Continuous Monitoring Of Turbidity And Conductivity: A Reliable, Easy And Economic Tool For Sanitation Management

To monitor sanitation, the urban catchment of Pau urban area (south west France), which is about 50 km super(2) with about 150 000 inhabitants was equipped with four rain gauges, thirty four flowmeters, two turbidimeters and one conductimeter. Good correlations were obtained between turbidity, Total Suspended Solids (TSS) and Chemical Oxygen Demand (COD) on the one hand and conductivity and total nitrogen on the other. These probes were installed in March 2012 and allowed an instantaneous and continuous estimation of pollutants concentrations from this date. In this paper results from November 2012 are presented. Firstly turbidity and conductivity raw data show different trends during the study period depending on rain events. Mass/volume curves have been established and used to compare the behaviour of the network during different rain events. Very different curves are obtained between TSS and total nitrogen. Finally, pollutant fluxes are calculated daily during the month of November. This presentation allows the synthesis of the data and a global comprehension and monitoring of the sewer system. These results highlight the potential of online monitoring to better understand the behaviour of the sewer network on long or short term scales. This could be a useful tool to manage wastewater treatment.