An online monitoring system for atmospheric nitrous acid (HONO) based on stripping coil and ion chromatography

Cheng, Peng; Cheng, Yafang; Lu, Keding; Su, Hang; Yang, Qiang; Zou, Yikan; Zhao, Yanran; Dong, Huabing; Zeng, Limin; Zhang, Yuanhang

doi:10.1016/s1001-0742(12)60251-4

Cited by 20 publications

(14 citation statements)

References 65 publications

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“…As part of the CAREBEIJING 2008 campaign, the measurements of VOCs and other air pollutants (CO, NO x , O 3 , etc) were conducted at an intensive observation site on the campus of Peking University (PKU) from 3 July to 27 August 2008. The PKU site (39.99 • N, 116.31 • E) was located in the northwest of downtown Beijing, which has been considered to be representative of a typical urban environments with different mixtures of high density traffic, commercial, residential, and electronic companies (Liu et al, 2009;Cheng et al, 2008;Song et al, 2007). The air inlets for the instruments were set up on the top of a six-story building (∼ 25 m a.g.l).…”

Section: Monitoring Sites and Experimental Methodsmentioning

confidence: 99%

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Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications

Liu

Yuan

et al. 2015

Atmos. Chem. Phys.

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Abstract. Oxygenated volatile organic compounds (OVOCs) are important products of the photo-oxidation of hydrocarbons. They influence the oxidizing capacity and the ozone-forming potential of the atmosphere. In the summer of 2008, 2 months of emission restrictions were enforced in Beijing to improve air quality during the Olympic Games. Observational evidence reported in related studies that these control measures were efficient in reducing the concentrations of primary anthropogenic pollutants (CO, NOx and non-methane hydrocarbons, i.e., NMHCs) by 30–40%. In this study, the influence of the emission restrictions on ambient levels of OVOCs was explored using a neural network analysis with consideration of meteorological conditions. Statistically significant reductions in formaldehyde (HCHO), acetaldehyde (CH3CHO), methyl ethyl ketone (MEK) and methanol were found to be 12.9, 15.8, 17.1 and 19.6%, respectively, when the restrictions were in place. The effect of emission controls on acetone was not detected in neural network simulations, probably due to pollution transport from surrounding areas outside Beijing. Although the ambient levels of most NMHCs were reduced by ~35% during the full control period, the emission ratios of reactive alkenes and aromatics closely related to automobile sources did not present much difference (< 30%). A zero-dimensional box model based on the Master Chemical Mechanism version 3.2 (MCM3.2) was applied to evaluate how OVOC production responds to the reduced precursors during the emissions control period. On average, secondary HCHO was produced from the oxidation of anthropogenic alkenes (54%), isoprene (30%) and aromatics (15%). The importance of biogenic sources for the total HCHO formation was almost on par with that of anthropogenic alkenes during the daytime. Anthropogenic alkenes and alkanes dominated the photochemical production of other OVOCs such as acetaldehyde, acetone and MEK. The relative changes of modeled HCHO, CH3CHO, methyl vinyl ketone and methacrolein (MVK + MACR) before and during the pollution controlled period were comparable to the estimated reductions in the neural network, reflecting that current mechanisms can largely explain secondary production of those species under urban conditions. However, it is worth noting that the box model overestimated the measured concentrations of aldehydes by a factor of 1.4–1.7 without consideration of loss of aldehydes on aerosols, and simulated MEK was in good agreement with the measurements when primary sources were taken into consideration. These results suggest that the understanding of the OVOCs budget in the box model remains incomplete, and that there is still considerable uncertainty in particular missing sinks (unknown chemical and physical processes) for aldehydes and absence of direct emissions for ketones.

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Section: Monitoring Sites and Experimental Methodsmentioning

confidence: 99%

“…HONO was measured using an online stripping coil sampler/ion chromatography (IC) system at the time resolution of 15 min. The instrument has a detection limit of 8 ppt with an uncertainty of 7 %, other technical details were presented in Cheng et al (2013).…”

Section: Measurements For Other Air Pollutants and Parametersmentioning

confidence: 99%

Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications

Liu

Yuan

et al. 2015

Atmos. Chem. Phys.

