RESEARCH ARTICLE Minimizing the Risk of Disease Transmission in Emergency Settings: Novel In Situ Physico- Chemical Disinfection of Pathogen-Laden Hospital Wastewaters

The operation of a health care facility, such as a cholera or Ebola treatment center in an emergency setting, results in the production of pathogen-laden wastewaters that may po-tentially lead to onward transmission of the disease. The research presented here evaluat-ed the design and operation of a novel treatment system, successfully used byMédecins Sans Frontières in Haiti to disinfect CTC wastewaters in situ, eliminating the need for road haulage and disposal of the waste to a poorly-managed hazardous waste facility, thereby providing an effective barrier to disease transmission through a novel but simple sanitary in-tervention. The physico-chemical protocols eventually successfully treated over 600 m3 of wastewater, achieving coagulation/flocculation and disinfection by exposure to high pH (Protocol A) and low pH (Protocol B) environments, using thermotolerant coliforms as a dis-infection efficacy index. In Protocol A, the addition of hydrated lime resulted in wastewater disinfection and coagulation/flocculation of suspended solids. In Protocol B, disinfection was achieved by the addition of hydrochloric acid, followed by pH neutralization and coagu-lation/flocculation of suspended solids using aluminum sulfate. Removal rates achieve