Abstract
The electro-oxidation of recalcitrant compounds, phthalic acid, tyrosol, and catechin was studied in simulated and real winery wastewater samples using a boron-doped diamond (BDD) anode. In the simulated samples, catechin, although presenting a higher removal rate than that of phthalic acid and tyrosol, attained lower combustion efficiency, indicating that this compound is readily converted into other products rather than being completely oxidized. On the other hand, phthalic acid was easily mineralized. Regarding the electro-oxidation assays performed with the spiked winery wastewater, recalcitrant compounds and overall organic load removal rates increased with applied current density (j), but the removal efficiency of recalcitrant compounds decreased with the increase in j, and the specific energy consumption was significantly raised. The increase in treatment time showed to be a feasible solution for the WW treatment at lower j. After 14 h treatment at 300 A m−2, phthalic acid, tyrosol, and catechin removals above 99.9% were achieved, with a chemical oxygen demand removal of 98.3%. Moreover, the biodegradability index was increased to 0.99, and toxicity towards Daphnia magna was reduced 1.3-fold, showing that the electro-oxidation process using a BDD anode is a feasible solution for the treatment of winery wastewaters, including phthalic acid, tyrosol, and catechin degradation.
Highlights
Academic Editor: Ruben MirandaThe industrial production of wine involves the consumption of large volumes of water, with approximately 70% being discharged as wastewater [1]
Tyrosol, and catechin concentrations were determined by high-performance liquid chromatography (HPLC) utilizing a Shimadzu 20A Prominence HPLC system equipped with diode array detector SPD-M20A, column oven CTO-20AC, and an LC20AD SP pump, all purchased from Izasa Scientific (Carnaxide, Portugal)
Sample composition influences the removal rate of the recalcitrant compounds, and catechin presented the highest removal rate in all the studied experimental conditions, meaning that catechin is more degraded than phthalic acid or tyrosol is
Summary
The industrial production of wine involves the consumption of large volumes of water, with approximately 70% being discharged as wastewater [1]. Hydroxyl radicals (HO ) are a highly reactive oxidizing species that reacts unselectively and instantaneously with organic compounds present in wastewater, leading to their degradation and mineralization [14]. BDD(HO ) adsorption leads to high amounts of hydroxyl radicals available to oxidize organic compounds and mineralize them more effectively than other anode materials can [22–24]. The degradation of specific recalcitrant and toxic compounds, such as some phenolic compounds that are present in WW, was disregarded in these studies, as well as the ecotoxicological evaluation of the EO process in the treatment of this kind of wastewater. The degradation of the recalcitrant and toxic compounds phthalic acid, tyrosol, and catechin through EO using a BDD anode was assessed in simulated and real WW samples. The influence of applied current density and the ecotoxicological performance of the process was assessed using real WW samples spiked with the recalcitrant compounds under study
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
