Qualitative and Quantitative Assessment of The Effects of Hospital Wastewater Pollutants on Treatment Plants Performance of Medical Sciences University of Shiraz Hospitals
Background and purpose: Despite the similarity in quality of hospital wastewater to municipal wastewater in terms of quantity, and containing toxic and hazardous substances as well as having disease-causing pathogens, in case of improper treatment and disposal , it cause serious risks to human and the environment health. Accordingly, the present study is an attempt to assess the performance of wastewater treatment and effluent quality of Medical Sciences University of Shiraz hospitals. Materials and methods: in the current study, we assessed wastewater treatment systems of Medical Sciences University’s hospitals in Shiraz via a one-year descriptive- cross sectional study. Certain parameters like pH، total suspended solids (TSS), biological oxygen demand (BOX), and chemical oxygen demand (COD) besides total coliform were measured in 205 input and effluent hospital wastewater. The standards were based on the Public Health Association of America manual naming “standard methods of testing water and wastewater”. Findings: the results showed that all the measured parameters in effluent (pH=7.19, BOD=28.12mg/l, 59.14 mg/l, TSS= 36.41 mg/l, NH3=.3mg/l) were in accordance with the Environmental Protection Agency of Iran’s standards (EPA). These standards are specified for discharge into surface water, and agricultural and green spaces irrigation. Moreover, testing coliform in hospital wastewater treatment plant effluent revealed that the amount of this substance for whole coliform was equal to MPN/100ml 29.17 and fecal coliform was equal to MPN/100 ml 30.11. Consequently, the treatment plant had good efficiency. Accordingly, the system efficiency in TSS, BOD, COD and total coliform pollutants removal was 87.14%, 92.17% and 99.99%, respectively. Conclusion: The results of the present study suggest that regular and strict monitoring of operating conditions such as back sludge ratios, waste sludge discharge time besides controlling aeration basin dissolved oxygen and regular measurement of output parameters are the main reasons for proper performance of wastewater treatment plant at the studied hospitals.
Keywords- Hospital Wastewater, Pollutants, Plants Performance, Shiraz.