Book Synopsis Urea for SCR-based NOx Control Systems and Potential Impacts to Ground Water Resources by :
Download or read book Urea for SCR-based NOx Control Systems and Potential Impacts to Ground Water Resources written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the key challenges facing manufacturers of diesel engines for light- and heavy-duty vehicles is the development of technologies for controlling emissions of nitrogen oxides, In this regard, selective catalytic reduction (SCR) systems represent control technology that can potentially achieve the NOx removal efficiencies required to meet new U.S. EPA standards. SCR systems rely on a bleed stream of urea solution into exhaust gases prior to catalytic reduction. While urea's role in this emission control technology is beneficial, in that it supports reduced NOx emissions, it can also be an environmental threat to ground water quality. This would occur if it is accidentally released to soils because once in that environmental medium, urea is subsequently converted to nitrate--which is regulated under the U.S. EPA's primary drinking water standards. Unfortunately, nitrate contamination of ground waters is already a significant problem across the U.S. Historically, the primary sources of nitrate in ground waters have been septic tanks and fertilizer applications. The basic concern over nitrate contamination is the potential health effects associated with drinking water containing elevated levels of nitrate. Specifically, consumption of nitrate-contaminated water can cause a blood disorder in infants known as methemoglobinemia.
