Sewage sludge (SS) is a byproduct generated after processing municipal and industrial waste in sewage treatment plants. organic matter (OM), water and inorganic elements are the major components of the SS. Raw sludge contains between 93% and 99% water, carbon (C) - 50-70%, oxygen (O) - 21-24%, hydrogen (H) - 6.5 -7.3%, nitrogen (N) 15-18%, phosphorous (P) - 1.0-1.5%, sulfur (S) 0-2%. Sewage is a favorable environment for a group of microorganisms known as ""sewage fungus,"" bacteria, protozoa, and fungi. Moreover, viruses have been discovered in sewage and several taxa of microalgae. Communal sewage microorganisms found in the bowel and soil include lactobacilli, streptococci, micrococci, Proteus, pseudo-monas, and coliforms (Negi et al., 2022). It is a challenging profile for the world due to its composition. On one side, it is dominated by OM; on the other, HMs stretch their toxicity to the limit. The generation of SS is high due to the population expansion that gives a large platform to contaminate the water, soil, and air. This era is defined by the globalization of economics and the intensification of anthropogenic practices such as urbanization, transportation, mining, agronomy and industry; yet, the waste that is produced along with these activities demands everyone's supreme attention. Waste not properly segregated puts the world in danger of having plants and animals witness man-made or natural tragedies. Waste is typically laden with heavy metals (HMs) like As, Cr, Cd, Hg, Pb, and Zn, which eventually end up in the air, water, and soil (Sarwar et al., 2017). Because HMs are non-biodegradable and have a lengthy life of toxicity, a natural body exposed to HMs once, will retain that toxicity for a very long time (Shah and Daverey, 2020). Even at low concentrations Pb, Cd, and Cr directly target the endocrine and neurological systems, which may cause lethargy in the animal (Rizwan et al., 2018). These HMs are concentrated in a large amount in SS.
