Proposta de metodologia operacional de reator biológico anaeróbio em estação de tratamento de esgoto visando a eficiência de produção de biogás via sensoriamento eletrônico

Abstract

Anaerobic biological reactors have been increasingly used as a technological option to promote the design of more compact and efficient sewage treatment plant projects, in terms of the degradation of the organic load of wastewater. In this context, the upstream flow reactor technology of the UASB (Upflow Anaerobic Sludge Blanket) reactors has become a widespread alternative in Brazil, as it complies with normative parameters for the ideal secondary treatment for domestic effluents and for reconciling with the production of biogas, viable to the sustainability of the ETEs, with regard to its use as a renewable energy source. The performance of this type of reactor is influenced by biological, physical-chemical and structural factors, which affect the efficiency of the anaerobic digestion process as a whole, moreover, by treating domestic sewage, it is subject to several variations in concentration and chemical composition of the substrate (organic matter), seasonally, so the implementation of an Operation Manual focused on improving each step of the process. For this reason, the objective of this work is to propose a methodology for operating the ETE Alameda das Palmeiras - Fortaleza-CE administered by the Companhia de Água e Esgoto do Ceará (CAGECE) based on process quality indicators, with the purpose of contributing for the operation of a model organic waste treatment plant associated with the production of biogas. Through visits to the ETE and evaluations of the quality of the affluent sewage / efficiency of the treatment of the systems, it was possible to establish the necessary modifications for the ETE. The sensing system, consisting of submersible pH and thermocouples, an oxygen probe dissolved in the aerobic reactor to control O2, was proposed not only to improve the quality of the process, but also to mitigate to maintain the costs of operation and maintenance of the TEE. The analyzes collected at the collected ETE showed an efficiency in the removal of COD via UASB Reactor, between 70 to 80%. The expectation is to obtain a more efficient and profitable process control, in order to minimize environmental impacts and maximize the energetic sustainability of the WWTP, based on the use of the calorific power of biogas and the rational destination of process residues, such as stabilized sludge. and the sand that is carried by the wastewater.