Assessment of heavy metals released into the air from the cement kilns co-burning waste: Case of Oujda cement manufacturing (Northeast Morocco)

Cement manufacturing and the treatment of sludge are considered both energy-intensive industries and major greenhouse gas (GHG) emitters. However, there are still few studies on comprehensive carbon footprint analysis for adding municipal sludge in the cement production. In this study, the lime-dried sludge blended with calcium oxide at the mass mixing ratio of 10% was utilized as raw material for the preparation of Portland cement. The chemical and physical properties of sludge were analyzed. A set of carbon footprint calculation methods of lime-drying treatment of sludge and reuse in cement kilns was then established to explore the feasibility of coprocessing lime-dried sludge in cement kilns. The results showed lime-dried sludge containing CaO, SiO2, Al2O3, and Fe2O3 was ideal for cement production as raw material. However, the water content of lime-dried sludge should be strictly limited. The lime-drying process presented the biggest carbon emission (962.1 kg CO2-eq/t sludge), accounting for 89.0% of total emissions. In the clinker-production phase, the lime-dried sludge as raw material substitute and energy source gained carbon credit of 578.8 and 214.2 kg CO2-eq/t sludge, respectively. The sludge used for producing cement clinker could reduce carbon emissions by 38.5% to 51.7%. The addition ratio of lime and stacking time in the sludge lime-drying process could greatly affect the carbon footprint of coprocessing lime-dried sludge in cement kiln.

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The emission of particulate matters and heavy metals from cement kilns - case study: co-incineration of tires in Serbia

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq090902010j ◽

2010 ◽

Vol 16 (3) ◽

pp. 213-217 ◽

Cited By ~ 4

Author(s):

Aleksandar Jovovic ◽

Zoran Kovacevic ◽

Dejan Radic ◽

Dragoslava Stojiljkovic ◽

Marko Obradovic ◽

...

Keyword(s):

Heavy Metals ◽

Alternative Fuels ◽

Risk Estimation ◽

Cement Industry ◽

Cement Kiln ◽

Particulate Matters ◽

Cement Kilns ◽

Health Risk Estimation ◽

Stack Emissions

Co-incineration of wastes started more than 20 years ago. In the last 10 years, the use of alternative fuels in the cement industry is continuously increasing. The use of solid wastes in cement kilns is one of the best technologies for a complete and safe destruction of these wastes, due to the fact that there is a simultaneous benefit of destroying wastes and getting the energy. However, particulate matters (PM) and gaseous chemicals emitted from a source into the environment could be directly transmitted to humans through air inhalation. Therefore, for accurate health risk estimation, the emission of pollutants must be determined. In this work, the analysis of the emission of different pollutants when replacing partially the fuel type used in a cement kiln is done. PM, PM10, heavy metals and inorganic pollutants are analyzed. The methods used for sampling and analysis are the standard methods suggested by the EU regulations for stack analysis. Experimental results have shown the encouraging results: in particular clinker characteristics were unmodified, and stack emissions (NOx, SO2 and CO mainly) were in the case of tires, slightly incremented but remaining almost always below the law imposed limits, and in some cases were even decreased.

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Volatilization of Heavy Metals (As, Pb, Cd) During Co-Processing in Cement Kilns

Environmental Engineering Science ◽

10.1089/ees.2014.0175 ◽

2015 ◽

Vol 32 (5) ◽

pp. 425-435 ◽

Cited By ~ 14

Author(s):

Jing Cong ◽

Dahai Yan ◽

Li Li ◽

Jingxuan Cui ◽

Xuguang Jiang ◽

...

