Identify the true statement concerning water treatment ?
Show answer Hide answer
Answer: D. Normally, the turbidity is removed by adding a coagulant prior to sedimentation
Explanation
In municipal water treatment, turbidity is normally removed by adding chemical coagulants prior to sedimentation. Coagulation neutralizes colloidal particle charges, allowing them to clump into larger flocs that settle easily. Sedimentation basins then capture these heavy flocs before the clarified water passes through rapid sand filters. Alum and iron salts are standard chemical coagulants widely used in municipal drinking water treatment plants. Rapid mixing ensures uniform distribution of the coagulant throughout the incoming raw water stream. Flocculation basins provide gentle stirring to encourage the growth of settleable particle agglomerates.
Delivering safe, clear drinking water to urban populations requires rigorous clarification and filtration stages. Removing suspended turbidity protects public health by eliminating pathogens attached to particulate matter. Water treatment operators continuously monitor turbidity levels to ensure compliance with stringent health standards. Slow sand filters operate primarily through biological surface layers and cannot remove intense color completely alone. Activated carbon controls taste and odor effectively, but subsequent filtration is always required to remove carbon fines. Activated carbon adsorption targets organic molecules and does not reduce the temporary hardness of water.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Phenol formaldehyde is categorized as____________________?
Show answer Hide answer
Answer: B. Employs condensation polymerisation
Phenol-formaldehyde resins are classified as condensation polymers because their formation eliminates small water molecules. The reaction proceeds through stepwise joining of phenol and formaldehyde with the simultaneous...
Q2. Identify the erroneous statement ?
Show answer Hide answer
Answer: D. None of these
Metals form basic or amphoteric oxides rather than acidic ones when reacting with oxygen. The statement claiming all metals form acidic oxides is chemically incorrect because elements like sodium form bases. Acidic oxide...
Q3. Select the false statement?
Show answer Hide answer
Answer: D. Red color is imparted to glass by addition of arsenic oxide
Pre-tensioning systems generally experience higher total initial prestress losses due to elastic shortening and relaxation. Pre-tensioning factory environments ensure excellent quality control and superior concrete place...
Q4. Penicillin is extracted from fermentation broth through ____________________?
Show answer Hide answer
Answer: A. Extraction with amyl or butyl acetate
Penicillin is recovered from the fermentation broth by liquid-liquid solvent extraction using organic solvents like amyl or butyl acetate. The antibiotic is selectively extracted from the aqueous broth into the organic s...
Q5. Pick out the erroneous statement ?
Show answer Hide answer
Answer: B. Acetylene gas cannot be used for illumination purpose
Natural gas consists mainly of methane, which has a lower energy density than LPG. LPG contains heavier hydrocarbons like propane and butane with higher volumetric heating values. Thus, the statement claiming natural gas...
Q6. Identify the incorrect statement?
Show answer Hide answer
Answer: D. None of these
Ester hydrolysis catalyzed by acids or alkalis follows first-order kinetics with respect to the ester. Claiming that ester hydrolysis is a zero order reaction directly contradicts established chemical kinetics data. Reac...