Testing the feasibility of geothermal heat sinks with concentrated solar power for effective municipal wastewater disinfection: A pilot study

Efficient disinfection is of prime importance for safe drinking. Despite Kolkata’s significant progress in the socio-economic fronts, the conservative and disjointed approaches used in dealing with the city’s sanitation and wastewater treatment problems have collectively made it one of the hotspots of water-borne diseases, resulting in thousands of deaths per year. Additionally, the high operating cost of the conventional wastewater treatment plants based in Kolkata poses a major concern. This study has therefore, for the very first time integrated geothermal heat sinks with concentrated solar power for wastewater treatment, replacing the need for mechanical heat exchangers and excess cooling water requirement. It is estimated that nearly 67% of the total operating cost of the treatment process associated with disinfection would be reduced, along with zero electricity consumption for cooling the high temperature treated effluent. The study reports that with addition of catalyst, namely TiO₂, the disinfection could be further enhanced by removing almost 99.999% of the microbial population. Applications of geothermal heat sinks are available in other domains such as building heating or cooling, refrigerated storages and many others, but, literature specific to its use in wastewater treatment is missing till date.