Submitted by: Submitted by sintubmb
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Category: Science and Technology
Date Submitted: 10/25/2011 01:07 AM
Industrial Waste Treatment Plant
Departement of Environment, Ministry of Environment and Forrest, Bangladesh
The Bangladesh Environmental Management Project (BEMP) has invented a sustainable technology to treat industrial wastes discharge particularly by the textile and dyeing industries creating a great scope of preventing pollution.
BEMP had already conducted a successful experiment at a demonstration project plant at Madhabdi in Narsingdi.There are about 200 small and medium-sized textile and dyeing mills at Madhabdi. An on-the-spot investigation revealed that most of the mills used to discharge the liquid wastes having high toxic materials into the nearby ponds, ditches or the canals that carry the pollutants into the nearby rivers, especially in the old Brahmaputra or Shitalakkhya..
In this process, liquid textile waste is filtered through several layers that separate a large portion of dyeing chemicals. BEMP sources said that 75 per cent of the fresh dye solution used in dyeing could be recovered for potential reuse. Then the flow of the wastes is pressed to enter into a reed-bed, a constructed wetland of several layers consisting of brick chips, sand, tiny stones and soil atop where selected vegetation is cultivated. The experiment found that some typical wetland vegetation in Bangladesh like Nalkhagra, Keya, Bamboo, Murta are highly suitable for absorbing the soluble contaminants from the reed-bed with at least three feet deep cluster roots.
Later, the reed-bed drains clean water through the way opposite to the entering side of polluted water. Beside, the sediment that was filtered first is burnt carefully to make sludge, which can be used in making bricks after mixing with mud or cement. The experimental project costs Tk 4.5 lakh only.