Pharmaceutical Effluent Based Biochemical Contamination In The Sirsa Tributary of River Sutlej, India

Abstract

The pharmaceutical and chemical effluents from the Baddi Barotiwala Nalagarh industrial cluster have severely degraded the Sirsa tributary of the River Sutlej. This study demonstrates an environmental emergency threatening aquatic biodiversity and reflected downstream human water security demand. The contamination is a multi-parameter pollution syndrome rather than pharma residuals alone due to persistence wastewater inflow and ineffective pollution management. The complete failures across all recorded water quality indicators under study, as extreme acidic pH (3.2), anoxic dissolved oxygen (1.22 mg/L) due to the addition of chemical residues resulted in mass mortality of fishes and carnivorous birds, very high chemical oxygen demand (365 mg/L), TDS, BOD, high nutrient concentrations, elemental contaminations and warm foothill water temperature (57.5°C). It may be due to the toxicity of ammonia (6.65 ± 2.96 mg/L at S₂), exceeding the WHO limit of 0.5 mg/L for drinking water supply. Further, such changes in hydrobiological parameters, supported by principal component analysis that also resulted in 89% of total variance related to water quality dynamics with PC1 showed high positive loadings for TDS, COD and turbidity as well as strong negative loadings for DO and pH. The water pollution is chronic and enduring rather than episodic is confirmed by seasonal studies. Even during peak discharge season has constantly resulted in the exceeded concentrations (Mean ± SD in ppb) at S2 for Boron (2156 ± 72), Magnesium (31315 ± 192) and Thallium (03.34 ± 0.64) with overall MI values at S1 (1.55), S2 (5.82) and S3 (2.57) demonstrating that monsoon flows are insufficient to provide effective dilution. The predominance of pharmaceutical chemicals (antibiotics) that are not biodegradable and resistant to traditional biological treatment methods is confirmed by very high COD:BOD ratio. This site S2 was strongly affected and found to be uninhabitable due to the presence of elemental dust and untreated wastewater discharged by chemical industrial units of the Baddi region. The water quality index value (106.94) at S3 also indicated very poor and strongly impaired river health. Palmer's algal index score at S₃ exceeded 20, confirming heavy organic pollutant load with declined trends read as H′ = 0.87 at S₁ to H′ = 0.36 at S₃ and increased in S = 2.8 at S₁ to S = 6.2 at S₃ with predominance of Tubifex tubifex, Chironomus larvae and Oscillatoria sp. as classical bioindicators responded to present polysaprobic conditions with a severe dip in dissolved oxygen. There is also serious hazard to public due to the biochemical collapsed of niche, extreme dangers are faced by downstream communities that depend upon the Sutlej river water for their survival. The results placed the Sirsa tributary among the most seriously polluted freshwater system in India that have been touched by pharmaceuticals, requiring immediate rehabilitation and restoration practices.