Continuous flow solar thermal pasteurization of drinking water: Methods, devices, microbiology, and analysis

The ability to simply and robustly pasteurize drinking water would present tremendous worldwide human health benefits. Ingestion of unsafe drinking water is a leading cause of sickness and death in the developing world. A simple method to use concentrated solar power is presented here with two complimentary numerical models. The first model allows a prediction of water temperatures within the concentrator and enables a user to vary operating parameters to assess the impact on the temperatures. The second model relates the temperatures to pathogen inactivation kinetics so that predictions of pathogen populations can be made. It is found that with a modest size system that includes a parabolic trough concentrator, a thermally activated valve, and a fluid-to-fluid heat exchanger, near complete pathogen inactivation can be achieved. Comparisons are made between simulated and experimentally determined temperatures. The comparison demonstrates the veracity of the model.