Ecotoxicological assessment of wastewater treated by the novel solar chlor-photo-Fenton process for sustainable crop irrigation

Potential ecotoxicity of the solar chlor-photo-Fenton (SCPF) process as a novel approach for wastewater reclamation has been investigated in relation to reuse for crop irrigation. Several secondary effluents from wastewater treatment plants across different geolocations were treated by applying the process with low reagent concentrations of 0.1 mM of ferric nitrilotriacetate (Fe 3+ -NTA), 0.73 mM of hydrogen peroxide, at different chlorine doses ranging from 0.13 to 0.40 mM. Chlorination, using comparable chlorine concentrations, and the solar photo-Fenton process were evaluated in parallel to compare with SCPF. A UVB-LED system was also used to perform the SCPF treatment, demonstrating its adaptability to both solar and artificial light-driven applications. Potential environmental toxicity was assessed using a battery of bioassays, including bacterial toxicity and genotoxicity, phytotoxicity in algae and plants, and toxicity toward mixed microbial communities (microrespirometry). Water treated with SCPF exhibited minimal bacterial and algal toxicity (