The Synergistic Role of Ozonation and Hydrolysis Acidification on the Enhanced Pre-Treatment of High-Strength Refractory 2-Butenal Manufacture Wastewater: Performance, Metabolism, and Mechanisms

Abstract

The targeted removal of the three key TOMs in 2-BMW has been critical to enhance pre-treatment by HA. We investigated the pre-treatment of 2-BMW using HA coupled with ozonation. Our results indicated that the removal rate of the key TOMs and detoxification rate reached almost 100% and 46.26% by pre-ozonation under only 0.099 mg O3/mg COD. Then the tolerated maximum OLR improved up to 10.25±0.43 kg COD/m3·d, and the highest AD and detoxication efficiency reached 56.0% and 98.3%, with an enhancement of 35.1% and 55.2% compared with single HA. The three key TOMs removal improved by above 75%. The major degradation pathways of these key TOMs were ring-cleavage and esters formation by pre-ozonation, and then fermentation and acid production by HA. Ultimately, a synergistic role mechanism of ozonation and HA was revealed. The preferential cleavage of these key TOMs by pre-ozonation was achieved due to their highest electron cloud density and multiple reaction sites with ozone, generating more fermentation-friendly products. Then the fermentation and acid production reactions in HA could be directly involved by these products due to their lower electron cloud density. The functional bacteria and key metabolisms in HA were also enhanced through substance role from ozonation.

Keywords: 2-Butenal manufacture wastewater, Toxic refractory organic matters, Hydrolysis acidification, Ozonation, Synergistic role