The release of industrial chemical waste into waterbodies is a global concern; the approach to tackling this has generally involved the use of catalytic materials that rely on sunlight to drive chemical reactions. However, most photocatalysts are difficult to reuse, limiting their practicality in largescale applications. Further, these catalysts require ultraviolet (UV) light to drive the conversions, which necessitates dedicated UV sources, adding to the complexity and cost of the system.
A team of researchers at NIT-Rourkela, led by Prof Subhankar Paul of the Biotechnology and Medical Engineering department, has developed an innovative photocatalyst system.
The system combines iron-doped nano-titania with graphene oxide and immobilises the compound on specially designed spherical concrete beads.
These beads are made from green concrete using coal fly ash derived zeolite, a sustainable approach that repurposes industrial waste and offers high mechanical strength, porosity and absorption capacity. This composite material uses sunlight to break down toxic pollutants in wastewater efficiently.
The photocatalyst beads can be added to the wastewater reservoir, exposed to sunlight and easily removed once the water treatment is complete.
Since the developed technology does not rely on external energy sources, it can be used easily in rural and resource- constrained areas.
This technology has the potential to treat industrial effluents, municipal wastewater and contaminated natural water sources.
“As the global concerns over water pollution continue to grow, this NIT- Rourkela innovation provides a timely and sustainable response to address the challenge,” says a press release from the institute.
Eco-safe lubrication
Lubrication reduces friction and wear in machinery, ensuring efficiency and longevity. Conventional mineral or synthetic oil-based lubricants pose environmental risks, driving the demand for sustainable alternatives. Scientists at the Institute of Advanced Study in Science and Technology (IASST), Guwahati, have developed an environmentally friendly lubricant formulation that significantly enhances friction reduction, wear resistance and overall performance. The lubricant has been developed by integrating surface-modified graphitic carbon nitride into bio-based castor oil.
This advancement offers a sustainable alternative to conventional lubricants, addressing both efficiency and environmental concerns.
A study of friction, lubrication and wear of interacting surfaces in relative motion (tribological evaluations) demonstrated remarkable improvements — reduction of friction by around 54 per cent and decrease of wear volume by 60.02 per cent compared to castor oil alone. The lubricant also exhibited a higher load-bearing capacity and greater thermal stability, with the oxidation onset temperature rising from 320 degree C to 339 degree C, demonstrating the efficiency of the lubricating formulation. Further, toxicity assessments confirm minimal formation of free radicals (thereby curbing secondary reactions), making the formulation safe for environmentally sensitive applications.