The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
R C Phadke - One of the best experts on this subject based on the ideXlab platform.
-
flue gas conditioning for reducing Suspended Particulate Matter from thermal power stations
Progress in Energy and Combustion Science, 2008Co-Authors: S Shanthakumar, D N Singh, R C PhadkeAbstract:Increased population and industrial development demands sustainable electricity, the majority of which is produced by thermal power stations, which utilize coal as a fuel all over the world. Coal burning results in generation of large quantities of coal residues, which contains very fine particles that tend to become air-borne and which contribute to the formation of Suspended Particulate Matter (SPM). Hence, in order to safeguard the environment against the emission of SPM, pollution control devices, such as cyclone separators, bag filters and electrostatic precipitators (ESPs) have been employed. In addition, flue gas conditioning (FGC) is practiced to increase the efficiency of ESPs, with the addition of chemical additives, or sprinkling water to the flue gas. This process increases the collection efficiency of the electrostatic precipitators, and thereby results in reduction of the SPM level. However, the effects of the process, which play an important role in efficient FGC, need to be investigated thoroughly before utilizing this method. With this in view, a critical review of various flue gas conditioning techniques employed for controlling the SPM level in thermal power stations is presented in this paper. The present study also reports analyses of data obtained from different thermal power stations in India as well as the rest of the world.
-
flue gas conditioning for reducing Suspended Particulate Matter from thermal power stations
Progress in Energy and Combustion Science, 2008Co-Authors: S Shanthakumar, D N Singh, R C PhadkeAbstract:Increased population and industrial development demands sustainable electricity, the majority of which is produced by thermal power stations, which utilize coal as a fuel all over the world. Coal burning results in generation of large quantities of coal residues, which contains very fine particles that tend to become air-borne and which contribute to the formation of Suspended Particulate Matter (SPM). Hence, in order to safeguard the environment against the emission of SPM, pollution control devices, such as cyclone separators, bag filters and electrostatic precipitators (ESPs) have been employed. In addition, flue gas conditioning (FGC) is practiced to increase the efficiency of ESPs, with the addition of chemical additives, or sprinkling water to the flue gas. This process increases the collection efficiency of the electrostatic precipitators, and thereby results in reduction of the SPM level. However, the effects of the process, which play an important role in efficient FGC, need to be investigated thoroughly before utilizing this method. With this in view, a critical review of various flue gas conditioning techniques employed for controlling the SPM level in thermal power stations is presented in this paper. The present study also reports analyses of data obtained from different thermal power stations in India as well as the rest of the world.
Thijs Van Kessel - One of the best experts on this subject based on the ideXlab platform.
-
estuarine Suspended Particulate Matter concentrations from sun synchronous satellite remote sensing tidal and meteorological effects and biases
Remote Sensing of Environment, 2014Co-Authors: M A Eleveld, Daphne Van Der Wal, Thijs Van KesselAbstract:Abstract Optical data from a sun-synchronous satellite were used to investigate how large-scale estuarine Suspended Particulate Matter (SPM) concentrations were affected by tidal and bulk meteorological drivers, and how retrieved SPM is biased by tidal aliasing and sampling under clear sky conditions. Local absorption and scattering properties were used to derive surface SPM maps from 84 cloud-free ENVISAT MERIS FR reflectance images of the Westerschelde estuary (51° 30′ N, 3° 30′ E) for the period 2006–2008, and validated with in situ SPM at fixed stations (r = 0.89 for geometric means). The distinctly different SPM maps were categorized for different tidal and seasonal conditions. Resulting composites reveal spatial patterns in SPM as a function of semi-diurnal tidal phase, fortnightly tidal phase, or season. For the estuary proper, tidal and seasonal effects on the variation of SPM are similar in magnitude. Observed controls for surface SPM are distance to shallow source area, tidal current velocity, and advection of North Sea and estuarine surface waters. Turbidity maxima appear only during favourable tidal and meteorological conditions. For the Westerschelde, the bias introduced by sun-synchronous sampling causes low water image acquisitions to uniquely coincide with spring tides, and high water images with neap tides. Cloud-free images were associated with low wind velocities. Simulations from a mud transport model confirmed the overestimation of geometric mean SPM from the tidal aliasing, and underestimation from fair weather. This resulted in a net relative error of − 8% at the wave-exposed mouth, but biases cancelled out in the upper estuary. We argue that local biases should be considered when interpreting water quality products for estuaries and coasts around the world.
V K Jain - One of the best experts on this subject based on the ideXlab platform.
