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Chromatography is a widely used technique in Chemistry Topics for separating and analyzing mixtures based on their different affinities to a stationary phase.
Distinguish between biodegradable and non-biodegradable substances
A material which gets decomposed through natural processes (such as the action of bacteria) is called biodegradable. Plant wastes (such as peels of vegetables and fruits, fallen leaves, left-over food stuffs, etc.), animal wastes, paper, cotton cloth, woollen cloth, jute and wood, are all biodegradable materials. Biodegradable materials rot away with time and hence do not cause pollution in the environment. Thus, biodegradable materials are environment friendly.
A material which is not easily decomposed by natural processes (such as the action of bacteria) is called non-biodegradable. Plastics, glass, tin, aluminium cans, and other metal objects are non-biodegradable. Non- biodegradable materials do not rot away on their own and hence cause pollution in the environment. So, non-biodegradable materials are not environment friendly.
From the above discussion we conclude that two types of waste materials are produced in our day to day life : biodegradable wastes and non-biodegradable wastes. The biodegradable wastes and non-biodegradable wastes in our homes should be collected separately and disposed of separately.
Plastics And The Environment
When we go to the market, we usually get things put in plastic bags (polythene bags), or wrapped in plastic sheets or packed in plastic cartons. After we reach home, the plastic bags (polythene bags), plastic sheets and plastic cartons are no longer needed and become a waste. This is just one way in which the plastic wastes keep on getting accumulated in our homes. Ultimately the plastic wastes are dumped alongwith the household garbage. The use of plastics has a bad effect on the environment. The use of plastic materials affects the environment because of the following reasons :
(i) Plastic is non-biodegradable. So, the articles made of plastics (such as plastic bags, bottles and cartons) do not rot when they are thrown away after use. The waste plastic articles keep on accumulating in the surroundings and pollute the environment (see Figure 10). Thus, plastics are not environment friendly.
(ii) The waste plastic articles (like polythene bags, etc.) thrown here ai there carelessly get into dirty water drains and sewers, and clog them (block them). This makes the dirty drain water (or sewer water) to flow over the streets and roads causing unhygienic conditions.
(iii) Sometimes the animals (like cows) eat up the used polythene bags or plastic wrappers alongwith the left-over food and vegetable wastes thrown on garbage dumps. The plastic wastes can choke the respiratory system of these animals or form a plastic lining in their stomach. This can cause the death of these animals.
(iv) When the plastic waste materials are burnt, they produce poisonous gases which pollute the air.
The Disposal of Plastic Wastes is a Major Problem. This is because of the following two big disadvantages of plastics :
- The articles made of plastics are non-biodegradable. They do not decompose (or rot) easily. This causes a great problem in the disposal of plastic wastes. So, plastic wastes cannot be disposed of easily.
- The burning of plastic wastes gives out harmful gases which pollute the air. So, it is not advisable to dispose of the used plastic articles by burning.
How to Save the Environment From Excessive Plastic Wastes
Since the use of plastic articles is not good for the environment, we should take some steps to save the environment from the harmful effects of excessive use of plastics. Please note that plastics are very useful materials for us, so it is not possible to stop the use of plastic articles altogether. We can take steps only to minimise the use of plastics, wherever possible. Some of the steps which can be taken to save the environment from plastic wastes are as follows :
(i) We should try to reduce (or minimise) the use of plastics by using other materials in their place. For example, we should use bags made of cotton cloth or jute for shopping instead of polythene bags (plastic bags). Paper bags can also be used. Similarly, a stainless steel lunch box can be used instead of a plastic lunch box.
(ii) We should not throw polythene bags (plastic bags), wrappers of chips, biscuits and other eatables in water bodies, on the roads, in parks or picnic places. The used plastic materials should be put in the dustbins provided at various public places. This will keep our surroundings clean and also prevent the blockage of dirty water drains and sewers.
(iii) We should reuse the plastic containers which come with jams, pickles, oils and other packed food materials for storing salt, spices, tea-leaves, and sugar, etc., in the kitchen. We can also reuse the plastic carry bags for shopping purposes instead of throwing them as a waste.
(iv) Plastic wastes should be recycled. All the plastic wastes in the homes, shops and industry should be collected and sent for recycling to plastic making factories. In plastic factory, the waste plastic articles are melted and used to make new plastic articles. During recycling of used plastic articles, certain colours are added. This is to tell the buyers that it is a recycled plastic product, and to avoid its use for the storage of food. Most of the articles made of thermoplastics can be recycled. The articles made of thermosetting plastics cannot be recycled.
We should remember the 3R’s to save the environment from the harmful effects of the excessive use of plastics. The three R’s stand for : Reduce, Reuse and Recycle. This means that we should reduce the use of plastic articles by using articles made of other suitable materials ; we should reuse plastic articles wherever possible; and we should recycle old and discarded plastic articles, if possible.