Toward a comprehensive life-cycle carcinogenic impact assessment: A statistical regression approach based on cancer burden.

The current approach to life cycle carcinogenic impact assessment (LCCA) is hindered by its static and linear characteristics. This situation prevents the accurate prediction of the incidence, associated damage, and potential economic burden of cancer. This study explores a highly comprehensive pathway for LCCA assessment. It uses the impacts of Tracheal, bronchus, and lung (TBL) predicted by the LCCA of China's coal power industry through a screened statistical regression model as the research target. The latest global burden of disease estimates is utilized to quantify the health damage from TBL incidence, whereas an approach combining the actual cost of health and human capital is applied to further assess the economic burden of TBL. Findings indicate that the traditional and static LCCA method, which relies on animal toxicity data, can lead to underestimations in actual LCCA. The interaction among spatiotemporal meteorological factors, epidemiological cancer disease burden, and socioeconomic behaviors allows exhibits nonlinearity due to the changes in the combined toxicity of mixed key substances. Following the active implementation of ultralow emission and energy-saving transformations in China's coal power industry, the national percentage of TBL cancer incidence caused by pollutants from the coal power industry decreased from 25.2 % in 2004 to 11.5 % in 2020. Results indicate that the established dynamic LCCA model based on temporal and spatial climate, socioeconomic, and epidemiological cancer data can be feasibly employed for the accurate impact evaluation and mitigation of carcinogens in practical applications.

Experimental study on the removal of PM2.5 using modified carbon steel collectors with hydrophilic properties in wet ESPs.

Along with the increasingly stringent dust emission concentration standards for the thermal power plants and the challenge of market competition, wet electrostatic precipitators (ESPs) have been widely used as terminal equipment for the flue gas treatment. The wet ESPs pilot test platform using the modified carbon steel collectors with hydrophilic properties was established in this paper and the experimental research on PM2.5 removal characteristics were carried out. The mechanism of the particles removal efficiency enhancement by water film on the surface of modified collectors was studied. The effect of gas temperature, residence time, working voltage, inlet concentration, and flushing water flowrate on the particles removal efficiency was investigated. The results indicated that the fibrous layer over the surface of the modified collectors could reduce the effect of the airflow recoil and the electromigration resistance of particles. The surface of the modified collectors could also maintain a uniform and stable water film with a lower amount of water consumption. The water film could restrain the back corona and the re-entrainment of dust. And the evaporation of water film increased the humidity of the flue gas, meanwhile, the particles charge capacity and electromigration velocity increased. Those all could improve the particles removal efficiency. The particles removal efficiency increased with the increase of the flue gas residence time and the applied voltage, but the particles removal efficiency improved less with the increase of the particles inlet concentration and flushing water flow rate after maintaining uniform and stable water film. The modified rigid collector provided high removal efficiency for particles with diameters of 0.04～0.48 µm under lower energy and water consumption.Implications: The wet electrostatic precipitators (ESPs) have been widely used as terminal equipment of the flue gas treatment to purify the flue gas deeply. The surface of the modified carbon steel collectors with hydrophilic properties could maintain a uniform and stable water film with a lower amount of water consumption. The evaporation of water film improved the particle charge capacity and electromigration velocity. The wet ESPs using the modified rigid collector exhibited significantly higher removal efficiency of particles than using the conventional rigid collector especially to the particles with diameter of 0.04～0.48 µm.

Experimental study on the removal of fine particles using hole-slotted collectors in wet electrostatic precipitators.

The fine particles are considered a significant environmental pollution problem. The wet electrostatic precipitators (ESPs) are now used most widely among the advanced fine particle removal technologies. The rigid glass fiber reinforced plastics (FRP) collectors modified with hole-slotted structures were used to enhance the water film distribution over their surfaces. This paper experimentally investigated the effects of the hole-slot patterns and the operating parameters on the particle removal performance in wet ESPs using the hole-slot-structured collector. The voltage-current characteristics and the energy consumption among the different pattern collectors were discussed. Besides, the effects of the water film on the particle number concentration classification and the effects of the applied voltage and the specific collecting electrode areas (SCA) on the relative collection efficiency (RCE) were investigated and discussed. The experiment results show that the corona current of three hole-slot structured FRP collectors was higher than that of the conventional rigid collectors (CRC) at the same voltage. Using the FRP collectors with circular holes and horizontal slots could decrease the energy consumption and using the FRP collectors with vertical slots increases the energy consumption compared with the CRC when the collection efficiency was lower than 92.5%. The water film could increase the collection efficiency of the fine particles and prevent the fine particles cross through the holes and the slots. The hole-slot-structured FRP collectors were appropriate for the working conditions of high SCA and long residence time. When the water film in the hole and slotted structures was incomplete, the fine particles could pass through the collector plate to form secondary back-mixing.Implications: The wet ESPs are used most widely among the advanced treatment technologies of the fine particles' removal. The rigid glass fiber reinforced plastics (FRP) collectors modified with hole-slotted structures were used to enhance the water film distribution over their surfaces. The hole-slot-structured FRP collectors were appropriate for the working conditions of high SCA and long residence time. When the water film in the hole and slotted structures was incomplete, the fine particles could pass through the collector plate to form secondary back-mixing.

