BACKGROUND: Under the current global energy scenario, the need for self-sustainable processes is encouraged. The photovoltaic solar powered electrochemical oxidation (PSEO) process has been developed to remove the organic matter from a lignosulfonate wastewater. RESULTS: An electrochemical reactor using boron-doped diamond electrodes, in a batch configuration, is directly supplied with current from a set of photovoltaic solar modules. Experimental results show that the process can oxidize about 90% of the total organic carbon (TOC) of the organic matter in the wastewater under the described operating conditions. CONCLUSION: The technical suitability of the PSEO process has been demonstrated. A model to relate solar irradiance and electrical current was applied and used in a kinetic expression which depends on solar irradiance to describe the removal of TOC. (C) 2010 Society of Chemical Industry