Wetlands construídos de fluxo vertical aplicados no pós-tratamento de efluente de abatedouro de ovinos e bovinos

Abstract

Red meat consumption has increased in recent years, mainly due to the economic growth that has increased the general consumption power of the population. In order to meet this demand, animal slaughtering processes have intensified and, consequently, the generation of wastewater from slaughterhouses has also been increased, which are often misdirected and may have negative impacts on human health and ecosystems. One of the alternatives used in many countries, mainly in Europe, for the treatment of various types of wastewater, has been the system of wetlands type built, it is a natural process, with low construction costs, maintenance and operation and by the high removal efficiency of carbonaceous and nitrogenous organic matter that they can reach. In this work, the objective of this work was to evaluate the performance of two vertical-flow wetlands on bench scale in the secondary effluent treatment of a slaughterhouse of cattle and sheep in Caçapava do Sul-RS. The two units were planted with the macrophyte Typha domingensis Pers and present as substrate a layer of 0,30 m of gravel 0. The bench system (0,114 m2) was set up in may 2017 and operated with effluent application three times a week until September of 2017. Two hydraulic application rates (TAH) of 421.04 L.m-2.d-1, distributed in 3 batchings per day (16 L each batch for both WCFV) and 52.62 L.m-2.d-1(2 L each batch). Physical-chemical analyzes, substrate granulometric tests, hydraulic tests and the monitoring of plant development were performed. Based on the results of the four months of operation, it was concluded that: With average organic load application of 203.50 g COD.m-2.d-1, it provided a mean removal efficiency of 3% and 9% for COD and Turbidity, respectively for WCFV1. As for WCFV2, it presented average removal efficiencies of 8% and 6% for COD and Turbidity. On the other hand, in the reduction of TAH, it was possible to improve the WCFV performance, and submitted to loading of 15,21 g COD.m-2.dia-1, promoted a mean removal efficiency of 15% and 23% for COD and Turbidity for WCFV1, WCFV2 showed average removal efficiency of 21% and 40%, respectively for COD and Turbidity. Neither TAH showed good efficiencies for removal of total solids.