Load of infectious microorganisms in hospital eluent treat- ment plant in Madurai Pandian Manonmani 1, *, Samuel Paul Raj 1 , Marimuthu Ramar 2 , Rajagopal Raskin Erusan 3 1 School of Energy, Environment and Natural Resources, Madurai Kamaraj University, Madurai-21, Tamil Nadu, India 2 Division of Entomology, Deptartment of Zoology, Bharathiar University, Coimbatore, Tamil Nadu-641046, India 3 Department of Genetics, Dr.A.L.M. Post Graduate Institute of Basic Medical, Sciences, University of Madras, Chennai-600113, Tamil Nadu, India *Corresponding author Dr. P. Manonmani E-mail: pmano_phd@yahoo.co.in Tel: +919445153518 Article History: Received 1 April 2015 Revised 31 May 2015 Accepted 5 June 2015 Published 25 June 2015 Keywords: Pathogenic microbes E. coli Coliforms Eluent treatment plant Waste water Manuscript details Abstract Hospital eluent is oten regarded as an important source of pathogenic microorganisms like bacteria, viruses and parasitic ova. Counts of all these microorganisms were enumerated in various stages of eluent treatment plant (ETP) such as equalisation tank (ET), aeration tank (AT), settling tank (ST), chlorination tank (CT), polishing tank (PT) and sludge dry beds. he microbial parameters includes total viable count (TVC), total coliforms (TC), faecal co- liforms (FC), faecal Streptococci (FS), Staphylococci, Pseudomonas, Salmonella and Shigella. he raw sewage contains 35 % of 19.6 X 10 2 CFU/mL of bacteria as coliforms and E. coli as a typical faecal lora. here was a substantial reduction (> 2 log) noticed for the eluent in settling tank. Mass of the bacteria in the hospital eluent remains tightly attached to the solid particles. hese are removed by aeration and clariication or settling by physical processes like locculation. he treated eluent still contains sizeable counts or loads of bacteria even though disinfection procedures like chlorination are followed. Bacteria in sludge dry beds are ex- ceedingly rigorous and higher concentration of chlorine is required for decontamination and other disinfection procedures such as UV radiation, Ozonization and sunlight disinfection are required for the reduction. Further work will be carried out to design and construct a portable low cost disinfection unit for the disinfection of harmful pathogenic microbes. 1. Introduction Biomedical waste can pose a grave hazard to patients, workers in health care centres and to community if pro- posed waste management is not exercised (Kramer et al., 1996; Mohee, 2004; Chitnis et al., 2005). Liquid waste forms an important source of hazardous and infectious waste. In developing countries like India, treatment plants are not so common and it is mostly drained into public sewer without any proper treatment (Gorgun et al., 1999; Chitnis et al., 2004; Okoh et al., 2007). he liq- uid waste being discharged from hospital and the sludge formed during the eluent treatment both have a poten- tial risk of transmitting infectious disease besides the involvement of chemical hazards (Grabow and Nupen 1972; Tsai et al., 1998). It is a matter of interest that reg- ulations prevailing in force in certain developing coun- tries including India emphasise on limiting biological oxygen demand (BOD) and chemical oxygen demand (COD) of the eluent, but does not give due emphasise on the pathogens (Mitra and Gupta 2000) present in the treated eluent. Information on the load of infectious micro organisms in hospital eluents is essential when deciding on the necessity of treating hospital waste water prior to disposal into city sewers or irrigation (Pipes and Zmuda 1997; Laber et al., 1999). Hospital waste water is oten regarded as an important source of pathogenic mi- cro organisms (Geldrich 1990). Hence the present work was carried out to ind out the load of infectious micro South Indian Journal of Biological Sciences 2015;1(1);30-33 30 Online ISSN: 2454-4787