Application of NaCl-plant extracts to decrease the costs of microfiltration for winery wastewater treatment

The present study aimed, for the first time, the production and application of NaCl plant extracts of Acacia dealbata Link. (pollen), Chelidonium majus L. (seed), Daucus carota L. (seed), Tanacetum vulgare L. (seed) and Vitis vinifera L. (rachis) in a coagulation-flocculation-decantation process (CFD process) for the optimization of microfiltration process (MF process) for the treatment of winery wastewater (WW). To evaluate the efficiency of the NaCl-plant extracts, aluminium sulfate (10%) was applied as comparison. The CFD process was optimized, by varying the WW pH, coagulant dosage, agitation, type and dosage of flocculants, before microfiltration process. The plants composition was investigated by Fourier-transform infrared spectroscopy (FTIR), Gas Chromatography with Flame Ionization Detection (GC-FID) and high-performance liquid chromatography with diode-array detection (HPLC-DAD). FTIR analysis showed the presence of alcohols, phenols, carbohydrates and fatty acids. GC-FID showed differences in fatty acid composition and the HPLC analysis showed differences in the phenolic composition of the plants. Under the best operational conditions: [TOC]₀ = 400 mg C/L, turbidity = 296 NTU, TSS = 750 mg/L, pH = 3.0, [Coagulant] = 0.5 g/L, fast mix (rpm/min) = 150/2, slow mix (rpm/min) = 50/30, [Bentonite] = 5 mg/L, sedimentation time 12 h, pump flow rate of 1.9 m³/h, glass microfiber filters, with micrometric retention of 1.2 µm, the application of Chelidonium majus L. (seeds) achieved 29.7, 99.7 and 95.3% total organic carbon, turbidity and total suspended solids removal, respectively, with 108 mg of filter consumption. In conclusion NaCl-plant extracts are a promising technology for WW treatment.