Coal particles choked 30 acres of mangroves in Sewri: Study
A preliminary analysis of soil samples from Sewri Bay, where large portions of mangroves lie dead, has revealed that carbon particles have altered the physical properties of the soil. Snehal Rebello reports.mumbai Updated: Mar 20, 2012 01:13 IST
A preliminary analysis of soil samples from Sewri Bay, where large portions of mangroves lie dead, has revealed that carbon particles have altered the physical properties of the soil.
The study, conducted by non-government organisation Vanashakti has revealed that the pH value of the soil is 6.3, indicating that the soil is turning acidic. PH value denotes the degree of acidity or alkalinity with 7 being a neutral value. For mangroves to flourish, the soil’s pH value should denote alkalinity. While pH value below 7 indicates acidity, a value above 7 denotes alkalinity. Also, the chemical analysis has shown high carbon content and sulphur traces in the soil. The carbon particles found in the soil are believed to have come from coking coal, which was stored near the mangroves on land belonging to the Mumbai Port Trust. Coking coal, which is soft bituminous coal, is heated to produce coke — a hard, grey, porous material — used to blast furnaces for extracting iron from the iron ore, steel-making and power generation.
“Besides the pH value of 6.3, physical choking due to the excessive deposition of coke particles in the soil has hardened the wetlands and changed its alkaline nature. There is no doubt that coking coal is the culprit,” said Stalin D, project director, Vanashakti.
“The drastic change in pH level is mostly due to emission of gases such as carbon monoxide and carbon dioxide released by the heat generated from coking coal stored around the area. It is turning the soil acidic,” said a chemistry professor who conducted the soil analysis.
The professor, who did not wish to be named, added, “Carbon dioxide when combined with water vapour forms carbonic acid and has the ability to turn the soil acidic. Mangroves will not grow in acidic soil.”
On February 28, HT had highlighted the destruction of 30 acres of mangroves at Sewri Bay.
Reacting to the HT report, the Bombay high court on March 2 took suo motu cognisance of mangrove destruction and issued notices to the port trust and Maharashtra Coastal Zone Management Authority and asked them to file their replies within two weeks.