Economic, environmental and grid-resilience benefits of converting diesel trains to battery-electric

Nearly all US locomotives are propelled by diesel-electric drives, which emit 35 million tonnes of CO2 and produce air pollution causing about 1,000 premature deaths annually, accounting for approximately US$6.5 billion in annual health damage costs. Improved battery technology plus access to cheap renewable electricity open the possibility of battery-electric rail. Here we show that a 241-km range can be achieved using a single standard boxcar equipped with a 14-MWh battery and inverter, while consuming half the energy consumed by diesel trains. At near-future battery prices, battery-electric trains can achieve parity with diesel-electric trains if environmental costs are included or if rail companies can access wholesale electricity prices and achieve 40% use of fast-charging infrastructure. Accounting for reduced criteria air pollutants and CO2 emissions, switching to battery-electric propulsion would save the US freight rail sector US$94 billion over 20 years.

Geographic Graph Hybrid Network for Robust Inversion of Particulate Matters

Although remote sensors have been increasingly providing dense data and deriving reanalysis data for inversion of particulate matters, the use of these data is considerably limited by the ground monitoring samples and conventional machine learning models. As regional criteria air pollutants, particulate matters present a strong spatial correlation of long range. Conventional machine learning cannot or can only model such spatial pattern in a limited way. Here, we propose a method of a geographic graph hybrid network to encode a spatial neighborhood feature to make robust estimation of coarse and fine particulate matters (PM10 and PM2.5). Based on Tobler’s First Law of Geography and graph convolutions, we constructed the architecture of a geographic graph hybrid network, in which full residual deep layers were connected with graph convolutions to reduce over-smoothing, subject to the PM10–PM2.5 relationship constraint. In the site-based independent test in mainland China (2015–2018), our method achieved much better generalization than typical state-of-the-art methods (improvement in R2: 8–78%, decrease in RMSE: 14–48%). This study shows that the proposed method can encode the neighborhood information and can make an important contribution to improvement in generalization and extrapolation of geo-features with strong spatial correlation, such as PM2.5 and PM10.

The Impacts of Dry & Wet Seasons Induced Criteria Air Pollutants Concentrations in Old Port Harcourt Gra, Rivers State, Nigeria

This paper evaluated the air quality in Old Port Harcourt GRA in order to determine if it is within or above the acceptable limits/standards by the WHO. To measure the ambient air quality in the study area, a portable gaseous emission analyzer was used. Gaseous pollutants were monitored continuously by pulsed fluorescence. In this method, air is drawn via a sample chamber where it is irradiated with pulses of ultra-violet light. Any specified gas of interest in the sample is excited to a higher energy level and upon returning to its original state, light or fluorescence is released. The amount of fluorescence measured is proportional to the gas concentration. The Suspended particulate matter was measured with an EGVOC SPM Monitor. This is a hand held Aerosol particle counters that operates by counting and sizing the number of particles in the air. In the data analysis, all the average measurements were done in uniform unit of µg/m3. From the findings, in Old Port Harcourt GRA, the ozone (O3) for both dry and wet seasons, and wet season PM10 were within the WHO standards. Sox for both wet and dry seasons were above the WHO limit by 80%; NOx for both wet and dry seasons were above WHO limits by 60%. However, the mean concentration of PM2.5 in dry season was above the WHO limits by 88.2%, while in wet season, the average concentration of PM2.5 was higher than the WHO limits by just 11.5%. The average concentration of PM10 in dry season was higher than the WHO limits by 79.5%. The implications of the findings are that the levels/concentrations of the ozone (O3) both in the dry and wet seasons and the PM10 level in wet season are safe enough for the people of old Port Harcourt GRA as they are within the WHO standards for criteria air pollutants. The level of PM2.5 in wet season is relatively safe but more works still need to be done to further reduce it to be within WHO acceptable limits. The levels/concentrations of the other criteria air pollutants are very unsafe for the people of old Port Harcourt GRA. Key words: Criteria air pollutants, Wet season, Dry Season, Port Harcourt, WHO guidelines.

