Combined use of coagulation (M. oleifera) and electrochemical techniques in the treatment of industrial paint wastewater for reuse and/or disposal
Autor: | Andreia D. Barbosa, Lincoln L. Romualdo, Leonardo S. Andrade, Geraldo Sadoyama, Heber Martins de Paula, Larissa F. da Silva |
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Rok vydání: | 2018 |
Předmět: |
Environmental Engineering
02 engineering and technology Wastewater 010501 environmental sciences Waste Disposal Fluid 01 natural sciences Chloride Electrolysis Water Purification law.invention chemistry.chemical_compound Nitrate law Paint medicine Electrodes Waste Management and Disposal Electrolytic process 0105 earth and related environmental sciences Water Science and Technology Civil and Structural Engineering biology Chemistry Ecological Modeling Flocculation Electrochemical Techniques 021001 nanoscience & nanotechnology biology.organism_classification Pulp and paper industry Pollution Sewage treatment Artemia salina 0210 nano-technology Water Pollutants Chemical medicine.drug Mesophile |
Zdroj: | Water Research. 145:153-161 |
ISSN: | 0043-1354 |
Popis: | In this work, water-based paint (WBP) wastewater was treated using a natural coagulant, Moringa oleifera aqueous extract (MOAE), fortified with Ca2+ (from nitrate and chloride salts). In order to improve the quality of the treated wastewater and render it suitable for disposal, an electrolytic flow process was associated with the wastewater treatment using a filter-press reactor with a boron doped diamond (BDD) electrode. The feasibility of the treatment was evidenced by the reuse of the treated wastewater in the production of a new paint (manufactured by the company supplying the raw wastewater), whose quality was compatible with the water used by the manufacturer. The best conditions for the coagulation-flocculation process involved the use of 80 mL of MOAE (50 g/L of MO and 0.125 mol/L of Ca2+) for every 1.0 L of wastewater at pH 6.5. The limiting current density (35 mA/cm2) and an electrolysis time of 90 min (charge passed of 3.68 A h/L) were used in the electrochemical treatment. Biotoxicity assays using the brine shrimp Artemia salina revealed that the mortality (in %) of microcrustaceans was reduced from 100% (raw wastewater) to only 11% at the end of the electrolysis process, in addition to eliminating the strong odor and 85% of the organic load. Moreover, microbiological tests showed that the number of mesophiles decreased by more than six orders of magnitude and there was no growth of thermotolerant coliforms (TC). |
Databáze: | OpenAIRE |
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