Wastewater reuse for resolving water shortage is increasingly emphasized. The presence of DOM in wastewater is a main consideration for wastewater reuse. Therefore, systematic understanding of characteristic changes of DOM in different wastewater treatment processes is needed. As biotechnology together with disinfection operation has been used widely by WWTPs to treat wastewater, this review aims to introduce the recent advances in the effects of wastewater biological treatment and disinfection on the characteristics of DOM. Firstly, the composition of DOM in WWTPs is introduced. Then, the effects of wastewater treatments on hydrophobicity, MW distribution and optical characteristics of DOM and their correlations are reviewed. Also, the influences of wastewater treatments on biodegradability and biotoxicity of DOM are discussed. Finally, the environmental impact of effluent DOM is summarized. Since the discharge of wastewater effluent DOM to the environment not only influences nutrient uptake by bacteria, plankton and algae, and phototransformation rate of micropollutants in natural water, but also changes DOM level and physicochemical properties of soil. •The changes of MW distribution, hydrophobicity and optical properties of DOM during wastewater treatment were reviewed.•The relationship between MW distribution, hydrophobicity and composition of DOM was analyzed by optical properties.•The transformation of DOM characteristics changed its biodegradability and biotoxicity.•Effluent DOM affected nutrient uptake, pollutant phototransformation in river, and physicochemical properties of soil.