Integration of catalytic wet peroxidation and membrane distillation processes for olive mill wastewater treatment and water recovery

• OMW catalytic wet peroxidation & water recovery by membrane distillation is studied. Higher fluxes and rejection of contaminants achieved upon oxidation OMW. Several parameters for safe discharge were met after the integrated process. The retentate stream may be recirculated treated initial step. degradation organic matter present in olive mill wastewater (OMW) studied integration (CWPO) direct contact (DCMD) first time. step was performed a fixed–bed reactor (FBR) working continuous mode (pH 0 = 4.0 ± 0.2, 60 °C, Q 0.75 mL/min, [H 2 O ]/[COD] feed 2.3 0.1 g H /g ). Samples diluted 5– 7.5–fold used (OMW–5× OMW–7.5×, respectively), corresponding to inlet chemical oxygen demand (COD) values 3562 68 2335 54 mg/L, total phenolic content (TPh) 177 17 143 7 mg GA eq /L, carbon (TOC) 1258 63 842 45 respectively. FBR loaded with 2.0 Fe–activated derived–catalyst, prepared using stones as precursor, line circular economy model approach. catalyst selected based on activity stability towards polyphenolic synthetic solutions shown previous works team, while actual samples this work. CWPO–treated allowed operation DCMD unit at higher than analogous untreated ones, also showing rejections from solution DCMD, highlighting beneficial effect novel configuration. Using pre-treated sample OMW–7.5× (Q 100 T permeate ≈ 18 66 °C), produced presented several well–below legislated thresholds required crops irrigation, including suspended solids (TSS < 10 mg/L), TPh (<0.01 /L), biochemical (BOD 5 40 dissolved Fe (<0.06 mg/L). Moreover, resulting concentrated OMW–retentate streams could maintain same removal efficiencies obtained previously, despite increased loadings DCMD.