-
winter time size distribution and source apportionment of total Suspended Particulate Matter and associated metals in delhi
Atmospheric Research, 2009Co-Authors: Arun Srivastava, Sandeep Gupta, V K JainAbstract:Abstract A study of the winter time size distribution and source apportionment of total Suspended Particulate Matter (TSPM) and associated heavy metal concentrations have been carried out for the city of Delhi. This study is important from the point of view of implementation of compressed natural gas (CNG) as alternate of diesel fuel in the public transport system in 2001 to reduce the pollution level. TSPM were collected using a five-stage cascade impactor at six sites in the winters of 2005–06. The results of size distribution indicate that a major portion (~ 40%) of TSPM concentration is in the form of PM0.7 (
-
source apportionment of total Suspended Particulate Matter in coarse and fine size ranges over delhi
Aerosol and Air Quality Research, 2008Co-Authors: Arun Srivastava, Sandeep Gupta, V K JainAbstract:Source apportionment of total Suspended Particulate Matter (TSPM) and associated heavy metals has been carried out for the city of Delhi using the Chemical Mass Balance Model, Version 8 (CMB8), as well as principle component analysis (PCA) of SPSS (Varimax Rotated Factor Matrix method) in coarse-and fine-size mode. Urban particles were collected using a five-stage impactor at six sites in the winter of 2005-06. The impactor segregates the TSPM into five different size ranges (viz.＞10.9, 10.9-5.4, 5.4-1.6, 1.6-0.7 and ＜0.7 µm). Four samples were collected from six different sites every 24 hours. Samples were analyzed in five size ranges gravimetrically and chemically for the estimation of SPM and metals. The five different size ranges were divided into two broad categories: coarse (1.6 to＞10.9 µm) and fine (＜1.6 µm). The CMB8 and PCA were executed separately for both coarse and fine size ranges. Results obtained by CMB8 indicate the dominance of vehicular pollutants (62%), followed by crustal dust (35%) in the fine size range; while in the coarse size range crustal dust dominated (64%) over vehicular pollution (29%). Little contribution from paved-road dust and industrial sources was observed. Results of PCA (or factor analysis) reveal two major sources (vehicular and crustal re-suspension) in both coarse and fine size ranges. The correlations of factors (sources) with the metals show that in the coarse size range the dominant source is crustal re-suspension (68%) followed by vehicular pollution (23%). However, this is reversed in the case of the fine size range factor analysis where vehicular pollution (86%) dominated over crustal re-suspension (10%).
-
size distribution and source identification of total Suspended Particulate Matter and associated heavy metals in the urban atmosphere of delhi
Chemosphere, 2007Co-Authors: Arun Srivastava, V K JainAbstract:Abstract A study of the atmospheric Particulate size distribution of total Suspended Particulate Matter (TSPM) and associated heavy metal concentrations has been carried out for the city of Delhi. Urban particles were collected using a five-stage impactor at six sites in three different seasons, viz. winter, summer and monsoon in the year 2001. Five samples from each site in each season were collected. Each sample (filter paper) was extracted with a mixture of nitric acid, hydrochloric acid and hydrofluoric acid. The acid solutions of the samples were analysed in five-particle fractions by atomic absorption spectrometry (AAS). The impactor stage fractionation of particles shows that a major portion of TSPM concentration is in the form of PM0.7 (i.e.
Haijun Huang - One of the best experts on this subject based on the ideXlab platform.
-
observations of the distribution and flocculation of Suspended Particulate Matter in the north yellow sea cold water mass
Continental Shelf Research, 2020Co-Authors: Zhenyan Wang, Kainan Zhang, Y C Agrawal, Haijun HuangAbstract:Abstract Flocculation has a great influence on the biogeochemical cycle by altering the particle size, density and settling velocity of Suspended Particulate Matter (SPM) from coastal to shelf sea areas. However, the flocculation process in the shelf sea areas of China has not been systematically studied. In this study, the influencing mechanism of the North Yellow Sea cold water mass (NYSCWM) on the distribution and flocculation process of SPM is studied based on a comprehensive investigation during the summer of 2016. The results revealed that the mass concentration and turbidity of SPM showed a decreasing trend from coastal to offshore areas and an increasing trend from surface to near-benthic layers. Sediments from the Shandong subaqueous clinoform that were reSuspended by the tidal mixing effect were the main source of inorganic SPM in the North Yellow Sea in summer. The existence of the bottom cold water mass enhanced the thermocline and pycnocline in the North Yellow Sea shelf area. The pycnocline obstructed the vertical diffusion of nutrients in the NYSCWM, resulting in a subsurface maximum chlorophyll a (chl a) layer, which further contributed to the maximum subsurface volume concentration of SPM. Flocculation was ubiquitous in the study area and was the main reason for the asynchronous variability in the mass concentration, turbidity and volume concentration of SPM. Three different kinds of flocculation mechanisms were identified, including the effects of biological activities in water masses above the NYSCWM, physicochemical effects in the near-benthic nepheloid layer within the NYSCWM, and their combined effects in shallow coastal areas. The flocculation of SPM enhanced the transport of particles from the surface to the bottom of the water column and made an important contribution to the formation of the North Yellow Sea mud deposit.
