Elevated Black Carbon Concentrations and Atmospheric Pollution around Singrauli Coal-Fired Thermal Power Plants (India) Using Ground and Satellite Data

Abstract

The tropospheric NO2 concentration from OMI AURA always shows high concentrations of NO2 at a few locations in India, one of the high concentrations of NO2 hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health. Furthermore, elevated BC concentrations, over the Indo-Gangetic Plain (IGP) and the Himalayan foothills, have emerged as an important subject to estimate the effects of deposition and atmospheric warming of BC on the accelerated melting of snow and glaciers in the Himalaya. For the first time, this study reports BC concentrations and aerosol optical parameters near dense coal-fired power plants and open cast coal mining adjacent to the east IGP. In-situ measurements were carried out in Singrauli (located in south-east IGP) at a fixed site about 10 km from power plants and in transit measurements in close proximity to the plants, for few days in the month of January and March 2013. At the fixed site, BC concentration up to the 95 μgm−3 is observed with strong diurnal variations. BC concentration shows two maxima peaks during early morning and evening hours. High BC concentrations are observed in close proximity to the coal-fired TPPs (>200 μgm−3), compared to the outside domain of our study region. Co-located ground-based sunphotometer measurements of aerosol optical depth (AOD) show strong spatial variability at the fixed site, with AOD in the range 0.38–0.58, and the highest AOD in the range 0.7–0.95 near the TPPs in transit measurements (similar to the peak of BC concentrations). Additionally, the Angstrom exponent was found to be in the range 0.4–1.0 (maximum in the morning time) and highest in the proximity of TPPs (~1.0), suggesting abundance of fine particulates, whereas there was low Angstrom exponent over the surrounding coal mining areas. Low Angstrom exponent is characterized by dust from the unpaved roads and nearby coal mining areas. MODIS derived daily AOD shows a good match with the MICROTOPS AOD. The CALIPSO derived subtypes of the aerosol plot shows that the aerosols over Singrauli region are mainly dust, polluted dust, and elevated smoke. The preliminary study for few days provides information about the BC concentrations and aerosol optical properties from Singrauli (one of the NO2 hotspot locations in India). This preliminary study suggests that long-term continuous monitoring of BC is needed to understand the BC concentrations and aerosol optical properties for better quantification and the estimation of the emission to evaluate radiative forcing in the region.

Source Quantification of South Asian Black Carbon Aerosols with Isotopes and Modeling

“… 32 , 33 Furthermore, BC concentrations reaching as high as 200 μg m –3 have been reported in transit regions in the vicinity of such thermal power plants. 34 In fact, the coupling between the BC concentrations and air mass origin, visualized using CWT maps ( Supporting Information Figure S3.c ), shows that BC at BCOB (although an order lower than expected in the vicinity of power plants; Supporting Information Figure S4 ) mostly arrived from the IGP.…”

“…PI is known to have significant emissions from C 4 -plants during this period, 38 − 40 while the coal combustion sources are smaller compared to the IGP. 12 , 32 − 34 We therefore judge the MCMC 3,C4 scenario to be the most fitting for MCOH, also since this implies a smaller change in the biomass source class contributions (up to 10% increase of C 4 -biomass) relative to BCOB, compared to the massive change in fossil fuel source class contributions (up to 27% increase in coal; MCMC 3,coal ) needed to be consistent with the isotope data. This conclusion is further corroborated by the FEG simulations, which suggest that the main potential geographical emission regions for MCOH during the winter period were a combination of PI and the IGP ( Supporting Information Figure S11 ).…”

Long Term Air Quality Analysis in Reference to Thermal Power Plants Using Satellite Data in Singrauli Region, India

“…Similar results were reported for thermal power plants in and around Delhi. A study conducted near thermal power plants of Singrauli concluded high BC concentration >200 µg/m 3 with peaks during early morning and evening hours, compared to the outside domain of the study region (Singh et al, 2018).…”

Himalaya Air Quality Impacts From the COVID‐19 Lockdown Across the Indo‐Gangetic Plain

“…However, the marked reduction in surface NO 2 concentrations observed in Delhi and Ludhiana were not uniform across the IGP. Singrauli, a city with a number of large coal-fired power plants in its vicinity (Singh et al, 2018), recorded no significant reduction in surface NO 2 concentrations, i.e. the means over the period February 15-March 15 2020 and April 1-30 3030 were both 42 µg/m 3 , suggesting that the emissions from these plants were not reduced during the…”