The aim of this work is to investigate a novel cork wastewater (CW) purification method that combines flocculation/adsorption with the microwave assisted regeneration of coconut powder activated carbon (CPAC). The flocculation treatment made use of FeSO4·7H2O/NaOH and provided high removal efficiency, as shown by the observed values of UV254 (90%), chemical oxygen demand (COD, 86%), polyphenols (PP, 81%),total solid (TS, 40%), total suspended solid (TSS, 62%), and total dissolved solid (TDS, 18%). After the flocculation and filtration, CPAC was used to further remove left TSS, TDS and dissolved organics. The effects of CPAC amount, pH value and adsorption time have been studied. It was found that 250 mg is the optimum CPAC amount for the treatment of 50 mL CW at pH 3.5 for 10 min. Overall process effectiveness can be summarised as follows: UV254 (100%), COD (98%), PP (100%), TS (58%), TSS (93%), and TDS (24%), while the characteristic colour of the CW completely disappeared. The microwave regenerated CPAC can undergo five runs without appreciable losses in removal efficiency. Predictably, this simple and scalable process could afford a promising treatment method for other industrial wastewaters with high content of organic matters such as PP, phenolic acids and tannins.
Keywords: Activated carbon; Adsorption; Cork wastewater; Flocculation; Microwave-assisted regeneration.
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