Bangladesh invents low-cost technology to treat industrial waste

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.

The method, operated by minimum machinery to separate dyeing sediments and liquid wastes of the fabrics-dyeing mills, is also proved to be environment-friendly apart from being a cheaper-than-hi-tech technology of waste treatment, local daily New Age reported on Monday.

Sye M Iqbal Ali, Director of BEMP, narrated the process of developing the low-cost technology.

The salient features of the technology are demonstration of good house keeping practices, waste minimization through reuse of dyes and chemicals, and process modification, pre-treatment of effluent and settling, treatment of pre-treated effluent through areed-bed and management of sludge in environmentally sound manner,Ali was quoted as saying by the daily.

In this process, liquid textile waste is filtered through several layers that separate a large portion of dyeing chemicals. BEMP sources said that 75 percent 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.

According to the daily, 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 oppositeto the entering side of polluted water. Beside, the sediment that was filtered first is burnt carefully to make sludge, which can beused in making bricks after mixing with mud or cement.

Iqbal Ali said that the experimental project costs 450,000 taka(about 6,900 US dollars) only.

Now the government plans to introduce the technology in all of the industries that produce a lot of liquid wastes.

Environment and Forest Minister Tariqul Islam said, "This local technology is affordable by the small and medium-scale entrepreneurs. These plants are capable of serving almost all hi-tech treatment plants."

Source: Xinhua