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

• Published in: Water, air, and soil pollution Vol. 227; no. 8; p. 1
• Main Authors: Aquino, José M., Pereira, Gabriel F., Rocha-Filho, Romeu C., Bocchi, Nerilso, Biaggio, Sonia R.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.08.2016; Springer; Springer Nature B.V
• Subjects: Aluminum sulfate; Atmospheric Protection/Air Quality Control/Air Pollution; Boron; Carbon; Chemical treatment; Climate Change/Climate Change Impacts; Coagulation; Crustaceans; Dyes; Earth and Environmental Science; Effluents; Electrochemistry; Electrodes; Energy consumption; Environment; Environmental monitoring; Experiments; Health aspects; Hydrogeology; Investigations; Mass transport; Mineralization; Organic carbon; Organic loading; Oxidation; Pollutants; Soil Science & Conservation; Textile fibers; Textile industry wastes; Textile industry wastewaters; Toxicity; Turbidity; Water Quality/Water Pollution; Industrial effluents; Dyes; Toxicity test; Wastewater; Persistent organic pollutants; Coagulation
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-016-2967-z

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 (SO 4 ) 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 −1 Al 2 (SO 4 ) 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 (∼40 %) and low energy consumption (∼16 kW h m −3 ). The use of the electrochemical method solely led to poor TOC and turbidity removals, thus not being recommended.