Keyword(s):

Heavy Metals ◽

Cement Kilns

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A Feasibility Study on Co-Processing of Soil Contaminated with Heavy Metals in Cement Kilns

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.768.135 ◽

2015 ◽

Vol 768 ◽

pp. 135-141 ◽

Cited By ~ 1

Author(s):

Ye Qing Li ◽

Huan Zhong Wang ◽

Jiang Zhang ◽

Song Bai Yu ◽

Wen Juan Miao

Keyword(s):

Crystal Structure ◽

Heavy Metals ◽

Raw Materials ◽

Feasibility Studies ◽

Circulation Pattern ◽

National Standards ◽

Cement Kiln ◽

Bag Filter ◽

Cement Kilns ◽

High Level

The national general survey manifests that the Chinese soil is suffering from serious contamination, mainly arising from heavy metals (HM). Due to the large amount of heavy metal waste, many researchers have performed the feasibility studies on co-processing this kind of waste in cement kilns. In this paper, we review these results from the perspectives of national standards, the crystal structure of clinker, and the volatility of metals in cement kiln system. The crystal structure of clinker mineral offers physical possibility for the solidification of HM atoms. The volatility studies also indicate that most of the metals will not emit from the kiln system. For the incorporated metals in clinker, their release ratio is very low, and the leaching HM atoms can be immediately enclosed by the cement hydration products. Based on these theoretical results, we measured the HM in the raw materials and in the cement product for 1 year in a cement plant. The bag filter dust contained high level of Tl with an average of 219.30 ppm. The other metals were almost solidified by the clinker. With the vaporization of Tl in the raw materials, the circulation pattern causes the accumulation and buildup of Tl in the system. The incorporation capacity of clinker on HM is predicted in this paper, but the incorporation ratio of HM from contaminated soil, the circulation pattern of HM in cement kiln system, and the emission of HM is currently not clear and further work is in progress.

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Use of Non-Hazardous Solid Waste as Alternative Fuels in Cement Manufacturing Process

European Journal of Engineering Research and Science ◽

10.24018/ejers.2020.5.1.1657 ◽

2020 ◽

Vol 5 (1) ◽

pp. 1-7

Author(s):

Ghizlane Bouabid ◽

Fouzia Byoud ◽

Nisrine Benzbiria ◽

Driss Nahya ◽

Mohammed Azzi

Keyword(s):

Heavy Metals ◽

Solid Waste ◽

Manufacturing Process ◽

Alternative Fuels ◽

Combustion Regime ◽

Injection Rate ◽

Gaseous Emissions ◽

Flow Acceleration ◽

Hazardous Solid Waste ◽

Cement Manufacturing

The incineration of non-hazardous solid waste and its use as alternative fuel in cement manufacturing process was studied and simulated under the effect of air flow acceleration in a laboratory scale reactor. Firstly, analysis of the different waste materials (textile, wood and paper) was performed separately, showing that textile samples presented the highest levels of heavy metals (H.M). In the course of a test run using solid recovered fuel (SRF), the mass balance of heavy metals revealed that lead and chromium probably volatilized during firing while arsenic, cadmium and zinc were trapped in clinker. As to gaseous emissions, heavy metals concentration in the stack remained relatively low and below the standard limits. Secondly, the temperature and concentration of gases flue was monitored. It was shown that the combustion regime is characterized by low reaction temperatures and an oxygen-deficient environment. Air injection rate affected significantly the formation and degradation mechanisms of the emitted gases concentrations, particularly CO, CO2, NO, NOx, SO2. Textile waste exhibited the lowest concentration of emitted gases compared to the other types of waste.

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The Effects of Switching from Coal to Alternative Fuels on Heavy Metals Emissions from Cement Manufacturing

Chemistry of Trace Elements in Fly Ash ◽

10.1007/978-1-4757-4757-7_4 ◽

2003 ◽

pp. 45-61 ◽

Cited By ~ 1

Author(s):

Arun B. Mukherjee ◽

Ursula Kääntee ◽

Ron Zevenhoven

Keyword(s):

Heavy Metals ◽

Alternative Fuels ◽

Cement Manufacturing

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Sampling and analysis of the air-water interface with SEM and EDS of microlayers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100157000 ◽

1989 ◽

Vol 47 ◽

pp. 1004-1005

Author(s):

Randall W. Smith ◽

John Dash

Keyword(s):

Heavy Metals ◽

Surface Microlayer ◽

Surface Films ◽

Water Interface ◽

Physical Processes ◽

Infrared Spectroscopic Analysis ◽

Eds Analysis ◽

Air Water Interface ◽

Significant Area ◽

Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

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