Development of Sustainable Brick Using Textile Effluent Treatment Plant Sludge

A huge quantity of textile effluent treatment plant (TETP) sludge is generated from 21,076 units in India. Significant environmental impacts occur due to the landfilling of TETP sludge, such as land and water pollution. Thus, effective management of this sludge is important, which otherwise adds to the ever-escalating cost of disposal. With the rapid industrialization and urbanization, there is also an increased demand for construction materials to fulfill the shortage of housing in India (i.e., 18.78 million in urban and 43.9 million in rural). Brick is one of those significant construction materials, whose production is found to increase by 30% from 2000 to 2020 which consequently leads to an increase in carbon footprints. The present study, therefore, focuses on the effective utilization of TETP sludge to develop cost-effective, environmentally friendly bricks, which serve as an alternate solution for solid waste management, conservation of natural resources, and earning carbon credits. Sludge incorporated bricks were prepared with varying compositions of cement (6–24%), sludge (50–70%), and quarry dust (25%). Bricks are tested as per the Bureau of Indian Standards (BIS). The TETP sludge is characterized using X-ray fluorescence (XRF) and the properties of bricks were evaluated by conducting various tests such as compressive strength, water absorption, and density. Obtained results were also compared with commercially available fly ash bricks and clay bricks. The maximum strength of 4.2 N/mm2 was observed for the combination of 24% cement, 51% sludge, and 25% quarry dust, which exceeds the value of 4 N/mm2 for grade D, load-bearing units of IS: 2185(part1)—1979 and found to be greater than 3.5 N/mm2 that meets the criteria of IS: 1077–1979 for bricks in load-bearing units. When textile sludge is used in the range of 50–57%, the water absorption value of bricks was found to be less than 20%, thus meeting the requirement of BIS. The resultant unit weight of the brick is also found to be lesser than the conventional bricks. Thus, it can be said that TETP sludge has the potential to develop sustainable bricks that meet the requirements of BIS, similar to the other sustainable materials, viz., concrete, mortar, etc., developed using other industrial wastes.