Application of material flow analysis for the assessment of current municipal solid waste management in Karachi, Pakistan.

This article assesses the status of the solid waste management system (SWMS) in Karachi, the largest city of Pakistan, using the material flow analysis approach, a widely applied method in waste management (WM) studies. It involves a systematic assessment of the material flows of solid waste under the current WM system. A material flow diagram is developed to visualize the input and output waste flows. This study shows the quantification and identification of municipal solid waste (MSW) flow for the year 2019, from the point of generation to the end-use and disposal. Results show that the MSW generation increased from 10,435 to 15,600 metric tonnes per day (TPD) between 2017 to 2019. Approximately, 75% of the waste generated is collected: formally (50%); and informally (25%). The material recovery is low, accounting for only 26.28% of the total waste. There is no official material recovery and recycling facility. Therefore, material recovery solely depends on the informal sector. Results show that 70% of the daily waste ends up in landfills, which is 3120 TPD more than the formally collected waste. This estimated waste of 3120 TPD flows in either due to disposal activities of the backlogged waste or informally collected waste. Overall, Karachi's SWMS performs poorly with a significant need for improvement. This study recommends adopting integrated WM approaches and inclusion of the informal sector to ensure the affordability and sustainability of the WM system.