A method for removing fluoride and phosphorus from psry molecular sieve production wastewater

Abstract

The invention relates to a defluorination and dephosphorization method of PSRY molecular sieve production wastewater. The method comprises the following steps: (1) solid waste residues generated during treatment process of PSRY molecular sieve production wastewater and other molecular sieve production wastewater are mixed, and aluminum in the solid waste residues is dissolved in the form of Al<3+> in the wastewater, wherein pH value of the mixed system during the dissolution process is less than 4.5; (2) pH value of the mixed system obtained from the step (1) is adjusted to more than 6 to make Al<3+> reacts with F<-> and PO4<3-> so as to fully precipitate F<-> and PO4<3->; and (3) a coagulant aid is added into the mixed system obtained from the step (2), and solid-liquid separation is carried out on the mixed system which has undergone coagulantion enhancement, wherein dosage and dissolution conditions of the solid waste residues in the step (1) enable Al<3+> in the step (2) to fully precipitate F<-> and PO4<3->. By the method, fluorine and phosphor in the PSRY molecular sieve production wastewater can be effectively removed.

Description

Technical field [0001] The invention relates to a method for wastewater treatment, in particular to a method for removing fluorine and phosphorus from wastewater produced by PSRY molecular sieve. Background technique [0002] Phosphorus-containing framework silicon-rich ultra-stable Y molecular sieve (ie PSRY molecular sieve) is a new type of framework silicon-rich molecular sieve prepared by NaY molecular sieve through hydrothermal roasting and composite acid dealumination and silicon supplementation. It is prepared by using PSRY molecular sieve as the main active component. Fluidized catalytic cracking (FCC) catalyst has the characteristics of good coke selectivity, high gasoline octane number, strong heavy oil cracking capacity, and high diesel yield. Since the successful industrial trial production, FCC with PSRY molecular sieve as the main active component The catalyst has been used in many heavy oil catalytic cracking units across the country and has achieved good economic ...

AI Technical Summary

Problems solved by technology

Because PSRY molecular sieve production wastewater contains a large amount of SO 4 2- ion, CaSO 4 The generation of calcium salts, especially CaF 2 The generation efficiency and precipitation performance of PSRY molecular sieves, while the high content of silicon in PSRY molecular sieve production wastewater will seriously affect the recovery and utilization efficiency of adsorbents

Therefore, the above methods are difficult to be effectively applied to the removal of fluoride and phosphorus from PSRY molecular sieve production wastewater.