Electrochemical process and Fenton reaction followed by lamellar settler to oil/surfactant effluent degradation

• Published in: Journal of water process engineering 2019-10, Vol.31, p.100841, Article 100841
• Main Authors: da S., J.L. Duarte, L., Meili, L. de M., Gomes, J.I., Soletti, de P. e S., C.L.Zanta
• Format: Article
• Language: English
• Subjects: Electro-Degradationo; Fenton; OIly water; Surfactant
• ISSN: 2214-7144; 2214-7144
• DOI: 10.1016/j.jwpe.2019.100841

[Display omitted] Degradation of simulated oil-surfactant effluent was tested using electro-oxidation with commercial Dimensionally Stable Anode (DSA®) and Fenton reaction followed by lamellar settler to remove iron sludge. Chemical Oxygen Demand (COD), turbidity, iron monitoring, Total Current Efficiency (TCE) and Power consumption for electrolytic reactions were used to evaluate the efficiency of the degradation process. Fenton experiments showed good COD and Turbidity removal, mainly when catechol (0.5 mM) was used as catalyst, and promoted the COD removal from 37 to 67% ([Fe2+] = 0.5 mM; [H2O2] =200 mM), however, 88% was removed when [Fe2+] = 0.7mM. The lamellar settler was effective for iron waste removal, reducing the overall time for the whole process. Electrochemical degradation provided good results, either by direct oxidation at the electrode surface or indirect, by the strong oxidants electrogeneratedfrom electrolytes, achieving 82 and 89% of COD removal for H2SO4(90 mA cm−2) and HCl (60 and 90 mA cm−2), respectively. First order constant showed sulfate base reaction faster, with 72% removal at 30 min. Turbidity, TCE and Energy analysis corroborate COD, revealing the possibility of lower reaction time when sulfate was used and lower current density with chloride, leading to economic viability of the process.