Ozone/peroxide advanced oxidation in combination with biofiltration for taste and odour control and organics removal

Abstract

The objective of this pilot-scale study was to investigate the effectiveness of incorporating ozone (O) and advanced oxidation (hydrogen peroxide/ozone: HO/O) in combination with biofiltration for taste and odour control, organic carbon removal, and disinfection byproduct (DBP) precursor reduction. Implementation of O and HO/O with and without biofiltration was investigated at pilot-scale in terms of geosmin, 2-methylisoborneol (MIB), and DBP precursor removal efficiency. Two media types (granular activated carbon and anthracite) were compared in conjunction with investigating the impact of pre-oxidation with O (2 mg/L) and varying HO/O mass ratios (0.1, 0.2, 0.35, and 0.5 mg/mg). When O preceded biologically active carbon (BAC) or biologically active anthracite, geosmin removals of 80% and 81%, respectively, were observed at 10 °C; this increased to 89% and 90%, respectively, at 16 °C. Optimal MIB removal (67%) was achieved with 0.1 HO/O (mg/mg) in combination with BAC at 16 °C. In general, geosmin proved to be more amenable to biodegradation than MIB. BAC without pre-oxidation removed 87% geosmin and 85% MIB, at 22 °C. MIB removals decreased to 60% and 46%, respectively at 16 °C and 10 °C. The application of 0.2 HO/O (mg/mg) prior to BAC provided treatment which effectively removed geosmin and MIB. However, in terms of DBP precursor reduction, there was no beneficial impact of HO addition on trihalomethane or haloacetic acid formation potentials.

Organic Degradation Potential of Real Greywater Using TiO2-Based Advanced Oxidation Processes

“…In experiments without TiO2, peroxonation and UVA-peroxonation (Figure 7a and Figure 7c), the enhancement decreased with high H2O2/O3 molar ratios, with an optimal ratio observed between 0.3 and 0.5 in line with previous studies [14,54,58]. Excess hydrogen peroxide has been reported to lead to hydroxyl radical scavenging [39,57].…”

“…Figure 6 shows TOC reduction by H2O2 combined with TiO2 investigated under different irradiation conditions (dark, visible and UVA) using a range of catalyst loadings (0.19-1.98 mg TiO2/cm 2 ) and H2O2 dosages (1.45-53.01 mg/L). In those experiments, H2O2/TiO2 molar ratios (0.0-0.7) were adopted from the H2O2 to O3 ratios used in peroxonation (H2O2/O3) studies [14,54,58] specifically to prevent excess H2O2 hindering treatment efficiency [59].…”

Evaluation of ozone-based oxidation and solar advanced oxidation treatment of greywater

“…Peroxonation [47], often referred to as wet peroxide ozonation [62] and perozonation [37], couples O3 with H2O2 for water treatment. In this study, we examine GW treatment efficiency by peroxonation (in the dark) and solar peroxonation (under solar irradiation), three O3 flow rates (8.3, 25, and 41.7 mg O3/min) in combination with H2O2 in different H2O2/O3 molar ratios (ranging from 0 -0.7)in line with parameters from previous research [47,63,64]. The results of those experiments are represented in Fig.…”

“…In previous studies, a range of H2O2/O3 molar ratios have been described as optimal for water treatment, such as 0.3 [65], 0.14 [64], 0.08 [66]; the largest recommended being 0.5 [63]. As can be seen from Fig.…”

Odors Emitted from Biological Waste and Wastewater Treatment Plants: A Mini-Review

“…Although H 2 S removal is properly accomplished by biofilters, biotrickling filters, and activated carbon adsorbers, fluctuating loads and the presence of other odorants make selection complex. Often a combination of different configurations in-series is an appropriate alternative [66,80].…”