Wastewater from hospitals is of similar quality to municipal wastewater, but also potentially contain various hazardous components like enteric pathogens, including bacteria, viruses and helminthes, small amounts of chemicals from cleaning and disinfection operations, pharmaceuticals and also radioactive isotopes, which may easily reach to water resources (Kummerer, 2001). In some developing and industrialized countries, the outbreaks of cholera are periodically reported. Sewers of hospitals where cholera patients are treated are not always connected to efficient sewage treatment plants, and sometimes municipal sewer networks may not even exist (Majlessi, 2001). In developed countries, the rate of water uses is commonly high and the sewage is therefore greatly diluted; effluents are treated in municipal treatment plants and therefore no significant health risks should be expected, even without further specific treatment of these effluents (WHO, 1996). Only in some rare event of an outbreak of acute diarrhea disease, excreta from patients should be collected separately and disinfected.
Study on wastewater treatment systems in hospitals of Iran
Water resources shortage is one of the most important issues due to the population growth and ever increasing water demands as well as its conservation. Wastewater treatment can serve as a logical way to recycle water to consumption cycle. Due to variety of water uses, it seems that there are certain treatment techniques for different types of wastewater, such as municipal and hospital wastewater, which are produced by sanitary centers. Hospitals are considered as high risk places because of being located within municipal and human societies (Pruss, 1999).