Acid Fog Research Articles

Intelligent hybrid hydrogel with nanoarchitectonics for water harvesting from acidic fog

With the development of society, the demand for water resources has risen has increased sharply, and water shortage is becoming a huge challenge to mankind. Therefore, it is extremely urgent to develop a convenient, low-cost, and environmentally friendly fog harvesting material. In this work, inspired by lotus stem with efficient water transport characteristics, the intelligent hybrid hydrogel (IHH) synergistically combines the characteristics of the pH-sensitive PDMAEMA polymer chain and thermo-switchable PNIPAM polymer chain, which simultaneously realizes superior efficient acidic fog uptake (∼6.5 g/g), high-density acidic fog storage, ultra-fast clean water releasing in the efficiency of ∼90 % for 12 min at 60 °C and high cycling stability (∼25 cycles). It is mainly attributed that the amine groups of the PDMAEMA chains are protonated under acidic state, and further the hydration is enhanced, and thus resulting the hydrogel to absorb the acid fog and swell. The PNIPAM polymer can achieve a rapidly reversible phase transition from a hydrophilic state to a hydrophobic one when the temperature beyond LCST, achieving the water releasing quickly. This IHH achieves preliminary water purification, which converts the harvested acidic fog into clean water as the freshwater generator. The IHH offers an insight into the design of novel materials that serve as the freshwater generator in complex environments of practical applications such as fog harvesting devices or systems.

Techno-economic-environmental analysis based on life cycle carbon accounting and pollutants audit for cleaner production of electrolytic manganese

The electrolytic manganese metal (EMM) industry faces significant environmental challenges, including substantial resource and energy consumption, severe pollution, and high CO2 emissions. This study introduced a novel approach for developing collaborative strategies aimed at mitigating pollutants and CO2 emissions. Through the implementation of life cycle carbon accounting and critical pollutant audits, a process enhancement program incorporating 17 advanced technologies was developed. Aligned with the principles of cleaner production, this project effectively mitigates the environmental burden at the source and offers viable solutions for addressing prominent emissions, such as manganese residue and acid fog. Furthermore, the marginal abatement cost curves demonstrate the economic practicality and applicability of these measures. This study provides a strategic blueprint for achieving sustainable green development in China’s EMM industry and offers valuable guidelines for formulating relevant environmental policies.

Decontamination Effect of Hypochlorous Acid Dry Mist on Selected Bacteria, Viruses, Spores, and Fungi as Well as on Components of Electronic Systems.

This publication presents the effect of hypochlorous acid dry mist as a disinfectant on selected bacteria, viruses, spores, and fungi as well as on portable Microlife OXY 300 finger pulse oximeters and electronic systems of Raspberry Pi Zero microcomputers. The impact of hypochlorous acid on microbiological agents was assessed at concentrations of 300, 500, and 2000 ppm of HClO according to PN-EN 17272 (Variant I). Studies of the impact of hypochlorous acid fog on electronic components were carried out in an aerosol chamber at concentrations of 500 ppm and 2000 ppm according to two models consisting of 30 (Variant II) and 90 fogging cycles (Variant III). Each cycle included the process of generating a dry mist of hypochlorous acid (25 mL/m3), decontamination of the test elements, as well as cleaning the chamber of the disinfectant agent. The exposure of the materials examined on hypochlorous acid dry mist in all variants resulted in a decrease in the number of viruses, bacteria, spores, and fungi tested. In addition, the research showed that in the variants of hypochlorous acid fogging cycles analyzed, no changes in performance parameters and no penetration of dry fog of hypochlorous acid into the interior of the tested medical devices and electronic systems were observed.

