▎ 摘　　要

NOVELTY - The method for co-processing sodium extraction wastewater and oxalic acid precipitation mother liquor involves (1) processing crude sodium extraction wastewater, (2) preparing deoiled sodium chloride wastewater, (3) clarifying sodium chloride water, (4) preparing modified graphene heavy metal adsorbent by mixing graphene oxide, terephthalic acid and ethylene glycol, esterifying, reacting the modified graphene heavy metal adsorbent at 280 degrees C for 20-30 minutes, cooling, centrifuging and drying, (5) subjecting modified graphene heavy metal adsorbent and clarified sodium chloride wastewater to adsorption treatment, removing heavy metals and radioactive elements from the filtrate and filtering to remove modified graphene and adding pyrolusite to adsorb impurities, (6) transferring the clarified sodium chloride wastewater to three-effect evaporation device for concentration and crystallization, centrifuging to separate the sodium chloride crystals and recovering the condensate. USE - Method for co-processing sodium extraction wastewater and oxalic acid precipitation mother liquor. ADVANTAGE - The method enables co-processing sodium extraction wastewater and oxalic acid precipitation mother liquor ensuring enhanced radioactive elements removal effect and increased reusability of recovered extractant by simple, non-toxic and environmentally-friendly process. DETAILED DESCRIPTION - The method for co-processing sodium extraction wastewater and oxalic acid precipitation mother liquor involves (1) discharging sodium extraction wastewater into grease trap and installing an adjustable vibration device at the bottom of the grease trap, turning on slight amplitude vibration wastewater for 10-15 minutes, leaving the mixture still for 1-2 hours and recovering the extractant to obtain crude sodium extraction wastewater, (2) passing the obtained crude sodium chloride wastewater through demulsification reaction bed, carrying out demulsification and precipitation of oxalic acid precipitation mother liquor for 15-20 minutes, stirring at 1200-1800 rpm, ultrasonically reacting with frequency of 23-25 kHz, mixing crude sodium chloride wastewater and oxalic acid precipitation mother liquor at mass ratio of 1:(1-1.2) and separating emulsion and metal oxalate precipitate to obtain deoiled sodium chloride wastewater, (3) adding pullulan to flocculate and precipitate, subjecting the obtained wastewater to sand filtration treatment through sand and separating the filter residue and clarifying the sodium chloride water, (4) preparing modified graphene heavy metal adsorbent by mixing 5 pts. wt. graphene oxide, 6-14 pts. wt. terephthalic acid and 15-20 pts. wt. ethylene glycol, esterifying at 200 degrees C for 40-100 minutes, reacting the modified graphene heavy metal adsorbent at 280 degrees C for 20-30 minutes, cooling to room temperature, centrifuging and drying, (5) subjecting modified graphene heavy metal adsorbent and clarified sodium chloride wastewater to adsorption treatment, removing heavy metals and radioactive elements from the filtrate and filtering to remove modified graphene and adding pyrolusite to adsorb impurities, (6) transferring the clarified sodium chloride wastewater to three-effect evaporation device for concentration and crystallization, centrifuging to separate the sodium chloride crystals and recovering the condensate.