Disinfection of Contaminated Water by Using Solar Irradiation

Abstract

Contaminated water causes an estimated 6 to 60 billion cases of gastrointestinal illness annually. The majority of these cases occur in rural areas of developing nations where the water supply remains polluted and adequate sanitation is unavailable. A portable, low-cost, and low-maintenance solar unit to disinfect unpotable water has been designed and tested. The solar disinfection unit was tested with both river water and partially processed water from two wastewater treatment plants. In less than 30 min in midday sunlight, the unit eradicated more than 4 log 10 U (99.99%) of bacteria contained in highly contaminated water samples. The solar disinfection unit has been field tested by Centro Panamericano de Ingenieria Sanitaria y Ciencias del Ambiente in Lima, Peru. At moderate light intensity, the solar disinfection unit was capable of reducing the bacterial load in a controlled contaminated water sample by 4 log 10 U and disinfected approximately 1 liter of water in 30 min.

Captação, Manejo e Uso de Água de Chuva

“…A nível doméstico a fervura e o uso de compostos de cloro são comumente utilizados para desinfecção. Caslake et al (2004) ressaltam que a falta de recursos e de infraestrutura de distribuição torna a aplicação de métodos como a cloração caseira extremamente limitada nos países em desenvolvimento, em que os casos de doenças de veiculação hídrica são elevados. Quanto à fervura, o gasto energético é muito alto sendo necessário o consumo de 1 kg de madeira para cada litro de água.…”

Drinking Water Disinfection by Solar Radiation

“…The use of sunlight for supplying healthy water is not a new phenomenon. It has been demonstrated that solar disinfection inactivates microorganism by direct exposure is volume independent economic process and avoids production of hazardous by-products of chemically driven technologies [13]. Solar radiation removes a broad range of microorganisms such as viruses, bacteria and protozoa [14].…”

Domestic Wastewater Disinfection Using Solar Radiation for Agricultural Reuse

“…Studies carried out by Acra et al (1997) proved the bactericidal effect of the solar UV rays in water disinfection. Wegelin et al (1994), Joyce et al (1996), Solarte et al (1997), Saitoh and El-Ghetany (2002), and Caslake et al (2004) evaluated the synergism between UV exposition, water temperature, and turbidity in disinfection of water for human consumption. McGuigan et al (1998) and Oates et al (2003) reported that it is possible to achieve 100% E. coli inactivation in less than 8 h of solar exposition.…”