Nalgonda technique for defluoridation of water consists of adding in sequence?: (A) Lime + Soda, (B) Soda + Alum, (C) Alum + Soda, (D) Lime + Alum
Answer is D. NALGONDA TECHNIQUE:- Developed by National environment engineering research institute (NEERI), Nagpur for Defluoridation of water. It involves 'addition of Lime, Alum, and Bleaching powder' (Mnemonic: LAB) followed by Flocculation, Sedimentation and Filtration. In Nalgonda technique, Aluminum is major de-fluoridating agent.