| dc.description.abstract | Improper methods of treatment, disposal and management of sludge generated by
wastewater treatment plants has become a major environmental issue at present.
This research focuses on identifying the environmental impact caused by the
methods used when disposing and reusing the produced sludge as fertilizer, by the
Biyagama CWWTP, Ratmalana/ Moratuwa WWTP, Ja-Ela/ Ekala WWTP and
Raddolugama sewerage treatment plant. The sludge samples collected from the
dumpsites were tested for heavy metals, nutrients, and organic compounds present
in them. After analysing the constituents present in the sludge, the issues in
respective treatment plants and its procedures were identified. Moreover, the
possibility of using the sludge as construction material, fertilizer and whether it
satisfies the requirements to use as a fertilizer for crops cultivated for human
consumption were discussed. In addition, a model limitation scale for the sludge
standards was introduced through this study after observing various limitations
maintained in other international standards. As per the results, only sludge from
Raddolugama Plant was assured as safe for land application, and sludge in Biyagama
plant was found to be the most suitable for fertilization among the others although
other minor hitches were found. Conclusively, eco-friendly and sustainable
solutions were suggested to improve the sludge qualities and overcome the issues
found and proposed how sludge could be utilized for greater uses without wasting
a valuable asset. | en_US |
