Integrated rapid treatment system for nuclear medical radioactive wastewater and application method thereof

An integrated rapid treatment system for nuclear medical radioactive wastewater, comprising:

• a wastewater collection unit for receiving and temporarily storing wastewater from clinical practice in nuclear medicine;
• a pretreatment unit for performing solid-liquid separation on wastewater outputted from a wastewater collection pool;
• a deep purification unit for performing multi-level nuclide extraction and separation on clear liquid outputted from the pretreatment unit;
• a solid decay unit for performing natural decay on solid impurities outputted from the pretreatment unit over time;
• a buffer unit for temporarily storing decayed clear liquid;
• an online detection unit matching the respective units;
• and
• a control unit connected in communication with the online detection unit to switch working states of the respective units, wherein
• the online detection unit comprises:
• a radioactivity level detection module for detecting total α and total β radioactivity concentrations of a medium in each unit, and a process parameter monitoring module for detecting key process parameters of the treatment process in real time;
• the solid decay unit is configured to include a plurality of decay pools that is poured by concrete and is independent of each other;
• each decay pool is communicated with a buffer pool through a matching pipeline VII, and each decay pool receives and temporarily stores solid impurities generated by the pretreatment unit according to a chronological production order of the solid impurities, respectively;
• the deep purification unit is configured to include a plurality of independent nuclide extraction and separation modules in a serial connection arrangement;
• the outside of each nuclide extraction and separation module is covered with a radiation protection layer in a detachable manner, and the nuclide extraction and separation module located at the tail end is communicated with the buffer pool through a matching pipeline V;
• the nuclide extraction and separation module at the lower level is communicated with the nuclide extraction and separation module at the upper level through a matching pipeline VI to form a self-circulation path of the deep purification unit;
• the nuclide extraction and separation module is an ion exchange adsorber, and an ion exchange fiber adsorbent material in the ion exchange adsorbers at all levels adopts the following biquaternary ammonium cationic type ion exchange fiber:
• a preparation process of the biquaternary ammonium cationic type ion exchange fiber comprises:
• step 1:
• performing melt spinning on polypropylene masterbatch, soaking the spun fiber in an acetone solvent, removing an organic solvent after 24 h, washing with distilled water, then performing ultrasonic cleaning, and drying at 60° C. to obtain a polypropylene fiber;
• step 2:
• performing a grafting reaction:
• swelling the polypropylene fiber in dichloroethane, then immersing in a styrene grafting solution, heating to a temperature of 70-120° C. and grafting for 3-8 h, thereby obtaining a grafted fiber with a predetermined grafting rate at the end of the reaction;
• step 3:
• performing chloromethylation:
• first adding a zinc chloride catalyst to a predetermined volume of chloromethyl ether and ensuring that a weight ratio of a catalyst to a fiber is 1:1;
• standing at room temperature for 0.5 h, so that zinc chloride can be partially dissolved;
• then adding a certain amount of grafted styrene fiber, so that the fiber is fully immersed in a chloromethyl ether solution;
• then standing at room temperature for 0.5 h;
• then putting a reactor into a water bath and slowly heating to 30-80° C.;
• reacting for 8-13 h, and stirring every 1 h, to ensure that the reaction is more uniform and sufficient;
• and
• step 4:
• performing a quaternarization reaction:
• first adding an ethyl bromide solution in a tetramethylpropanediamine aqueous solution according to a molar ratio of 1:0.8-1:1.2, reacting at a temperature of 20-40° C. for 12-18 h, and then adding the fiber subjected to the chloromethylation reaction in the reaction product, wherein a molar ratio of the fiber to tetramethylpropanediamine is 1:0.8-1:1.2;
• and reacting at a temperature of 20-40° C. for 14-24 h, and stirring every 1 h during the reaction process to ensure the sufficiency and uniformity of the reaction.