Environmental Pollution due to Chemical Industrial Processes and Controlling

Environmental pollution is a major concern currently in the world. Activities of humans is the main reason for environmental pollution. Here we are going to the discuss about different types of environmental pollution due to various chemical industries and reasons for those environmental pollution and how to control and minimize the effects of this issue.



Think! what will happen to the world, if there is no amazon rainforest or it is used as a bio-mass for power generation?


In this tutorial, we discuss following sections of environmental pollution.

  • What is environmental pollution and what are the categories of it?
  • Global environmental issues due to industrial activities
  • What is the industrial pollution?
  • Different industries and their participation to environmental pollution.
  • Different technics to reduce environmental pollution.

First, we take an industrial process and see how that industry effects to the environment in harmful way?


Petroleum Industry

Petroleum industry is a very hazardous industry and have to maintain very carefully to prevent any kind of harmful incidents. Petroleum industry produces very toxic gases such as hydrogen sulfide, ammonia, HCl and hydrocarbons in its production process. So we have to stop emission of these gases to the environment (to air).

Usually, ammonia and HCl are very much soluble in water. Therefore, these gases are dissolved in water. Later we have to recover HCl and ammonia from water. If water is leaked to the soil or another water source, water pollution is occurred.


Some petroleum industries (1st generation) convert hydrogen sulfide to sulfur dioxide and emit it directly to the atmosphere. ( 3rd generation petroleum industries do not emit sulfur dioxide to the atmosphere, they use hydrogen sulfide to produce by products such as sulfuric acid). If sulfur dioxide is emitted to the atmosphere, it causes acid rains.



Environmental pollution

Introduction of contaminants (impurities) into the natural environmental that cause a adverse change.


Environmental pollution can be categorized to the components of environment being damaged.

  • Air pollution - Due to addition of toxic gases, green house gases
  • Water pollution - Due to addition of acids, bases, organic compounds, fertilizers and heavy metals
  • Soil (land pollution) - Mainly due to adding solid waste like food waste

Pollutant

A substance which causes the pollution is called pollutant. As an example, sulfur dioxide is a pollutant which causes acid rains.

What are the gaseous pollutants which are emitted everywhere in the world?

Carbon dioxide, sulfur dioxide and hydrocarbon gases are emitted due to fuel combustion. If combustion temperature is very high, nitric oxide (NO) can be given.



Global environmental issues due to industrial activities

Main reason for environment pollution is Industrial activities of humans.

Now we study how the industry is involved in environmental pollution.


What is the industry?

Industry is defined as the production of goods or services within an economy.


What industry do?

Industry needs raw materials, energy, money, labor and more to produce goods. When products are manufactured, wastes are also produced.

Products can be categorized to two categories such as main product and by products.


What kind of wastes are formed in industry?

We can ask this question also as what are the pollutants?

  • Solid waste - one of the most serious problem in our daily life too. There is are some places these solid wastes are stored. Examples of these type of waste and their industries are explained later in this tutorial.
  • Waste water - may contain heavy metals, acids, bases or salts
  • Gases - Toxic gases which are not good to inhale

Environmental pollution can be occurred in different ways from these different waste.


Solid waste formation from industries

Industrial wastes are categorized as biodegradable and non-biodegradable. Usually bio-degradable wastes are generated by food processing units, cotton mills and textile factories.

Non-degradable wastes and their industries are listed below.

  • Aluminium, zinc, copper and other metal manufacturing industries will produce mud and tailings.
  • Gypsum is produces by fertilizer industries.
  • Thermal plants (for producing electricity) produce fly ash.
  • Iron and steel manufacturing plants produce blast furnace slag and steel melting slag.

Air Pollution methods

  • Photochemical smog
  • Global warming - greenhouse effect
  • Ozone depletion
  • Acid rains

Greenhouse gases under air pollution

Carbon dioxide has the major role as a greenhouse gas. Other greenhouse gases are methane, nitrous oxide, ozone, CFCl3, CF2Cl2 etc.



Natural environment

Natural environment encompasses all the living and non living things accruing naturally on earth.


What is the industrial pollution?

Pollution due to the industrial activities is defined as industrial pollution.

Examples:

  • Tons of CO2 gas are manufactured by cement manufacturing industry. CO2 is caused to global warming.
  • Also accidents in industries can cause large environment problems. As an example, if carbide factory had an accident, it release poisonous methyl isocyanite (MIC) to the environment. (accident of Union Carbide Factory on December 3 1984 in Bhopal, India)

Where can be polluted?

