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Category Archives: ocean acidification

Those who studied chemistry and conducted laboratory experiments in universities will be familiar with precautionary measures we take to avoid  accidents. Aprons, gloves, goggles and fume cub-boards with exhaust fans are some few examples of protective measures from flames, hot plates and fumes. The blue color of the flame represented the degree of hotness of the flame from Bunsen burner; the pungent smell pointed to the ‘Gas plant’ that generated ‘water gas’ for Bunsen burners. The familiar smells of chemicals would bring ‘nostalgic memories’ of college days. Each bottle of chemicals would display a sign of warning ‘Danger or Poison’. We could recognize and identify even traces of  gases or fumes or chemicals immediately. Those memories embedded deeply in our memories and I vividly remembered even after few decades I left university.

I could smell traces of Chlorine in the air even at a distance of 20 miles from a Chloroalkali plant in sixties, when air pollution controls were not stringent. People who lived around the factory probably were used to live with that smell for generations. Many families had not breathed  fresh air in their life time, because they have not breathed air without traces of chlorine.They lived all their lives in the same place because agriculture was their profession. Many people developed breathing problems during  their old ages and died of asthma and tuberclosis.The impact of these fumes cannot be felt in months and years but certainly can be felt after decades especially at old ages, when the body’s immune system deteriorates. Bhopal gas accident in India is a grim reminder of  such tragedy of chemical accidents and how they can contaminate air, water and earth and degrade human lives. But we learnt any lessons from those accidents?

During experimental thermonuclear explosion in the desert of Australia by then British army, people were directly exposed to nuclear radiation. Many of those  who saw this explosion developed some form of cancer or other later in their life .They were treated as heroes then. After several decades of this incident, many exposed to this experiment are now demanding compensation from current British government. But have we learnt any lessons from those incidents? Many politicians still advocate ‘Nuclear energy as a safe and clean energy’. Yes, until we meet with an another accident!

We human beings identified the presence of  chemicals in Nature and used them for our scientific developments. We identified fossil fuels as ‘Hydrocarbons’ and burn them to generate power and to run our cars. We emit toxic gases and fumes every second of our lives, when we switch our lights on or start our cars.Imagine the amount of gases and fumes we emit everyday all over the world by billions of people for several decades. It is a simple common sense that we are responsible for these emissions and we contaminate the air we breathe. Nature does not burn Hydrocarbons everyday or every month or every year. In fact Nature buried these Hydrocarbons deep down the earth like we bury our dead.

Can people who breathed Chlorine for decades and died of asthma or tuberculosis prove that they died due constant inhalation of Chlorine emitted by the Chloroalkali plant? The Court and Authorities will demand ‘hard evidence’ to prove that Chlorine emitted by Chloroalkli plants caused these diseases. We use science when it suits us and we become skeptics when it does not suit us. They know it is almost impossible to prove such cases in our legal system and they can get away scot-free. The same argument applies to our ‘Greenhouse gas emission’ and ‘Global warming’.

We contaminate  our air, water and earth with our population explosion, industrialization and our life styles. Yet, major industrialized countries are not willing to cut their emissions but want to carry on their ‘economic growth’. But these countries got it completely wrong. In chemical experiments, one can draw conclusions by ‘observations’ and ‘Inference’. Inference is a scientific tool and not a guess work. From overwhelming evidences of natural disasters occurring around the world one can ‘infer’ that human activities cause these disasters. Nature is now showing this by devastating ‘the business and economic’ interest of nations because that is the only way Governments can learn lessons. They don’t need ‘harder evidence’ than  monetary losses. According to recent reports:

“The monetary losses from 2011’s natural catastrophes reached a record $380 billion, surpassing the previous record of $220 billion set in 2005. The year’s three costliest natural catastrophes were the March earthquake and tsunami in Japan (costing $210 billion), the August-November floods in Thailand ($40 billion), and the February earthquake in New Zealand ($16 billion).

