Artificial neural networks for performance prediction of full-scale wastewater treatment plants: a systematic review.

Wastewater treatment plants (WWTPs) are complex systems that must maintain high levels of performance to achieve adequate effluent quality to protect the environment and public health. Artificial intelligence and machine learning methods have gained attention in recent years for modeling complex problems, such as wastewater treatment. Although artificial neural networks (ANNs) have been identified as the most common of these methods, no study has investigated the development and configuration of these models. We conducted a systematic literature review on the use of ANNs to predict the effluent quality and removal efficiencies of full-scale WWTPs. Three databases were searched, and 44 records of the 667 identified were selected based on the eligibility criteria. The data extracted from the papers showed that the majority of studies used the feedforward neural network model with a backpropagation training algorithm to predict the effluent quality of plants, particularly in terms of organic matter indicators. The findings of this research may help in the search for an optimum design modeling process for future studies of similar prediction problems.

Municipal wastewater discharge standards for ammonia nitrogen in Brazil: technical elements to guide decisions.

In Brazil, domestic effluents represent the primary source of pressure on water resources. Water pollution can be controlled by defining, applying, and enforcing the effluent standards for wastewater discharge. Discussions are ongoing in Minas Gerais State regarding the possibility of setting a discharge standard for ammonia nitrogen in municipal wastewater, which is currently not required. However, providing technical support for decision-making is challenging because of the difficulties in accessing monitoring data from sewage treatment plants. This study aimed to analyze the monitoring data from 49 sewage treatment plants operating in Minas Gerais to offer guidance for decision making. High concentrations of ammonia nitrogen in the effluents of the treatment plants were found, reinforcing the need for better control and the adoption of more advanced technologies. Furthermore, it was observed an increase in concentrations downstream of the discharges in the receiving water bodies. Adopting a progressive and adaptable discharge standard can be a solution for better control of treatment systems.