Use of cassava wastewater treated anaerobically with alkaline agents as fertilizer for maize (Zea mays L.)

• Autor(a) principal: Ribas,Maria Magdalena Ferreira
• Data de Publicação: 2010
• Outros Autores: Cereda,Marney Pascoli, Villas Bôas,Roberto Lyra
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Archives of Biology and Technology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000100007
• topic: Reuse; manipueira; anaerobic digestion; hydroxide sodium; dolomitic limestone

The wastewater of the processing of cassava's flour (manipueira) was submitted to the anaerobic treatment in two phases: acidogenic and methanogenic. In the acidogenic phase, the wastewater was stabilized with NaOH (ASH) and with limestone (ASL). After that, both stabilized effluents were treated by a methanogenic reactor. Then, the effluent of the methanogenic reactor was used as fertilizer on maize in the initial growth stage (30 days), cultivated in pots in a greenhouse. The treatments were T1: control without urea addition (only N from soil); T2: NPK (2.2 g of urea with 45% of N); T3: ASH (84 mL.kg soil-1); T4: ASL (102 mL.kg soil-1); T5: double dose ASH (168 mL.kg soil-1) and T6: double dose ASL (204 mL.kg soil-1). Each treatment was composed by 4 plants/pot in five repetitions. It was observed that all the treatments with stabilized wastewater had favorable effect to the soil pH (> than 7.5) and basis saturation (V%) in the soil around to 90%. The performances of nitrogen absorption by the maize plants were 64, 54, 80 and 78% for T3, T4, T5 and T6, respectively.