Influence of Wastewater Particles on Ozone Degradation of Trace Organic Contaminants

Abstract

In this Article, we demonstrate the influence of effluent particles (in the range of <50 μm) on ozone degradation of trace organic contaminants (TrOCs) and effluent-quality parameters. Secondary effluent was filtered through different pore-size filters and ozonated at various ozone doses. Degradation of both ozone-reactive and ozone-refractory contaminants improved following ozonation of effluent filtered with smaller pore size filters, indicating that particles in this range may adversely affect ozonation. The inhibitory effect of particles was attributed to their reaction with ozone, reducing available ozone and HO(•) radicals. In addition, increasing filtration level decreased the effluent's (instantaneous) ozone demand and increased removal of effluent UV absorbance (UVA254), further establishing that ozone reacts with effluent particles, in competition with dissolved matter. Moreover, ozone was shown to react with particles even during the first seconds of the process, suggesting a high rate of some ozone-particle reactions, comparable to ozone reaction with highly reactive dissolved organic matter moieties. Particle image analysis revealed that particle formation/aggregation and particle disintegration occurs simultaneously during wastewater (WW) ozonation. Our study implies that particles could affect the efficiency of WW ozonation, by increasing the effluent's ozone demand and decreasing contaminant degradation.

A hybrid process of biofiltration of secondary effluent followed by ozonation and short soil aquifer treatment for water reuse

“…In this study, we succeeded to reduce oxygen demand and supply of additional DO during infiltration with the proposed pretreatment of biofiltration and ozonation. The proposed technology, based on a multistage post-treatment of Shafdan secondary effluent, demonstrated synergistic effects of the hybrid system components, which might improve the quality of the reclaimed water in multiple ways: improved effluent quality during biofiltration in terms of nitrite and particle removal, and enhanced performance of the ozonation stage via higher removal of TrOCs due to less consumption of ozone by nitrite and particles (Zucker et al, 2014). In addition, reducing DOC and ammonium during biofiltration significantly decreases the oxygen demand by > 20 mg L À1 for additional aerobic processes occurring during infiltration.…”

“…Aside from the positive aspects of particle removal in preventing clogging in the short SAT and reducing ozone demand (Zucker et al, 2014), the efficient removal of ammonium, nitrite and DOC strongly reduced oxygen demand for biological processes in the short SAT, by approximately 23 mg L À1 (calculated with 4.6 mg O 2 per mg NH 4 eN, 1.1 mg O 2 per mg NO 2 eN and 2.6 mg O 2 per mg DOC). In addition, nitrite removal reduced ozone demand by approximately 1.5 mg L À1 (calculated with 3.4 mg O 3 per mg NO 2 eN).…”

Predicting trace organic compound attenuation by ozone oxidation: Development of indicator and surrogate models

“…Filtration exhibited little difference of TOrC attenuation. In general, bigger particles generally consume more ozone based upon a rule of additivity (Westerhoff et al, 1999), thereby removing particles can enhance mitigation of TOrCs (Zucker et al, 2015). No noticeable difference of TOrC attenuation among tested water qualities were observed.…”

One‐step deposition of nano‐Ag‐TiO2 coatings by atmospheric pressure plasma jet for water treatment: Application to trace pharmaceutical removal using solar photocatalysis

“…The incident irradiance, as measured by a spectroradiometer (International Light, Model ILT 900 R, MA, USA), was approximately 500 W/m 2 integrated in the wavelength range of 280‐950 nm. Each solution was irradiated for 60 min under stirring and 0.3 ml samples were collected periodically for further analysis by high‐performance liquid chromatography (HPLC; 1100 series HPLC; Agilent, Les Ulis, France) configured with a ACE‐RP phenyl column (2.1 mm × 250 mm; Aberdeen, Scotland) coupled to a mass spectrometer (Q‐Tof MS, Waters Premier, Milford, MA) following a method reported by Zucker et al The analysis was conducted at 45°C with a water:methanol (1:9) mixture eluent. The eluent was adjusted to pH 3 using formic acid.…”