Characterization of Medical Wastewater and Appropriate Treatment Strategies in Dhaka, Bangladesh: A Comparative Analysis of Public Hospitals

Dhaka, the economic hub of Bangladesh, houses numerous healthcare facilities resulting in increased medical waste generation. However, waste management systems in these facilities are often inadequate, posing a threat to public health and the environment. Wastewater characteristics vary regionally, making treatment strategies location-specific. This study characterizes medical waste streams in Dhaka and suggests appropriate treatment strategies. Twenty samples from four major public hospitals were analyzed for various parameters including dissolved oxygen (DO), pH, total dissolved solids (TDS), total suspended solids (TSS), color, total coliform counts, chemical oxygen demand (COD), and biochemical oxygen demand (BOD₅). Samples were categorized as acceptable, moderate, or highly polluted. Results were compared to the standard values provided by the department of Environment of Bangladesh to find that samples show moderate to high pollution levels in terms of TDS, TSS, color, and bacteria. Effective wastewater treatment strategies are needed to mitigate pollution and ensure health safety. Treatment recommendations include the implementation of pre-treatment processes such as sedimentation and filtration to remove solids and aeration to increase dissolved oxygen levels. To reduce organic pollution, treatment methods including activated sludge process (ASP), sequencing batch reactor (SBR) or moving bed bio reactor (MBBR) etc. were recommended according to the applicability of the processes in respective hospitals. Advanced treatment methods such as activated carbon adsorption and ultraviolet disinfection processes were also suggested to address the specific issues like color and bacterial contamination.