Water scarcity has become a serious issue facing our communities due to the population growth, increased demands on water resources, and climate change. In the US, water shortage has forced many cities to consider reusing the municipal treated wastewater to augment the drinking water supplies. This has raised concerns about the potential impact of the treated wastewater on drinking water quality. The formation of disinfection byproducts (DBPs) in the wastewater effluent during the chlorination process, can affect the quality of the source water for drinking water supplies. This has raised concerns about the potential impact of those DBPs on water reuse practices. Solar Photo-Fenton process has emerged as a promising energy-efficient process for degradation of a variety of toxic organic compounds present in wastewater. The primary objective of this research was to investigate the kinetics of photocatalytic degradation of DBPs by photo-Fenton process using natural solar irradiation. In this study, we used outdoor photolysis experiments to investigate the solar photo-Fenton process on the degradation of total organic halogen and specific DBPs including trihalomethanes and haloacetic acids. Commercial organic extract (fulvic acid) and several municipal wastewaters were used as precursors to produce DBPs using chlorine and chloramines. Ethylenediamine-N,N′- disuccinic acid (EDDS) was used as a chelating agent to allow the photo-fenton process to be conducted under neutral conditions. The impact of Fe(III), H<sub>2</sub>O<sub>2</sub>, EDDS, and pH on the degradation of DBPs were evaluated. In addition, chloride, sulfate, nitrate, humic acid and alkalinity were varied during the experiments to simulate a wide range of water quality conditions for water reuse. The results of this study suggest that DBPs can be effectively degraded by EDDS-modified solar photo-fenton. The half-lives of TOX compounds produced by fulvic acids and wastewater and drinking water samples were generally less than one hour. The degradation rates of specific DBPs increased with increasing number of halogens (tri- &gt; di- &gt; mono-halogenated) and size of the substituted halogens (I &gt; Br &gt; Cl). Monoiodoacetic acid, one of the most toxic DBPs, was rapidly degraded by the solar-fenton process with a half-life of 13 min. Overall, this study demonstrates that this process is highly effective treatment technology for removing DBPs in water and reducing the health risks associated with it during water reuse.

Disinfection byproducts removal during water reuse using natural solar photo-fenton process

255th National Meeting (2018)

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