Do trees respond to pollution? A network study of the impact of pollution on spruce growth from Europe

Tree rings have been reliably used as an environmental proxy over the past decades for environmental reconstructions, simulations and forecasting. In our study, we investigated whether tree-ring chronologies are impacted by pollution. We chose sites in the Krušné hory and the Krkonoše Mountains in the Czech Republic which have a known history of pollution. We sampled Norway spruce (Picea abies [L.] Karst) in both ranges and compared their chronologies. We found no significant difference in the overall radial growth in the chronologies from both regions. However, we observed an increased heterogeneity in the growth of trees from the 1970s till the 1990s. Coherently, a severe reduction in tree growth from the late 1970s and a recovery towards the early 1990s was evident. We collected and analysed soil samples for pH and exchangeable element concentrations. All seven sampling sites' soils were strongly acidic (pHCaCl2 = 3.3 ± 0.4). The average soil base saturation at Krušné hory was higher than at Krkonoše (39% versus 12%), likely due to more intensive liming.Further, we compared these chronologies to other sites in Europe. Analysing 89 sites, we found that most (9 out of 14) of the sites with significantly reduced radial tree growth were located within the former ‘Black Triangle’, an area which was subjected to heavy industrialisation and pollution from the 1960s to the 1990s. Atmospheric sulphur deposition was found to negatively affect radial tree-growth, while limited quantities of oxidised nitrogen appeared to have a positive effect. Our results are consistent with previous research, indicating that atmospheric SO2 pollution and subsequent acid fog and rime have led to a reduction in annual radial tree growth across the Black Triangle.

Failure Characterization of Silicone Rubber in Corrosive Environments Based on Leakage Current Characteristics

Due to the growing usage of composite insulators in transmission and distribution networks, the development of composite insulators has reached the stage of systematic reliability study. This paper discusses the failure properties of HTV silicone rubber in different energized corrosive environments and explores the characteristics that can characterize insulation failure. The findings demonstrate that the leakage current characteristics (the maximum values, the number of characteristic pulses, and cumulative charge) can effectively characterize the surface state of silicone rubber in corrosive environments. The flashover tests during the withstand voltage experiment accelerated the electrical performance degradation of silicone rubber and increased the leakage current. The three leakage current characteristics increase with experimental time, applied voltage, and fog conductivity. The occurrence of flashover is related to the fluctuation range of leakage current. The three leakage current characteristics in the alkali fog with the same conductivity and applied voltage are significantly higher than those in salt and acid fog. A failure characterization method of silicone rubber based on the proportion of pulse number and cumulative discharge is proposed in this paper. The findings are helpful in forecasting pollution flashovers and insulation failure in heavy fog, coastal, and industrial pollution areas.

Long term trends of dry and wet deposition of air pollutants at declining forest site of Mt. Oyama in Japan during 1994–2019

Forest decline, which occurs in mountainous regions in many countries, may result from the effects of acid fog, ozone, or deposition of other pollutants. We observed wet deposition of air pollutants at different altitudes on Mt. Oyama, situated southwest of Tokyo, for 1994 until 2019. During this period, the domestic atmospheric environment was improved in Japan. The average concentration of air pollutants around all the sampling sites on Mt. Oyama decreased by 63.01%, 32.08%, 8.80%, and 39.73% for NH3, HCl, HNO3, and SO2, respectively. The volume weighted mean (VWM) pH values showed an increasing trend for bulk deposition (+0.70% y-1), fog water (+2.58% y-1), and throughfall (+2.60% y-1). Stemflow also increased (cedar, +1.17% y-1; fir, +0.82% y-1), although it included organic acids dissolved from the stem and it primarily had a low VWM pH value. The overall pH value of the fog water increased at the site, although acidic fog was still observed. Comparing fog water between winter and summer, a significant increase in pH occurred in summer, whereas no change occurred in winter. In summer, the sources of pollutants at Mt. Oyama are mainly from mainland Japan, and the frequency of low-pH acidic fog decreased annually. In winter, Mt. Oyama was affected by transboundary pollution, and acid fog occasionally occurred. Improvements in the domestic atmospheric environment and control of transboundary pollution will provide better conditions for mountain ecology that are free from acidic pollutants.

Application of Infrared Spectroscopy in Research on Aging of Silicone Rubber in Harsh Environment.