Study on sulfur migration in activated carbon adsorption-desorption cycle: Effect of alkali/alkaline earth metals.

Activated carbon (AC) has been widely used in the removal of SO2 from flue gas owing to its well-developed pore structure and abundant functional groups. Herein, the effect of alkali/alkaline earth metals on sulfur migration was investigated based on the dynamic adsorption and temperature programmed desorption experiment. The adsorption and desorption properties of six types of AC (three commercial and three laboratory-made) were carried out on a fixed-bed experimental device, and the physical and chemical properties of samples were determined by X-ray fluorescence, X-ray diffraction, scanning electron microscopy/energy dispersive X-ray, and X-ray photoelectron spectroscopy analysis. The experimental results showed that the adsorbed SO2 cannot be completely desorbed by increasing the regeneration temperature (350 - 850°C), while the SO2 fixed in the AC combines with the Ca-based minerals in the ash to form a stable sulfate. For different samples, higher ash content, higher CaO content in the ash and a more developed pore structure lead to a higher SO2 fixation rate. Moreover, the multiple adsorption-desorption cycles experiment showed that the effect of SO2 fixation is mainly reflected in the first cycle, after which the adsorption and desorption amount are approximately the same. This study elucidates the effect of alkali/alkaline earth metals on the adsorption-desorption cycle of AC, which provides a deeper understanding of sulfur migration in the AC flue gas desulfurization process.

NO x reduction by CO over ASC catalysts in a simulated rotary reactor: effect of CO2, H2O and SO2.

The influence of CO2, H2O and SO2 on the NO reduction by CO over Fe/Co activated semi-coke catalyst was investigated in a simulated rotary reactor. The results showed that, in the simulated rotary reactor, the influence of CO2 and H2O on the NO adsorption was significant at low temperatures, and the inhibition became weak when increasing the temperature. However, the NO adsorption efficiency could not be improved by increasing temperature after catalyst sulfur poisoning. The heavily inhibited NO adsorption process, which was due to the competitive adsorption and formation of the sulfate, resulted in a low NO reduction efficiency in the presence of CO2, H2O or SO2. The in situ DRIFT study showed that the dominant effect of CO2, H2O and SO2 on the NO adsorption was the inhibition of the free nitrate ions formation. In addition, the introduction of CO2, H2O and SO2 could not change the route of NO reduction, but just reduced the degree of the NO + CO reduction.

Wetting properties and performance test of modified rigid collector in wet electrostatic precipitators.

UNLABELLED: The fine particles are considered a significant pollution problem. The wet electrostatic precipitators (ESPs) have advantages of efficient collection of the fine particles with lower pressure drop and eliminating reentrainment. The wetting properties of the collector surfaces have significantly important effect on wet ESPs' stable and secure operation. The modified rigid collector (MRC) was modified by coating specific vinyl ester resin composites and loose glass fiber cloth over the conventional carbon steel in a certain way. The rigid collector surfaces before and after modification had been characterized by scanning electron microscopy (SEM) and interface tensiometer. The effect of operating temperatures on the wetting properties of the rigid collector surfaces before and after modification was investigated. The temperature range was 40~90 °C, and the wetting properties contained liquid holdup, surface flow rate, film rate, average film thickness, and critical saturation time. The modified rigid collector surface exhibited excellent wetting properties at the operating temperatures. The fine particles collection performance compared among the MRC, the conventional rigid collector (CRC), and the flexible collector (FC) in the wet ESPs was investigated. The effects of the applied voltage, the water film, corona power, and the specific collecting area on the fine particles collection were evaluated. The modified rigid collector provided high fine particles collection effect with lower energy and water consumption. IMPLICATIONS: To improve the submicron particles collection efficiency and decrease energy and water consumption, the formation of uniform water film over the collector surfaces has been widely studied. The modified rigid collector was modified by coating specific vinyl ester resin composites and loose glass fiber cloth (ERGF) over the conventional carbon steel (CCS) in a certain way. The modified rigid collector surface exhibited excellent wetting properties. The wet ESPs by the modified rigid collector exhibited significantly higher particles collection efficiency than by the conventional rigid collector.