Table 10.

The removal of color, COD, and TOC from tannery wastewater by using selected methods.

Parameter	Results (This Study)	Results (Other Studies)
COD	↓86.1% (oxidation using K2FeO4)	↓78.7 ± 1.3% (carbon felt); ↓93.8 ± 1.7% (LTA zolite-modified anode); ↓96.3 ± 2.1% (bentonite-modified anode); bioelectrocatalytic oxidation [77]
		↓80–87% (UF membranes); ↓65% (MF membranes); ↓96% (RO; reverse osmosis) [78]
		↓96.33% (primary treatment process); ↓99.81% (NF; nanofiltration); ↓99.84% (RO; reverse osmosis) [79]
TOC	↓80.5% (oxidation using K2FeO4)	↓52%; simulated tannery wastewater (MF membranes) [78]; ↓87%; (hydrodynamic cavitation with addition of H2O2) [80]; ↓50.0%; (coagulation-flocculation/adsorption; CF-ADS) [81]; ↓46.5%; (coagulation-flocculation/ozonation; CF-OZ) [81]
Color	↓99.3% (oxidation using K2FeO4)	↓61.13%; (coagulation-flocculation/adsorption; CF-ADS) [81] ↓85.34%; (coagulation-flocculation/ozonation; CF-OZ) [81] ↓87%; (electrochemical oxidation; EO) [82]