Effluent treatment plant is a crucial part of a pulp and paper industry, especially considering how Ethical has opted for green technology, it is paramount to adopt an efficient ETP to ensure that the water discharged off the plant is safe to be released back to the environment.

Wastewater from paper mills depends on the raw material and chemicals used, pulping process applied and management practices. Typical range for wastewater characteristics from paper mills using imported pulp/waste paper are pH 6.9 – 8.7, Suspended Solid Particles of 400 – 1100 mg/l, Dissolved Materials 100 – 700 mg/l, BOD at 20º C 90 – 150 mg/l, COD 320 – 800 mg/l.

The treatment options are:

• Physicochemical method,
• Biological method,
• Combination of Physicochemical and Biological method.

Biological treatment can further be classified as anaerobic and aerobic.
Ethical has opted to utilize the combined method where both the biological and the physicochemical method is used to ensure the proper management of the waste water and the sludge obtained.

Our physicochemical treatment processes remove suspended solids, colours and even BOD and COD by screening, coagulation, flocculation, sedimentation, flotation, adsorption. Additive chemicals as well as enzymes are used to facilitate the breakdown of the suspended organic solid particles and to coagulate them for sedimentation and filtration processes. Chemical precipitation is used for further removal of heavy metals and dissolved solids, by rendering then in soluble and then settling them out or being filtered.

In biological treatment, metabolic functions of microorganisms are used to correct detrimental BOD, COD and capture suspended and super fine colloidal solids either in aerobic or anaerobic processes.

Furthermore, fungal treatment of coloured effluents from the mill, ensures satisfactory results, hence significant decrease in pollution load and wastewater volume has been observed due this treatment making the final discharge perfectly safe for the environment.

Selection of the appropriate method for the treatment for the effluent is vitally important, because it not only safe guards the hazards to the environment, but also minimises the cost for the processes but using the correct technology for the correct process.