Comprehensive treatment of latex wastewater and resource utilization of concentrated liquid

Abstract

Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen. In this work, the combined process of forward osmosis (FO) and reverse osmosis (RO) was designed to treat the latex wastewater in the whole process, achieving the water recovery rate of 99% and basically no waste discharge after the catalytic oxidation process. The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment, and then using MgCl2 worked as the draw solution for FO process to treat the latex wastewater. Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process. After the treatment of the whole process, the concentration of COD was less than 20 mg⋅L−1, the concentration of NH3-N was less than 10 mg⋅L−1, and the concentration of TP was less than 0.5 mg⋅L−1 for the treated latex wastewater. The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater, meanwhile, useful substances of L-Quebrachitol (L-Q) were successfully extracted from the concentrated solution. Therefore, the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater, which provided with some important guidance on the industrial application.