Aspectos do funcionamento de uma estação de tratamento de laticínios (Campina Grande-PB).

Abstract

The objective of this study was to evaluate the operation of the effluent treatment plant produced by ILCASA (Dairy Industry of Campina Grande S / A), which is located on highway BR 230, km 116, District of Santa Terezinha - Campina Grande (? 13'11 "S, 35 ° 52'31" 0, 550 m above sea level), State of Paraíba, northeastern Brazil. The investigated experimental system ETE of ILCASA, consists of a preliminary treatment unit, consisting of bar grille, sandbox, pourer and separator of oils and greases; followed by a unit for the secondary treatment, which contains a surface aerator equalization tank and a series upflow anaerobic filter system. Samples of the raw sewage (Bet 1), equalization tank (Bet 2) and anaerobic filters (Bet 3) were collected every two weeks between 8 and 9 am in the period from October to December 1994 experiment) and from October 1995 to June 1996 (2nd experiment). Studies were also carried out along the 12-hour daily cycle and samples were collected every 3 hours. During the experimental period, physical-chemical and microbiological parameters were investigated. The final effluent of the ILCASA ETE was characterized by the concentrations of DB05 (139- 306 mg / L), suspended solids (326-443 mg / L) and high faecal decoliforms (105-106 CFU / 100 mL) ). The phosphorus and nitrogen concentrations of the final effluent were also high, with mean values ​​between 8.0 and 9.6 ng / L for total phosphorus, between 5.4 and 6.1 mgP / L for soluble orthophosphate and between 15.5 and 20.2 mgN / L for ammonia. These high values ​​of eutrophic nutrients make these wastewater attractive to controlled agricultural reuse in semi-arid regions, contributing to the solution of the problem of water scarcity, as well as ensuring the production of vegetable protein and reducing the pollution of surface water.