This paper presents an experimental work, which carried out to test the feasibility of using dealuminated metakaolin (DaMK) as an additive to metakaolin (MK) in the production of geopolymer concrete. DaMK is produced as a byproduct from the aluminum sulfate industry. The chemical composition and physical properties of DaMK were investigated in this study. Results showed that DaMK is a good pozzolan material, which added to MK by 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, and 70% in producing geopolymer concrete. The compressive strength was measured by testing standard cubes at 7 and 28 days. Satisfactory results are achieved by using 20, 25, 30, 35, and 40% of DaMK. It is recommended to use MK with added proportions of DaMK up to 40% of MK to produce an ecofriendly and economic geopolymer concrete.
This study assesses the environmental aspects and air quality in chemical fertilizer industry. Misr Fertilizers Company (MOPCO) at Damietta, Egypt was used as a case study to monitor indoor and outdoor air emissions to find out the main source of air pollution and evaluate the air quality in the facility. MOPCO is located within the general free zone of Damietta Port and covers an area of 400,000 m 2 including three factories, three ammonia plants, and three urea production plants and a service area. Monitoring of carbon monoxide (CO), nitrogen dioxide (NO 2), ammonia (NH 3) and sulfur dioxide (SO 2) in addition to particulate matter (PM 10), noise and heat stress was carried out in the production units in MOPCO (e.g., filling area, ammonia pumping area, and boiler area (BFW) from January 2018 to July 2019. Outdoor air emissions were measured from the outlet stacks of granulation, reformer and the boiler at MOPCO. The obtained results from the three sites were less than the maximum permissible limits for CO (25 ppm), SO 2 (2 ppm), NO 2 (3 ppm), and NH 3 (25 ppm) according to Egyptian Environment Protection Low No. 4/1994 and its amendments (No. 9/2009). Detailed air dispersion modeling (AERMOD) was applied to determine the likelihood ground level concentrations resulting from the outdoor air emissions of NO 2 , NH 3 , CO and PM 10 from the stacks in MOPCO. The individual risk exposures from MOPCO have been evaluated and found to be below the maximum tolerable risk levels allowed by the Egyptian Environment Protection Low No. 4/1994.
The Mine Waste Directive (2006/21/EC) requires the risk-based inventory of all mine waste sites in Europe. The geochemical documentation concerning inert classification and ranking of the mine wastes requires specific field study and laboratory testing and analyses of waste material to assess the Acid Mine Drainage potential and toxic element mobility. The procedure applied in this study used a multi-level decision support scheme for the inert classification of waste rock material including: 1) expert judgment, 2) data review, 3) representative field sampling and laboratory analysis and testing of rock formations listed in the National Inert Mining Waste List, and 4) requesting available laboratory analysis data from selected operating mines. Based on a preliminary expert judgment, the listed formations were classified into three categories. A: inert B: probably inert, but has to be checked, C: probably not inert, has to be examined. This paper discusses the heavy metal contamination risk assessment (RA) in the Hungarian quarrymine waste sites. In total 30 waste sites (including both abandoned mines and active quarries) were selected for scientific testing using the EU Pre-selection Protocol. Altogether 93 field samples were collected from the waste sites including andesite, rhyolite, coal (lignite and black coals), peat, alginite, bauxite, clay and limestone. Laboratory analyses of the total toxic element content (aqua regia extraction), the mobile toxic element content (deionized water leaching) carried out according to the Hungarian GKM Decree No. 14/2008. (IV.3) concerning mining waste management. A detailed geochemical study together with spatial analysis and GIS were performed to derive a geochemically sound contamination RA of the mine waste sites. Key parameters such as heavy metals, in addition to the landscape metric parameter such as the distance to the nearest surface and ground water bodies, or to sensitive receptors such as settlements and protected areas calculated and statistically evaluated in order to calibrate the RA methods. Results show that some of the waste rock materials, assumed to be inert, were found non-inert. Thus, regional RA needs more spatial and petrological examination with special care to rock and mineral deposit genetics.
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