Evaluation of an anoxic-aerobic mbr process with high nitrogen content

Abstract

The fishmeal processing industry generates wastewater with high content of organic load and nitrogen, therefore it should be treated before its discharge into a receiver body. The objective of this research work was to evaluate a biological treatment system (anoxic-aerobic-membrane biological reactor) operated by a company dedicated to the processing of sardine and tuna meal. This treatment system presents incomplete nitrification and denitrification reactions, which cause deficient removal of nitrogen and non-compliance with the maximum allowable discharge limits. The work was developed with scenarios for evaluation, extension and modification of this process through a simulation with the GPS-X software. The results showed deficient denitrification in the anoxic reactor, therefore increased nitrification is required in the aerobic reactor, and the membrane biological reactor (MBR) only fulfilled the objective of filtration. On this basis, scenarios were simulated for modifications in the process, including the elimination of the MBR and the adequacy of a secondary clarifier, which would help in the denitrification process due to its anoxic conditions. The actual system it has a total effectiveness 49.5% for nitrogen removal, while the adequacy of the system improved the efficiency to 94.7%.