Question

How can you apply green chemistry to reduce use of chlorine in bleaching ??

Answer 1

Answer:

(i) The primary precursors of photochemical smog can be controlled which consists ofcompounds as Nitrogen dioxide and hydrocarbons, the secondary precursors such as ozone and PAN, the photochemical smog will automatically be reduced. Usually, catalytic converters are used in automobiles, which prevent the release of nitrogen oxide and hydrocarbons to the atmosphere. Certain plants e.g., Pinussp., Juniparussp., Quercussp., Pyrussp. and Vitissp.can metabolise nitrogen oxide and therefore, their plantation could help in this matter.

(ii) Tetra Chloroethene is now being replaced by a process, where liquefied Carbondioxide, with a suitable detergent, is used. Replacement of halogenated solvent by liquid

will result in less harm to groundwater. These days hydrogen peroxide (

) is used for the purpose of bleaching clothes in the process of laundry, which gives better results and makes use of a lesser amount of water. Chlorine gas was used earlier for bleaching paper. These days, hydrogen peroxidewith a suitable catalyst, which promotes the bleaching action of hydrogen peroxide, is used.

(iii) Synthetic detergents are salts of Na having long chains of Benzene sulphonic acids or salts of Na having long chains of alkyl hydrogen sulphates. But unlike, other pollutants, detergents are not biodegradable as they are not acted upon by microorganisms. Due to the presence of Mg or Ca salts they are not easily degraded and they form bubbles in water where oxygen and sunlight gets tapped and they hinder the normal growth of the planktonic species growing in the water. Thus, the use of synthetic detergents should be reused.

(iv) The consumption of petrol and diesel should be reduced being fossil fuels, they release compounds containing sulphur (mainly sulphur dioxides) which get released in the atmosphere and comes on the ground in the form of acid rain by forming respective acids.

Therefore, they should be replaced by bio-diesel and bio-petrol so that environmental pollution can be controlled. These are made using green chemistry (by using plant-based materials) and eco-friendly.