Real-time monitoring of organic load discharged (BOD5) during combined sewer overflows (CSO)
Context
While combined sewer systems carry wastewater and stormwater to treatment plants, they can be overloaded during heavy rainfall events. A combined sewer overflow (CSO) diverts excess, yet untreated, water into the environment, potentially causing adverse human health and environmental impacts.
Limits of the current strategies for BOD5 measurement for CSO monitoring:
·Strategy based on a flow-controlled sampler.
·Need power supply on worksite.
·Sample reproducibility & representativeness biases due to average measurement.
·Sample conservation (weekends, public holiday).
Monitoring CSOs with NODE Solutions & Services biosensor enables network operators to understand the hydraulics of the sewer system, allowing teams to respond in real time to identify and control pollution discharges into the environment.
Solutions & Results
·Permanent and real time analysis of BOD5.
·Installation in difficult to access sites/areas.
·Easy and fast installation.
·No additional work costs.
·Online data management.
·Energetically sufficient and communicant.
·Limited maintenance.
·Use of indigenous micro-organisms coming from the sewage system or WWTP.
·No consumable nor reagent.
·Coupled with a flow measurement, the solution meets the requirements of local regulations (pollutant flux discharged in the environment).
Feedback & Perspectives
Applied to CSO monitoring, NODE Solutions & services allows the assessment of the pollution discharged into the Environnement during rainfalls, or storm events. Depending on the local regulations, we are able to convert the pollutant concentration into daily flux (BOD5 kg/day). Compared to spot sampling and lab analysis, the online monitoring solution proposed by the NODE Solution & Services generates an accurate measurement and cost savings.
