Luca Luccarini

Nitrogen removal optimization in a sequencing batch reactor treating sanitary landfill leachate.

Biological nitrogen removal via nitrite may represent a promising process for the optimization of nitrogen removal, in particular in the presence of a low biodegradable COD/TKN ratio. In the present study a lab-scale sequencing batch reactor (SBR) was monitored for approximately 2 years to evaluate the use of dissolved oxygen (DO), pH and oxidation-reduction potential (ORP) as monitoring parameters in order to optimize nitrogen removal via nitrite from leachate generated in old sanitary landfills. The SBR manifested a nitrification efficiency exceeding 99% whereas, due to the low biodegradability of the organic matter presents in the leachates, COD removal reached approximately 40% and the addition of external COD was required to accomplish denitrification process. Moreover, the results demonstrate that DO, pH and ORP are reliable parameters for use in the monitoring of nitritation and denitritation processes in SBRs treating landfill leachates. Through manual modification of the length of the SBR phases to achieve nitrogen removal via nitrite, the nitritation and denitritation processes were rendered unstable leading to the saving of 20% in addition of external COD, almost half the theoretically achievable value. Furthermore, the low dissolved oxygen concentration applied during the oxic phases in an attempt to increase the nitritation process would appear to cause the settling characteristics of the activated sludge to deteriorate.

A CEP-based SOA for the management of WasteWater Treatment Plants

In the last years, integrated hardware/software architectures for the remote and/or automatic management of WasteWater Treatment Plants have been developed using different approaches and techniques. In this paper, we propose a different modular infrastructure which extends a Service-Oriented Architecture with the concept of Complex Event Processing. Our proposal is based on an Enterprise Service Bus, a distributed message-oriented middleware, extended with a Rule Service, embedding a rule engine in the system, an Event Router and an Event Scheduler. The infrastructure is then used to implement a modular and flexible management system for a Sequencing Batch Reactor treatment plant: this system includes a database facility, a user interface, a temporized manager to schedule the different phases of the treatment process and, finally, a signal-aware real-time DSS used for an adaptive process control.

A Pool of Experts to Evaluate the Evolution of Biological Processes in SBR Plants

In order to minimize the costs and maximize its efficiency, a Sequencing Batch Reactor requires continuous monitoring. The sensors it can be reasonably equipped with provide only indirect information on the state of the chemical reactions taking place in the tank, so the data must be analysed and interpreted. At present, no optimum, completely reliable procedure exists: instead, there exist several criteria which can be applied under different conditions. This paper shows that estimating the confidence in the quality of the response of a criterion can increase the robustness of a criterion. Then, interpreting the responses in terms of possibility distributions, the different answers can be merged, thus obtaining a more reliable overall estimate.