponds are very suitable for wastewater treatment because of the relative great land availability and environmental conditions (e.g., high temperature) favorable for microorganism optimal development. However, blooms of potentially toxic cyanobacteria may affect the use of these treatment ponds due to resulting effluent poor quality. The objective of this study was to evaluate the dynamics of phytoplankton communities and the occurrence of cyanobacteria in a maturation pond located immediately after a series of two ponds. Temperature, dissolved oxygen, pH, BOD, N, and P were measured during a period of four months when samples were collected from the surface and the bottom of 7 sampling points distributed inside the pond. The phytoplankton of collected samples was also identified and classified using a conventional optical microscopy. Analysis of variance and Tukey test were used to evaluate the results. The three phytoplankton divisions found (Cyanophyta, Chlorophyta, and Euglenophyta) did not change considerably through surface and bottom. However, they changed greatly over the sampled months; great dominance of Cyanophyta was found at April and October, while Chlorophyta dominated the lagoon in September. Low superficial organic loads (between 78 and 109 kg BOD.ha-1.d-1) and N:P ≤ 10 were the determinant factors that favored the predominance of Cyanophyta. The presence of two potentially toxic species of Cyanophyta, Oscillatoria sp. and Microcystis aeruginosa, indicates that caution is required when considering the final destination of treated effluent and suggests a need to assess the risks and benefits associated with the use of the treatment technology.

Structure and dynamics of the phytoplankton community within a maturation pond in a semiarid region / Estrutura e dinâmica da comunidade fitoplanctônica de uma lagoa de maturação em região semiárida

Abstract In northeastern Brazil, stabilization ponds are very suitable for wastewater treatment because of the relative great land availability and environmental conditions (e.g., high temperature) favorable for microorganism optimal development. However, blooms of potentially toxic cyanobacteria may affect the use of these treatment ponds due to resulting effluent poor quality. The objective of this study was to evaluate the dynamics of phytoplankton communities and the occurrence of cyanobacteria in a maturation pond located immediately after a series of two ponds. Temperature, dissolved oxygen, pH, BOD, N, and P were measured during a period of four months when samples were collected from the surface and the bottom of 7 sampling points distributed inside the pond. The phytoplankton of collected samples was also identified and classified using a conventional optical microscopy. Analysis of variance and Tukey test were used to evaluate the results. The three phytoplankton divisions found (Cyanophyta, Chlorophyta, and Euglenophyta) did not change considerably through surface and bottom. However, they changed greatly over the sampled months; great dominance of Cyanophyta was found at April and October, while Chlorophyta dominated the lagoon in September. Low superficial organic loads (between 78 and 109 kg BOD.ha–1.d–1) and N:P ≤ 10 were the determinant factors that favored the predominance of Cyanophyta. The presence of two potentially toxic species of Cyanophyta, Oscillatoria sp. and Microcystis aeruginosa, indicates that caution is required when considering the final destination of treated effluent and suggests a need to assess the risks and benefits associated with the use of the treatment technology.

Resumo No nordeste do Brasil, as lagoas de estabilização são muito adequadas para o tratamento de águas residuárias por causa da disponibilidade relativamente grande de terra e das condições ambientais (por exemplo, altas temperaturas) favoráveis ao melhor desenvolvimento dos microorganismos. Entretanto, florações de cianobactérias potencialmente tóxicas podem afetar o uso dessas lagoas de tratamento, devido à consequente qualidade inferior do efluente. O objetivo deste estudo foi avaliar a dinâmica das comunidades de fitoplâncton e a ocorrência de cianobactérias em uma lagoa de maturação situada após duas lagoas em série. Temperatura, oxigênio dissolvido, pH, DBO, N e P foram medidos durante um período de quatro meses, durante o qual amostras foram coletadas na superfície e fundo em sete pontos de amostragem da lagoa. As comunidades de fitoplâncton das amostras coletadas foram também identificadas e classificadas utilizando-se um microscópio óptico convencional. Para avaliar os resultados utilizou-se a análise de variância e o teste de Tukey. Para as três divisões de fitoplâncton encontradas (Cyanophyta, Chlorophyta e Euglenophyta), não houve diferença significativa para as amostras de superfície e de fundo de um mesmo mês. Entretanto, ocorreu grande variação para as amostras dos diferentes meses; nos meses de abril e outubro houve uma predominância de Cyanophyta, ao passo que em setembro o predomínio na lagoa foi de Chlorophyta. Os fatores determinantes que favoreceram o predomínio de Cyanophyta foram a baixa carga orgânica superficial aplicada (entre 78 e 109 kg DBO.ha–1.d–1) e N:P ≤ 10. A presença de duas das espécies de Cyanophyta, Oscillatoria sp. e Microcystisaeruginosa, consideradas potencialmente tóxicas, indica que é necessária precaução quando se considera o destino final do efluente tratado e sugere a necessidade de avaliar os riscos e benefícios associados ao uso da tecnologia de tratamento.

Anaerobic treatment of crude glycerol from biodiesel production.

In this study, we evaluated the use of an up-flow anaerobic sludge blanket (UASB) reactor to treat crude glycerol obtained from cottonseed biodiesel production. The laboratory-scale UASB reactor (7.0 L) was operated at ambient temperature of 26.5°C with chemical oxygen demand (COD) concentrations between 0.5 and 8.0 g/L. The volatile fatty acid contents, pH, inorganic salt contents and biogas production were monitored during a 280-day experimental period. Molecular biology techniques were used to assess the microbial diversity in the bioreactor. The reactor achieved COD removal efficiencies of up to 92% except during one phase when the efficiency decreased to 81%. Biogas production remained stable throughout the experimental period, when the fraction converted to methane reached values as high as 68%. The profile of the denaturing gradient gel electrophoresis (DGGE) bands suggested slight changes in the microbial community during reactor operation. The overall results indicated that the crude glycerol from biodiesel production can serve as a suitable substrate for anaerobic degradation with a stable reactor performance and biogas production as long as the applied organic loads are up to 8.06 kg COD/m3·d.