Polymer insulators using silicone rubber materials as sheds and sheaths are widely used in power systems to replace traditional porcelain and glass insulators which are heavy, inconvenient to install, and prone to pollution flashover. However, in recent years, polymer insulators that have been operating in harsh outdoor environments for many years have experienced different degrees of aging. The aging degree and aging products of silicone rubber are the focus of research. Fourier transform infrared spectroscopy (FTIR) is a technical method to analyze the internal molecular bonds and functional groups of materials, and it is often used to study the aging degree and aging products of silicone rubber. In this paper, the aging characteristics of silicone rubber samples in a high altitude area, salt fog environment, and acid environment were studied by FTIR. The results showed that the silicone rubber in a harsh environment, such as strong radiation, salt fog, and acid fog was degraded to some extent, and its main chain was cut off, the degree of polymerization was reduced, and the content of hydrophobic functional groups was reduced. Infrared spectroscopy can be used to analyze the aging phenomenon of polymers.

Efficacy of hypochlorous acid (HOCl) fog in sanitizing surfaces against Enterococcus faecalis

Fogging is an efficient method when disinfection of large areas is desired. Two methods of ultrasonic fogging, pulsed and continuous, were compared on bacteria dried on either aluminum or polystyrene surfaces. We characterized commercial and home-made hypochlorous acid (HOCl) with respect to storage and means of production. We found that the initial chlorine concentration of the commercial solution was approximately 550 ppm, and when stored open under ambient conditions, the chlorine content decreased at a rate of 30% every 100 days. The HOCl produced using the home synthesizers had a maximum chlorine content of 257.6 ppm which decayed by 65% after 100 days. A second synthesizer produced a liquid with high chlorine content and pH, 750ppm and pH = 8.55. The anti-bacterial efficacy was probed using Enterococcus faecalis, a persistent source of infection in public and clinical spaces. Time course studies determined that E. faecalis could survive dry on surfaces for more than 12 weeks, but was easily eliminated in half the fogging time. The most effective mode of application was determined to be continuous fogging where a 6.59 log reduction was established in vertical geometry. The optimal pulsed fogging protocol produced a similar reduction, but required nearly 5 times as long. The home synthesized versions yielded much lower log bacterial reductions. No significant differences in outcome were determined between polymer or metal surfaces.

INFLUENCE OF ACID AND CO-CATALYST ON PHOTOCATALYTIC HYDROGEN PRODUCTION

In recent years, the use of fossil fuels such as oil, coal and natural gas has increased along with the advanced economic activities of developed countries, resulting in urban air pollution, acid rain due to NOX and SOX, acid fog and carbon dioxide (CO2) emissions, as a result global warming issue becomes hot issue for all international organizations. On the other hand, there is an urgent need to introduce new environmentally friendly energy. New clean energy includes renewable energy such as solar power, wind power, geothermal power, ocean, hydropower, and hydrogen energy has been attracting significant attention in recent years. In this work hydrogen production by using different acid solutions and different co-catalysts were successfully achieved. Maximum production was 1767 μmol g-1 when Pd was used and 2229 μmol g-1 when oxalic acid was applied. The mechanism could be attributed to that promotion of hydrogen production on the surface of metal particles (Pd) can be considered. This is because the electrons that have moved to the conduction band move from the top of TiO2 onto the surface of the co-catalyst particles, as a result promotes the reduction reaction and improves the ability to generate hydrogen.

Answering the call for #GenerationRestoration: The Special Feature from the Society for Ecological Restoration and British Ecological Society to meet the challenges under the United Nations Decade on Ecosystem Restoration

