Characteristics of Effluent Wastewater in Hospitals of Babol University of Medical Sciences, Babol, Iran

Wastewater effluent in hospitals has been increasing during the recent decades due to developments in medical services and products. This study aimed to investigate the qualitative parameters of effluent wastewater in hospitals affiliated to Babol University of Medical Sciences (BUMS). Four hospitals were included and their wastewater effluent was studied. Ninety-six composited samples were collected and sent to the laboratory for determining pH, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), total kjeldahl nitrogen (TKN), total phosphorous (TP), heavy metals, total coliforms (TC) and total heterotrophic bacteria counts (THBC) based on standard methods. Mean ± SD pH of the wastewater was 7.6 ± 0.4. Mean ± SD BOD5, COD, TSS, TKN and TP were 372 ± 173 mg/L, 687 ± 231 mg/L, 289 ± 132 mg/L and 15 ± 5.5 mg/L, respectively. Mean concentration of Pb, Cd, Zn, Cr, Ni, Co, Hg, Fe and Cu were 26.5 (g/L), 2 (g/L), 429 (g/L), 34 (g/L), 30 (g/L), 3.7 (g/L), 7.5 (g/L), 2.1 mg/L and 49 (g/L), respectively. The total coliforms and heterotrophic bacteria were 5.4 × 108 MPN/100 mL and 2.6 × 1010 CFU/mL, respectively. Total wastewater quantity and its organic loading rate were 169 263 m3 and 62 966 kg in a year, respectively. Most of the qualitative indices evaluated in wastewater effluent of hospitals of BUMS were higher than effluent discharge standards of Iran Environment Protection Agency (IEPA). These wastewaters are usually purified improperly by wastewater treatment plants of these hospitals and polluted effluents which empty to the Babol Rood River and Caspian Sea can potentially endanger public health, natural resources and wildlife.