Photoelectrochemical Water Treatment of Sewage Priya Chandulal Vithalani and Nikhil Sumantray Bhatt Abstract Emerging industrial and human activities are depleting water and other environmental resources due to the massive production of synthetic complexes. Compounds present in sewage are resistant to degradation and have various toxico- logical properties, which generate various environmental issues. Many conventional methods based on physical, chemical and biological principles are applied to treat sewage. Currently, a combination of different conventional methods is in practice for effective treatment. The photoelectrochemical technique is a combination of light and electrical energy used in the treatment of sewage. In this technique, different types of metals and semiconductor types of photocatalyst are utilized to treat sewage due to its stability, efficiency and remediation performance. In the modified photocatalytic reactor, solar or artificial energy is applied for the oxidation of hazardous compounds which generate hydrogen. The modified photocatalyst has been employed in recent times for efficient treatment and refining hydrogen production. Recently, diverse photocatalytic reactors are designed for a large-scale treatment perspective. Photo- electrochemical reactors have an eco-friendly approach and are less harmful to the environment. Thus, recently researchers are focusing more on this technique from a treatment perspective. Keywords Hydrogen production · Photocatalyst · Photocatalytic reactor · Photoelectrochemical technique · Sewage treatment · Synthetic complexes 1 Introduction Water is an essential source for every lifeform on earth so, the removal of pollutants from water is a major concern. Generation of wastewater is estimated at 22,900 million litres per day (MLD) domestic wastewater and 13,500 MLD industrial wastewater in an urban area. Around 26% of wastewater is treated before discharge, and the rest is deposited as untreated. The sewage waste has two types: domestic, P. C. Vithalani · N. S. Bhatt (B ) Department of Biogas Research and Microbiology, Gujarat Vidyapith, Sadra, Gandhinagar, Gujarat, India e-mail: bhatt@gujaratvidyapith.org © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022 T. Karchiyappan et al. (eds.), Industrial Wastewater Treatment, Water Science and Technology Library 106, https://doi.org/10.1007/978-3-030-98202-7_16 399