Aproveitamento da água residual da termorretificação do cedro indiano e avaliação do potencial de aplicação como biofertilizante
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2023-05-23
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Universidade Estadual Paulista (Unesp)
Resumo
Na busca por técnicas para reduzir a poluição ambiental, bem como de novas matérias-primas a serem utilizadas, torna-se cada vez mais comum a realização de pesquisas e estudos para aproveitamento de resíduos gerados pelas indústrias. A termorretificação da madeira produz, por suas características, um líquido residual contendo frações de matéria vegetal, oriundas da degradação parcial da madeira. Desse modo, o presente trabalho buscou avaliar o aproveitamento do líquido residual da termorretificação de madeira da espécie Acrocarpus fraxinifolius (Cedro Indiano) como biofertilizante. Foram realizados análise de macro e micronutrientes, ensaios de germinação, com sementes de milho (Zea mays), além disso, efetuaram-se testes de toxicidade, aguda (com Daphnia magna) e crônica (com Desmodesmus subspicatus), de modo a avaliar possíveis efeitos danosos do líquido residual, partindo posteriormente para a Avaliação e Identificação de Toxicidade (AIT). Utilizou-se um delineamento em blocos casualizados, aplicando-se tratamentos com concentrações de 0 (tratamento de controle); 1; 2; 3; 4 e 5 mL (ensaio de germinação). A análise química indicou teores satisfatórios de Ca, Mg, Cu, Fe, Mn, Zn e K, no que diz respeito à aplicação como biofertilizante. Durante o ensaio de germinação, as sementes que receberam doses do líquido residual não apresentaram desenvolvimento, ou seja, somente as sementes que foram irrigadas com água germinaram. Assim, os testes de toxicidade tiveram o objetivo de avaliar se o líquido é tóxico. O teste de toxicidade aguda indicou um fator de toxicidade (FT) >16 (unidade de medida que expressa quantas vezes a toxicidade de um material ultrapassa o limite estabelecido pela legislação), expressando efeitos tóxicos por parte do resíduo. Logo, o ensaio de Avaliação e Identificação da Toxicidade (AIT) foi utilizado para encontrar o composto químico tóxico presente no líquido. Desse modo, detectou-se concentrações de compostos fenólicos acima da legislação vigente (CONAMA – Resolução 430 de 2011). Tais compostos, provavelmente, originaram-se da degradação parcial da lignina presente na madeira e podem ser prejudiciais a ambientes aquáticos, devido à sua letalidade a organismos aquáticos, de modo que, mesmo em doses pequenas, pode causar a mortandade de peixes. Portanto, o líquido residual produzido durante a termorretificação da madeira de Cedro Indiano não apresentou viabilidade para aplicação como biofertilizante. Pode-se realizar tratamentos no resíduo, com o objetivo de neutralizar seus efeitos tóxicos, avaliando-se, posteriormente, sua utilização como biofertilizante ou ensaios para extração do fenol presente, para uso como matéria-prima em indústrias químicas.
In the pursuit of reducing in environmental pollution, as well as new raw materials to be used, it becomes increasingly common to elaborate works and research for the use of waste generated by industries. The thermorectification of wood, due to its characteristics, produces a residual liquid containing fractions of organic matter, arising from the partial degradation of the wood. Thus, the present work sought to evaluate the use of residual liquid from the thermamortification of wood of the species Acrocarpus fraxinifolius (Indian Cedar) as a biofertilizer. Macro and micronutrient analysis, germination assays were performed with corn seeds (Zea mays), in addition, acute (with Daphnia magna) and chronic (with Desmodesmus subspicatus) toxicity tests were performed in order to evaluate possible harmful effects of the residual fluid, starting later for the Toxicity Evaluation and Identification (TIA). A randomized block design was used, applying treatments with concentrations of 0 (control treatment); 1; 2; 3; 4 and 5 mL (germination assay). The chemical analysis indicated satisfactory contents of Ca, Mg, Cu, Fe, Mn, Zn and K, with regard to the application as biofertilizer. During the germination test, the seeds that received doses of the residual liquid did not show development, that is, only the seeds that were irrigated with water germinated. Thus, the toxicity tests aimed to evaluate whether the liquid is toxic. The acute toxicity test indicated a toxicity factor (TF) >16, expressing toxic effects on the part of the residue. Therefore, the Toxicity Assessment and Identification (TIA) assay was used to find the toxic chemical compound present in the liquid. Thus, concentrations of phenolic compounds above the current legislation were detected (CONAMA – Resolution 430 of 2011). Such compounds probably originated from the partial degradation of the lignin present in the wood. Therefore, the residual liquid produced during the thermorectification of Indian Cedar wood did not present viability for application as a biofertilizer. Treatments can be carried out on the waste, with the objective of neutralizing its toxic effects, later evaluating its use as a biofertilizer or assays for extraction of the phenol present, for use as raw material in chemical industries.
In the pursuit of reducing in environmental pollution, as well as new raw materials to be used, it becomes increasingly common to elaborate works and research for the use of waste generated by industries. The thermorectification of wood, due to its characteristics, produces a residual liquid containing fractions of organic matter, arising from the partial degradation of the wood. Thus, the present work sought to evaluate the use of residual liquid from the thermamortification of wood of the species Acrocarpus fraxinifolius (Indian Cedar) as a biofertilizer. Macro and micronutrient analysis, germination assays were performed with corn seeds (Zea mays), in addition, acute (with Daphnia magna) and chronic (with Desmodesmus subspicatus) toxicity tests were performed in order to evaluate possible harmful effects of the residual fluid, starting later for the Toxicity Evaluation and Identification (TIA). A randomized block design was used, applying treatments with concentrations of 0 (control treatment); 1; 2; 3; 4 and 5 mL (germination assay). The chemical analysis indicated satisfactory contents of Ca, Mg, Cu, Fe, Mn, Zn and K, with regard to the application as biofertilizer. During the germination test, the seeds that received doses of the residual liquid did not show development, that is, only the seeds that were irrigated with water germinated. Thus, the toxicity tests aimed to evaluate whether the liquid is toxic. The acute toxicity test indicated a toxicity factor (TF) >16, expressing toxic effects on the part of the residue. Therefore, the Toxicity Assessment and Identification (TIA) assay was used to find the toxic chemical compound present in the liquid. Thus, concentrations of phenolic compounds above the current legislation were detected (CONAMA – Resolution 430 of 2011). Such compounds probably originated from the partial degradation of the lignin present in the wood. Therefore, the residual liquid produced during the thermorectification of Indian Cedar wood did not present viability for application as a biofertilizer. Treatments can be carried out on the waste, with the objective of neutralizing its toxic effects, later evaluating its use as a biofertilizer or assays for extraction of the phenol present, for use as raw material in chemical industries.
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Palavras-chave
Tratamento térmico, Madeira, Nutrientes, Toxicidade, Fenol, Heat treatment, Wood, Nutrient, Toxicity, Phenol