Abstract Anaerobic biological treatment can comprise a viable route of CH4 production through the energy recovery of organic solid waste (OSW). This work therefore presented a bibliometric analysis of research trends on the theme "Applicability of biological treatment via Anaerobic Digestion in Organic Solid Waste", considering experimental articles published from 2018 to 2022 in the Web of Science database™; the analysis used VoSviewer software to define research trends, and found that the main terms addressed in the mapped scientific articles were anaerobic, waste, sludge, waste food, municipal waste, anaerobic co-digestion, sewage sludge, organic fraction, co-digestion and biogas. As a product of such mapping, an Interaction Network Diagram was constructed comprising the main terms in addition to a theoretical foundation on anaerobic digestion and biochemical and microbiological aspects about the process.

Resumo O tratamento biológico por via anaeróbia pode compreender uma rota viável de produção de CH4 através da recuperação energética dos resíduos sólidos orgânicos (RSO). Logo, neste trabalho apresentou-se uma análise bibliométrica das tendências de pesquisa acerca da temática “Aplicabilidade do tratamento biológico via Digestão Anaeróbia em Resíduos Sólidos Orgânicos”, considerando artigos experimentais publicados no período do ano de 2018 ao ano de 2022 na base de dados da Web of Science™; para definir as tendências de pesquisa fez-se uso do software VoSviewer, que evidenciou que os termos principais abordados nos artigos científicos mapeados foram: anaerobic digestion, waste, sludge, food waste, municipal solid waste, anaerobic co-digestion, sewage sludge, fraction organic, co-digestion e biogas. Como produto de tal mapeamento construiu-se um Diagrama de Rede de Interações, compreendendo os termos principais, além de uma fundamentação teórica sobre digestão anaeróbia e os aspectos bioquímicos e microbiológicos sobre o processo.

ABSTRACT The main objective of this study was to evaluate the anaerobic conversion of vinasse into biomethane with gradual increase in organic loading rate (OLR) in two upflow anaerobic sludge blanket (UASB) reactors, R1 and R2, with volumes of 40.5 and 21.5 L in the mesophilic temperature range. The UASB reactors were operated for 230 days with a hydraulic detection time (HDT) of 2.8 d (R1) and 2.8-1.8 d (R2). The OLR values applied in the reactors were 0.2-7.5 g totalCOD (L d)−1 in R1 and 0.2-11.5 g totalCOD (L d)−1 in R2. The average total chemical oxygen demand (totalCOD) removal efficiencies ranged from 49% to 82% and the average conversion efficiencies of the removed totalCOD into methane were 48-58% in R1 and 39-65% in R2. The effluent recirculation was used for an OLR above 6 g totalCOD (L d)−1 in R1 and 8 gtotalCOD (L d)−1 in R2 and was able to maintain the pH of the influent in R1 and R2 in the range from 6.5 to 6.8. However, this caused a decrease for 53-39% in the conversion efficiency of the removed totalCOD into methane in R2 because of the increase in the recalcitrant COD in the influent. The largest methane yield values were 0.181 and 0.185 (L) CH4 (gtotal COD removed)−1 in R1 and R2, respectively. These values were attained after 140 days of operation with an OLR of 5.0-7.5 g totalCOD (L d)−1 and total COD removal efficiencies around 70 and 80%.

A poluição da água e do solo causada pela suinocultura provoca impactos ambientais severos nas regiões produtoras. Uma alternativa eficiente para atenuar esse problema pode ser a utilização de reatores anaeróbios de alta taxa. Neste trabalho, avaliou-se o efeito das águas residuárias de suinocultura com concentrações de sólidos suspensos totais em torno de 6.000 mg.L−1 no desempenho do reator anaeróbio compartimentado, com três câmaras. O volume da primeira câmara foi de 210 L e da segunda e terceira de 160 L. O reator anaeróbio compartimentado foi submetido a tempos de detenção hidráulica de 56, 28 e 18 horas e a cargas orgânicas volumétricas de 5,0 a 10,1 g DQOtotal (L.d)−1. As maiores remoções de demanda química de oxigênio total, de 42 a 68%, e das produções volumétricas de metano, de 0,261 a 0,454 L CH4 (L reator d)−1, ocorreram na segunda câmara.