-
indication of size distribution of Suspended Particulate Matter for sediment transport in the south yellow sea
Estuarine Coastal and Shelf Science, 2020Co-Authors: Zhenyan Wang, Haijun HuangAbstract:Abstract The Yellow Sea is a key area for studying source-to-sink sediment transport systems in East China shelf seas. However, the sediment transport and dispersal patterns in the Yellow Sea are not fully understood because of the significant seasonal variation in ocean circulation. In this study, we identify the ocean circulation patterns in the South Yellow Sea based on temperature, salinity and depth data collected from 52 hydrographic stations during the winter of 2016. The mass concentrations and particle size distributions of Suspended Particulate Matter are also determined to decipher the sediment transport pattern in the South Yellow Sea. The results show that particles from the Yellow Sea Coastal Current and Shandong Peninsula Coastal Current display a bimodal size distribution, with peaks at approximately 2.5 μm and 32–64 μm, while particles from the Yellow Sea Warm Current and residual Yellow Sea Cold Water Mass display a trimodal size distribution, with peaks at 2.5 μm, 32–64 μm and 391 μm. The fine and medium particles ( 256 μm) include organic materials. The peak at 391 μm is dominated by organic particles and reflects the influence of the Yellow Sea Warm Current in the surface layer. The Yellow Sea Warm Current enhances the nutrient and temperature conditions in the South Yellow Sea, which facilitates phytoplankton growth under appropriate light conditions. The content of inorganic particles with sizes of 64–159 μm decreases sharply in the central South Yellow Sea, which reflects the transport of Suspended Particulate Matter from the southern study area to the central Yellow Sea mud area. The synthesized evidence suggests that the Yellow Sea Warm Current, as the main driving force, transports particles from the Jiangsu coast or the Changjiang River into the central Yellow Sea mud area in winter.
Qilin Zhou - One of the best experts on this subject based on the ideXlab platform.
-
effects of riverine Suspended Particulate Matter on the post dredging increase in internal phosphorus loading across the sediment water interface
Environmental Pollution, 2016Co-Authors: Cheng Liu, Qiushi Shen, Shiguang Shao, Lei Zhang, Chengxin Fan, Qilin ZhouAbstract:Dredging is frequently used in the river mouths of eutrophic lakes to reduce internal phosphorus (P) loading from the sediment. However, the accumulation of P-adsorbed Suspended Particulate Matter (SPM) from the inflowing rivers negatively affects the post-dredging sediment-water interface and ultimately increases internal P loading. Here, a 360-d experiment was carried out to investigate the influence of riverine SPM on the efficacy of dredging in reducing internal P loading. SPM was added to dredged and undredged sediments collected from the confluence area of Lake Chaohu. Several parameters related to internal P loading, including oxygen profile, soluble reactive P, and ferrous iron across the sediment-water interface, organic Matter, alkaline phosphatase activity, and P fractions, were measured throughout the experimental period. The results showed that the P content (especially mobile P) in the sediment increased to the pre-dredging level with the accumulation of SPM in the dredged sediment. In addition, the P flux across the sediment-water interface increased with the accumulation of SPM. Several characteristics of SPM, including high organic Matter content, mobile P, high activity of alkaline phosphatase, and high biological activity, were considered correlated with the post-dredging increase in internal P loading. Overall, this study showed that the heavily contaminated riverine SPM regulates the long-term efficacy of dredging as a nutrient management option in the confluence area. Management is needed to avoid or reduce this phenomenon during dredging projects of this nature.
-
effects of riverine Suspended Particulate Matter on post dredging metal re contamination across the sediment water interface
Chemosphere, 2016Co-Authors: Qiushi Shen, Shiguang Shao, Lei Zhang, Qilin ZhouAbstract:Abstract Environmental dredging is often used in river mouth areas to remove heavy metals. However, following dredging, high levels of metal-adsorbed Suspended Particulate Matter (SPM) originating from polluted inflowing rivers might adversely affect the sediment–water interface (SWI). Here, we conducted a 360-day-long experiment investigating whether the riverine SPM adversely affects dredging outcome in a bay area of Lake Chaohu, China. We found that the heavy metal concentrations in the post-dredging surface sediment increased to pre-dredging levels for all metals studied (As, Cd, Cr, Cu, Ni, Pb, and Zn) after the addition of SPM. In addition, the increased concentrations were mostly detected in the relatively bioavailable non-residual fractions. Of the metals studied, the rate of increase was the greatest for Zn and Cd (482.98% and 261.07%, respectively), mostly in the weak acid extractable fraction. These results were probably due to certain characteristics of SPM (fine grain size, and high concentrations of organic Matter and heavy metals) and the good oxic conditions of the SWI. Furthermore, As was the only metal for which we observed an increasing trend of diffusive flux across the SWI. However, the flux was still significantly lower than that measured before dredging. In conclusion, the quantity and character of riverine metal-adsorbed SPM affect metal re-contamination across the post-dredging SWI, and this information should be incorporated into the management schemes of dredging projects dedicated to reducing metal contamination in similar areas.
