Drinking Water Disinfection by Solar Radiation

Abstract

A primary concern of developing countries throughout the world is that of obtaining safe drinking water. Waterborne diseases are still common in developing countries since drinking water sources are contaminated and the conventional rural water treatment plants are often inefficient to produce safe drinking water. This situation in developing countries is a major problem in terms of preventing public health. It is estimated that diarrhea accounted for 99% of the 69 million deaths among children before the age of five. Inadequate operation and maintenance after installations caused by a lack of trained operators, by a treacherous supply of chemicals and spare parts, and by financial problems lead to produce unhealthy drinking water. Since major urban water supplies are also not always capable of maintaining a regular supply of qualitatively good water, the distributed water is often considered unsafe for direct consumption. Treatment of water at the household level (etc. boiling) or purchasing of mineral water for consumption is more real than an exception in urban areas of developing countries. Recently, another small-scale approach using the lethal effect of sunlight has gained importance to sanitary contaminated water. Solar disinfection (SODIS) is one of the simplest methods for providing acceptable quality drinking water and consists of filling transparent containers (plastic bags, plastic bottles or glass bottles) with water and exposing the containers to sunlight for approximately 6 hours. Because of the low cost and easy usage, solar disinfection is commonly used in developing countries in Asia, Africa and South America. The aim of this literature review is to give information about solar disinfection mechanism, to compare the efficiency of solar disinfection on different microorganisms based on the past studies, and to discuss the several applications of solar disinfection in the world.

Insights into Solar Disinfection Enhancements for Drinking Water Treatment Applications

“…Luzi et al [75] stated that on a clear sunny day, 6 h of exposure is enough compared with cloudy conditions. The effectiveness of SODIS was found to be the best in locations with significant amounts of strong sunlight during midday, mostly located around the equator [76]. Various studies have been conducted to overcome the weather issue in term of partially sunny or during cold season and enhance SODIS; Sommer et al [77] suggested using darker containers or painting the underside of them with black to enhance the thermal disinfection.…”

Ozone and Photocatalytic Processes for Pathogens Removal from Water: A Review

“…The conventional method is based on UV light. However, solar light is also efficient for the deactivation of biohazards [68,69] and research regarding its application is increasing using several combinations (Figure 1). when monopersulfate was used as additive.…”

“…Based on this finding, the idea of solar water disinfection, or SODIS, one important point-of-use technology for drinking water treatment, has been developed [100,101]. In many regions of the world, the UVA part of sunlight is employed for disinfection purposes [33,69,100,101]. The germicidal effect of sunlight is attributed to the synergistic effect of solar UV light and mild-thermal heating that is produced during exposure [69,102,103].…”

“…In many regions of the world, the UVA part of sunlight is employed for disinfection purposes [33,69,100,101]. The germicidal effect of sunlight is attributed to the synergistic effect of solar UV light and mild-thermal heating that is produced during exposure [69,102,103]. However, the SODIS method requires oxygen in the water to create Reactive Oxygen Species (ROS), which are partly responsible for the disinfection [102,104].…”

“…The schematic range of electromagnetic radiation used in photochemical disinfection processes and its effects on patogens (based on[35,51,[69][70][71][72][73][74][75]). …”