Avaliação de processos de remoção química de fósforo de efluente de suinocultura

• Autor(a) principal: Fernandes, Gabriela Wendler
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• Texto Completo: http://repositorio.ufsm.br/handle/1/10418
• topic: Química; Química analítica; Fósforo; Suinocultura; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA

The increasing of swine growing in confinement area have forced the application of new technologies to increase production and costs reduction. Large amount of manure containing pollutants is generated as a consequence. Therefore, it is necessary to develop and establish good practices and methodologies of swine manure that are of low cost and capable to reduce environmental pollution. Phosphorus is present in high concentration in the swine manure and is potentially harmful to the environment. A methodology for chemical removal of phosphorus from swine effluent using hydrated lime [Ca(OH)2xH2O] was evaluated in the present work. Phosphorus is separated by precipitation as Ca3(PO4)2. The phosphorus removal efficiency was compared to those obtained using Al2(SO4)3 and Fe2(SO4)3, it was observed that the best performance was obtained using Ca(OH)2. The main parameters that can influence on phosphorus (Ptot or Psol) removal efficiency were evaluated. The pH, CO3 2- and NH4 + influence were studied, whereas it was observed at pH 9.0 the removal of Ptot and Psol is higher than 96%. Even higher phosphorus removal can be achieved, but the cost is much higher. It was observed the ions CO3 2- and NH4 + influence markedly on the phosphorus removal; when the CO3 2- concentration is 750 mg L-1 and that of NH4 + is 500 mg L-1, the consumption of Ca(OH)2xH2O increases in 27%, if compared to Ca(OH)2xH2O consumption by an effluent containing 570 mg L-1 of CO3 2- and 130 mg L-1 of NH4 +. The sludge generated from the treatment using Ca(OH)2xH2O has a gelatinous aspect, where the water content is about 95%. Analysis by X-ray diffraction revealed that the main phosphorus compound present in the precipitate is amorphous Ca3(PO4)2.xH2O. Therefore, depending on the desired disposal, the sludge must be dried. It was concluded that the Ca(OH)2xH2O addition reduces the concentration of phosphorus in the swine effluent, but it is still not possible to discard the effluent directly in water receivers in view of the current Brazilian legislation. However, the reuse of the treated effluent in irrigation systems can be a good alternative.