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“…As one of two super sites, various gaseous (HNO 3 , HONO, sulfur dioxide/SO 2 , NO x and volatile organic compounds/ VOCs) and aerosol pollutants were measured in Kaiping. A strict QA/QC procedure was performed, with details provided in Cheng et al (2013). In this study, the period of 2008-10-28 to 2008-10-31 was selected because of the low wind velocity (mean value: 1.5 m s −1 and maximum: < 3.5 m s −1 ) and wet weather (mean rela- Figure 1 shows the observed hourly gaseous HONO, HNO 3 , NO x , HNO 3 /NO x , and black carbon (BC) at Kaiping during 2008-10-28 to 2008-10-31.…”

Section: Sampling Site and Measurement Techniquementioning

confidence: 99%

“…Levels of CO, O 3 , and soot were measured by commercial instruments (Thermo Electron, Model 48C, 49C, and MAAP Model 5012, respectively). Levels of NO/NO 2 were measured with a photolytic chemiluminescence NO x analyzer (Cheng et al 2013). Aerosol extinction was measured by an integrating nephelometer.…”

Section: The Uptake Coefficients For Heterogeneous Reactions (R1 and mentioning

confidence: 99%

Exploring Possible Missing Sinks of Nitrate and Its Precursors in Current Air Quality Models —A Case Simulation in the Pearl River Delta, China, Using an Observation-Based Box Model

Dong

Zeng

et al. 2015

SOLA

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Nitrate and its precursor (gaseous HNO 3 ) in China are generally overestimated by current chemical transport models in comparison to in-situ observations. In this study, we used an observation-based box model and in-situ measurements at a rural site in southern China to investigate possible missing sinks of nitrate. We found that a heterogeneous reaction of HNO 3 to NO x on soot can better balance the NO x /HNO 3 chemistry in models and improve model performance with regard to nitrate, particularly where an additional HONO source (the heterogeneous reaction of NO 2 on soot) is incorporated into current models. Through a series of sensitivity simulations, the uptake coefficients of heterogeneous reactions were suggested to be 3.0 × 10 −3 and 1 × 10 −4 for HNO 3 and HONO over southern China in fall, respectively. A 3-D simulation with the suggested uptake coefficients further confirmed that heterogeneous reactions significantly decreased the nitrate concentrations (PNO 3 ) in southern China, by up to 10 μg m −3 (50%−80% of simulated PNO 3 ) in polluted regions (e.g., the Yangtze River). In contrast to nitrate and HNO 3 , NO x concentrations in China were enhanced, which partly explained the underestimation of NO 2 in current models compared to satellite observations.(Citation: Li, J., H. B. Dong, Z. F. Wang, Yele Sun, and Pingqing Fu, 2015: Exploring possible missing sinks of nitrate and its precursors in current air quality models-A case simulation in Pearl River delta of China using an observation-based box model.

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“…Hardware structure design is the key and the innovation point of this system, which determines how we convert the exhaust gas into physical quantity that can be directly measured (Cheng and Cheng 2013). As the chimney is often high on the rooftop, the whole system should be as small as possible.…”

Section: Hardware Structure Designmentioning

confidence: 99%

A new online exhaust gas monitoring system in hydrochloric acid regeneration of cold rolling mills

Tuo

Zheng

Chen

2015

Environ Sci Pollut Res

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Measuring the content of hydrogen chloride (HCl) in exhaust gas used to take time and energy. In this paper, we introduce a new online monitoring system which can output real-time data to the monitoring center. The system samples and cools exhaust gas, and after a series of processing, it will be analyzed by a specific instrument. The core part of this system is remote terminal unit (RTU) which is designed on Cortex-A8 embedded architecture. RTU runs a scaled-down version of Linux which is a good choice of OS for embedded applications. It controls the whole processes, does data acquisition and data analysis, and communicates with monitoring center through Ethernet. In addition, through a software developed for windows, the monitoring process can be remotely controlled. The new system is quite beneficial for steel industry to do environment monitoring.

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An online monitoring system for atmospheric nitrous acid (HONO) based on stripping coil and ion chromatography

Cited by 20 publications

References 65 publications

Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications

Impact of pollution controls in Beijing on atmospheric oxygenated volatile organic compounds (OVOCs) during the 2008 Olympic Games: observation and modeling implications

Exploring Possible Missing Sinks of Nitrate and Its Precursors in Current Air Quality Models —A Case Simulation in the Pearl River Delta, China, Using an Observation-Based Box Model

A new online exhaust gas monitoring system in hydrochloric acid regeneration of cold rolling mills

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