Water and soil pollution caused by the waste from the swine production causes severe environmental impacts in producing areas. An efficient alternative to reduce these impacts can be the use of high-rate anaerobic reactors. In this work, it was evaluated the effect of the swine wastewater with total suspended solids concentrations around 6.000 mg.L−1 in the anaerobic baffled reactor with three compartments. The volume of the first compartment was 210 L and of the second and third ones of 160 L. The anaerobic baffled reactor was submitted at hydraulic detention times of 56, 28 and 18 hours and to organic load rates of 5.0 to 10.1 g total COD (L.d)−1. The highest total COD removals, of 42 to 68%, and volumetric methane productions, of 0.261 to 0.454 L CH4 (L reactor d)−1, occurred in the second compartment.

Foi avaliado o desempenho de dois reatores anaeróbios de fluxo ascendente com manta de lodo (UASB) em escala-piloto (908 e 188 L), instalados em série (R1 e R2), para o tratamento de águas residuárias de suinocultura com concentrações médias de SST em torno de 5 e 13 g L-1. Os TDH foram de 36 e 18 h com COV de 5,5 a 34,4 g DQO (L d)-1 no R1 e TDH de 7,5 e 3,7 h com COV de 5,1 a 45,2 g DQO (L d)-1 no R2. As eficiências médias de remoção de DQO variaram de 55 a 85% no R1 e de 43 a 57% no R2, resultando valores de 82 a 93% nos reatores UASB em dois estágios. As concentrações de metano no biogás foram de 69 a 74%, com produções de 0,05 a 0,27 L CH4 (g DQOremovida)-1 no R1 e de 0,10 a 0,12 L CH4 (g DQOremovida)-1 no R2. Os valores médios de eficiência de remoção de Ptotal foram de 61 a 75%; de NK de 39 a 69%; de Norg. de 82 a 93%, e de Fe, Zn, Cu e Mn de 20 a 94%. As concentrações de N-am. não foram reduzidas, indicando a necessidade de pós-tratamento para disposição do efluente em corpos d'água. Houve redução de coliformes totais de 99,8123 a 99,9989%, e de coliformes termotolerantes de 99,9725 a 99,9999%. As condições impostas aos reatores UASB em dois estágios propiciaram reduções acentuadas da carga poluidora orgânica e inorgânica das águas residuárias de suinocultura, com conversão de até 77% da DQO removida em metano.

The performance of two upflow anaerobic sludge blanket (UASB) reactors was evaluated in pilot scale (908 and 188 L), installed in series (R1 and R2), fed with swine wastewater with TSS around 5 and 13 g L-1. The UASB reactors were submitted to HDT of 36 and 18 h with VOL of 5.5 to 34.4 g COD (L d)-1 in the R1 and HDT of 7.5 e 3.7 h with VOL from 5.1 to 45.2 g COD (L d)-1 in the R2. The average removal efficiencies of COD ranged from 55 to 85% in the R1 and from 43 to 57% in the R2, resulting in values from 82 to 93% in the UASB reactors in two stage. Methane concentrations in the biogas were 69 to 74% with specific production from 0.05 to 0.27 L CH4 (g removedCOD)-1 in the R1 and of 0.10 to 0.12 L CH4 (g removedCOD)-1 in the R2. The average removal efficiencies were 61 to 75% for totalP, 39 to 69% for KN, 82 to 93% for orgN and 20 to 94% for Fe, Zn, Cu and Mn. The amN concentration were not reduced indicating the need to post-treatment for effluent disposal into water bodies. There were reductions of total coliforms from 99.8123 to 99.9989% and of thermotolerant coliforms from 99.9725 to 99.9999%. The conditions imposed to the UASB reactors in two stage provided high conversions of removedCOD into methane (up to 77%) and reductions of organic an inorganic pollution loads from swine wastewater.

