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Industrial Applications
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
The applicability of the EB flue gas treatment technology for purification of marine diesel exhaust gases containing high SO2 and NOx concentration gases was studied by Licki et al. (2015). The measurements were performed in the laboratory plant with NOx concentration up to 1700 ppm and SO2 concentration up to 1000 ppm. Such high NOx and SO2 concentrations were observed in the exhaust gases from marine high-power diesel engines fueled with different heavy fuel oils. In the first part of study, the simulated exhaust gases were irradiated by the EB from accelerator. The simultaneous removal of SO2 and NOx were obtained and their removal efficiencies strongly depend on irradiation dose and inlet NOx concentration. For NOx concentrations above 800 ppm, low removal efficiencies were obtained even if applied high doses. In the second part of study, the irradiated gases were directed to the seawater scrubber for further purification. The scrubbing process enhances removal efficiencies of both pollutants. The SO2 removal efficiencies above 98.5% were obtained with irradiation dose greater than 5.3 kGy. For inlet NOx concentrations of 1700 ppm the NOx removal efficiency about 51% was obtained with dose greater than 8.8 kGy.
Chemical Weapons Holdings and Their Internationally Verified Destruction
Published in Brian J. Lukey, James A. Romano, Salem Harry, Chemical Warfare Agents, 2019
In the baseline system, liquid chemical agent drained from the munitions and storage containers is collected in a storage tank, from which it is fed into a high-temperature liquid incinerator (LIC), where it is burned at a temperature of 1480°C. The LIC is a two-stage refractory-lined incinerator designed to destroy the nerve agents GA, GB, and VX, and mustard gas (H, HD, HT). The drained agent is atomized by a nozzle and mixed with air to sustain combustion. Auxiliary fuel is used to maintain combustion at or above 1400°C with the flue gases being passed to an afterburner maintained at a minimum temperature of 1090°C for 2 s before ducting to the pollution abatement system.
Radioactive waste and the decommissioning of radioactive facilities
Published in Alan Martin, Sam Harbison, Karen Beach, Peter Cole, An Introduction to Radiation Protection, 2018
Alan Martin, Sam Harbison, Karen Beach, Peter Cole
A reduction in volume is usually beneficial and this can be achieved either by compaction of the waste or, in the case of combustible waste, by incineration. In the latter case, the flue gases from the incinerator are normally filtered and the filters and ash then constitute the reduced volume of waste. In the United Kingdom, a further category, very low-level waste (VLLW), is recognized. This is material that is only mildly radioactive and that can in many cases be disposed of by conventional landfill.
Evaluating the efficiency of enzyme accelerated CO2 capture: chemical kinetics modelling for interpreting measurement results
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Lorenzo Parri, Ada Fort, Anna Lo Grasso, Marco Mugnaini, Valerio Vignoli, Clemente Capasso, Sonia Del Prete, Maria Novella Romanelli, Claudiu T. Supuran
Recently, it has been realised a three-phase bioreactor (gas, liquid, and solid), which was filled with the recombinant SspCA immobilised on polyurethane (PU)14. The results obtained using the lab-scale bioreactor showed that the immobilised PU-SspCA is capable of converting CO2 from a gas mixture, whose initial concentration was 20%. Russo et al., using the SspCA covalently immobilised on paramagnetic Fe3O4 nanoparticles via carbodiimide activation of the enzyme and the protocol based on CO2 absorption experiment in a stirred cell apparatus, determined the kinetics of the immobilised SspCA for the CO2 hydration reaction15. Abdelrahim et al.16 provided an innovative concept for the removal of CO2 from flue gas streams, using biomimetic SILMs (Supported Ionic Liquid Membranes) containing SspCA that enhances the selective transport of CO2.
