Advertisements
Advertisements
प्रश्न
What is water recycling? Explain the conventional wastewater recycling treatment methods.
उत्तर
Water recycling is reusing treated wastewater for beneficial purposes such as agricultural and landscape irrigation, industrial processes, flushing in toilets, and groundwater recharge. Conventional wastewater treatment consists of a combination of physical, chemical, and biological processes which remove solids, organic matter, and nutrients from wastewater.
The wastewater treatment involves the following stages:
- Primary treatment: Primary treatment involves the temporary holding of the wastewater in a tank. The heavy solids get settled at the bottom while oil, grease and lighter solids float over the surface. The settled and floating materials are removed. The remaining liquid may be sent for secondary treatment.
- Secondary treatment: Secondary treatment is used to remove the biodegradable dissolved organic matter. This is performed in the presence of oxygen by aerobic microorganisms (Biological oxidation). The microorganisms must be separated from treated wastewater by sedimentation. After separating the sediments of biological solids, the remaining liquid is discharged for tertiary treatment.
- Tertiary treatment: Tertiary or advanced treatment is the final step of sewage treatment. It involves the removal of inorganic constituents such as nitrogen, phosphorus, and microorganisms. The fine colloidal particles in the sewage water are precipitated by adding chemical coagulants like alum or ferric sulfate.
APPEARS IN
संबंधित प्रश्न
At temperature below _______ water freezes to form ice.
_______ is a broad inlet of the water body where the land curves inwards.
State for the following whether it is due to evaporation or condensation:
Steam rising from a hot girdle when water is sprinkled on it.
Suppose you want to dry your school uniform quickly. Would spreading it near an anghiti or heater help? If yes, how?
One of the following processes is not a step involved in the water-cycle operating in nature
Some definitions are given below which can be corrected by changing one word. Correct them.
- The aquifer is groundwater stored between layers of hard rock above the water table.
- The process of evaporation of water in the ground is called infiltration.
- The evaporation of water from oceans and its arrival back into oceans is called the vapour cycle.
Explain the three stages of the water cycle.
Water kept in sunlight gets heat from sun and is evaporated. But how does water kept under the shade of a tree also gets evaporated? Explain.
Match the following:
| Water cycle | Application of fertilizers |
| Nitrogen cycle | Sunlight |
| Carbon cycle | Deforestation |
| Abiotic factor | Volcanic activities |
List the forms of Precipitation.
