In this work, the performance of medium-pressure UV/peracetic acid (MPUV/PAA/H2O2) was explored on removing reactive black 5 (RB5), aniline (ANL), and polyvinyl alcohol (PVA), three typical refractory contaminants in printing and dyeing wastewater, compared with MPUV/H2O2. MPUV/PAA/H2O2 showed 75.0, 44.9, and 57.7% removals of RB5, ANL, and PVA, respectively, within 5 min. The removal of RB5 increased from 68.98 to 91.2%, with pH increasing from 6 to 9, while the removals of ANL and PVA were much less pH-dependent. Quenching experiment results indicated that UV photolysis and radical (i.e., •OH and R-C•) oxidation contributed to RB5 removal, while PAA showed high activity in the oxidation of ANL. For PVA, •OH oxidation and UV photolysis were likely the main mechanisms. The coexisting natural organic matter had a negative effect on the degradation of RB5 and PVA. In addition, MPUV/PAA/H2O2 could effectively degrade those pollutants without increasing the toxicity. This work provides a theoretical reference for the utilization of MPUV/PAA/H2O2 in removing structurally diverse refractory contaminants from printing and dyeing wastewater.

The direct disposal of waste milk (WM) leads to severe environmental pollution and resource loss. Considering the high content of nutrients, WM has a potential as an ideal raw material for organic fertilizer. In this work, base-activated persulfate (KOH/PS) was used as a new artificial humification technology to transform WM into product with 45.3% of fulvic-like acid (FLA) and 18.9% of humic-like acid (HLA) in 1 hour. Therein, FLA had more active groups (-COOH, -CNOH, -OH) than natural fulvic acid likely owing to hydroxylation, carboxylation and the Millard reaction. Reactive species of •OH and SO4−• generated in KOH/PS system may be related to degradation or polymerization reactions during humification. The product was mixed with attapulgite to fabricate a slow-release nano FLA fertilizer which could increase the yield of chickweeds by 107% compared with the blank as well as the abundance of beneficial bacteria in soil. Overall, this study provided a rapid method for the recycling of waste food and highly-concentrated organic wastewater, which may have a huge application prospect in sustainable agriculture.