"Avaliação da qualidade das águas do córrego que atravessa o campus II da UFPB".

Abstract

The pollution of water reservoirs which constitute a part of urban drainage system is quite common in the Brazilian Cities. The environmental degradation of the streams, rivers and dams occurs due to the presence of organic matter in quantities beyond the inherent treatment capacity of the main water. In this research the evaluation has been done for some physic-chemical, microbiological and biological parameters for a 1 km section of the drainage system in Campina Grande which passes the Campus II of the Federal University of Paraiba. The aquatic ecosystem investigated comprises a stream followed by a lake and stream. Samples were collected at four points along the 1 km segment for investigation during a period extending from Sept/96 to Aug/98. The analysis revealed high values of electric conductivity (1946-1703 u.mho/cm), organic matter (142-10 mg/L), suspended solids (123-8 mg/L), total phosphorous (5,7-2,7 mg/L), soluble orthophosphate (3,9-2,1 mg/L), ammonia (36,6-18,6 mg/L), faecal coliforms (I,9xl07-5,4xl04 UFC/lOOmL) and faecal streptococci (4,2xl06-6,9xl03 UFC/lOOmL) and low dissolved oxygen (< 2,0 mg/L). This implies the presence of domestic sewage without previous treatment. The aquatic ecosystem functioned as a biological reactor for effective treatment where sedimentation proved efficient in the removal of BOD5 (78%), suspended solids (78%), faecal coliforms (77%) and faecal streptococci (97%). It is interesting to propose an adequate despollution management for this lake in order to reassume its paisagistic role and to provide water for the irrigation of Campus green áreas.