Jonathas Batista Gonçalves Silva

Avaliação do efeito do extrato de sementes de Moringa oleifera Lam na eficiência de filtros orgânicos no tratamento de águas residuárias de bovinocultura de leite

Objetivou-se avaliar o efeito do extrato de Moringa oleifera Lam na remocao de solidos totais (ST), solidos em suspensao totais (SST) e demanda quimica de oxigenio (DQO), em distintos meios filtrantes, no tratamento da agua residuaria de bovinocultura de leite (ARB). O extrato de sementes de moringa foi obtido triturando-se 50 g de sementes em um litro de agua destilada e, apos passar a solucao em papel de filtro quantitativo de 25 µm, foram adicionados 60 mL do extrato a agua residuaria de bovinocultura, antes do processo de filtracao em filtros orgânicos constituidos por fino de carvao, folhas de bambu, folhas de eucalipto, ramos de gliricidia e serragem de madeira. Seguiu-se o delineamento experimental inteiramente aleatorizado, adotando um esquema fatorial de 5 x 2. Aliquotas do efluente filtrado foram coletadas, e determinaram-se as concentracoes de solidos totais (ST), solidos em suspensao totais (SST) e demanda quimica de oxigenio (DQO). Verificou-se que o aumento na eficiencia de remocao de solidos totais e DQO pode ser atribuido ao poder coagulante do extrato de sementes de moringa, sendo que o meio filtrante com folhas de bambu apresentou melhor desempenho, demonstrando potencial de utilizacao como material filtrante alternativo no tratamento primario de ARB.

Avaliação do desenvolvimento do capim Tifton cultivado em latossolo adubado com lodo de ETA

O tratamento da agua gera grandes quantidades de lodo, que se origina nos decantadores e filtros das estacoes de tratamento de agua (ETAs). Dentre algumas alternativas de disposicao final deste residuo, destacam-se o aterro sanitario, aplicacao em areas agricolas, fabricacao de cimento e tijolos e compostagem. Diante do exposto, o trabalho teve por objetivo avaliar o desenvolvimento do capim Tifton ( Cynodon spp. cv) cultivado em um Latossolo Vermelho-Amarelo adubado com lodo de ETA. A pesquisa foi conduzida na universidade federal de Juiz de Fora, no municipio de Juiz de Fora – MG e avaliou a aplicacao de distintas doses de lodo de ETA em relacao as caracteristicas de crescimento, producao de massa seca e acumulo de nutrientes da parte aerea e radicular de dois ciclos consecutivos de 45 dias cada. Os tratamentos avaliados foram T0, T1, T2, T3 e T4 que receberam 0; 1,36; 2,73; 4,09 e 5,45 Kg m-², respectivamente, de lodo de ETA. O experimento foi conduzido em delineamento inteiramente casualizado, cada tratamento com quatro repeticoes, totalizando 20 unidades experimentais. A aplicacao dos tratamentos resultou em uma baixa produtividade e sintomas de toxidade por manganes e ferro. Concluiu-se com base nos resultados que o lodo de ETA nao apresentou potencial agronomico.

Mobilidade dos íons nitrato e amônio em área agrícola sob adubação com água residuária de bovinocultura de leite e torta de Mamona

The aim of this study was to evaluate the mobility of nitrate and ammonium ions in a Ultisol when applied wastewater dairy cattle ( ARB ). The experiment was conducted in the Agroecological Production Integrated System, located in the municipality of Seropedica, State of Rio de Janeiro. In the area used in this work is cultivated the culture of fig (Ficus carica L.), variety Roxo de Valinhos. Different blades of ARB were applied to the soil as a source of nitrogen fertilization (T1-0% of ARB and additional fertilizers with castor pie, T2-50% of the recommended dose of N supplied by the ARB and the other 50% with the castor pie, T3-75% of the recommended dose of N supplied by the ARB and the other 25% provided by the castor pie, T4-100% of recommended dose of N provided by the ARB). In the experimental plots were installed extractors 0.15 and 0.60 m deep. Nitrate concentrations obtained were very high, with values of up to 323 mg.L- 1. However, the values of ammonium in the soil solution were low, with values below 0.44 mg L-1. The results indicate the need for close monitoring in the use of ARB and castor cake in agricultural areas.

Variations in the chemical composition of the solution extracted from a Latosol under fertigation with vinasse

The aim of this work was to evaluate the change in electrical conductivity and pH of a soil solution and its composition, with regard to the levels of nitrate and potassium, in a Latosol cultivated with pineapple and subjected to applications of different levels of vinasse. The experiment was conducted in a greenhouse at the Department of Biosystems Engineering of ESALQ/USP. The treatments comprised the application of five levels of vinasse: T1 - 0 m3 ha-1, T2 - 231 m3 ha-1, T3 - 347 m3 ha-1, T4 - 462 m3 ha-1, and T5 - 578 m3 ha-1. Application was every 20 days, using a localised irrigation system with emitters having a nominal flow rate of 4 L h-1 and spaced 0.40 m apart. The applied doses of vinasse were calculated by following the recommendations of CETESB standard P4.231, so that treatment T4 would supply the demand of the pineapple plant for potassium. The solution was collected by means of porous capsule extractors at 30, 120 and 210 days from the start of vinasse application. It was found that increases in the volume of the applied levels resulted in greater values for the electrical conductivity of the soil (ECs) and in the concentration of potassium (K) and nitrate (NO3), with higher values being obtained in the 0.20 m layer. The results demonstrated that pH decreased with increases in the vinasse being applied.

CONCENTRAÇÃO DE METAIS EM UM SOLO ADUBADO COM ÁGUA RESIDUÁRIA DA BOVINOCULTURA DE LEITE

In this work aimed to evaluate the effects of the use of wastewater from dairy cattle in the concentration of metals in a cultivated ultisol with fig (Ficus carica L.). The work was developed in the area of the Integrated Agroecological Production in the municipality of Seropedica, RJ. The nitrogen was used as a reference element in fertilization of the fig tree with application of wastewater from dairy cattle. We evaluated the following parameters of the soil Zn, Cu, Fe and Mn availables. The data were submitted to analysis of variance and means were compared using the Tukey test at 10% probability. Regarding the content of metal, it was observed that the use of wastewater of cattle in the fig tree fertilization was able to reduce the concentration of Zn elements Cu, Fe and Mn that were in high concentrations in the soil indicating toxic levels. Also noteworthy that the organic matter incorporated into the soil may have acted in thechelation and complexation, forming precipitates of low mobility of Zn, Cu, Fe and Mn.