Evaluation of Potential for Mercury Volatilization from Natural and FGD Gypsum Products Using Flux-Chamber Tests

2009 ◽  
Vol 43 (7) ◽  
pp. 2282-2287 ◽  
Author(s):  
Scott S. Shock ◽  
Jessica J. Noggle ◽  
Nicholas Bloom ◽  
Lisa J. Yost
2008 ◽  
Vol 148 (6-7) ◽  
pp. 893-901 ◽  
Author(s):  
M.R. Jones ◽  
J.A. Raven ◽  
I.D. Leith ◽  
J.N. Cape ◽  
R.I. Smith ◽  
...  

2011 ◽  
Vol 105-107 ◽  
pp. 2204-2208 ◽  
Author(s):  
Run Xia Hao ◽  
Xiao Yan Guo

The properties of flue gas desulphurization (FGD) gypsum were analysized by Thermo-gravimetry/differential scanning calorimetry (TG/DSC), technical performance analysis, optical microscope and Scanning electron microscope (SEM). Mechanical properties of FGD gypsum-steel slag powder cementitious material were researched. The results revealed that FGD gypsum have similar moisture content, major component CaSO4·2H2O with natural gypsum, and has better technical performance than natural gypsum. The results of optical microscope and SEM of the FGD gypsum hydration support this further. When the dosage of steel slag powder is 15%, containing activator ,better mechanical properties can be obtained. Key words: FGD gypsum, Property, Cementitious material


2013 ◽  
Vol 67 (2) ◽  
pp. 311-318 ◽  
Author(s):  
Madawala Liyanage Duminda Jayaranjan ◽  
Ajit P. Annachhatre

Investigations were undertaken to utilize flue gas desulfurization (FGD) gypsum for the treatment of leachate from the coal ash (CA) dump sites. Bench-scale investigations consisted of three main steps namely hydrogen sulfide (H2S) production by sulfate reducing bacteria (SRB) using sulfate from solubilized FGD gypsum as the electron acceptor, followed by leaching of heavy metals (HMs) from coal bottom ash (CBA) and subsequent precipitation of HMs using biologically produced sulfide. Leaching tests of CBA carried out at acidic pH revealed the existence of several HMs such as Cd, Cr, Hg, Pb, Mn, Cu, Ni and Zn. Molasses was used as the electron donor for the biological sulfate reduction (BSR) process which produced sulfide rich effluent with concentration up to 150 mg/L. Sulfide rich effluent from the sulfate reduction process was used to precipitate HMs as metal sulfides from CBA leachate. HM removal in the range from 40 to 100% was obtained through sulfide precipitation.


2017 ◽  
Vol 603-604 ◽  
pp. 279-289 ◽  
Author(s):  
Rute Cesário ◽  
Laurier Poissant ◽  
Martin Pilote ◽  
Nelson J. O'Driscoll ◽  
Ana M. Mota ◽  
...  

2014 ◽  
Vol 43 (1) ◽  
pp. 246-252 ◽  
Author(s):  
Dexter B. Watts ◽  
Warren A. Dick

2011 ◽  
Vol 8 (6) ◽  
pp. 1595-1613 ◽  
Author(s):  
M. V. Thomas ◽  
Y. Malhi ◽  
K. M. Fenn ◽  
J. B. Fisher ◽  
M. D. Morecroft ◽  
...  

Abstract. We present results from a study of canopy-atmosphere fluxes of carbon dioxide from 2007 to 2009 above a site in Wytham Woods, an ancient temperate broadleaved deciduous forest in southern England. Gap-filled net ecosystem exchange (NEE) data were partitioned into gross primary productivity (GPP) and ecosystem respiration (Re) and analysed on daily, monthly and annual timescales. Over the continuous 24 month study period annual GPP was estimated to be 21.1 Mg C ha−1 yr−1 and Re to be 19.8 Mg C ha−1 yr−1; net ecosystem productivity (NEP) was 1.2 Mg C ha−1 yr−1. These estimates were compared with independent bottom-up estimates derived from net primary productivity (NPP) and flux chamber measurements recorded at a plot within the flux footprint in 2008 (GPP = 26.5 ± 6.8 Mg C ha−1 yr−1, Re = 24.8 ± 6.8 Mg C ha−1 yr−1, biomass increment = ~1.7 Mg C ha−1 yr−1). Over the two years the difference in seasonal NEP was predominantly caused by changes in ecosystem respiration, whereas GPP remained similar for equivalent months in different years. Although solar radiation was the largest influence on daily values of CO2 fluxes (R2 = 0.53 for the summer months for a linear regression), variation in Re appeared to be driven by temperature. Our findings suggest that this ancient woodland site is currently a substantial sink for carbon, resulting from continued growth that is probably a legacy of past management practices abandoned over 40 years ago. Our GPP and Re values are generally higher than other broadleaved temperate deciduous woodlands and may represent the influence of the UK's maritime climate, or the particular species composition of this site. The carbon sink value of Wytham Woods supports the protection and management of temperate deciduous woodlands (including those managed for conservation rather than silvicultural objectives) as a strategy to mitigate atmospheric carbon dioxide increases.


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