# Recent Developments and Emerging Trends in Paint Industry Wastewater Treatment Methods
## 3 Paint Industry Wastewater Treatment Methods
### Electrochemical Treatment
#### 3.3.1 Electroflotation
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**Treatment Method** & **Treatment Parameters** & **Results** & **Source of Wastewater** & **References** \\ \hline Electroflotation & NaOH added to mixture to adjust pH total testing time was 40 min & TSS removal from 90.39 to 97.43\% & Automotive paint solvent-based auto paint (clear coat and primer) synthetically prepared in the laboratory & [60] \\ \hline Continuous flow electroflotation & Stainless-steel electrodes & TSS removal rate 95 \(\pm\) 7\% under initial TS 500 mg/L, current density 100 A/m\({}^{2}\), retention time 8 min & Automotive paint wastewater was synthetically prepared in the laboratory & [61] \\ \hline Electrochemical oxidation & Batch-wise in the presence of NaCl electrolyte with carbon electrodes & Removal of COD—65.68\%, color—98.74\%, and turbidity—96.56\% & Synthetic water-based paint wastewater & [62] \\ \hline Indirect electrochemical oxidation & Reaction time = 1 h pH = 3–12 graphite electrodes NaCl = 1–3 g/L & COD removal 55\% NaCl = 1–3 g/L & Mixed wastewater from textile and chemical industry & [63] \\ \hline Electrooxidation & Peroxymonosulfate and transition metals (Fe\({}^{2+}\), Cu\({}^{2+}\), Zn\({}^{2+}\)) graphite cathode material (Ti/IrO\({}_{2}\), Ti/RuO\({}_{2}\), Ti/SnO\({}_{2}\)) & COD and true color removal efficiencies as a result of validation studies & Paint manufacturing industry wastewater & [22] \\ \hline Electrooxidation & pH = 4, temperature 39.99 \({}^{\circ}\)C, NaCl concentration 100 mM, feed rate of 40 mL/min current 5.21 A & COD removal 80.95\%, color removal 79.12\% under optimum conditions & Paint manufacturing plant wastewater & [64] \\ \hline Electrochemical treatment in tubular reactor & Batch-wise in the presence of NaCl electrolyte with carbon electrodes & COD removal 44.3\% color removal 86.2\% turbidity 87.1\% & Synthetic water-based paint wastewater & [28] \\ \hline Electro coagulation with advanced electricity and flow control & BDD electrode & 12 mL/L of Al\({}_{2}\)(SO\({}_{4}\))\({}_{3}\) & & \\ \hline Electrooxidation & current dosage & TS decreased from 10.7 kg/m\({}^{3}\) to 0.37 kg/m\({}^{3}\) coagulant: aluminum sulfate dosage 12 mL/L & Wall paint manufacturing (97\% removal TS) COD removal 85\% & [28] \\ \hline Electro coagulation with advanced electricity and flow control & Current density for batch process i = 14.2 mA/cm\({}^{2}\) and for continuous process i = 14.4 mA/cm\({}^{2}\) & COD removal 69.7\% in continuous flow reactor & Mixed wastewater from textile and chemical industry & [65] \\ \hline Electro coagulation with advanced electricity and flow control & Current density for batch process i = 14.2 mA/cm\({}^{2}\) and for continuous process i = 14.4 mA/cm\({}^{2}\) & COD removal 43–55\% chemical industry & Mixed wastewater from textile and chemical industry & [63] \\ \hline \hline \end{tabular}
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Table 3: Electrochemical treatment methods for paint industry wastewater.