UGC NTA NET/JRF Exam, Environmental Sciences, June-2020

Hardness is a measure of the ability of a mineral to resist abrasion or scratching. A simple scale, based on empirical tests and known as Moh's scale of hardness, has been universally accepted. The 10 minerals selected to form the standard of comparison are listed below in order of increasing hardness:

Carbon dioxide emissions are the primary driver of global climate change. It's widely recognised that to avoid the worst impacts of climate change, the world needs to urgently reduce emissions.

The top 10 largest emitter countries account for 67.6% of the world total. Countries/group of countries credited with the highest to the lowest shares of cumulative CO₂ emissions: USA, EU, China, Japan, India.

Greenhouse gases are those that absorb and emit infrared radiation in the wavelength range emitted by Earth. Carbon dioxide (0.04%), nitrous oxide, methane and ozone are trace gases that account for almost 0.1% of Earth's atmosphere and have an appreciable greenhouse effect.

In order, the most abundant greenhouse gases in Earth's atmosphere are:
• Water vapour (H₂O)
• Carbon dioxide (CO₂)
• Methane (CH₄)
• Nitrous oxide (N₂O)
• Ozone (O₃)
• Chlorofluorocarbons (CFCs)
• Hydrofluorocarbons (includes HCFCs and HFCs).

Pesticides with high vapour pressures are easily lost to the atmosphere during application, and shortly thereafter they are lost from the soil through gaseous diffusion.

Some highly vola-tile pesticides, however, may also move down-ward into aquifers. Roots are the principal absorbing organs for soil-applied pesticides.

Incineration is a chemical reaction in which carbon, hydrogen and other elements in the waste mix with oxygen in the combustion zone and generates heat. The air requirements for combustion of solid wastes are considerable.

Liquid RAW can be divided into process drains, floor drains and laundry drains based on the sources of waste generation.

It is mainly generated from the clean-up and maintenance processes of reactor coolant and related systems containing radioactivity.

The main sources of primary liquid radioactive waste (LRAW) from NPPs are pipelines leakages. water from spent nuclear fuel storage pools.

Solutions remaining after sorbent regeneration and spent decontamination solutions.

The risks from radioactive liquid wastes are caused under decontamination, solidification and disposal procedures.

E-waste is a popular, informal name for electronic products nearing the end of their "useful life." Computers, televisions, VCRs, stereos, copiers, and fax machines are common electronic products. Many of these products can be reused, refurbished, or recycled.

There are hazardous materials, such as lead, mercury, and hexavalent chromium, in circuit boards, batteries, and colour cathode ray tubes (CRTs) are present in electronic waste. Land filling of electronic waste is not the best operation for the environmental viewpoint.

In the field of waste management, extended producer responsibility (EPR) is a strategy to add all of the environmental costs associated with a product throughout the product life cycle to the market price of that product.

Extended producer responsibility legislation is a driving force behind the adoption of remanufacturing initiatives because it "focuses on the end-of-use treatment of consumer products and has the primary aim to increase the amount and degree of product recovery and to minimize the environmental impact of waste materials"

Provision of Extended Producer Responsibility (EPR) of producer, importer and brand owner for collecting back the waste generated by their product has been in the:

(a) Solid Waste Management Rules, 2016
(b) Construction & Demolition Waste Management Rules, 2016
(c) Plastic Waste Management Rules, 2016
(d) E-waste (Management) Rules, 2016
(e) Biomedical Waste Management Rules, 2016.

The basic objectives of the National Forest Policy, 1988 are:

• Maintenance of environmental stability through preservation and, where necessary, restoration of the ecological balance that has been adversely disturbed by serious depletion of forests.

• Conservation of the natural heritage by preserving the remaining natural forests with the vast variety of flora and fauna, which represents remarkable biological diversity and genetic resources.

• Substantial increase of forcst/tree cover through massive afforestation and social forestry programmes, especially on denuded, degraded and unproductive lands

• Meeting of the requirements of fuelwood, fodder, minor forest produce and small timber of the rural and tribal population

• Increasing the productivity of forests to meet essential national needs.
• Encouragement of efficient utilization of forest produce and maximization of wood substitution.

• Recognition of the rights of forest dependent communities.