Archive for August, 2010

21
Aug
10

Groundwater, arsenic and irrigation

Tube well irrigation in West Bengal and Bangladesh is very common. Nearly 9,00,000 tube wells n Bangladesh and 5,50,000 in West Bengal constantly pump groundwater to irrigate rice fields. The groundwater contains greater than 3.2 mg/L of arsenic. In Bangladesh nearly 2 million ha of land is irrigated using arsenic rich groundwater while a little less than 2 million ha land is under irrigation through arsenic contaminated groundwater in West Bengal. Estimates by FAO indicates that 1 million kg of arsenic is added to arable soil every year in these regions. From groundwater, arsenic now has entered the food chain and both As (III) and As (V) is found to enter the rice plant and other vegetable by different mechanism. Thus an arsenic – path – chain, from water to food through soil  has been established. A large number of scientific reports have documented these facts and a great debate is on at several international conferences on the fate of human race due to this menace. In fact more recent studies indicate that the entire Gangetic drainage basin is affected arsenic problem. What is not clear is  1) the fate of arsenic that enters the animals through fodder, 2) crop growth and yield, 3) mechanism of up-take of arsenic by plants 4) genetic effect on humans and animals. This opens up a chain of problems that need to be addressed by the future scientists. Now it is clear that this problems has to be tackled, not by a single group, but by a multi disciplinary group consists of geologists, biologists and  physicians.

 Mind set and will to change is what is needed to tackle this problem failing which generations may get affected in future……..read the article posted in Down to Earth in 2006!!

Arsenic 3 Nov 06_Down to Earth

14
Aug
10

Arsenic in groundwater is a global calamity!!

Arsenic is a killer element. Groundwater in West Bengal and Bangladesh is contaminated with arsenic and people are  drinking arsenic contaminated water for the last several decades. Since it is tasteless, millions drink such water unknowingly and succumb to its poisonous effect. Nearly 40 % of 80 million people in West Bengal are suffering from arsenic related diseases. Children are the worst affected. The arsenic content in groundwater in West Bengal is ~ 3.2 mg/L while the limit is between 10 to 50 mgm/L. In fact several SE countries have this problem.  According to WHO this problem in West Bengal and Bangladesh is termed as global problem and several scientific bodies are seeking solution to this problem. Now from groundwater this menace has entered the food chain through irrigation practice. A large number of bore wells operate continuously pumping groundwater from different depths to rice fields. The amount of water required is quite large since 90% of the land in West Bengal is under rice cultivation.  The arsenic content in the water pumped for irrigation is same as that mentioned above. A recent study conducted in parts of West Bengal has revealed that paddy crop has maximum concentration of arsenic scavenged from groundwater. The arsenic content in rice grain is 0.3 mg/L, in husk it is 1 mg/L and in the steam and leaves it is > than 2 mg/L. The root accumulate large amount of arsenic. In the present study it was found to be as high as 169 mg/L. Except roots, all parts of rice plant is eaten by humans and animals. Now are in an arsenic web!! Now this problem is no longer confined to West Bengal and Bangladesh. Besides rice, the vegetable cultivated through irrigation also have high levels of arsenic.  Common leafy vegetable like Red Spinach, Amaranth, Chinese Spinach, Indian Spinach have arsenic content > 0.3 mg/L.  With the growing awareness on contaminated groundwater, arsenic contamination is slowly surfacing in other parts of the country.  Arsenic contaminated groundwater is reported within the Godavari sub-basins bordering Chattisgarh.  Millions of population depend on groundwater in the rural areas. Both arsenic and fluoride has become a nightmare to rural population.   

 

for more details go to the link

Food and Water Security

 

 

 

12
Aug
10

International Geothermal Association

International Geothermal Association (IGA) is an international non-profit organization promoting geothermal energy across all the countries. It is scientific, educational and cultural organization established in 1988  and operates worldwide. IGA has a very strong membership of more than 2000 from over 65 countries. IGA is affiliated to the Renewable Energy Alliance (IREA) with a special consultative status with the Economic and Social Council of UN. IGA encourages use of geothermal energy for power and direct applications through publications and spreads scientific and technical data to uplift the socio-economic status of all the countries. World Geothermal Congress is a major event of IGA conducted every 5 years. Its aim, as defined in the Charter of the Association, is to encourage, facilitate and promote coordination of activities related to worldwide research, development and application of geothermal resources.  IGA currently operates from Iceland. 

In the recently concluded IGA Board of Directors elections, an Indian is elected for the first time to the Board. India has sufficiently large wet geothermal systems while the country’s EGS potential in unlimitted.

04
Aug
10

EGS Carbondioxide and earthquakes

Enhanced Geothermal Systems and carbon dioxide