Photovoltaic and photocatalytic performance study of SOLWAT system for the degradation of Methylene Blue, Acid Red 26 and 4-Chlorophenol

The SOLWAT system is a combined system for solar water purification and renewable electricity generation. Its photovoltaic and photocatalytic performance, along with the photovoltaic (PV) electricity production was studied under the degradation of three different pollutants: Methylene Blue, Acid Red 26 and 4-Chlorophenol in present paper. The spectrum loss of the system was analyzed theoretically. Spectral transmittance experiments with different medium were conducted and compared with the results of outdoor experiments. The photovoltaic performance of the SOLWAT system was studied comparatively by measuring the Pm and Isc under actual climatic conditions with a reference PV system. To investigate the photocatalytic performance of the SOLWAT system, the degradation of sample pollutants were detected by analyzing the UV absorption and the TOC. In the presence of the additional wastewater layer, PV cells in the SOLWAT system could work under lower temperature. Depending on the spectral absorption of pollutants, if it is within the spectral response of the PV cell, the electricity output is affected by the pollutant degradation (Methylene Blue, Acid Red 26). When the spectral absorption of pollutant is out of the spectral response of the cell, the PV output is not affected by the contaminant degradation (4-Chlorophenol). The output power of SOLWAT system, though decreased due to the light absorption, was sufficient to drive the whole system. The degradation of sample pollutants was detected by analyzing the UV absorption and the TOC to investigate the photocatalytic performance of the SOLWAT system. For the wastewater with different initial concentrations, the decolorization rate ran up above 99% and the mineralization rate was above 80%.