Combined Coagulation and Electrochemical Process to Treat and Detoxify a Real Textile Effluent

Author(s)

Aquino, Jose M. ; Pereira, Gabriel F. ; Rocha-Filho, Romeu C. ; Bocchi, Nerilso ; Biaggio, Sonia R.

• Document type: Journal article
• Source: WATER AIR AND SOIL POLLUTION; v. 227, n. 8 AUG 2016.
• Web of Science Citations: 8

Abstract

Combined coagulation and electrochemical treatment processes were used to mineralize the organic load and detoxify a real textile effluent. The coagulation step was investigated for distinct pH values (4 to 11) and Al-2(SO4)(3) concentrations (0.25 to 9.00 g L-1). Complete turbidity and partial total organic carbon (TOC) removals were attained at pH 5, using 0.50 g L-1Al2(SO4)(3). Moreover, the coagulation process totally removed the initial toxicity (100 % mortality) of the effluent, assessed by toxicity tests with the crustacean Artemia salina. The remaining TOC was mineralized by the electrochemical step in a flow cell with a boron-doped diamond (BDD) anode, when the investigated parameters were the BDD boron-doping level (100, 500, 2500 ppm), pH (3, 7, 11, no control), and current density (10, 20, 30 mA cm(-2)). No significant differences in TOC removal were observed when the BDD anode or pH value was changed; however, as the system was under mass transport limitation, mineralization attained at low current densities led to a reasonable current efficiency (similar to 40 %) and low energy consumption (similar to 16 kW h m(-3)). The use of the electrochemical method solely led to poor TOC and turbidity removals, thus not being recommended. (AU)

• FAPESP's process: 12/13587-7 - Use of metallic oxides deposited on planar and tridimensional substrates for the electrochemical and photochemical degradation of organic pollutants
• Grantee: José Mario de Aquino
• Support Opportunities: Scholarships in Brazil - Post-Doctoral