Nitrogen Transformations and Removal in Waste Stabilization Ponds in Portugal: Seasonal Variations

Abstract

Nitrogen transformations that can occur in WSP depend on pond and waste characteristics and are also influenced by climatic factors, like temperature and precipitation. Experiments described have been carried out using a system of three ponds in series: anaerobic, facultative and maturation, treating domestic sewage. In this paper we aim to identify the processes that might contribute to N transformations in each pond and the seasonal variations in the removal of nitrogen and its bioconversion throughout the year. Results have proved that there was an important organic N removal in the anaerobic pond, mainly due to mineralisation and not exclusively by sedimentation. Some of the processes of N transformation observed in the ponds were more strongly influenced by weather conditions than others. In some cases, the increase of biological activity that was induced by the increase in air temperature, was masked by reduced precipitation which produced less diluted treated effluents. These climatic factors can explain some of the variations observed along the year, in what concerns nitrogen compounds concentrations.

The Effects of Hydraulic and Organic Loadings on the Performance of a Full-Scale Facultative Pond in a Temperate Climate Region (Argentine Patagonia)

“…), mostly during colder months. Such pattern is attributed to well-defined changes in the metabolism of the biological communities supported within WSPs, which includes variations in the dynamics of nutrients, soluble and suspended organic matter concentrations and phytoplanktonic activity Mara 2003, 2005;Heaven et al 2003 andSantos andOliveira 1987).…”

Proteção de comunidade aquática em efluente tratado por tanques de estabilização de resíduos no rio São Lourenço em São Lourenço da Serra Vale do Ribeira – Estado de São Paulo

“…Em relação ao Nitrogênio amoniacal, os valores médio (9,5 mg/L), mínimo (3,6 mg/L) e máximo (19,6 mg/L) apresentaram valores na faixa limite entre Classe 1 (3,7 mg/L) e Classe 2 (13,3 mg/L); apenas o valor máximo um pouco acima para Classe 2, de acordo com a resolução CONAMA n. questão, pois a amônia, principalmente na forma não ionizada pode ser tóxica aos organismos vivos da cadeia alimentar aquática, como peixes, que vivem no corpo d'água que recebe este efluente (Von Sperling, 1996;Ruffier, Boyle, Kleinsschmidt, 1981;Santos, Oliveira, 1987;Hargreaves, 1998).…”

Dinâmica de nitrogênio em um sistema de lagoas de estabilização na região do Vale do Ribeira (São Paulo - Brasil)

“…Santos & Oliveira (1987) afirmaram que as concentrações de proteína são normalmente menores na lagoa anaeróbia devido aos processos de mineralização da matéria orgânica e sedimentação de sólidos suspensos, geralmente em elevadas concentrações neste tipo de sistema.…”