Asbestos dust concentrations and health conditions of workers at asbestos-cement corrugated sheet production manufacturers in Vietnam: a nationwide assessment
Published in International Journal of Occupational Safety and Ergonomics, 2023
Hang Thi Le, Hoa Thi Dinh, Tam Thi Ngo
Asbestos fiber dust concentration analysis, presented in Table 1, showed that 108 out of 206 samples had asbestos fiber dust, accounting for 52.4%. However, none of the samples exceeded the national standards for the occupational exposure limits (OELs) (0.1 fibers/ml per 8 h and 0.5 fibers/ml per 1 h) [11]. The average concentration of asbestos fibers was 0.19 ± 0.14 fibers/ml, of which the highest in group 1 was 0.19 ± 0.15 fibers/ml, in group 2 was 0.19 ± 0.12 fibers/ml and in group 3 was 0.17 ± 0.11 fibers/ml. Our evaluation results were better than previous evaluations in 2009 (3/56 samples), 2010 (1/71 samples) and 2011 (1/54 samples) of 14 companies using asbestos in production [9]. This phenomenon could be explained because, recently, many asbestos-cement roof sheet manufacturers had actively invested in technology to treat the working environment, and install and renovate crusher dust extraction and mixer machines. Besides, the process of solid waste and boiler flue gas treatment had been effective when companies had installed a system of crushing and mixing asbestos in a closed cycle with cyclones to collect and treat dust. This investment had positive results when reducing the dust concentration from 3 to 4 fibers/ml to the current result, which was within the allowed standard limits of the Government of Vietnam. On the other hand, the government’s regulations on monitoring and managing air quality, especially in asbestos-using factories, as well as putting environmental quality standards into the factory quality assessment process helped improve the perception of factory leaders, thereby helping to improve the working environment for workers [10,12,13].
Levels of PCDDs/PCDFs in waste incineration ash of some Jordanian hospitals using GC/MS
Published in Toxin Reviews, 2021
Sharif Arar, Mahmoud A. Alawi, Nisreen E. Al-Mikhi
As Tables 2 and 3 show, the PCDD/Fs in hospital waste ash are almost broken down, and PCDD/Fs cannot be synthesized in a high-temperature environment like a furnace; thus, the PCDD/Fs content in bottom ash is extremely low compared to the limit value of 10,000 pg I-TEQ/g. Still if taking as example the lowest value of 206,000 pg I-TEQ/kg (sample 9 from Queen Rania hospital) × 40.9 bottom ash generation rates in kg/batch equals to 8.4 µg per batch. Assuming batches were produced daily; 8.4 µg per batch × 365 day equals to 3.1 mg per year. Table 5 shows the same calculations for all samples. These estimated amounts, produced per year, would pose future concentration accumulation of PCDD/Fs in landfills- and dumping sites. The IPEN Dioxin PCBs and Waste Working Group (2005) report that indicated contamination of chicken eggs near the dump site for bottom ash from incinerator on the edge of Peshawar, Pakistan with dioxins reaches 2.91 pg WHO-TEQ/g fat compared to eggs samples from Egypt containing 125.78 pg WHO-TEQ/g fat. Eggs near the medical waste incinerator in Accra, Ghana (50–661 pg WHO-TEQ/g fat) and eggs sampled near the facility in Yaoundé (4.6–11.40 pg WHO-TEQ/g fat) exceeded the limit by EU Regulation (Petrlik et al.2019). According to the EU Regulation (EC) N°1259/2011 maximum level (ML) for food with PCDD/Fs and dl-PCBs concentrations = 2.5 pg WHO-TEQ/g fat, above this level is considered to be contaminated and is not suggested for consumption. Avoiding dioxin (PCDD/Fs) formation in medical waste management could be achieved by using different technologies like using possible alternatives for incinerators like autoclaves and rotors, where a boiler generates steam for disinfection at ≥121 °C for 30 min (Diaz et al.2005). Appropriate treatment of bottom ashes and residues from flue gas cleaning is essential for the reduction of PCDD/PCDF releases into the environment (Stockholm Convention on POPs 2008).