Sewage Treatment — Prelims Strategy
Prelims Strategy
For Prelims success in sewage treatment, focus on memorizing specific technical parameters: CPCB standards (BOD ≤30 mg/L, COD ≤250 mg/L, TSS ≤100 mg/L), treatment efficiency percentages (primary 25-40% BOD removal, secondary 85-95%), and cost ranges (₹2-10 crore per MLD).
Understand the distinction between different biological processes - activated sludge vs trickling filters vs SBR/MBBR technologies. Master the legal framework: Water Act 1974 (Section 25 consent requirement), Environment Protection Act 1986 (standard-setting authority), and key Supreme Court cases (MC Mehta 1988, Vellore Citizens 1996).
Government schemes require precise knowledge: Namami Gange components (Nirmal Dhara for pollution abatement), Swachh Bharat Mission sewage treatment targets, and AMRUT urban infrastructure focus. Common elimination techniques include identifying technology-specific advantages (MBR for reuse quality, constructed wetlands for low cost, SBR for nutrient removal) and avoiding confusion between sewage and industrial waste treatment standards.
Practice questions on polluter pays principle, decentralized vs centralized approaches, and sludge management options.