Q. What is the excess growth of plankton in water due to the presence of nutrients called? Fungal bloom Algal bloom Plantae bloom Animal bloom Answer: Algal bloom

Q. Who utilizes the maximum amount of oxygen in the upstream of sewage discharge? Animals Microorganisms Humans Plants Answer: Microorganisms

Q. What happens when the maximum amount of oxygen in the upstream of sewage discharge is utilized by microbes? Natality of aquatic plants Natality of aquatic fishes Mortality of aquatic creatures Mortality of bacteria Answer: Mortality of aquatic creatures

Q. How is the amount of biodegradable organic matter in sewage water estimated? Chemical Oxygen Demand Physical Oxygen Demand Biological Oxygen Demand Mathematical Oxygen Demand Answer: Biological Oxygen Demand

Q. Which sewage contains biodegradable waste such as organic matter? Medical waste Plastic waste Domestic waste Wild waste Answer: Domestic waste

Q. Who is responsible for the degradation of biodegradable organic matter present in the domestic sewage? Animals Humans Plastic Bacteria and other microbes Answer: Bacteria and other microbes

Q. Which materials are hard to remove from the polluted water? Sand Plastic Solids Dissolved salts Answer: Dissolved salts

Q. Which materials are easily removed from the polluted water? Liquid Solids Dissolved Nutrients Answer: Solids

Q. How much percent of impurities are enough to make domestic sewage unfit for humans? 0.1 percent 1 percent 5 percent 10 percent Answer: 0.1 percent

Q. Which of the following are the dissolved materials present in domestic sewage? Sand Clay Nutrients Bacteria Answer: Nutrients