Study on the pretreatment of high concentration polyester resin wastewater

Unsaturated polyester resin (UPR) wastewater is highly acidic with poor biodegradability, which is difficult to treat. In this paper, the UPR wastewater was treated by distillation and cooling to solve these problems. And the effects of distillation and cooling on the parameters, such as conductivity, total dissolved solids, chemical oxygen demand (COD)Cr, biochemical oxygen demand (BOD)5and organic acid content of the UPR wastewater were studied. Through experiments, it was found that there is no obvious effect on the treatment of UPR wastewater by distillation or cooling. But through combination of distillation and cooling, the CODCr, conductivity and the BOD5of the wastewater decreased by 22.4%, 24.6% and 30.9%, respectively, and the pH was increased from 2.23 to 4.03. A mass number of white flocs were precipitated while the irritating odor is significantly reduced, and the biodegradability of the UPR wastewater was improved. The experiment results showed that the distillation or cooling could not affect the parameters above of the UPR wastewater, but the method designed in this paper can easily and effectively treat UPR wastewater, which can be used in industry.