Tag: strategies to control environmental pollution and green chemistry

Acid rain is the emission of oxides of sulphur and nitrogen in the atmosphere. This includes burning of fossil fuels containing sulphur and nitrogenous matter (such as coal and oil in furnaces and power stations, petrol and diesel in automobiles). 
Due to increase in acid gases in rain, the pH will change due to acid rain.

The Bhopal disaster or Bhopal gas tragedy was an industrial accident. It happened at a Union Carbide subsidiary pesticide plant in the city of Bhopal, India. On 3 December 1984, the plant released 42 tons of toxic methyl isocyanate (MIC) gas, exposing more than 500,000 people to toxic gases.

Sewage treatment is the process of removing contaminants from wastewater, primarily from household sewage. It includes physical, chemical, and biological processes to remove these contaminants and produce environmentally safe treated wastewater (or treated effluent).

The sewage treatment involves three stages, called primary, secondary, and tertiary treatment. First, the solids are separated from the wastewater stream. Then, dissolved biological matter is progressively converted into a solid mass by using indigenous, water-borne micro-organisms. Finally, the biological solids are neutralized, then disposed of or re-used, and the treated water may be disinfected chemically or physically (for example by lagoons and micro-filtration).

DDT, plastics, polythene, bags, insecticides, pesticides, mercury, lead, arsenic, metal articles like aluminum cans, synthetic fibres, glass objects, iron products and silver foils are non-biodegradable pollutants.

Anaerobic digestion is a series of biological processes in which microorganisms break down biodegradable material in the absence of oxygen. One of the end products is biogas, which is combusted to generate electricity and heat, or can be processed into renewable natural gas and transportation fuels.

Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerization. Its manufacture employs the same method today.

The waste materials which cannot be broken down into non-poisonous or harmless substances in nature are called non-biodegradable waste.
Examples are plastics, polythene bags, ball-point pen refills, synthetic fibres, and glass objects, metal articles like aluminium cans, iron nails, silver foil and radioactive wastes.

Biodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane or simple organic molecules by micro-organisms and other living things using composting, aerobic digestion, anaerobic digestion or similar processes.

The process of composting requires making a heap of wetted organic matter known as green waste (leaves, food waste) and waiting for the materials to break down into humus after a period of weeks or months.

Rainfall made so acidic by atmospheric pollution that it causes environmental harm, chiefly to forests and lakes. The main cause is the industrial burning of coal and other fossil fuels, the waste gases from which contain sulphur and nitrogen oxides which combine with atmospheric water to form acids.
These gases are released by automobiles, industries, power plants etc.