Audit tools for smart energy and sludge management
The audit tools were developed to measure the effectiveness of the process applied at wastewater treatment plants and outline the potential for improvements of these plants. The audit tools provide an opportunity for operators to perform self-auditing at their WWTPs, and thereby enhance the energy efficiency of the treatment, improve sludge handling, and detect measures for both short and long-term improvement of the treatment process.
The audit tools analyse efficiency and feasibility of smart energy and sludge management taking into account such factors as full process analysis, on-site energy measurements, sludge handling technology and flows, energy and chemical consumption, automatic calculations of operational parameters and others. Most of the results are shown in comparison with the data collected for the benchmark, which enables comparability of the achieved values with other plants and developed benchmarks in the Baltic Sea Region.
First energy and sludge management audits in order to develop the audit tools were performed on 9 WWTPs (Estonia, Latvia, Lithuania, Poland and Germany).
The audits on the sludge management part revealed that there is a large amount of waste activated sludge produced in the Baltic Sea Region. Waste activated sludge contains variety of pollutants (heavy metals, pharmaceuticals, pathogens) and nutrients (nitrogen, phosphorous). In order to reduce the flow of pollutants into water bodies and to promote recycling of nutrients, it is essential to support smart sludge management.
The uniform and thorough audit concept considers regional and technological peculiarities, which increases the potential of practical application of the tool. Based on achieved results, WWTPs can obtain knowledge about important operational parameters and possibilities for the improvement of the process. Plants can benefit from the enhancement of sludge management, as it leads to higher energy production, lower energy consumption and reduces loads of hazardous substances and nutrients in the effluent.