Evaluation of monitoring data of wastewater treatment plants operating with UASB reactors, in the Velhas River hydrographic basin (MG), Brazil

ABSTRACT

Only 30% of the Brazilian municipalities have wastewater treatment service. Even when existent, many wastewaters treatment plants face operational and design problems. This study evaluated the performance of ten Upflow Anaerobic Sludge Blanket reactors, a widely adopted technology in the country, whether or not followed by post-treatment, located in the Velhas River hydrographic basin and operating at full scale. Effluent concentrations and removal efficiencies were compared with typical values reported in the literature, as well as systems’ performances were statistically compared among plants. Violation percentages were calculated, according to the local discharge standards, and Cluster Analysis was carried out with effluent concentrations data of the ten treatment plants to evaluate whether the systems would be grouped according to their configurations. In seven of the ten wastewater treatment plants (70% of the systems), lower performance than expected were observed, taking into account the adopted treatment technologies, with operational and design problems being the main factors responsible for the behavior of the analyzed systems.

Keywords:
comparative performance evaluation; domestic effluent; effluent quality; anaerobic treatment