Avaliação da mobilidade de íons e metais da vinhaça através de ensaios de colunas em solo da Formação Rio Claro
Carregando...
Data
2018-09-04
Autores
Ferreira, Thelma Maria [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
No processo industrial da produção sucroalcooleira um dos efluentes gerados é a vinhaça, que se destaca pelo grande volume com que é produzida e pelo alto potencial fertilizante, característica que possibilita seu aproveitamento em atividades agrícolas, no entanto, a vinhaça também possui alto poder poluente. Neste contexto, o uso da vinhaça na fertilização de cana-de-açúcar, embora seja uma prática aceita, deve ser realizado de forma controlada, sendo regulamentado no Estado de São Paulo pela Companhia Ambiental do Estado de São Paulo – CETESB através da Norma Técnica P4.231. Devido a composição da vinhaça ser muito variável não há como estabelecer doses fixas, assim, atualmente as dosagens de aplicação no solo são calculadas em função das necessidades da planta em relação ao potássio, sendo consideradas a capacidade de troca catiônica do solo e as concentrações de potássio no solo e na vinhaça. Todavia, além da oscilação composicional da vinhaça, seus efeitos sobre cada tipo de solo também são muito diversos, podendo modificar parâmetros hidráulicos do solo e, consequentemente, alterar a velocidade de percolação da água e dos contaminantes presentes na solução. Diante desta problemática, para avaliar o uso da dosagem calculada pela Norma P4.231 da CETESB, foram realizados ensaios laboratoriais de percolação a carga constante, em colunas com amostras de solo arenoso da Formação Rio Claro previamente infiltradas com as doses de 0 (testemunho), 55 (equivalente a dose máxima permitida pela CETESB), 80, 400 e 800 m3/ha. A aplicação destas doses permitiu a avaliação de seus efeitos nos parâmetros hidráulicos do solo estudado e a possível geração de diferentes graus de contaminação nos efluentes percolados, implicando um potencial risco para a água subterrânea e superficial. Os resultados obtidos indicam que com a aplicação das doses de 55 e 80 m3/ha houve um aumento na capacidade de retenção do solo, fator este positivo tanto para o aspecto fertilidade do solo quanto ao ambiental. Entretanto, com a aplicação de doses elevadas como as de 400 e 800 m3/ha observa-se uma queda progressiva na capacidade de retenção do solo, que implica em perdas por lixiviação e consequente aumento nas concentrações de sólidos totais dissolvidos, cloreto, fluoreto, acetato, carbono orgânico total, alumínio, ferro, manganês e zinco, que em algumas amostras apresentaram concentrações superiores aos valores de referência ambiental e de potabilidade adotados podendo, portanto, gerar riscos à qualidade do solo e da água subterrânea tornando-a imprópria para consumo humano. Quanto à condutividade hidráulica saturada, os valores obtidos para a coluna com 55 m3/ha foram muito similares aos obtidos na coluna sem aplicação de vinhaça, indicando que para o solo estudado esta dosagem não trouxe nenhuma alteração significativa, porém, com o aumento das dosagens houve redução gradual destes valores. Com base nos resultados obtidos para a configuração dos testes laboratoriais realizados, pode-se afirmar que, a aplicação de vinhaça na dose máxima estabelecida pela norma P4.231 CETESB (2015) não apresentou riscos à qualidade do solo estudado e da água subterrânea.
