Unidades combinadas RAFA-SAC para tratamento de água residuária de suinocultura – parte II nutrientes

Abstract

RESUMO:Neste trabalho, avaliou-se o efeito combinado de duas unidades de tratamento na remoção de nitrogênio total Kjeldahl (NTK) e fósforo total (PT). As unidades avaliadas receberam alimentação contínua, sendo um reator anaeróbio de manta de lodo e fluxo ascendente tipo RAFA, com volume útil de 96 L, seguido de um sistema alagado construído (SAC) As eficiências de remoção de NTK e PT no sistema como um todo foram de, aproximadamente, 35%, não havendo diferença significativa entre as fases. Porém, em termos de COV removida, houve maior remoção com o aumento da carga aplicada. As características apresentadas pelo efluente do sistema nas diferentes fases não alcançaram os padrões ambientais para lançamento em cursos de água no Estado de Minas Gerais, dentre as variáveis avaliadas, mas seu potencial nutricional deve ser utilizado para produção agrícola. PALAVRAS-CHAVE:carga orgânica, nutrientes, taxa de aplicação superficial, tratamento biológico, wetlands. COMBINED UNITS FOR SWINE WASTEWATER TREATMENT -PART II NUTRIENTSABSTRACT: In this study, we assessed the combined effect of two treatment units on removal of total Kjeldahl nitrogen (TKN) and total phosphorus (TP). Continuous feeding was provided to the units which consisted of an upflow anaerobic sludge blanket (UASB) reactor with a working volume of 96 L and a constructed wetland system (WS) with a capacity of 237 L. The experiment was performed in three phases with variation in hydraulic retention time (HRT). UASB reactor had a HRT of 59, 19.5 and 5 hours; and for the WSs, HRTs were 146, 48 and 13 hours. Volumetric organic loading rates (VOLR) applied to the reactor were 1.2, 1.3 and 13.0 kg.m -3 d -1 of COD. Surface application rates (SAR) in the WS were 120, 130 and 464 kg ha -1 d -1 of TKN, and 13, 51 and 240 kg ha -1 d -1 of TP. Removal efficiency of TKN and TP reached approximately 35% for the entire system with no significant differences among phases. However, such removal rates achieved higher values with increasing loads. Regarding the evaluated variables, we concluded that the effluent generated by the combined system at all phases did not reach the environmental standards proposed by the state of Minas Gerais (Brazil) to be released into water bodies. On the other hand, this waste has a great nutritional potential that should be used to enhance agricultural production.

Nutrient Removal From Swine Wastewater in a Combined Vertical and Horizontal Flow Constructed Wetland System

“…However, Amorim et al (2015) observed nitrogen removal of the order of 30% (22.9 g d −1 ) in an upward flow anaerobic reactor when treating swine wastewater.…”

Efeito da vegetação em sistemas alagados construídos para tratar águas residuárias da suinocultura

“…Amorim et al (2015), mesmo trabalhando com taxas de carregamento de P superiores às avaliadas neste trabalhoentre 13 e 240 kg ha -1 d -1 -obtiveram baixa eficiência na remoção de P, que variou entre 20 e 30%. Lee et al (2004) também verificaram menores eficiências na remoção de P (47 a 59%) que as obtidas aqui.…”

Influence of Substrate and Species Arrangement of Cultivated Grasses on the Efficiency of Horizontal Subsurface Flow Constructed Wetlands

“…The different media and crop combination of the treatments did not interfere in the removal of Total-P. Mendonça et al (2012) verified that there was no significant difference between the cultivated and non-cultivated HSSF-CWs in the removal of phosphorus, with average efficiencies varying from 19 to 34%. Amorim et al (2015), worked with loading rates of P higher than those evaluated in this study, between 13 and 240 kg ha -1 d -1 , obtained efficiency in the removal of P, which varied between 20 and 30%.…”