Advertisements
Advertisements
Question
What is water recycling? Explain the conventional wastewater recycling treatment methods.
Advertisements
Solution
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
RELATED QUESTIONS
What is rain water harvesting? List out the advantages of rain water harvesting.
_______ is a broad inlet of the water body where the land curves inwards.
Seas are formed when the water table meets the land surface.
Describe the processes involved in the water cycle.
The Antartic region has about ______ of the worlds fresh water.
Transpiration takes place in rivers and lakes.
Some definitions are given below which can be corrected by changing one word. Correct them.
- Aquifer is ground water 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 vapour cycle.
Place the following statements in a proper order to form a meaningful paragraph.
- Which in turn decreases the seepage of rain water into the ground.
- This decreases the open areas like parks and playgrounds.
- Increasing population create demand for construction of houses, shops, offices, roads and pavements.
- This results in depletion of water table and creates scarcity of more water.
Most of the water that falls on the land as rain and snow, sooner or later goes back to a sea or an ocean. Explain how it happens?
______ is the study of patterns, and processes in the natural world and their modifications by human activities.
