Avaliação do comportamento de lagoas de estabilização profundas - lagoas facultativas primárias.

Abstract

The objective of this work is to evaluate the behavior of primary facultative stabilization lagoons, with a depth greater than the normally adopted depths. For this, during an experimental period of 01 (one) year, that is, from August 1985 to July 1986, 04 (four) pilot-scale lagoons with a depth of 2.30m and organic loads between 214 and 320 kg DBOg.ha-1 day. The lagoons treated raw sewage from the city of Campina Grande, Paraíba, Brazil (latitude 7 ° 13 '17 "S, longitude 35 ° 52'31" 0). The raw sewage that fed the ponds presented, on average, a BOD of 160 mg / l, 1.23 x 10 fecal coliforms per 100 ml and a concentration of suspended solids of 272 mg / l. On average, lagoons achieved removal of intestinal parasites, fecal coliforms, suspended solids and DB05 of 99%, 95%, 78% and 71% respectively. Throughout the experimental period the byrobotrys flagellated algae genera, Chlamydomonas and Euglena. were present in the effluent of the 04 (four) lagoons with a frequency higher than 95% of the analyzed samples. While the non-flagellated algae genera Scenedesmus, Oscillatoria and Navicula appeared less than 20% of the analyzed samples.