Dear Pandit ji, I like Gobar Times a lot. It is really a very interesting concept and helps in participating children through various means. The simple ways and pictorial representations are really appreciable. Although I am no more a child, I really like Gobar Times. Nidhi Singh, Ph.D. Scholar JNU, New Delhi Dear Pandit ji, I love reading Gobar Times. It is very interesting, informative and fun. The last Gobar Times on packaging is extremely good. It talks about every possible thing that can be said or known about packaging. The way it is presented to the readers is also very good. Gobar Times never bores its readers, may it be children or adults. It always makes its readers turn the next page, which is again filled with surprises! Mridul Via e-mail

I have learned from your magazine that mines affect the environment very badly and it should be restored after closure. How many mining operations in India actually get restored after closure?

Charmy
Via e-mail

Dear Charmy ji,
In India, mine closure has been reduced to a long series of paperwork, with little impact on the ground. It is a ‘formality’ that needs to be done over with to get the clearance. And it was only in 2003 that India put mine closure as a regulatory requirement for operating mines. Thus, there are many fissures in the plans of mine closure.

The plans that are being approved today in the country are all about water bodies, stabilised overburden dumps and plantations. None of the plans discusses alternate land uses, pollution control or remediation (assuming that there is no pollution once the mines are closed). But, mine closure is not simply planting trees and stabilising overburden. It is a combination of environmental, social, economic, and development issues that must be clearly defined, understood, and planned for before a mine is allowed to operate.

It is also about creating a sustainable ecosystem in which the community affected by mining can live after the activity is over. Plans should have provisions for alternate economic activities and livelihoods, development of infrastructure in a way that it can be utilised after the mine is closed, utilisation of the mine land for economic and social uses, and compensation for workers. Moreover, the mined land should be transferred to the commons, instead of the government (mainly the forest and revenue departments).


Dear Pandit ji,

I read your magazine thoroughly. It is very good and informative for young students. Can you please give me a detailed explanation about what are asphalt roads? Can you also explain desalination?

Vignesh Kumar
Coimbatore

Dear Vignesh Kumar ji,
Thank you for appreciating Gobar Times. Here are your answers – Asphalt roads or asphalt concrete roads are roads made using Asphalt – a sticky, black, semi-solid material that is present in most crude petroleum and in some natural deposits. It is also called bitumen. Asphalt (bitumen) is used as the glue or binder for the aggregate particles (coarse particulate material used in construction, including sand, gravel, crushed stone, slag, and recycled concrete) laid down in layers and compacted.

Asphalt was first used for roads in 1824, when asphalt blocks were placed on the Champs-Élysées in Paris. Modern road asphalt is the work of Belgian immigrant Edward de Smedt at Columbia University in New York City. By 1872, De Smedt had engineered modern, “well-graded,” maximum-density asphalt. The first uses of this road asphalt were in Battery Park and on Fifth Avenue in New York City in 1872 and on Pennsylvania Avenue, Washington DC, in 1877.

Asphalt concrete is often touted as being 100 per cent recyclable. It can be removed, crushed to a consistent gradation, and used as a base course material later. The ‘tarmacs’ in airfields are actually asphalt concrete pavements, called so for historical reasons.

Desalination or desalinisation refers to any of the several processes that remove excess salt and other minerals from a substance such as water or soil. For instance, water is desalinated to convert it into fresh water suitable for consumption or irrigation. Sometimes the process produces table salt as a by-product. Then, soil is desalinated to prevent soil degradation by excess salt (salinisation), and reclaim and improve already salty (saline) soils.


Dear Pandit ji,

I wanted to know more about how to handle organic industrial waste. That might sound like a contradiction in terms but I'm interested in it. Can you suggest some ways to deal with the liquid as well as solid organic waste the most efficiently?

Athang Jain
Via e-mail

Dear Athang Jain ji,
Organic industrial waste does not sound contradictory. Commercial, institutional and industrial effluent can also contain significant amount of organic waste.

The present technologies used for disposing solid waste are either incineration or landfilling. Both the methods have many disadvantages. Incineration causes air pollution and generates highly concentrated toxic ash residue. In landfills, as biodegradable waste decomposes, it produces greenhouse gases and leaves behind potentially toxic liquids that can escape the landfill and pollute the surrounding environment. Even though ‘scientific landfilling’ claims to be safer, it requires a lot of land.

There are other alternatives – composting and anaerobic digestion. Organic waste can be processed in the presence of oxygen by composting or in the absence of oxygen using anaerobic digestion. Both methods produce a soil conditioner, which can be used as a valuable source of nutrients for agriculture. Anaerobic digestion also produces methane gas – an important source of bio-energy. These methods, therefore, reduce both pollution and the amount of land used for waste disposal.

Many other experiments are being done to deal with organic industrial waste. Vermicomposting of the sludge that remains after the effluent treatment is one of them.

While the sludge settles down, the clearer water outflows into outer drainage system. But, this sludge still has about 70-80 per cent water that can be removed by a belt press filter. The remaining 20-30 per cent solid sludge contains organic and inorganic materials. The sludge is spread on a vermiculture bed, which converts the organic matter into manure.

But if the sludge contains toxic material, the earthworms will absorb it, and die. True, but according to researchers, even with their shortened life span, earthworms regenerate 10-20 times. Dead worms too form organic matter. The same quantity of toxic matter gets distributed in multiplied worms leaving manure toxic free.