Estudo da co-digestão anaeróbia entre glicerol e resíduos sólidos alimentares em reator batelada
Carregando...
Data
2023-01-09
Autores
Menezes, Rebeca Mendonça de
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Atualmente, com a crescente população mundial, tem-se uma abundância de resíduos orgânicos
das mais diversas origens e, paralelamente a este cenário, uma crescente tendência de busca por
consumo e soluções mais eficientes e sustentáveis. Neste contexto, observa-se um crescimento
no uso e na produção de biocombustíveis, com destaque para o biodiesel, cuja produção, tem
como coproduto o glicerol. Apesar de possuir um amplo uso nas mais variadas indústrias -
como alimentícia, cosmética e farmacêutica - há um alto custo para refinar o glicerol bruto até
a pureza necessária, o que fomenta um crescente interesse em buscar novas soluções para este
triálcool. No âmbito do tratamento destes resíduos, destaca-se, por seus resultados atrativos
tanto em termos econômicos quanto ambientais, a digestão anaeróbia, apresentando potencial
de redução de volume, estabilização, recuperação de energia, e obtenção de produtos químicos
de alto interesse como biogás, hidrogênio, ácidos graxos e álcoois. Assim, este trabalho se
propõe a estudar a co-digestão anaeróbia entre glicerol e resíduos sólidos alimentares, em reator
operado em bateladas sequenciais, em cinco fases de operação, pautadas na alimentação do
reator: (I) substrato sintético; (II) resíduo alimentar (250 mL); (III) resíduo alimentar (25 mL);
(IV) resíduo alimentar (25 mL) + glicerol bruto (1%) e, por fim, (V) resíduo alimentar (25 mL)
+ glicerol bruto (0,5%). Tratando-se de métodos biológicos de tratamento de efluentes e dos
substratos envolvidos na co-digestão estudada neste trabalho, são parâmetros importantes a
serem observados e analisados: a concentração da carga orgânica do meio, que pode ser
mensurada através da análise de Demanda Química de Oxigênio (DQO); o pH, a alcalinidade
do meio (tanto parcial quanto total) e os ácidos voláteis; a quantidade de carboidratos presentes
e a quantidade de glicerol no meio. Através das análises realizadas para acompanhamento dos
parâmetros mencionados, é possível afirmar que a co-digestão anaeróbia entre glicerol bruto e
resíduos alimentares é um método adequado para tratamento destes resíduos, com destaque para
os cenários com concentrações mais brandas tanto de resíduo alimentar quanto de glicerol,
tendo em vista que, na fase V, observou-se valores superiores a 90% para remoção de DQO,
entre 60 e 85%, aproximadamente, para remoção de carboidratos e próximos a 100% para
remoção de glicerol.
Currently, with world’s growing population, there is an abundance of organic waste from a wide range of origins and, in parallel to this scenario, a growing trend of search for a more efficient and sustainable consumption and solutions. In this context, there is a growth in the use and production of biofuels, especially biodiesel, whose production has glycerol as its co product. Despite having a wide use in the most varied industries – such as food, cosmetic and pharmaceutical – there is a high cost to refine the crude glycerol to the necessary purity, which fosters a growing interest in seeking new solutions for this trialcohol. In the context of the treatment of this class of waste, anaerobic digestion stands out for its attractive results, both in economic and environmental terms, presenting potential for volume reduction, stabilization, energy recovery, and obtaining chemicals of high interest such as biogas, hydrogen, fatty acids and alcohols. Thus, this work aims to study the anaerobic co-digestion between glycerol and solid food waste, in a batch reactor, from five phases of operation, based on the feeding of the reactor: synthetic substrate, food residue (250 mL), food residue (25 mL), food residue (25 mL) + crude glycerol (1%) and, at last, food residue (25 mL) + crude glycerol (0,5%). In the case of biological methods of effluent treatment and the substrates involved in the co-digestion here studied, are important parameters to be observed and analyzed: the concentration of the organic load of the medium, which can be measured through the analysis of Chemical Oxygen Demand (COD); pH, alkalinity of the medium (both partial and total) and volatile acids; the amount of carbohydrates present and the amount of glycerol in the medium. Through the analyses performed to monitor the mentioned parameters, it is possible to affirm that anaerobic co digestion between crude glycerol and food waste is an appropriate method for treating these wastes, especially scenarios with milder concentrations of both food residue and glycerol, considering that, in phase V, values above 90% were observed for DQO removal, between 60 and 85%, approximately for carbohydrate removal and close to 100% for glycerol removal.
Currently, with world’s growing population, there is an abundance of organic waste from a wide range of origins and, in parallel to this scenario, a growing trend of search for a more efficient and sustainable consumption and solutions. In this context, there is a growth in the use and production of biofuels, especially biodiesel, whose production has glycerol as its co product. Despite having a wide use in the most varied industries – such as food, cosmetic and pharmaceutical – there is a high cost to refine the crude glycerol to the necessary purity, which fosters a growing interest in seeking new solutions for this trialcohol. In the context of the treatment of this class of waste, anaerobic digestion stands out for its attractive results, both in economic and environmental terms, presenting potential for volume reduction, stabilization, energy recovery, and obtaining chemicals of high interest such as biogas, hydrogen, fatty acids and alcohols. Thus, this work aims to study the anaerobic co-digestion between glycerol and solid food waste, in a batch reactor, from five phases of operation, based on the feeding of the reactor: synthetic substrate, food residue (250 mL), food residue (25 mL), food residue (25 mL) + crude glycerol (1%) and, at last, food residue (25 mL) + crude glycerol (0,5%). In the case of biological methods of effluent treatment and the substrates involved in the co-digestion here studied, are important parameters to be observed and analyzed: the concentration of the organic load of the medium, which can be measured through the analysis of Chemical Oxygen Demand (COD); pH, alkalinity of the medium (both partial and total) and volatile acids; the amount of carbohydrates present and the amount of glycerol in the medium. Through the analyses performed to monitor the mentioned parameters, it is possible to affirm that anaerobic co digestion between crude glycerol and food waste is an appropriate method for treating these wastes, especially scenarios with milder concentrations of both food residue and glycerol, considering that, in phase V, values above 90% were observed for DQO removal, between 60 and 85%, approximately for carbohydrate removal and close to 100% for glycerol removal.
Descrição
Palavras-chave
Digestão anaeróbia, DQO, Alcalinidade, Ácidos, Carboidratos, Anaerobic digestion, Biogas, COD, Alkalinity, Acids, Carbohydrates