Ana Carolina Barbosa Kummer

Influência de nitrogênio amoniacal e vazão de ar no processo de nitrificação, etapa de tratamento de efluente de abatedouro de peixe

The fish slaughterhouse effluent presents high levels of nitrogen, one of the major causes of eutrophication in water bodies. Nitrogen removal can be accomplished in two separate stages: Nitrification and Denitrification. This experiment aimed to test the influence of air flow (values between 1 and 3 L min-1) and ammonia nitrogen concentration (between 40 and 100 mg L-1) in the nitrification process. A 2.5 L volume sequencing batch reactor with immobilized biomass was operated as central rotational composed design, where the evaluated results were conversion of ammonia nitrogen to nitrate in percentage and nitrite accumulation in percentage. The results with confidence interval of 95% showed that the increase of both variables resulted in the significant reduction of the percentage of nitrogen conversion to nitrate. The nitrite accumulation percentage significantly increased with the ammonia nitrogen increase, although it was not observed significant influence of air flow. During the experiment the best condition found for the equilibrium of the reactions was 70 mg L-1 of ammonia nitrogen and air flow of 2 L min-1.

Tratamento de efluente de abatedouro de tilápia com adição de manipueira na fase anóxica

The objective of this work was to evaluate the denitrification of tilapia slaughterhouse wastewater, in a batch reactor. For this, it was evaluated the wastewater from a cassava processing industry (manipueira) as a carbon source. It was also evaluated the shaking conditions of the process. The experiments were carried out in laboratory series, where five shaking levels were tested (20; 32; 60; 88 e 100 rpm) as well as five COD/N ratio levels (0.1; 1.0; 3.2; 5.4 and 6.3), forming a planning as a Central Composite Rotational Design (CCRD), with four essays in levels +1 and - 1; four essays on the axial points levels (-1.414 and +1.414) and one more triplicate in the central point (0), which meant eleven essays. The denitrification performance through the nitrate removal (%) and nitrite removal (%) were evaluated. During this process, temperature (oC), pH and alkalinity (mgCaCO3.L-1) were also observed. The results showed that the COD/N ratio had significant influence, with a 95 % of confidence interval, on the process of nitrate and nitrite removal, with a great operation range, from 3.2 to 5.4, whose nitrogen removal efficiencies were 100 %.

Efeito do lodo de esgoto e do nitrogênio nos fatores produtivos do girassol

Dentre as diversas alternativas de disposicao final de lodo de esgoto no Brasil, o uso agricola se destaca por sua economicidade e adequacao ambiental. Assim, o objetivo deste trabalho foi avaliar o efeito do lodo de esgoto compostado e do N nos parâmetros produtivos do girassol, apos a sexta aplicacao de lodo de esgoto em diferentes doses. O experimento foi conduzido na Fazenda Experimental Sao Manuel, SP, pertencente a Faculdade de Ciencias Agronomicas da UNESP de Botucatu,SP. Foi adotado o delineamento experimental em blocos casualizados constituidos por 6 tratamentos e 4 repeticoes, assim definidos: T0 - sem adubacao nitrogenada; T1 - adubacao quimica nitrogenada de acordo com a recomendacao da cultura; T2 - 50% adubacao nitrogenada proveniente do lodo de esgoto e 50% na forma mineral; T3 - 100% adubacao nitrogenada proveniente do lodo de esgoto; T4 - 150% adubacao nitrogenada proveniente do lodo de esgoto; T5 - 200% adubacao nitrogenada proveniente do lodo de esgoto. O aumento da dose de lodo de esgoto e o N proporcionaram um aumento no rendimento de graos, de oleo e de materia seca. O N influenciou no aumento de peso de mil graos.