Composition Analysis of Municipal Solid Waste in Colombo

Analysis of solid waste at selected locations within the Administrative District of Colombo during the current Lockdown and Semi-Lockdown periods due to the Covid-19 pandemic.

Solid waste management has become one of the major Environmental concerns in the Urban areas of Sri Lanka.

The uncertainty of the composition of collected waste impedes the selection of the most suitable method for waste management in terms of financial, technical and environmental feasibility, resulting in unsuccessful waste-related projects.



Also, it is crucial to obtain relevant and accurate data on contamination of recyclables, along with the segregated and non-segregated percentages to address the need for environmental education in different local communities.

This study determines the composition of daily collected Municipal solid waste generated in different socio-economic demographics within the Colombo District.

A total of 80 representative waste samples were collected using random collection techniques covering the following areas.

  • Urban and Semi-Urban
  • Residential and Commercial

Initially, the bio-degradable waste content in each sample was weighed as a Kilogram (Kg) at the collection point and the quantity of non-biodegradable waste in each area was accounted for separately, segregating the samples into six categories, namely; plastic, polythene, paper, cardboard, metal, and glass.

Based on the results obtained from all the areas, the percentages of biodegradable and non-biodegradable were estimated as 81.2 % and 18.8 % respectively.

The determined percentages of recyclables segregated from non-perishable waste collection were :

  • Plastic – 6.06 %
  • Polythene – 45.75 %
  • Paper – 16.23 %
  • Cardboard – 6.91 %
  • Metal – 4.08 %
  • Glass – 8.06 %

Polythene represented the largest segment of non-perishable waste generated in all three demographic areas which accounted for :

  • Mixed-developed Residential areas with mid-to-high income – 46.41 %
  • Under-developed Residential areas with mid-to-low income – 34.09 %
  • Commercial areas – 79.56 %

The second major component of non-perishable waste collected from the research area was paper which accounted for :

  • Mixed-developed Residential areas – 18.6 %
  • Under-developed Residential areas – 12.38 %
  • Commercial areas – 20.44 %

Most importantly, the findings of the present study discovered that 81.25 % of the collected non-perishable waste was contaminated with other waste, while segregated matter accounted for only 18.75 %.

Further analysis indicated that the underdeveloped Residential areas with mid-to-low income, which is populated with impoverished and low-literacy rate residences has the highest percentage of non-segregated waste, which is 100%; whereas 100% of the segregated percentage was reported from Commercial areas.


In conclusion, the outcome of the present study emphasized key investment opportunities in Recycling polythene and paper, and the need for conducting awareness programmes on waste segregation and the 4R concept for local communities in the under-developed Residential areas with mid-to-low income households.