O desempenho de dois sistemas de tratamento de águas residuárias de suinocultura com reatores anaeróbios de fluxo ascendente com manta de lodo (UASB), em dois estágios, foi avaliado com e sem pós-tratamento em reator operado em batelada sequencial alimentada (RBS), com etapa aeróbia. Os reatores UASB do primeiro estágio possuíam 908 L nos conjuntos I e II, e no segundo estágio, 350 e 188 L, respectivamente. No conjunto II foi realizado o pós-tratamento em RBS de 3000 L. Os tempos de detenção hidráulica nos sistemas de tratamento foram de 100; 75 e 58 h no conjunto I; de 87; 65 e 51 h no conjunto II, e de 240 e 180 h no RBS. As cargas orgânicas volumétricas nos reatores UASB do primeiro estágio variaram de 6,9 a 12,6 g DQOtotal (L d)-1 no conjunto I, e de 7,5 a 9,8 g DQOtotal (L d)-1 no conjunto II. As eficiências médias de remoção de DQOtotal, fósforo total (Ptotal), nitrogênio Kjeldahl (NK) e nitrogênio orgânico (Norg.) nos sistemas de tratamento anaeróbio atingiram valores máximos de 97; 64; 68 e 98 %, respectivamente. No RBS, as eficiências de remoção de DQOtotal e coliformes termotolerantes foram de até 62 e 92%, reduzindo para 135 mg L-1 e 2 x 10(4) NMP (100 mL)-1, respectivamente, os valores médios no efluente. Para o Ptotal, nitrogênio total (NT) e Norg, as eficiências de remoção no RBS foram de até 58; 25 e 73%, respectivamente.

In this work it was evaluated the performance of two systems of swine wastewater treatment consisting of two-stage upflow anaerobic sludge blanket (UASB) reactors, with and without post-treatment in sequencing batch reactor (SBR), fed continuously, with aerobic phase. The UASB reactors in the first stage had 908 L in the sets I and II, and in the second stage 350 and 188 L, respectively. In the set II the post-treatment was performed in a SBR of 3,000 L. The hydraulic detention times in the anaerobic treatment systems were 100, 75 and 58 h in the set I; 87, 65 and 51 h in the set II; and 240 and 180 h in the SBR. The volumetric organic load applied in the first stage UASB reactors ranged from 6.9 to 12.6 g total COD (L d)-1 in the set I and 7.5 to 9.8 g total COD (L d)-1 in the set II. The average removal efficiencies of total COD, total phosphorus (Ptotal), and Kjeldahl and organic nitrogen (KN and Norg) in the anaerobic treatment systems were similar and reached maximum values of 97%, 64%, 68%, and 98%. In the SBR, the removal efficiencies of total COD and thermotolerant coliforms were up to 62 and 92% resulting, respectively, in effluent concentrations of 135 mg L-1 and 2x10(4)MPN (100 mL)-1. For Ptotal, total nitrogen (TN) and Norg, the average removal efficiencies in the SBR were up to 58, 25 and 73%, respectively.

Esta pesquisa teve como objetivo investigar a utilização de diferentes estratégias de Leitura e Escrita no ensino de Matemática do Ensino Médio, e de instrumentos nos quais os alunos externaram as suas percepções durante o processo de ensino e aprendizagem. Para tanto, realizou-se uma pesquisa qualitativa com análise interpretativa sobre as atividades e os instrumentos propostos, os quais foram organizados em um Portfólio. A formulação e a aplicação da pesquisa, bem como a análise dos resultados e as conclusões foram baseadas no enfoque histórico-cultural de Vigotski e estudos sobre a linguagem matemática e a utilização da Leitura e Escrita nas aulas de Matemática, de diversos pesquisadores. As categorias emergentes da análise dos dados foram: a construção do conhecimento matemático, a semântica dos termos matemáticos, os valores demonstrados pelos alunos e a potencialidade das atividades. Os resultados, considerando-se todas as categorias, indicam que o processo pode tornar a relação professor-aluno e aluno-aluno mais interativa e mais efetiva para a construção do conhecimento matemático.

The main goal of this study was to investigate the utilization of different strategies of reading and writing in mathematics teaching at the high school level, and of instruments the students could use to externalize their perceptions during the teaching and learning process. A qualitative research methodology was used, with interpretative analysis of the activities and the proposed instruments, which were organized in a Portfolio Book. The formulation and the application of the research, as well as the analysis of the results and the conclusions, were based on Vygotsky's historical-cultural approach and on other studies regarding mathematical language and the utilization of reading and writing in mathematics classes. The categories that emerged from the analysis of the data were the construction of mathematical knowledge, semantics of the mathematical terms, values and the potentiality of the activities. Considering all the categories, the results indicate that the process can make the relationship among teacher and students more interactive and effective for the construction of mathematical knowledge.

