Design and Cost Analysis of an Integrated Waste-to-Resource System for Textile SMEs

In developing countries like Bangladesh, small textile factories often dump untreated waste because pollution control systems are too expensive. To address this, a low-cost prototype, named ‘Integrated Eco-Factory’, was designed and fabricated. This system simultaneously performs three critical functions: carbon capture, wastewater treatment, and energy harvesting: captures carbon soot from chimneys, treats wastewater, and harvests renewable energy. First, a cyclonic separator was utilized to collect carbon soot to collect carbon soot from exhaust gas and processed it into printing ink. Laboratory analysis revealed that the synthesized ink has a viscosity of 3.2 cP and surface tension of 38.5 mN/m, which is very close to commercial printer ink. Second, the traditional biological treatment was replaced with an Electrocoagulation (EC) unit. This unit removed 91% of the dye color from the water. Instead of throwing away the sludge we used it to make “Eco-Bricks” that have a strength of 14.2 MPa, making them safe for construction use. Finally, to ensure energy autonomy, a hybrid energy system (Solar, Thermal, and Hydro) that generates about 950 Wh per day—enough to run the system’s sensors and IoT monitoring 24/7. Our cost analysis shows that a factory can recover the full setup cost in just 7 months by selling the ink and bricks. The results demonstrate that that pollution control can be profitable for small industries.