The report notes that Asia experienced 70 percent, or $265 billion, of the total monetary losses from natural disasters around the world—up from an average share of 38 percent between 1980 and 2010. This can be attributed to the earthquake and tsunami in Japan, as well as the devastating floods in Thailand: Thailand’s summer monsoons, probably influenced by a very intensive La Niña situation, created the costliest flooding to date, with $40 billion in losses.”

Seawater is the largest source of Fresh water as well as the source of Hydrogen energy.However; Seawater cannot be used directly for these applications and it requires further treatment. Seawater has a number of dissolved salts and the TDS, total dissolved solids, of seawater is about 35,000ppm (parts per million).The commonly used industrial desalination process is by RO (reverse osmosis) as well as by multi flash distillation (MFD). Both these processes are energy intensive.RO process requires electrical energy and MFD requires thermal energy. Most of the countries in Pesian  Gulf use desalination process to convert seawater into drinking water as well as industrial water. These oil rich countries depend on the desalinated seawater as their main source of drinking water supply. In the desalination process by RO, the TDS level of seawater is reduced from 35,000ppm to 500ppm, meeting the WHO (World Health Organization) specifications for drinking purpose. The advantage with reverse osmosis process is it can remove even the smallest bacteria and virus, during the desalination. The water can further be disinfected by the injection of Chlorine before distributing for drinking purpose.

Majority of Desalination plants use RO process because it is economical. There is a worldwide shortage for safe Drinking water and more and more SWRO plants are coming up in various parts of the world. The technology of RO has advanced so much that the cost of desalinated seawater can compete with surface water in many parts of the world, especially in Gulf region where the energy cost is low. The rapid increase in population and industrial growth has created a greater demand for fresh water.

In conventional SWRO process, only 35-40% of fresh water is recovered and the balance 60-65% is discharged back into the sea as a highly saline brine, with TDS levels exceeding 65,000pm, almost double the salinity of seawater. Similarly most of the power plants located on sea coasts are using seawater for cooling purpose. In once through cooling system, the seawater is circulated into the power plant to condense steam in turbines and returned back to the sea. The temperature and salinity of the returning water into the sea is always higher than the intake water. Some oceanographers feel that such slow increase in salinity of seawater affects the temperature of the sea and the climate.

However, discharge of highly saline brine into the sea has become routine and EPA (Environmental and Pollution Authority) of various countries routinely approve such discharge, claiming it does not affect the marine life much. The environmental impact study conducted in one country is routinely followed by many countries and invariably conclude that such discharge has a very little or no impact to the environment. Human beings are concerned only with their environment and not with the Ocean environment where variety of marine species live. Our oceans have been heavily polluted from the time of industrial revolution by oil spills, toxic industrial effluent discharges, desalination and power plant discharges. The TDS levels of seawater in Gulf region has considerably increased in the past few decades. The TDS levels are about 50,000 ppm against conventional levels of 35,000PPM.The oceans are acidified by absorption of excess carbon dioxide from the atmosphere due to greenhouse gas emissions.

The power required to desalinate seawater is directly proportional to the osmotic pressure of seawater. The osmotic pressure increase as the TDS level increases, which in turn increases the energy consumption by desalination plants. A recent report from US government says that fresh water will become a serious issue after a decade and even wars may be waged between countries for the sake of fresh water. The human activities not only cause global warming but also changing the chemistry of our oceans. Steadily dwindling fish population is a clear sign of changing chemistry and biology of our oceans. In the absence of a proven scientific evidence to show that  human beings cause these changes in the ocean, we will carry on our business as usual until we reach a point of no return.

If you add salt to the water, it will not boil at 100C at 1 atmospheric pressure but slightly at a higher temperature. It is high school physics. When the salinity of the ocean increases from 35,000ppm to 50,000ppm, does it not affect the evaporation of the sea, which condenses into a cloud and come back as a rain? Does it mean there will be less precipitation in the future? Even if the ocean is under constant circulation, the overall salinity level keeps increasing.

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