Study of the effect of the Dienitro additive on the NO x and CO emissions in buses of collective transport to Diesel S-50 EGR and S-10 with SCR and EGR systems Michelle Maruska Mader Federal University of Paraná, Curitiba, Brazil, and Cássio Aurélio Suski IFSC, Itajaí, Brazil Abstract Purpose – Transport of people and goods has always been associated with the generation of some form of pollution, whether atmospheric, sound or visual. Managing the urban environment presents a major challenge: preserving environmental resources and also ensuring decent living conditions for the current population and for future generations. In the era of motorized and carbonized transport, vehicles are the main source of emission of atmospheric pollutants, mainly in large urban centers and important precursors of ozone. An important advance in minimizing vehicle emissions was the introduction of cleaner and additive fuels into the Brazilian market. The purpose of this paper is to study the effect of the Dienitro additive on the NO x and CO emissions in buses of collective transport, Diesel S-50 exhaust gas recirculation (EGR) and S-10 with selective catalytic reduction (SCR) and EGR systems. Measurements of CO and NO x gas emissions were carried out using a gas analyzer in S50 and S10 diesel buses with an EGR and SCR systems from a company operating in the collective transport of Biguaçu. Design/methodology/approach – In this study, 20 measurements were performed without additives and 20 measurements with additivation in each bus, making it possible to calculate the average emission rate of CO and NO x , pollutant gases with toxic effect. Findings – The usage of Dienitro additive in diesel engines resulted in a significant reduction in the emission of polluting gases, carbon monoxide (CO) and nitrogen oxide (NO x ), thus being efficient in reducing the emissions of these gases. Originality/value – The Dienitro additive was first tested on diesel engines by public transport buses, and there is great potential for reducing the emission of toxic gases. Keywords Emissions, Pollutants, Diesel, Buses Paper type Research paper 1. Introduction The rapid urbanization of the planet’s great cities over the last fifty years has already shown changes in the microclimate of their regions and may be related to global climate change. In Brazil, the population growth in the big cities occurred in the 1970s, with economic and industrial growth, which also appears as a source of pollution. Urban air quality is determined by a complex system of polluting sources, which can be fixed (industries, burning, ovens, boilers, etc.) or mobile (motor vehicles, etc.). The continuous increase in pollution sources without proper control has contributed to the increase of atmospheric pollution, constituting one of the most serious threats to the quality of life of its inhabitants in metropolitan areas (Teixeira et al., 2007). The relevance and complexity of the issue, atmospheric emissions, motivate the study of the type of source, which contributes most in the proportion of emitting sources: vehicular sources of air pollution. This type of source has a marked participation in the degradation of atmospheric air quality, mainly in large urban centers (Baird, 2002). Received 22 July 2019 Revised 15 September 2019 Accepted 9 October 2019 The current issue and full text archive of this journal is available on Emerald Insight at: www.emeraldinsight.com/1477-7835.htm Study of the effect of the Dienitro additive Management of Environmental Quality: An International Journal Vol. 31 No. 3, 2020 pp. 625-644 © Emerald Publishing Limited 1477-7835 DOI 10.1108/MEQ-07-2019-0158 625