6. Regulations and standards

Discharges subject to provisions for suspended solids (SS) require turbidity measurement to estimate the SS content, in agreement with DRIRE and water agencies. On physico-chemical industrial wastewater treatment plants, turbidity is an indicator of the proper functioning of the settling process. In activated sludge urban wastewater treatment plants in particular, it is also an indicator of the proper functioning of final settling (clarification), and a good estimate of TSS and COD (chemical oxygen demand). These measurements are governed by ministerial decrees. .

The main problems encountered concern the representativeness of the sample, and are as follows:

• non-homogeneity of the vein with respect to turbidity: floats on the surface and heavy materials on the bottom;

• ...