Comprehensive Analysis of Heavy Metal Aerosol Emissions and Health Risk from the Electrical Discharge Machining Process: A Control and Mitigation Approach for Green Manufacturing

Abstract

On a metal manufacturing shop floor, hazardous metal emissions are released from machines. These emissions remain suspended in the proximity of the working environment for an extended period despite the presence of a ventilation system and pose health risks to the workers. The present work discussed the need and demand for control and mitigation of emissions from the most demanding industrial shop floor electrical discharge machine (EDM) process for pollution-free manufacturing. The emissions of metal aerosols from the EDM process impose significant concerns for occupational safety. Health risk assessment of EDM emission reveals the presence of carcinogenic and non-carcinogenic elements in substantially high concentrations, causing several pulmonary and life-threatening diseases. The developed nanofiber-based multi-layer auxiliary filtration system reduces the PM1 particles of 170 × 10⁵ per litre of air concentration using the non-coated and nano-coated composite nanofiber-based multi-layer filters with filtration efficiency of ~ 87% and 97.27%, respectively. Moreover, the filtration efficiency of varying sizes of PM particles (average diameter of > 0.35 µm) is estimated to be ~ 99% using the above-mentioned in-house developed filtration systems with less pressure drop comparable with commercial filters. A comparative assessment of in-house developed filtration systems reveals nearly equal filtration efficiency with low flow resistance, reusable and cost-effectiveness than the high-efficiency particulate air (HEPA) filters. The presented study examines hazardous emissions from shopfloor machines and proposes a control mitigation approach through technological innovation to promote green manufacturing.