Validação de metodologia analítica para determinação de cromo e zinco em biossólido
The use of sewage sludge on agricultural soils has the main benefits the incorporation of the macronutrients nitrogen and phosphorus and the micronutrients zinc, copper, iron, manganese and molybdenum. You could say that, normally, the sewage sludge provides nutrients to the soil for crops, however, you must have knowledge of their composition in order to calculate the appropriate quantities to be incorporated, without the risk of toxicity plants and animals in certain situations and to man, and also without contaminating the environment. In this paper it is proposed the use of sewage sludge in addition to agricultural soils. Therefore, it is necessary to characterize the sludge to be added. Several parameters are used to characterize the sludge, namely: agronomic value, heavy metals, stability and sanity. The officially accepted analytical methodology for determination of elements involves atomic absorption spectroscopy or optical emission spectroscopy coupled to inductively coupled plasma. In this project, it is proposed to validate the methodology for determining the parameters: Zn and Cr by spectrophotometry using equipment Spectrophotometer, model DR/2500, HACH brand. Therefore, because of demand, it is necessary to validate a method where the tests are done with speed, safety, reliability and low cost compared with the official methods. The validation of the elements Cr and Zn was successful. All parameters for the physical and chemical characteristics were within the values permitted for disposal of biosolids as agricultural legislation.