Color, organic matter and sulfate removal from textile effluents by anaerobic and aerobic processes.

An upflow anaerobic sludge blanket (UASB)-submerged aerated biofilter (SAB) system was evaluated to remove color and chemical oxygen demand (COD) from real textile effluent. The system was operated for 335 days in three phases (P-1, P-2, P-3) with total hydraulic retention time varying from 21 h to 14 h. The results showed that high sulfate levels (>300 mg SO4(2-)/L) impaired the dye reduction. The best color removal efficiencies of 30% and 96% for the UASB and the reactor system, respectively, were obtained in P-1; the SAB higher efficiency was associated with adsorption. The best COD removal efficiency of 71% for the reactor system was obtained in P-2. Precipitation of some material composed mostly of sulfur (98%) and some metals occurred in the UASB. However, the precipitated sulfur was again oxidized in the SAB. The system also showed an effective toxicity reduction in tests (Daphnia magna) with the treated effluent.

Textile effluent treatment in a UASB reactor followed by submerged aerated biofiltration.

An upflow anaerobic sludge bed (UASB)-submerged aerated biofilter (SAB) system that treats effluents from a jeans factory was evaluated. The 210-day operational period was divided into three phases (PI, PII and PIII), each with a different hydraulic retention time (HRT in h) and organic loading rate (OLR in kg COD/m3.d). In PI, the best performance was achieved using the UASB (HRT 24, OLR 1.3) with COD and color removal efficiencies of 59 and 64%, respectively; the corresponding values were 77 and 86% for the final effluent. In PII, the efficiencies were 50 and 55% using the UASB (HRT 16, OLR 1.2), respectively, and 69 and 81% for the final system effluent, respectively. In PIII, the UASB (HRT 12 and ORL 3.2) showed the poorest performance; the efficiencies decreased to 48 and 50%, respectively. The same phenomenon occurred in the system with corresponding efficiencies decreasing to 69 and 61%. Throughout the experiment, the system removal efficiencies were between 57 and 88% for nitrogen and between 14 and 63% for sulfate. The final effluent showed relatively non-toxicity or moderate toxicity using Daphnia magna as an indicator. Therefore, the overall results showed that the use of a sequential anaerobic-aerobic system is promising for treatment of textile industrial wastewater.

Linfomas cutáneos de células T, CD30 (+) / Cutaneous T-cells lymphomas, CD30 (+)

El aspecto de desórdenes linfoproliferativos cutáneos primitivos CD 30 (ki-1) positivos está constituido por la papulosis linfomatoide, el linfoma de células grandes anaplásico y los linfomas inmunoblásticos y pleomórfico de células medianas y grandes. Durante el período enero de 1995 a septiembre de 1998, nuestro Servicio evaluó 7 casos, representados por 3 casos de papulosis linfomatoide (una de las cuales luego de remitir evolucionó a un linfoma de alto grado), 4 casos de linfomas de células grandes anaplásicas, uno de ellos se desarrolló sobre una micosis fungoidea previa. Los estudios de inmunohistoquímica confirmaron CD 30 (+) en todos los casos, 6 presentaron inmunofenotipo T CD 4(+) y 1 tipo null cel. Se observaron remisiones espontáneas parciales en varios casos y recidivas en la zona con aspecto clínico, similar a la lesión previa. Fueron sensibles a la radioterapia y no recidivaron luego de cirugía. Nuestra casuística confirma el buen pronóstico que la CD 30 positividad otorga a estos linfomas cutáneos, a diferencia de la localización cutánea secundaria de un linfoma de origen nodal que tiene mal prónostico (AU)

Linfomas cutáneos de células T, CD30 (+) / Cutaneous T-cells lymphomas, CD30 (+)

El aspecto de desórdenes linfoproliferativos cutáneos primitivos CD 30 (ki-1) positivos está constituido por la papulosis linfomatoide, el linfoma de células grandes anaplásico y los linfomas inmunoblásticos y pleomórfico de células medianas y grandes. Durante el período enero de 1995 a septiembre de 1998, nuestro Servicio evaluó 7 casos, representados por 3 casos de papulosis linfomatoide (una de las cuales luego de remitir evolucionó a un linfoma de alto grado), 4 casos de linfomas de células grandes anaplásicas, uno de ellos se desarrolló sobre una micosis fungoidea previa. Los estudios de inmunohistoquímica confirmaron CD 30 (+) en todos los casos, 6 presentaron inmunofenotipo T CD 4(+) y 1 tipo null cel. Se observaron remisiones espontáneas parciales en varios casos y recidivas en la zona con aspecto clínico, similar a la lesión previa. Fueron sensibles a la radioterapia y no recidivaron luego de cirugía. Nuestra casuística confirma el buen pronóstico que la CD 30 positividad otorga a estos linfomas cutáneos, a diferencia de la localización cutánea secundaria de un linfoma de origen nodal que tiene mal prónostico

Melanoma polipoide / Polypoid melanoma

El melanoma polipoide, variante exofítica del melanoma, es una forma agresiva y poco frecuente de presentación. Se comunica un caso en el dorso de una paciente de 76 años, sexo masculino, y se realiza una revisión bibliográfica de los factores pronósticos del melanoma (AU)

Melanoma polipoide / Polypoid melanoma

El melanoma polipoide, variante exofítica del melanoma, es una forma agresiva y poco frecuente de presentación. Se comunica un caso en el dorso de una paciente de 76 años, sexo masculino, y se realiza una revisión bibliográfica de los factores pronósticos del melanoma