Air, water, soil can be polluted. Loud noise is also an environmental pollution and may cause to hearing problems after exposing continuously.


Environmental pollution can be occurred in different ways such as for short periods, continuous, at fixed levels and wide fluctuations.


Boilers and Furnaces

Boilers and furnaces are essential units in most chemical industries. They are used to supply energy for power generation or heat up some materials. However, it has to increase the temperature. For that, fuels are burnt to obtain required heat. For burning, fuel oil / furnace oil may be used.

We know when a hydrocarbon burns, it produces carbon dioxide and water vapor. So boilers and furnace produce carbon dioxide gas due to combustion of fuel oil.

If sulfur content is high in the fuel oil, sulfur dioxide is given.


In the combustion process, all fuels are not burnt completely. So unburnt fuels (mainly hydrocarbons) are released to the atmosphere with produced carbon dioxide. These unburnt hydrocarbon can cause different type of diseases such as cancers. Furnaces and boilers are very noisy and unpleasant to the hearing.



Now we see several industries and what are the bad effects to the environment from those industries.


Destroying Coral Reef

Coral contains limestone (CaCO3) which is highly required raw material for so many chemical industries. Limestone is used in following industries.

  • cement
  • soda-lime
  • Iron extraction
  • Bleaching powder
  • and more

Limestone prevents coastal erosion. Due to breaking of coral for industries and adding different chemicals to the sea by hotels, will destroy the coral.



Cement Industry

Cement is one of the most required material in the world for construction purposes. As raw materials, limestone (calcium carbonate / CaO), silica (SiO2), alumina (Al2O3) and iron oxide (Fe2O3) are used.

When limestone is heated to take CaO, carbon dioxide gas emits. Carbon dioxide causes to greenhouse effect and global heating.

If sulfur containing compounds are with raw materials, sulfur dioxide is produced due to burning. Sulfur dioxide is an acidic gas and causes to acid rains and not good to inhale because it is very toxic gas.



Iron extraction

Again limestone is heated in iron extraction to take CaO. So again carbon dioxide is released as a pollutant.

As cement production, if sulfur containing ores are used, sulfur dioxide can be released to the environment.



Haber Process - Ammonia Production

If ammonia is released to the atmosphere, it causes so many problems to animals and humans. Otherwise if it is added to the water stream, water become basic and it will cause deaths of fishes.

There is a high sound due to higher pressure.

Temperature around the plant increases.


Sulfuric Acid Manufacturing Plants

Sulfuric acid production gives sulfur dioxide, sulfur trioxide gases. These gases are highly acidic and cause acidic rains. If sulfuric acid contaminate with water streams, water become acidic and unusable for consumption.



Textile Industry

Colourants are used to get colours of the textiles. Most colouranats are organic compounds (chemical materials). If these chemical colourants are added to the water, water is polluted.



How to prevent or reduce environmental pollution?

We have several options to decrease the environmental pollution.

  • Reduce the effect by reducing the emission of pollutants.
  • Pollutants can be used to manufacture new product or by product.

Reduce the effect by reducing the emission of pollutants.

We can reduce the amount of pollutant by replacing the raw materials. If new raw materials is environment friend than previous one, you can select the new raw material as the raw material. But, unfortunately companies consider cost of raw material as a huge fact when choosing raw materials. So selecting new environmental friendly raw material is critical.

If pollutant can be used as a raw material or intermediate raw material, it also reduces the amount of emission.


Pollutants can be used to manufacture new product or by product

This is a good thing to try for a private company to gain more profits. They can sell their new product which is made of pollutants to customers. Also it reduces the effect to the environment.



Technics to reduce environment pollution for manufacturing companies

Following technics can be implemented by organizations to reduce impacts to the environment.

  • Cleaner Production
  • Green Productivity


Why industries should be careful about their environmental pollution?

Their are strict environmental regulations to follow in many countries for industries. Their emissions should keep at a certain level to reduce the impact. If they exceeds those limits, government can take actions against the company.



Industrial pollution and its impacts on ecosystems


Food chain

A series of organisms eating and decomposition the preceding one is called food chain.


Food web

In natural ecosystems the organisms are involved in a complex network of many interconnected food chains called food webs.


Bio Accumulation

It is a process that results in a higher concentrations of the chemical in the organisms than in its surrounding medium.