Avaliação do comportamento de um reator anaeróbio aeróbio de leito fixo submetido à variação de carga hidráulica tratando efluente de abatedouro bovino

Abstract

The quantity and characteristics of the waste generated in slaughterhouses vary significantly from the type of animal being slaughtered, the same physical size, type of plant, techniques used during slaughter and degree of automation, in addition to cleaning techniques and sanitizing of equipment and environments. Therefore, we propose the use of an anaerobic-aerobic fixed bed (RAALF), with upstream and biomass immobilized in bovine effluent treatment, in order to assess their performance in the removal of carbonaceous matter and nitrogen at different times Hydraulic Detention 24 h, 18 h and 14 h. The RAALF useful volume of 4.75 L being sectioned into six compartments. The following parameters were tested for each TDH (24 h, 18 h and 14h) along the reactor height: Liquid temperature, dissolved oxygen, pH, bicarbonate alkalinity, volatile acids, crude and filtered COD, total solids, volatile suspended , NTK, ammonia, nitrite, nitrate and phosphorus. The concentration of organic matter present in the substrate was a larger variation in the parameters over the period of operation. On removal of organic matter obtained the following average efficiencies for COD and filtered gross 70.3 and 70.7% for the HRT of 24 hours, 83.9 and 83.3% for the HDT of 18 h; 78 9 and 63.4% for the HDT of 14 h. Despite the wide variation of the concentration of COD in raw and filtered substrate RAALF did not happen with their effluent, indicating that the RAALF presents robust to absorb variations in organic load. The bicarbonate alkalinity in the effluent ranged from RAALF 230-1260 mgCaCO3.L-1 during the operating period, averaging 776.3, 754.9 and 890.7 mgCaCO3.L-1 TDHS for 24 h, 18 h and 14 h respectively. The average removal efficiencies of NTK and ammonia nitrogen from effluent RAALF were 52.3 and 26.0% for the HRT of 24, 37.1 and 54.5% for the HDT of 18 h, as the HDT of 14 h results for NTK concentrations were below the minimum detection efficiency while will average ammonia nitrogen was 39.6%. The average concentration of nitrite and nitrate in the effluent were RAALF 0.54 mgN-NO2-.L-1 and 27.50 mgN-NO3-.L-1 for 24 h HDT, 0.64 mgN-NO2-.L-1 and 3.2 mgN-NO3-.L-1 for HRT of 18 h as the HDT of 14 hours results for nitrate concentration were below the minimum detection while the average concentration of nitrite was 0.05 mgN-NO2-.L-1. The efficiencies and mean concentrations of total phosphorus in RAALF were: 47.5% to 0.18 mgPO43-.L-1 for HDT of 24 hours, 69.1% and 0.4 mgPO43-.L-1 for HDT of 18 h, and 33.6% and 0.07 mgPO43-.L-1 with HDT of 14 h.