Saturday, August 8, 2009

Green Cement: thanks to NOVACEM.

A British start-up company, NOVACEM, has developed a cement which has low carbon footprint [ , dated06.08.09 ] . This cement has negative carbon footprint of 0.6 tonnes per tonne of standard cement. The conventional Portland cement is responsible for an estimated 5 percent of global carbon di-oxide emissions; this is more than the aviation industry.
In conventional method, the essential costituents of cement are the limestone, silica and alumina. During manufacturing process when reactions take place in rotary kiln, in average temperature zone [ 800-1000 degree Celsius ], the limestone, decomposes into lime and carbon di-oxide. Thus, this stage is the main emitter of carbon di-oxide. Novacem used a new technique; this is, to make cement from magnesium silicates rather than limestone coz this material does not emit carbon di-oxide in manufacture and absorbs the carbon di-oxide as it ages. Novacem estimates that for every ton of Portland cement replaced by its product, around three-quarters of a ton of carbon di-oxide is saved. This technology breakthrough by Novacem will definately turn the cement industry to a big absorber of carbon from a big emitter. Thank you NOVACEM. [ Prabhat Misra ]

Friday, August 7, 2009

Superbug: solution to the oil pollution.

Over 10 million metric tons of petro-pollutants enter the sea ecosystem each year and killing birds, shell fish, fishes, invertibrates and other sea animals and planktons. This poses more adverse effect on marine life and food chain.

To solve the problem of sea petro-pollution, the Indian-born American scientist, Dr. Anand Mohan Chakravarty succeded in producing a microbacterial SUPERBUG by genetically engineered strain of Pseudomonas putida. It is capable of utilising complex chemical compounds like hydrocarbons. It is also called oil eating bug.

Petro-products, including oils, genrally contains octane, xylene, camphor and naphthalene. No single strain of P. putida is able to digest all these four petro-chemical; for this needed four strains of P. putida with four different plasmid DNA's. Dr. Anand introduced four plasmid DNA's from four different strains into one single cell of Pseudomonas putida and formed a SUPERBUG.

Pseudomonas is an aerobic and gram-negative bacterium belongs to Pseudomonadaceae family of bacteria. P. aeruginosa and P. fluorescens are fluorescent pigment forming bacteria.
This superbug utilise a number of toxic chemicals like chlorobenzenes, 2.4-D, 2.4.5-T, and petro-chemicals like octane, camphor, etc. This discovery of superbug really open the door for checking oil-pollution in seas. [ Prabhat Misra ].