Impact of SS on river bodies
The environmental impact of raw sewage disposal in river water bodies is vast, and it represents one of the most serious challenges we face in our ecology as a result of human activities such as waste from houses, industry, and agriculture, which causes pollution. Residues formed in WTPs are often the result of filter washing water and decanter discharges, which comprise particles from the raw water as well as chemicals employed in the treatment process. Sludge is a quantitative and qualitative issue that needs proper categorization, treatment, and disposal solutions (Sharma et al., 2022). Because of the contaminating potential, direct discharge into water bodies should be avoided. There have been studies that have revealed the harmful effects of sludge as well as the potential threats that incorrect disposal might provide to soil and aquatic organisms. The majority of the environmental issues linked with WTP sludge are due to chemicals employed in raw water treatment, including various heavy metals, which are one of the key components of sludge.
Contaminants such as pathogenic microorganisms, polyaromatic hydrocarbons, organo-chlorine, and other heavy metals are frequently found in raw sewage or partially treated sewage sludge. All of these might significantly contribute to the negative impacts on the plant and human systems. The dumping of raw sewage into several rivers in India has become a major issue. If we particularly focus on states of the southern and western regions of India, where industrialization predominates, the dumping of raw sewage into different rivers is practiced regularly (Figure 2).