Avaliou-se o desempenho de um reator anaeróbio de fluxo ascendente com manta de lodo (UASB) seguido de um filtro anaeróbio, instalados em série, com volume total de 300 L e 190 L, respectivamente, no tratamento de águas residuárias de suinocultura. As cargas orgânicas volumétricas aplicadas no reator UASB foram de 12,4;15,5; 23,2 e 26,3 g DQOtotal (L d)-1. Para o pós-tratamento do efluente do sistema anaeróbio em dois estágios utilizou-se um filtro biológico percolador com volume total de 250 L. O meio suporte utilizado nos filtros anaeróbio e biológico percolador foi composto por anéis de bambu. No sistema de tratamento anaeróbio e de pós-tratamento foram observadas eficiências médias de remoção de demanda química de oxigênio total (DQOtotal), sólidos suspensos totais (SST), nitrogênio total (NT), fósforo total (P-total), Cu e Zn de até 98, 99, 78, 84, 99 e 98%, respectivamente.

The performance of an upflow anaerobic sludge blanket (UASB) followed by the anaerobic filter, installed in series, was evaluated for the treatment of swine wastewater. The total volume of UASB and anaerobic filter were of 300 L and 190 L, respectively. The organic load rate applied on the reactor UASB were of 12.4, 15.5, 23.2 and 26.3 g total COD (L d)-1. For the post-treatment of effluent the anaerobic system was used a trickling filter with total volume of 250 L. The supports used in the anaerobic filter and trickling filter were composed by bamboo rings. The efficiencies of removal the chemical oxygen demand, total solids suspended, nitrogen, total phosphorus, Cu and Zn were of up to 98, 99, 78, 84, 99 and 98%, respectively, for the anaerobic and aerobic treatment system.

Neste estudo avaliou-se o desempenho de um reator anaeróbio operado em batelada sequencial, em escala piloto, com volume total de 280 L, no tratamento de águas residuárias de suinocultura. As cargas orgânicas volumétricas aplicadas no reator foram de 4,42; 5,27; 9,33 e 11,79 g DQOtotal (L d)-1. As eficiências médias de remoção de DQOtotal, sólidos suspensos totais (SST) e sólidos suspensos voláteis (SSV) variaram de 56 a 87%. O nitrogênio total Kjedahl (NTK), fósforo total (P-total) e magnésio (Mg) foram removidos com eficiências médias de 26 a 39%. As produções volumétricas de metano variaram de 0,50 a 0,64 L CH4 (L reator d)-1 e não foram observadas diferenças significativas. As relações sólidos voláteis/sólidos totais (SV/ST) do lodo de tal reator variaram de 0,74 a 0,58. As maiores concentrações médias de nutrientes no lodo do reator foram para o nitrogênio, fósforo, ferro e cálcio, com valores de 30.610 a 64.400, 1.590 a 9.870, 6.180 a 8.700 e 1.180 a 6.760 mg kg-1 base seca, respectivamente.

In the present study, we evaluated an anaerobic sequencing batch reactor, in pilot scale and with a total volume of 280 L, for the treatment of swine wastewater. The organic loading rates applied in such reactor were 4.42; 5.27; 9.33 and 11.79 g CODtotal (L d)-1. The average efficiencies of removal of CODtotal total solids suspension (TSS) and volatile suspension solids (VSS) varied from 56 to 87%. The nutrients total Kjedahl nitrogen (TKN), total phosphorus (total P) and Mg were removed with average efficiencies from 26 to 39%. The volumetric methane productions varied from 0.50 to 0.64 L CH4 (L reactor d)-1 and did not present significant differences. The VS/TS relations of the aforementioned reactor's sludge varied from 0.74 to 0.58. The highest mean concentrations of nutrients in the reactor sludge were those of nitrogen, phosphorus, iron and calcium, with values from 30.610 to 64.400, 1.590 to 9.870, 6.180 to 8.700 and 1.180 to 6.760 mg kg-1 base dry, respectively.