Table 9.

Comparison among effluent treatment methods

S.no	Treatment methods	Illustration	Merits	Demerits	References
1	Membrane filtration	Removal of solids from wastewater based on ultrafiltration/microfiltration	Feasible to attain the required water and discharge concentration factors	Not applicable for shear sensitive materials and expensive	Barakat M.A (2011)
2	Activated carbon adsorption	Adsorption of toxic organic compounds from the effluent	Pertinent for the removal of wide variety of dyes like azo, reactive dyes, etc.	Regeneration is expensive and involves adsorbent loss	Barakat M.A (2011)
3	Photocatalysis	Advanced oxidation technology for eliminating the determined organic compounds and microbes from wastewater	Low operational costs and absolute mineralization of chemical substances	Fouling of photo- catalysts	Threrujirapapong T et al. (2017)
4	Electro-coagulation	Destabilization of suspended, emulsified and dissolved contaminants in the effluent by the application of electric current	No chance of secondary pollution as no chemicals are added	Requires regular replacement of anode	Gatsios E et al. (2015)
5	Bio-augmentation	Enzymatic treatment to remove pollutants from the wastewater	Improves contaminant degradation	Rehabilitation result may be incomplete	Bora T et al. (2014)
6	Biodegradation	Primary removal mechanism for emerging organic pollutants in wastewater	Simple, economically feasible	Necessary to create an optimally favorable environment	Barakat M.A (2011)
7	Nanotechnology	Application of nanoparticles for the removal of contaminants from the effluent	Complete degradation of pollutants	Recovery of nanocatalyst is tedious	Bora T et al. (2014)
8	Ozonation	Waste water treatment technique based on the infusion of ozone in water	Increases the dissolved oxygen content in water	Cost of treatment is comparatively high	Cano Quiroz A et al. (2011)