Credibility achieved with partnerships.

We are proud of our history and, specially, of the people who make and took part in it. Check it out through our cases and confirm the success we have achieved together with our customers in 10 years.



Implemented in 2016 in a region of high population density in the city of Niterói-RJ, the Maria Paula WWTP, which is comprised of physical and biological processes, was designed to meet the average flow of 105 Ls⁻¹ (57 thousand inhabitants) reaching the secondary level of treatment. As assumptions and guidelines of greater relevance to the client, the proposed technical solution for the treatment should contemplate the following:

  • Compliance with the current regulations and laws (EBOD > 85%; BOD < 40 mg.L⁻¹ ; SST < 40 mg.L⁻¹ ; N-NH4 < 5 mg N.L⁻¹ );
  • Optimization of the land occupation area (2,665 m² of total area with irregular geometry);
  • Reduction of implementation costs (modulation, following the population growth: 35, 70 and 105 L.s⁻¹ ) and operation (sludge and energy);
  • Reliability and process stability (robustness to load shocks);
  • Reduction of unpleasant odors around the unit (area of high density population with a municipal school and a residential condominium as neighbors);
  • Simple and low cost operation (remote monitoring with flexible operation);

Picture of Maria Paula WWTP – Niterói/RJ - Brazil


Thus, in order to achieve full customer satisfaction, BIOPROJ developed the following work plan:

  • Comparative studies of concepts and alternatives between technologies (suspended and immobilized biomass), with the objective of providing technical, operational and economic subsidies (CAPEX, OPEX and VPL) that help decision making regarding the most appropriate technology for the implementation of the unit;
  • Conceptual project, with the objective of providing necessary and sufficient subsidies for the definition of all manufacturers and their respective equipment, materials and construction methods;
  • Basic and executive project, with the objective of gathering a set of necessary and sufficient elements to characterize and implement the unit, ensuring technical and economic viability from the perspective of: processes, hydraulics, mechanics, electrical, instrumentation, automation and civil issues;
  • Follow-up on the execution of the works and unit assembly, including the technical support services, by having on-site a qualified technical team, in order to orient, set interferences and produce necessary detail boards for proper execution / assembly and building;
  • Training and qualification of the technical-operational team responsible for the operation and maintenance activities, transferring all the necessary knowledge and experience for the proper operation of the treatment unit, on a “on the job training” basis, until the client can take over the activities with his own team.

Picture of Maria Paula WWTP project– Niterói/RJ - Brazil


As a final result, the technology chosen by the client as the one with the highest adherence to the premises and guidelines established for the implementation of the Maria Paula WWTP consisted in the use of Combined Bioreactors of Anaerobic-Aerobic Fixed Biofilm (CBR), in which special supports for microbial immobilization (Biobob®) are applied, increasing the biomass concentration within biological reactors, thus increasing the station’s capacity for the removal of organic matter and nitrogen, as well as providing greater robustness (load shocks), flexibility (modulation) and operational simplicity (flexible operation) without losing the adhesion to the low costs with implementation and operation.

In addition, the absence of odor provided by the overlap of the aerobic stage to the anaerobic one, gives it the ideal solution for the region with high population density.

It is also worth mentioning that it is difficult to obtain a differentiated final result without a differentiated intermediate process. All BIOPROJ projects are developed in 3D using the BIM concept, which offers numerous advantages, such as interaction between project disciplines, greater speed, understanding, reliability and predictability (cost and schedule), as well as minimization of errors and interferences on the execution of the project.

With all these aspects, BIOPROJ was able to meet the client’s expectations and ensure the success of the MARIA PAULA WWTP, which has been meeting both the desired final quality of the treated effluent and the operational costs of the project since its start in early 2016.

Comparison between gross and treated sewage