Perspectives in the treatment of hospital wastewater

During recent years, the issue of hazardous substances in wastewater has become a major concern with respect to both human health and environment. This has lead to the launch of several studies into the monitoring of urban wastewaters (UWs). However, few of them have yet been devoted to the monitoring of hospital wastewater (HWs) in terms of either conventional pollutant or micropollutant concentrations and loads (Boillot et al. 2008; Verlicchi et al., 2012, Kovalova et al., 2013). With few exceptions, HWs are considered to possess the same pollutant load as UWs, and are therefore discharged into the same sewage network and conveyed for co-treatment at the nearest municipal wastewater treatment plant (WWTP). Nevertheless, HWs contain a great variety of toxic or persistent substances, such as pharmaceutical compounds (PhCs), radionuclides, heavy metals, solvents and disinfectants, not generally present in large quantities in UWs (Verlicchi et al., 2010b). These substances may be present in HWs in a wide range of concentrations, as products of laboratory and research activities as well as general hospital activity and excretion of medicines. In the last years investigations were carried out referring to characterization and treatability of HWs within some research groups in Italy, Luxembourg, Spain, France, Switzerland, Germany, the Netherlands and Wales. In this context, different treatments and their combinations were tested leading to suggestions or recommendations for the best strategies in HW management and treatment. In addition, full scale WWTPs have been built for the treatment of HWs in Italy, France and Germany (Verlicchi et al., 2010a, Beier et al., 2011) and others are in the design phase or construction. This study presents the state-of–the-art in the treatment of HW through the discussion of experiences carried out in different countries focusing on the advantages and drawbacks of investigated treatments. The main results achieved and here discussed refer to (i) ability in removing investigated pharmaceuticals, (ii) reliability of the tested treatment, (iii) analysis of investment and operational costs of suggested or adopted treatments, (iv) environmental risk assessment due to the occurrence of pharmaceuticals residuals in the treated effluent.