Solar photo-Fenton with simultaneous addition of ozone for the treatment of real industrial wastewaters.

Simultaneous application of solar photo-Fenton and ozonation (SPFO) for the efficient treatment of real wastewaters was studied. Four different industrial effluents were selected for the study: landfill leachate, pharmaceutical effluent and two textile wastewaters, in order to demonstrate the effectiveness and versatility of the proposed technology. SPFO performance was compared with individual processes (either solar photo-Fenton or ozonation), as well as the hybrid Fenton and ozonation treatment. In highly polluted wastewaters, combined strategies led to higher organic matter removal than O3 and photo-Fenton processes applied individually. Solar light favoured catalyst regeneration, allowing removal efficiencies up to 67% of chemical oxygen demand (COD) and 62% of total organic carbon (TOC) (in the case of textile wastewaters) using an initial concentration of only 10 mg Fe2+ L-1. The reduction of catalyst consumption, along with the absence of sludge production (since Fe2+ removal from the effluent is not required), led to a significant decrease in operational costs (up to 1.22 € kg-1 COD removed) when combined Fenton and ozonation was applied under solar light. SPFO results in a versatile, effective and economically efficient technology, thus postulating as a promising alternative for reducing the organic load of highly polluted industrial effluents prior to biological treatment.

Life cycle assessment of the removal of Diuron and Linuron herbicides from water using three environmentally friendly technologies.

Nowadays, every chemical treatment must be developed taking into account its global impact on the environment. With this objective a life cycle assessment (LCA) has been used as a tool for the assessment of the environmental impact of three environmentally friendly processes for the removal of Diuron and Linuron herbicides from water: artificial light assisted photo-Fenton, photo-Fenton coupled to biological treatment and solar assisted photo-Fenton. The inventoried data has been classified considering the potential environmental impacts categories included in the CML 2 baseline 2000 method. Among the three scenarios considered, photo-Fenton coupled to biological treatment proved to have the lowest environmental impact in all the studied categories due to the lower hydrogen peroxide and electricity consumptions. The environmental impacts associated with hydrogen peroxide and electricity production imply more than 72% in all the impact categories of the three scenarios, except for aquatic eutrophication potential category, where the main impacts are related to nitrogen emissions.