Prospective applications of renewable energy based electrochemical systems in wastewater treatment: A review

Recent decades are characterized by incredible rapid technological development resulting in the introducing of various new chemicals, materials and processes with various complexities. This, in turn, is associated with release of increased amounts of pollutants into the environment and for this reason their efficient removal is required. Environmental monitoring results show that many pollutants in ground water are at the excess limit which raises concerns on currently employed wastewater treatments. This review summarizes the electrochemical technology used in wastewater treatment covering its advantages such as high removal efficiency, clean energy conversion, low environmental impact, easy operation and compact design. Significant enhancement of electrochemical methods such as electrocoagulation, electroflotation, electrooxidation, electroreduction and electrodisinfection is discussed and these technologies are combined with an advanced photovoltaic (PV) technology. Important design parameters to obtain the highest efficiency from this combined technology are discussed in details. Moreover, it is shown that the combination systems are capable to produce hydrogen gas at high efficiency which can be used as a supplementary source for green energy thus minimizing the entire process cost.