Gaseous and particulate emission profiles during controlled rice straw burning

Abstract

Gaseous and particulate emission profiles during controlled rice straw burningSanchis, E 1 ., Ferrer, M 1 ., Calvet, S 1 ., Coscollà, C 2 ., Yusà, V 2 ., Cambra-López, M 1 . AbstractBurning of rice straw can emit considerable amounts of atmospheric pollutants. We evaluated the effect of rice straw moisture content (5%, 10% and 20%) on the emission of carbon dioxide (CO 2 ) and on the organic and inorganic constituents of released particulate matter (PM): dioxins, heavy metals, and polycyclic aromatic hydrocarbons (PAHs). Four burning tests were conducted per moisture treatment using the open chamber method. Gaseous emission profiles of carbon monoxide (CO), sulfur dioxide (SO 2 ), nitrogen monoxide (NO), and nitrogen dioxide (NO 2 ) were also measured. Additionally, combustion characteristics, including burning stages, durations, combustion efficiency, temperature, and relative humidity, were recorded. Burning tests showed flaming and smoldering stages were significantly longer in 20% moisture treatment (P<0.05) compared with the rest. The amount of burned straw and ashes decreased with increasing straw moisture content (P<0.001). Carbon dioxide was the main product obtained during combustion with emission values ranging from 692 g CO 2 kg dry straw -1 (10% moisture content) to 835 g CO 2 kg dry straw -1 (20% moisture content). Emission factors for PM were the highest in 20% moisture treatment (P<0.005). Fine PM (PM2.5) accounted to more than 60% of total PM mass. Emission factors for dioxins increased with straw moisture content, being the highest in 20% moisture treatment, although showing a wide variability among burning tests (P>0.05). Emissions factors for heavy metals were low and similar among moisture treatments (P>0.05). Emission factors for individual PAHs were generally higher in 20% moisture treatment. Average SO 2 and NO emissions decreased with moisture content. In contrast, CO emissions increased with moisture content.Overall, emission factors of atmospheric pollutants measured in our study were higher in the 20% moisture content. This difference could be attributed to the incomplete combustion at higher levels *Manuscript Click here to download Manuscript: Quema_sin tablas ni figuras_cor.docx Click here to view linked References 2 of rice straw moisture content. According to our results, rice straw burning should be done after straw drying and under minimal moisture conditions to lower pollutant emission levels.

Open burning of rice, corn and wheat straws: primary emissions, photochemical aging, and secondary organic aerosol formation

“…Akagi et al (2011) updated the emission data for 14 types of biomass burning, and newly identified species were included. Since biomass types and combustion conditions may differ in different studies, reported emission factors are highly variable, especially for agricultural residue burning (Li et al, 2007(Li et al, , 2017Cao et al, 2008;Zhang et al, 2008;Yokelson et al, 2011;Brassard et al, 2014;Sanchis et al, 2014;Ni et al, 2015;Kim Oanh et al, 2015;Stockwell et al, 2016;Bruns et al, 2017;Tkacik et al, 2017). Moreover, previous studies on agricultural residue burning were mostly carried out near fire spots or in chambers with low dilution ratios.…”

“…Since moisture content in straws would affect emission factors of atmospheric pollutants (Sanchis et al, 2014;Ni et al, 2015), all the agricultural residues used in this study were dried in a stove at 80 • C for 24 h before being burned. After baking, the water content in the crop residues was less than 1 %.…”

Incremental Lifetime Cancer Risk of PM2.5 Bound Polycyclic Aromatic Hydrocarbons (PAHs) before and after the Wildland Fire Episode

“…PAHs are a group of organic compounds that are generated during the incomplete burning of lignite (Liu et al, 2012), fuels (Lu et al, 2012), volcanic eruption (Schwandner et al, 2013), biomass (Sanchis et al, 2014), garbage (Chen et al, 2013), or other organic substances, such as tobacco (Chalbot et al, 2012). PAHs are highly toxic organic compounds that can cause a range of adverse health effects (e.g., cancer, endocrine disruption, reproductive and developmental effects) (Hoyer, 2001;Matsui, 2008;Liao et al, 2011;Wickramasinghe et al, 2012).…”

Study on the Effect of Crop Production on the Air Quality in Wuhan

“…Emission factors of atmospheric pollutants measured in their study were higher in the 20% moisture content. This difference could be attributed to the incomplete combustion at higher levels of rice straw moisture content [7]. Sopittaporn Sillapapiromsuk and Somporn Chantara conduct experiments in the self-designed stainless steel chamber to simulate the emissions of PM10.…”