Anaerobic treatment of wastewater from coffee pulping in upflow anaerobic sludge blanket (UASB) in two stages

In this work, the efficiency of two-stage upflow anaerobic sludge blanket (UASB) reactors was evaluated in bench scale, for treating a liquid effluent from coffee pulping. Hydraulic detention times (HDT) were 4.0; 5.2 and 6.2 days, resulting in organic loading rates (OLR) of 5.8; 3.6 and 3.0g total COD per (L-d) in the first reactor (Rl) and HDT of 2.0; 2.6 and 3.1 days with OLR of 5.8; 0.5 and 0.4 g total COD per (L-d) in the second reactor (R2). The medium values of total COD affluent varied from 15.440 to 23.040 mg O 2/L, and in the effluent to the reactors 1 and 2 were from l.lOO to 11.500 mg 0 2/L and 420 to 9.000 mg O 2/L, respectively. The medium values of removal efficiencies of total COD and TSS varied from 66 to 98% and 93 to 97%, respectively, in the system of treatment with the UASB reactors, in two stages. The content of methane in the biogas varied from 69 to 89% in the Rl and from 52 to 73% in the R2. The maximum volumetric methane production of 0.483 m 3 CH 4per (m 3 reactor d) was obtained with OLR of 3.6 g total COD per (L reactor d) and HDT of 6.2 days in the Rl. The volatile fatty acids concentration was kept below 100mg/L with HDT of 5.2 and 6.2 days in the Rl and HDT of 2.6 and 3.1 days in the R2.

Desempenho de reatores anaeróbios de fluxo ascendente com manta de lodo em dois estágios tratando águas residuárias de suinocultura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tratamento anaeróbio de águas residuárias do beneficiamento de café por via úmida em reatores UASB em dois estágios

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tratamento de manipueira em reator anaeróbio compartimentado

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Desempenho de sistemas de reatores anaeróbios e aeróbio na remoção de coliformes e ovos de helmintos de águas residuárias de suinocultura

Pós-graduação em Microbiologia Agropecuária - FCAV

Caracterização e estudo do comportamento térmico de lodo proveniente da indústria sucroalcooleira

Pós-graduação em Química - IBILCE

Reatores UASB em dois estágios seguidos de lodos ativados em batelada para o tratamento de águas residuárias do beneficiamento de café por via úmida

Pós-graduação em Microbiologia Agropecuária - FCAV

Biogas and bio-hydrogen: production and uses. A review

The first part of this essay aims at investigating the already available and promising technologies for the biogas and bio-hydrogen production from anaerobic digestion of different organic substrates. One strives to show all the peculiarities of this complicate process, such as continuity, number of stages, moisture, biomass preservation and rate of feeding. The main outcome of this part is the awareness of the huge amount of reactor configurations, each of which suitable for a few types of substrate and circumstance. Among the most remarkable results, one may consider first of all the wet continuous stirred tank reactors (CSTR), right to face the high waste production rate in urbanised and industrialised areas. Then, there is the up-flow anaerobic sludge blanket reactor (UASB), aimed at the biomass preservation in case of highly heterogeneous feedstock, which can also be treated in a wise co-digestion scheme. On the other hand, smaller and scattered rural realities can be served by either wet low-rate digesters for homogeneous agricultural by-products (e.g. fixed-dome) or the cheap dry batch reactors for lignocellulose waste and energy crops (e.g. hybrid batch-UASB). The biological and technical aspects raised during the first chapters are later supported with bibliographic research on the important and multifarious large-scale applications the products of the anaerobic digestion may have. After the upgrading techniques, particular care was devoted to their importance as biofuels, highlighting a further and more flexible solution consisting in the reforming to syngas. Then, one shows the electricity generation and the associated heat conversion, stressing on the high potential of fuel cells (FC) as electricity converters. Last but not least, both the use as vehicle fuel and the injection into the gas pipes are considered as promising applications. The consideration of the still important issues of the bio-hydrogen management (e.g. storage and delivery) may lead to the conclusion that it would be far more challenging to implement than bio-methane, which can potentially “inherit” the assets of the similar fossil natural gas. Thanks to the gathered knowledge, one devotes a chapter to the energetic and financial study of a hybrid power system supplied by biogas and made of different pieces of equipment (natural gas thermocatalitic unit, molten carbonate fuel cell and combined-cycle gas turbine structure). A parallel analysis on a bio-methane-fed CCGT system is carried out in order to compare the two solutions. Both studies show that the apparent inconvenience of the hybrid system actually emphasises the importance of extending the computations to a broader reality, i.e. the upstream processes for the biofuel production and the environmental/social drawbacks due to fossil-derived emissions. Thanks to this “boundary widening”, one can realise the hidden benefits of the hybrid over the CCGT system.

