Solar photo-Fenton optimization at neutral pH for microcontaminant removal at pilot plant scale

The increasing occurrence of micropollutants in natural water bodies has medium to long-term effects on both aquatic life and human health. The aim of this study is to optimize the degradation of two pharmaceutical pollutants of emerging concern: amoxicillin and acetaminophen in aqueous solution at laboratory and pilot scale, by solar photo-Fenton process carried out at neutral pH using ethylenediamine-N,N & PRIME;-disuccinic acid (EDDS) as a complexing agent to maintain iron in solution. The initial concentration of each compound was set at 1 mg/L dissolved in a simulated effluent from a municipal wastewater treatment plant (MWTP). A factorial experimental design and its surface response analysis were used to optimize the operating parameters to achieve the highest initial degradation rate of each target. The evolution of the degradation process was measured by ultra-performance liquid chromatography (UPLC/UV), obtaining elimination rates above 90% for both contaminants. Statistical study showed the optimum concentrations of Fe(III) at 3 mg/L at an Fe-EDDS ratio of 1:2 and 2.75 mg/L H2O2 for the almost complete removal of the target compounds by solar photo-Fenton process. Validation of the experimental design was successfully carried out with actual MWTP effluent spiked with 100 & mu;g/L of amoxicillin and acetaminophen, each at pilot plant scale.

Automated summary

The aim of this study is to optimize the degradation of two pharmaceutical pollutants, amoxicillin and acetaminophen, in water by solar photo-Fenton process. The use of ethylenediamine-N,N’-disuccinic acid (EDDS) as a complexing agent was found to be effective in maintaining iron in solution at neutral pH. The results showed that the highest initial degradation rates of the target compounds were achieved by using 3 mg/L of Fe(III), an Fe-EDDS ratio of 1:2, and 2.75 mg/L of H2O2. The experimental design was successfully validated using real wastewater samples spiked with the target compounds.