CHARACTERIZATION AND DEGRADATION PROCESS OF SLUDGE PROFILES INSIDE A FACULTATIVE POND (PATAGONIA, ARGENTINE)

FALESCHINI, MAURICIO; ESTEVES, JOSÉ LUIS

WATER SCIENCE AND TECHNOLOGY

I W A PUBLISHING

Lugar: Londres; Año: 2011 vol. 64 p. 2239 - 2245

0273-1223

To investigate the characteristics and degradation process in sludge profile, three sampling sessions were made in three different places inside the primary facultative pond of Puerto Madryn city, located in a region with temperate climate in coastal Patagonia (Argentine). The sludge showed an extremely negative redox potential (between -441 and -282 mV) and elevated water content and organic matter concentration, ranging from 83.3% to 97.1% for porosity and from 22.5% to 64.4% for organic matter. The surface layer at Outlet station during summer showed the greatest concentration of pigments, reaching a maximum value of 10.6 mg/g for chlorophyll-a and 40.9 mg/g for phaeophytin, and a fast diminution with sediment depth. The important concentration of pigment in surface layer, coincident with phytoplankton bloom in water column, could support the importance of nitrogen removal via uptake and organic sedimentation in water column. In warm months the degradation rate was clear, as reflected in a decrease in sediment layer, and even part of the clay bottom was captured inside an 8cm of core sample, registering extremely low concentrations of pigments, carbohydrates, proteins and lipids. The season and the degree of treatment have an influence on sludge characteristics and organic matter degradation process.