In the industrial production process of sugar and a lcohol, one of the effluents generated is vinasse, which stands out for the larg e volume produced and for the high fertilizing potential, allowing its use in agr icultural activities, however, the vinasse also has high pollution power. In this context, the use of vinasse in the fertilization of sugarcane, although it is an accepted practice, mus t be carried out in a controlled manner, being regulated in the State of São Paulo b y the Companhia Ambiental do Estado de São Paulo (CETESB) through Technical Stan dard P4. 231. Due to the composition of the vinasse being very variable, it is not possible to establish fixed doses, so, currently the dosages of application in the soil are calculated according to the needs of the plant in relation to potassium ion , considering the cation exchange capacity of the soil and the concentrations of pota ssium in soil and vinasse. In addition to the compositional oscillation of vinasse, its effects on each type of soil is also very diverse, being able to modify hydraulic p arameters of the soil and, consequently, to change the rate of percolation of the water and the contaminants present in the solution. In order to evaluate the u se of the dosage calculated by CETESB Standard P4.231, constant load percolation t ests were carried out in columns with samples of a sandy soil from the Rio C laro Formation previously infiltrated with the doses of 0 (control), 55 (equi valent to the maximum dose allowed by CETESB), 80, 400 and 800 m 3 /ha. The application of these doses allowed the evaluation of its effects on the hydraulic paramete rs of the studied soil and the possible generation of different degrees of contami nation in the percolated effluents implying a potential risk for groundwater and surfa ce water. The results indicated that for the doses of 55 and 80 m 3 /ha there was an increase in the retention capacity of soil, which is positive about the aspect of soil fe rtility as well as the environmental aspect. However the application of high doses such as 400 and 800 m 3 /ha, there is a progressive decrease in the soil retention capacity , which implies losses due to leaching and consequent increase in the concentrati ons of total dissolved solids, chloride, fluoride, acetate, total organic carbon, aluminum, iron, manganese and zinc, which in some samples presented concentrations high er than the values of potability and environmental reference adopted, what could gen erate risks to soil and groundwater quality. Regarding the saturated hydraulic conductivity, the values obtained for the column with 55 m 3 /ha dosage were very similar to those obtained in the control column, indicating that this dosage did not bring any significant change, but with the increase of the dosages there was grad ual reduction in those values. Based on the results obtained for the configuration of the laboratory tests carried out, it can be stated that the application of vinasse at the maximum dose established by standard P4.231 CETESB (2015) did not present risks to the quality of the studied soil and groundwater.
In the industrial production process of sugar and a lcohol, one of the effluents generated is vinasse, which stands out for the larg e volume produced and for the high fertilizing potential, allowing its use in agr icultural activities, however, the vinasse also has high pollution power. In this context, the use of vinasse in the fertilization of sugarcane, although it is an accepted practice, mus t be carried out in a controlled manner, being regulated in the State of São Paulo b y the Companhia Ambiental do Estado de São Paulo (CETESB) through Technical Stan dard P4. 231. Due to the composition of the vinasse being very variable, it is not possible to establish fixed doses, so, currently the dosages of application in the soil are calculated according to the needs of the plant in relation to potassium ion , considering the cation exchange capacity of the soil and the concentrations of pota ssium in soil and vinasse. In addition to the compositional oscillation of vinasse, its effects on each type of soil is also very diverse, being able to modify hydraulic p arameters of the soil and, consequently, to change the rate of percolation of the water and the contaminants present in the solution. In order to evaluate the u se of the dosage calculated by CETESB Standard P4.231, constant load percolation t ests were carried out in columns with samples of a sandy soil from the Rio C laro Formation previously infiltrated with the doses of 0 (control), 55 (equi valent to the maximum dose allowed by CETESB), 80, 400 and 800 m 3 /ha. The application of these doses allowed the evaluation of its effects on the hydraulic paramete rs of the studied soil and the possible generation of different degrees of contami nation in the percolated effluents implying a potential risk for groundwater and surfa ce water. The results indicated that for the doses of 55 and 80 m 3 /ha there was an increase in the retention capacity of soil, which is positive about the aspect of soil fe rtility as well as the environmental aspect. However the application of high doses such as 400 and 800 m 3 /ha, there is a progressive decrease in the soil retention capacity , which implies losses due to leaching and consequent increase in the concentrati ons of total dissolved solids, chloride, fluoride, acetate, total organic carbon, aluminum, iron, manganese and zinc, which in some samples presented concentrations high er than the values of potability and environmental reference adopted, what could gen erate risks to soil and groundwater quality. Regarding the saturated hydraulic conductivity, the values obtained for the column with 55 m 3 /ha dosage were very similar to those obtained in the control column, indicating that this dosage did not bring any significant change, but with the increase of the dosages there was grad ual reduction in those values. Based on the results obtained for the configuration of the laboratory tests carried out, it can be stated that the application of vinasse at the maximum dose established by standard P4.231 CETESB (2015) did not present risks to the quality of the studied soil and groundwater.
Descrição
Palavras-chave
Cana-de-açúcar, Norma técnica P4.231, Ensaios de coluna, Contaminação de solo e água subterrânea, Hidrogeologia de contaminantes, Sugar cane, Technical Standard P4.231, Column tests, Soil and groundwater contamination, Hydrogeology of contaminants