Effect of biofertilizer obtained by anaerobic digestion of cassava effluent on the development of crambe plants

ABSTRACT This study aimed to evaluate the effect of applying increasing doses of biofertilizer obtained by the anaerobic digestion of cassava effluent on the development of crambe plants. The experiment was conducted in a protected environment at the Federal University of Paraná (UFPR), Palotina Sector, between April and August 2015. A completely randomized design was used, and five different treatments with the following doses were applied in five replicates: 0, 40, 80, 120, and 160 kg ha-1 of K2O. The following parameters related to plant development were evaluated: final height, stem diameter, number of branches, dry shoot and root biomass, mass of the grains, and oil content. The 160 kg K2O ha-1 dose was found to have the best influence on the plant development, because all the measured parameters reached their highest values at this dose, except for oil content, which attained the highest percentage in the case of the control treatment (0 kg ha-1 of K2O). This study proved that the biofertilizer obtained by anaerobic digestion of cassava effluent can be used as an alternative to regular fertilizers in cultivating crambe

Effect of biofertilizer obtained by anaerobic digestion of cassava effluent on the development of crambe plants

<div><p>ABSTRACT This study aimed to evaluate the effect of applying increasing doses of biofertilizer obtained by the anaerobic digestion of cassava effluent on the development of crambe plants. The experiment was conducted in a protected environment at the Federal University of Paraná (UFPR), Palotina Sector, between April and August 2015. A completely randomized design was used, and five different treatments with the following doses were applied in five replicates: 0, 40, 80, 120, and 160 kg ha-1 of K2O. The following parameters related to plant development were evaluated: final height, stem diameter, number of branches, dry shoot and root biomass, mass of the grains, and oil content. The 160 kg K2O ha-1 dose was found to have the best influence on the plant development, because all the measured parameters reached their highest values at this dose, except for oil content, which attained the highest percentage in the case of the control treatment (0 kg ha-1 of K2O). This study proved that the biofertilizer obtained by anaerobic digestion of cassava effluent can be used as an alternative to regular fertilizers in cultivating crambe.</p></div

Nitrificação de efluente de abatedouro de tilápia em função da aeração e tempo de reação Nitrification of tilapia slugtherhouse effluent according to the aeration conditions and reaction time

A ocorrência de compostos nitrogenados em água residuária de abatedouro de tilápia acima dos limites legais, tem causado sérios problemas de poluição em corpos d'água receptores. O processo biológico para remoção dessas substâncias comumente encontradas sob a forma de nitrogênio amoniacal, é conhecido como nitrificação. Objetivou-se, com o presente trabalho, estudar o efeito do tempo de reação (TR) e da aeração na eficiência da remoção de nitrogênio amoniacal e na conversão do nitrogênio amoniacal a nitrato, de água residuária de abate de tilápia em um reator em batelada sequencial com biofilme. O experimento foi executado usando-se dois TR(6 e 12 h) e dois níveis de vazão de ar (3 e 6 L min-1); avaliaram-se quatro tratamentos a partir da combinação dessas variáveis configuradas em um planejamento experimental do tipo factorial 2², sendo: T1 (QAr = 3 L min-1 e TR = 6 h); T2 (QAr = 6 L min-1 e TR = 6 h), T3 (QAr = 3 L min-1 e TR = 12 h) e T4 (QAr = 6 L min-1 e TR = 12 h), e quatro repetições para cada tratamento. Os resultados mais significativos foram para o tratamento T4, com o qual se obteve média de eficiência para conversão de amônio a nitrato e remoção de nitrogênio amoniacal de 57,27 ± 27,05% e 81,90 ± 3,80%, respectivamente.<br>The occurrence of composts of nitrogen above the legal limits has been causing serious pollution problems in water receptor bodies. The biological process for removal of these substances commonly found in the ammoniacal nitrogen form is known as nitrification. The present study had as its objective the evaluation of the effects of the reaction time (TR) and of the aeration on the removal efficiency of the ammoniacal nitrogen and on the conversion of the ammoniacal nitrogen to nitrate in a nitrification process of the tilapia slaughterhouse effluent in sequential batch reactor with biofilm. The experiment was performed using two reaction times (6 and 12 h) and two levels of air flow (3 and 6 L min-1), four treatments, starting from the combination of these two variables, were evaluated in an experimental planning of the factorial 2² type: being: T4 (QAr = 3 L min-1 and TR = 6); T2 (QAr = 6 L min-1 and TR = 6), T3 (QAr = 3 L min-1 and TR = 12) and T1 (QAr = 6 L min-1 and TR = 12), and four repetitions. The most significant results were obtained for treatment T4, where the efficiency for conversion of the ammoniacal nitrogen to nitrate obtained was 57.27 ± 27.05 and removal of the ammoniacal nitrogen was 81.90% ± 3.80