Reactive Dye Bath Concentration Controls for Heavy Cotton Wovens
Dynamic progressive salt and alkali dosing profiles prevent surface exhaustion and core shade variance in heavy cotton woven dyeing.
Effluent Total Dissolved Solids
Wastewater Metric
Inorganic salts and organic compounds dissolved in textile wastewater represent a critical measure of chemical load from wet processing operations. High concentrations of effluent total dissolved solids originate from the extensive use of sodium chloride and sodium sulphate during the exhaustion phase of reactive dyeing. This parameter quantifies all mobile ions smaller than two microns that pass through a standard glass fibre filter.
The measurement is expressed in milligrams per litre and is used to calculate the environmental fees paid by the factory.
Environmental Harm
High salinity in water bodies disrupts the osmotic pressure of aquatic organisms and prevents the self-purification process of rivers. When highly saline textile wastewater is discharged without treatment, it alters the local soil chemistry and harms agricultural lands downstream. This damage is particularly severe in arid regions where dilution is low.
Local authorities enforce strict discharge limits to protect water resources.
Industrial Treatment
Conventional activated sludge systems cannot remove these dissolved salts, requiring advanced membrane technologies for purification. Reverse osmosis and multi-stage flash evaporation are the primary methods used to separate the salt from the treated water. This recycled water is then returned to the dyehouse.
The process requires a high amount of energy.
Mill Compliance
Conductivity meters provide a rapid estimation of the salt concentration in the effluent stream during daily operations. While these hand-held devices offer real-time data for operational control, gravimetric determination after drying at one hundred and eighty degrees Celsius is required for official regulatory reporting. This standard procedure ensures the mill avoids heavy fines and potential closure by local environmental protection agencies.