Brandix donates sludge bricks for training centre for differently-abled

Construction bricks made from primary sludge generated by industrial waste conversion, will form the walls of a new vocational training centre for the differently-abled in Sri Lanka in an initiative that showcases innovation, environmental conservation and caring by two apparel sector giants, Sri Lanka's Brandix Group and UK's Marks and Spencer along with other suppliers to Marks and Spencer in Sri Lanka.

The first consignment of these unique bricks developed and produced by Brandix Finishing at Ratmalana after extensive research and testing, were donated to Rehab Lanka by Brandix for the construction of a two-storied training centre cum workshop near the Khettarama Cricket Stadium. The project is funded by Marks and Start, the flagship community program of Marks and Spencer.

Made out of primary sludge, used pumice stones and silica waste from the sand used for sandblasting during the garment washing, dyeing and finishing processes at Brandix Finishing, these solid bricks have a compressive strength of 2.3 Newtons per square millimetre, more than double that of the standard concrete blocks used in construction.

The cost of production per brick at Rs. 14 (excluding the savings that would otherwise be incurred on disposing of the sludge) is more than two and a half times lower than the Rs. 37 at which concrete blocks of the same size are retailed in the market.

"The conversion of solid waste into bricks carries many notable advantages," said Hilary Nath, Head of Environment Management and Research at Brandix. "A large volume of primary sludge is generated in the garment washing industry, and this project enables us to recycle most of it and contribute to the preservation of the environment. We also produce high quality building material at a very low cost," he said.

Explaining the process, he said pumice stones decay during the washing process and come to the wastewater stream along with silica silt and pebbles. The silica silt and the pebbles of pumice stones form a major part of the primary sludge settled during the physical treatment process. To produce the bricks, the pumice pebbles are separated from the primary sludge, crushed and re-mixed with the sludge, waste sand some cement.

This process, perfected at Brandix Finishing earlier this year, utilises 60 percent of all the primary sludge generated by the plant and all of the used pumice stone and sandblast sand. With two people working on the project for two and a half hours a day, the company can produce 50 sludge bricks. The curing process takes 21 days, at the end of which the bricks reach their full compressive strength.