Comparação do tratamento de efluente de uma indústria cítrica usando lodos ativados com outros métodos de tratamentos em plantas industriais
Data
2021-08-30
Autores
Pereira, Ana Carolina
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A cultura de citros está entre os mais populares em regiões tropicais e subtropicais de todo o mundo. Entre os mais variados tipos de frutas cítricas, a laranja doce (Citrus sinensis) representa cerca de 70 % da produção e consumo, sendo considerada o principal fruto desse grupo. Além da laranja doce, a tangerina (Citrus retivulata), grapefruit(Citrus vitis), lima (Citrus aurantifulia) e limão (Citrus limonum) são largamente cultivados e consumidas. No que diz respeito à produção, o Brasil destaca-se por ser o maior produtor mundial de laranja doce (área plantada de 800 mil hectares) produzindo na safra 2015/2016 aproximadamente de 12.266.520 toneladas das quais, cerca de 90% foram destinadas para produção de suco. Entretanto este consumo acentuado gera uma elevada carga poluidora em termos de sólidos e DBO, necessitando condicionar o efluente aos padrões de emissão via a combinação de tratamento preliminar (gradeamento), tratamento primário (equalização) e tratamento secundário (processo biológico). No caso do tratamento secundário, os lodos ativados vêm sendo utilizados com maior frequência devido a menor influência da variação de carga orgânica e alto índice de remoção de sólidos e DBO (96-99%). Já, as lagoas aeradas, uma variante desse processo, apresentam remoção um pouco inferior, porém com custos de tratamento menores que os de um sistema convencional de lodos ativados. Diante a problemática, objetivo deste estudo é utilizar uma série histórica da operação de um sistema de lodos ativados de pequeno porte para realizar um comparativo com os sistemas de grande porte relatados na literatura.
Citrus cultivation is among the most popular in tropical and subtropical regions around the world. Among the most varied types of citrus fruits, sweet orange (Citrus sinensis) represents about 70% of production and consumption, being considered the main fruit of this group. In addition to sweet orange, tangerine (Citrus retivulata), grapefruit (Citrus vitis), lime (Citrus aurantifulia) and lemon (Citrus limonum) are widely cultivated and consumed. With regard to production, Brazil stands out for being the world's largest producer of sweet orange (planted area of 800 thousand hectares) producing approximately 12,266,520 tons in the 2015/2016 harvest, of which about 90% were destined for juice production. However, this accentuated consumption generates a high pollutant load in terms of solids and BOD, requiring conditioning the effluent to emission standards via a combination of preliminary treatment (grading), primary treatment (equalization) and secondary treatment (biological process). In the case of secondary treatment, activated sludge has been used more frequently due to the lower influence of organic load variation and high solids and BOD removal rate (96-99%). On the other hand, aerated lagoons, a variant of this process, have a slightly lower removal, but with lower treatment costs than a conventional activated sludge system. Faced with the problem, the objective of this study is to use a historical series of the operation of a small activated sludge system to make a comparison with the large systems reported in the literature.
Citrus cultivation is among the most popular in tropical and subtropical regions around the world. Among the most varied types of citrus fruits, sweet orange (Citrus sinensis) represents about 70% of production and consumption, being considered the main fruit of this group. In addition to sweet orange, tangerine (Citrus retivulata), grapefruit (Citrus vitis), lime (Citrus aurantifulia) and lemon (Citrus limonum) are widely cultivated and consumed. With regard to production, Brazil stands out for being the world's largest producer of sweet orange (planted area of 800 thousand hectares) producing approximately 12,266,520 tons in the 2015/2016 harvest, of which about 90% were destined for juice production. However, this accentuated consumption generates a high pollutant load in terms of solids and BOD, requiring conditioning the effluent to emission standards via a combination of preliminary treatment (grading), primary treatment (equalization) and secondary treatment (biological process). In the case of secondary treatment, activated sludge has been used more frequently due to the lower influence of organic load variation and high solids and BOD removal rate (96-99%). On the other hand, aerated lagoons, a variant of this process, have a slightly lower removal, but with lower treatment costs than a conventional activated sludge system. Faced with the problem, the objective of this study is to use a historical series of the operation of a small activated sludge system to make a comparison with the large systems reported in the literature.
Descrição
Palavras-chave
Tratamento de efluentes, Lodo Ativado, Indústria Cítrica, Resíduos Industriais, Lagoa de estabilização, Lagoa de Polimento, Effluent treatment, Activated Sludge, Citrus Industry, Industrial Waste, Stabilization Pond, Polishing Pond