The United Nations Decade on Ecosystem Restoration (https://www.decadeonrestoration.org/) offers hope in a particularly turbulent time in human history. We write this in the throes of the COVID-19 pandemic that has disrupted the entire planet's social systems exacerbated by increasing totalitarianism, kakistocracy, racism, sexism, homophobia, and transphobia. Hope seems in short supply. A practical path to build on hope might seem even scarcer. But letting the current state of the world bake into failure, ennui, and nihilism is not inevitable. In fact, restoration ecology was born of a failure to protect the environment and the socioecological systems as a whole. It has at the heart of its ethos an inherent optimism—that though we have damaged the environment, people also have the power and ability to repair that damage and imagine ecosystems of the future. It was—and is—one path out of the mess we have made. What we can achieve still depends on a seeming blizzard of “ifs”: it all depends on if we are successful in developing the technical, scientific, and engineering devices and engaging in the social, economic, policy, and governance processes. Some of this is achieved at the international and national level but the rise of economic systems that leave environmental damage and ecosystem services off of the ledgers, and the antipathy of too many citizens and political parties to grand plans, mean that the nurturing of restoration ecology is going to depend on making small efforts that are not only beautiful and functional but relevant to people. We launched the first joint project of the Society for Ecological Restoration and British Ecological Society in the spirit of cooperating to put our best minds and best efforts to the task of accomplishing the goals of the United Nations Decade on Ecosystem Restoration. This Special Feature runs across eight journals (Restoration Ecology, Ecological Solutions and Evidence, Functional Ecology, Journal of Animal Ecology, Journal of Applied Ecology, Journal of Ecology, Methods in Ecology and Evolution, and People and Nature) and readers will see the initial pulse of articles over the next year or more. We will not stop here. More initiatives are on a brighter horizon. As 2021 dawns and the Decade on Ecosystem Restoration breaks through the acidic fog of 2020, hundreds of restoration ecologists have answered the call. Not just our call for papers. The call to hope—and to make that hope into socioecological reality via #GenerationRestoration.

Improving the Reliability of the Corrosion Protection of Steel Products with Zinc Coatings by Nitriding

A method is proposed to improve the service properties of the zinc coatings on steels formed by cold galvanizing in order to increase their reliability and durability. As a result of annealing a zinc coating in an ammonia medium, the formation of a hardened modified layer due to diffusion processes in both a steel substrate and a zinc coating is experimentally established. The structure of the hardened layer provides an increase in the wear resistance of the nitrided zinc coating and an increase in the adhesion of the coating to the substrate. The corrosion resistance of the nitrided zinc coatings in various media, namely, a saline solution, a weakly acidic medium, seawater, and salt fog, is shown to increase due to a combination of cathodic and barrier protection mechanisms.

The preparation and characterization of uniform nanoporous structure on glass.

A novel fabrication method of uniform porous structures on the glass surface is proposed. The hydrofluoric acid fog formed by air-jet atomization etches the glass surface to fabricate nanoporous structure (NPS) on glass surface. This NPS shows the enhanced average light transmittance of approximately 92.9% and the superhydrophilic property with a contact angle less than 1° which presents an excellent anti-fog property. Passivated by fluorosilane, the NPS shows nearly the superhydrophobic property with a contact angle of 141.2°. This fabrication method has shown promising application prospects due to its simplicity, low cost and efficiency, which can be easily applied to large-scale industrial production.

Investigation of filter materials for gas cleaning from sulfuric acid

In the production of sulfuric acid, the final step is to clean the exhaust gases from the sulfuric acid mist. Currently, many industrial enterprises have abandoned the use of electrostatic precipitators to catch acid droplets in favor of the use of bag filters. The authors conducted an experimental study of the effectiveness of various filter materials and their combination in the form of a bag for catching sulfuric acid fog. A filter package was proposed from layers of fiberglass and fluoroplastic materials for industrial use, which showed a 98% efficiency for cleaning exhaust gases from a sulfuric acid mist.

Protecting Environment through Technology Innovation

Environmental issue associated with various types of power plants, is an international problem. The situation of the environment in developing countries, that it is being damaged and Pakistan is no exception. Energy is produced by different sources, and is creating a range of pollution problems. Consequently, environmental degradation is due to the production of harmful pollution constituents at the source of the energy. The purpose of this research is to determine solutions to such environmental problems and minimize pollution by using environmentally friendly equipment. This paper includes the practical example of ‘Tiefstack Thermal Power station’ in Germany, which is a modern power station with minimum population hazards to the environment. Considering today’s projects of setting up power plants, methods of using sophisticated equipment are chosen to limit the use of landfill and solid waste in the combustion process. Waste minimization measures are produced by modern technology applications, such as improved and efficient furnaces that are economical in fuel use. Increasing the sulphur content in the atmosphere, causing Acid fog, Acid rain, and other factors creating the situation of global warming is examined. Several methods of controlling compounds of sulphur and particulate emissions are described. Various types of nuclear waste are discussed and different types of disposal methods are illustrated. In the end, measures, recommendation and conclusions are drawn, concisely.