Trend Analysis of Air Quality Index (AQI) and Greenhouse Gas (GHG) Emissions in Taiwan and Their Regulatory Countermeasures

A reduction in the energy-related emissions of air pollutants would not only mitigate climate change but would also improve local air quality and public health. This paper aimed to analyze the trends of air quality index (AQI) and greenhouse gas (GHG) emissions in Taiwan by using the latest official statistics. In addition, this study also summarized regulatory measures for controlling air pollution from the energy sector with relevance to sustainable development goals (SDGs). With the joint efforts by the public and private sectors, the change in the total GHG emissions did not vary much with the exception of 2009, ranging from 250 to 272 million metric tons of CO2 equivalent from 2005 through 2019. Based on the data on AQI, the percentage of AQI by station-day with AQI > 100 has decreased from 18.1% in 2017 to 10.1% in 2020, indicating a decreasing trend for all criteria air pollutants. On the other hand, the coronavirus disease (COVID-19) lockdown, in 2019, has positively impacted Taiwan’s urban air quality, which was consistent with those observed in other countries. This consistent situation could be attributed to the climate change mitigation policies and promotional actions under the revised Air Pollution Control Act and the Greenhouse Gas Reduction and Management Act of 2015. In response to the SDGslaunched by the Taiwan government in 2018, achieving the relevant targets by 2030 can be prospective.

Estimation of Pollutants’ Emission Rates and Associated Impact on Local Air Quality: A Case Study of Cottage Industry in Ibadan Metropolis

Major urban cities in the developing countries are faced with the peculiar problem of poor air quality, which has resulted into millions of untimely death as well as other adverse environmental impacts including climate change. To combat this negative trend, regular documentation of the emission rates and concentrations of the various air pollutants has been identified as a suitable means of designing a sound mitigation approach. Here, we estimated the emission rates of criteria air pollutants (CAPs) and greenhouse gases (GHGs) generated from an industrial setting; as well as the associated environmental impact on local air quality, using emission inventory methodology and air dispersion model. In the study area, the energy consumption pattern was reported and the emission rates of associated gaseous pollutants were observed to range from 0.22 to 85500 kg/day. Similarly, the concentrations of major pollutants were observed to be within the thresholds stipulated by the World Health Organization.

Assessment of air quality within Maiganga coal mining area in Akko Local Government Area, Gombe State, Nigeria

Anthropogenic activity especially coal mining contributes immensely to environmental pollution within coalmine and the host community especially if not well managed. This study is on the assessment of air quality in and around Maiganga coalmine, with the objectives of finding out the ambient concentration levels of criteria air pollutants within the coalmine, the Maiganga community and the four control sites 2km north, south, east and west of the coalmine, as well as compare the findings with the concentration levels of pollutants recommended as acceptable safety limits set by Federal Ministry of Environment, FMEnv. Six sampling locations were selected for detail assessment, with one point in each of the sites mentioned. Measurement of concentrations of criteria air pollutants; sulphur dioxide (SO2), nitrogen dioxide (NO2) volatile organic compounds (VOCs), carbon monoxide (CO), ammonia (NH3), and ozone (O3) were taken in-situ using Personal Toxic Gas Monitor (Tango TXI single gas monitor). Fine particulate matter (PM2.5), coarse particulate matter (PM10), were collected using a Portable Counter HT – 9601 (PM2.5 and PM10) personal dust meter high volume gravity sampler. Volatile organic compounds (VOCs) were also measured using a Portable Hand Held Gas Detector (Porcheck+). The study was done during the dry season and the results revealed that, coarse paticulate matter (PM10) was above the stipulated safety limit of 250µg/m3 set by the FMEnv for the coal mine area and Maiganga community but all other parameters were within the safety limits of the FMEnv. CO, NO2, SO2, and NH3 in coalmine area had concentrations lower than in that in control areas because of other anthropogenic activities like burning, heating, waste disposal, agricultural practices and a host of others taking place in the control area and which are not available in the coalmine area. However, the concentrations of the aforementioned parameters were higher in Maiganga community than in the control areas due to higher rate of anthropogenic activities in the community than in the control areas. The hypothesis were tested using student t – test, and the alternative hypothesis was accepted which showed there was no significant variations in the values of fine particulate matter (PM2.5), coarse particulate matter (PM10), sulphur dioxide (SO2), nitrogen dioxide (NO2), volatile organic compounds (VOCs), carbon monoxide (CO), ammonia (NH3), and ozone (O3) obtain from the coalmine, Maiganga community and the Control (N.S.E.W) with safety limits set by FMEnv. It is however, recommended that the Federal Ministry of Environment and National Environmental Standards and Regulations Enforcement Agency (NESREA) should ensure strict compliance with safety and environmental standards agreed upon during Environmental Impact Assessment (EIA).