Cassava wastewater (manipueira) treatment using a two-phase anaerobic biodigestor

Um biodigestor anaeróbio de duas fases foi utilizado para se analisar a produção de metano com diferentes cargas de entrada de manipueira. A fase acidogênica foi realizada em processo de batelada e a metanogênica em biodigestor anaeróbio de fluxo ascendente e leito fixo com alimentação contínua. As cargas orgânicas de entrada variaram de 0,33 a 8,48 gDQO (Demanda Química de Oxigênio)/L.dia. A maior porcentagem de metano encontrada foi de 80,9%, com carga orgânica de 0,33g e a menor, 56,8%, obtida com 8,49gDQO/L.d. A maior taxa de redução de DQO foi de 88,89%, obtida com carga orgânica de 2,25g e a menor, 54,95%, com 8,48gDQO/L.d. Analisando-se os dados apresentados verificou-se que a biodigestão anaeróbia pode ser conduzida, pelo menos, de duas maneiras, ou seja, para produção de energia (metano) ou para redução de carga orgânica. A carga orgânica de entrada deve ser calculada em função do objetivo a ser alcançado com a biodigestão anaeróbia.

Sulfamethoxazole and ciprofloxacin removal using a horizontal-flow anaerobic immobilized biomass reactor

The antibiotics sulfamethoxazole (SMTX) and ciprofloxacin (CIP) are commonly used in human and veterinary medicine, which explains their occurrence in wastewater. Anaerobic reactors are low-cost, simple and suitable technology to wastewater treatment, but there is a lack of studies related to the removal efficiency of antibiotics. To overcome this knowledge gap, the objective of this study was to evaluate the removal kinetics of SMTX and CIP using a horizontal-flow anaerobic immobilized biomass reactor. Two different concentrations were evaluated, for SMTX 20 and 40 μg L(-1); for CIP 2.0 and 5.0 μg L(-1). The affluent and effluent analysis was carried out in liquid chromatography/tandem mass spectrometry (LC-MS/MS) with the sample preparation procedure using an off-line solid-phase extraction. This method was developed, validated and successfully applied for monitoring the affluent and effluent samples. The removal efficiency found for both antibiotics at the two concentrations studied was 97%. Chemical oxygen demand (COD) exhibited kinetic constants that were different from that observed for the antibiotics, indicating the absence of co-metabolism. Also, though the antibiotic concentration was increased, there was no inhibitory effect in the removal of COD and antibiotics.

Sequential nitrification-denitrification in a plug flow activated sludge system /

Mode of access: Internet.

Biometanazione della frazione organica dei rifiuti solidi urbani attraverso codigestione con letame bovino

An anaerobic consortium, capable of efficiently converting into methane the organic fraction of mechanically sorted municipal solid waste (MS-OFMSW), was obtained through a dedicated enrichment procedure in a 0.36 L up-flow anaerobic recirculated reactor. This result was obtained after several micro-reactor fed-batch procedures that allowed to obtain only a few methanization of the MS-OFMSW.

Start-up of horizontal anaerobic reactors with sludge blanket and fixed bed for wastewater treatment from coffee processing by wet method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II.

This work presents the preliminary study of new carbonaceous materials (CMs) obtained from exhausted sludge, their use in the heterogeneous anaerobic process of biodecolorization of azo dyes and the comparison of their performance with one commercial active carbon. The preparation of carbonaceous materials was conducted through chemical activation and carbonization. Chemical activation was carried out through impregnation of sludge-exhausted materials with ZnCl2 and the activation by means of carbonization at different temperatures (400, 600 and 800°C). Their physicochemical and surface characteristics were also investigated. Sludge based carbonaceous (SBC) materials SBC400, SBC600 and SBC800 present values of 13.0, 111.3 and 202.0m(2)/g of surface area. Biodecolorization levels of 76% were achieved for SBC600 and 86% for SBC800 at space time (τ) of 1.0min, similar to that obtained with commercial activated carbons in the continuous anaerobic up-flow packed bed reactor (UPBR). The experimental data fit well to the first order kinetic model and equilibrium data are well represented by the Langmuir isotherm model. Carbonaceous materials show high level of biodecolorization even at very short space times. Results indicate that carbonaceous materials prepared from sludge-exhausted materials have outstanding textural properties and significant degradation capacity for treating textile effluents.