To understand the environmental impact and efficiency of water usage in the production of man-made cellulosic fibre (MMCF), it is necessary to measure some important wastewater parameters in terms of load-based values1 rather than only concentration-based values2. For this, the pollutant concentration needs to be linked with the wastewater flow rate in the fibre or filament manufacturing process.
In the MMCF Guidelines 3.0, Table 15, Wastewater parameters to be assessed in load per tonne of fibre or filament (pg no. 42-43) outlines the norms to be achieved for COD, BOD, Zn, and sulphate (SO₄²⁻ ) parameters in terms of load per tonne of fibre production at Foundational, Progressive and Aspirational Levels for the different MMCF types.
The load per tonne is calculated by simply multiplying the concentration in mg per litre with the water flow rate in cubic metres per day.
Note: The month of determining the water flow rate should be the same as the month in which the wastewater testing has been done and the pollutant concentration has been measured