Pushpakumara, T. ., & Sandakelum, W. . (2021). Heavy Metal Potential of Domestic Biological Wastewater Treatment Plant Sludge: Research Article- DOI: 10.23953/cloud.ijaaeee.503. International Journal of Advanced Alternative Energy, Environment and Ecology, pp.90–113. Retrieved from https://cloudjl.com/index.php/AlternativeEnergy/article/view/30