Treating emulsified waste containing mineral oils and alkylphenolethoxylate by membrane and acid-heating processes

摘要

We applied a membrane process to treat emulsified industrial waste with mineral oils and alkylphenolethoxylate (APE).Besides the membrane process,we also investigated acid-heating processes for easy introduction into small factories.The present studies were carried out using factory waste for a practical application.In the NTU-2120 membrane process,99.0 to 99.1% of total organic carbon (TOC) and 97.1 to 98.2% of chemical oxygen demand (COD) were removed from the waste,demonstrating the efficacy of the waste treatment.Permeate fluxes were reduced by 60 to 80% until the volume reduction factor reached 10.The permeate flux was governed by the gel polarization model,and the specific resistance of the gel layer became greater with pressure.Regeneration of the used membrane by the back-pressure wash method completely restored the membrane capacities.The acid-heating process (pH<3,temperature>70 degC) reduced TOC by 96.0% and COD by 92.3%,demonstrating waste treatment efficacy similar to that of the membrane process.