The amount of oxygen that is required for the chemical oxidation of the organic and inorganic chemicals present in the wastewater by utilising oxidising agents like Potassium permanganate, Potassium dichromate etc. is called as chemical oxygen demand (COD). COD is the oxygen demand that is consumed by both inorganic and organic matter present in the wastewater sample.

Mosses are a common flowerless plant found in all cities especially in damp (humid) or shady locations. It generally absorbs water and nutrients from their immediate environments.
So, according to scientists, delicate mosses found on rocks and trees in cities around the world can be used as low-cost bio indicator to monitor urban pollution and to measure the impact of atmospheric change. As a bio indicator, mosses respond to pollution or drought- stress by changing its shape, density or disappearing. This characteristic will allow scientists to calculate atmospheric alterations and air pollution.

Bioremediation is the use of living microorganisms to degrade the environmental contaminants into less toxic forms.
Bioremediation can be effective only where environmental conditions permit microbial growth and activity.

Statement 3: This will be a standard practice in the industry in coming years. For e.g. Alcanivorax, a bacteria with oil-eating abilities, can be used to create species that are much more capable of cleaning oil spills.
Bio-remediation is a slow process, so. Heavy metals such as cadmium and lead are NOT readily absorbed or captured by microorganisms.

• The ’21’ in Agenda 21 refers to the 21st century.
• Agenda 21 is a non-binding action plan of the United Nations with regard to sustainable development. It is a product of the Earth Summit (UN Conference on Environment and Development) held in Rio de Janeiro, Brazil, in 1992

The National Adaptation Fund for Climate Change (NAFCC) is a Central Sector Scheme which was set up in the year 2015-16. The overall aim of NAFCC is to support concrete adaptation activities which mitigate the adverse effects of climate change. The activities under this scheme are implemented in a project mode. National Bank for Agriculture and Rural Development (NABARD) is the National Implementing Entity (NIE). The projects related to adaptation in sectors such as agriculture, animal husbandry, water, forestry, tourism etc. are eligible for funding under NAFCC.