Operation Condition Evaluation and Risk Prediction of Air Preheater in Coal-fired Power Plant

Air preheater is an important flue gas heat exchanger in tail flue for coal-fired power plant. In this paper, the operation of air preheater was evaluated from three aspects: the influence of denitrification system on the operation of air preheater, the calculation of air leakage rate of air preheater and the evaluation of low temperature corrosion for air preheater. The results shown that: the corrosion of downstream air preheater caused by ammonium bisulfate was limited due to the low ammonia escape rate; The air leakage rate is higher than the normal value of the air leakage rate; the temperature in the cold end of B-side for air preheater is lower than acid dew point of flue gas due to air leakage, which results in sulphuric acid fog condensation and sulphuric acid corrosion on the air preheater.

酸性霧とその環境影響( 酸性雨と森林衰退,研究の現場から)

酸性霧とその環境影響( 酸性雨と森林衰退,研究の現場から)

Transport and transformation of mercury during wet flue gas cleaning process of nonferrous metal smelting.

Reducing mercury emission is hot topic for international society. The first step for controlling mercury in fuel gas is to investigate mercury distribution and during the flue gas treatment process. The mercury transport and transformation in wet flue gas cleaning process of nonferrous smelting industry was studied in the paper with critical important parameters, such as the solution temperature, Hg0 concentration, SO2 concentration, and Hg2+ concentration at the laboratory scale. The mass ratio of the mercury distribution in the solution, flue gas, sludge, and acid fog from the simulated flue gas containing Hg2+ and Hg0 was 49.12~65.54, 18.34~35.42, 11.89~14.47, and 1.74~3.54%, respectively. The primary mercury species in the flue gas and acid fog were gaseous Hg0 and dissolved Hg2+. The mercury species in the cleaning solution were dissolved Hg2+ and colloidal mercury, which accounted for 56.56 and 7.34% of the total mercury, respectively. Various mercury compounds, including Hg2Cl2, HgS, HgCl2, HgSO4, and HgO, existed in the sludge. These results for mercury distribution and speciation are highly useful in understanding mercury transport and transformation during the wet flue gas cleaning process. This research is conducive for controlling mercury emissions from nonferrous smelting flue gas and by-products.

Energy-saving synthesis of electrolytic manganese dioxide using oxygen cathode with Pt/TiO2-CNx nanocatalysts

The awareness of energy, environment, and economy for electrolysis has required the development of new methods to prevent environmental pollution, such as the emission of acid fog, CO2, and SO2. Hence, the use of gas diffusion electrode as a cathode in the electrodeposition of manganese dioxide to save energy and protect the environment is attracting research interest. In this work, a gas diffusion electrode consisting of a mixture of Pt/TiO2-CNx nanocatalysts and two different additive conductor supports that activate carbon and acetylene black were synthesized. The Pt/TiO2-CNx nanocatalysts and Pt/TiO2-CNx gas diffusion electrode were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The Pt/TiO2-CNx nanowire catalyst showed strong interaction between the Pt nanoparticles (~2.21 nm) and TiO2-CNx nanowire support. Results of electrochemical tests in 120 g of MnSO4 + 30 g of H2SO4 at 80 °C show that the Pt/TiO2-CNx gas diffusion electrode used in the electrodeposition of manganese dioxide could save electric energy by approximately 60%. Furthermore, the lifetime of the gas diffusion electrode of Pt/TiO2-CNx nanocatalysts was about twofold longer than that of the gas diffusion electrode of Pt/C and Pt/TiO2 nanocatalysts. The Pt/TiO2-CNx nanowire catalyst exhibited high anti-acid corrosion, activity, and stability, indicating its potential important application in the electrodeposition of manganese dioxide.

Impact of mist and acidic fog on polymer insulator samples exposed to corona discharges

Corona resulting from the metallic parts of the transmission line insulators and hardware has proven to be the potential factor in inducing the degradation of polymer insulators. Corona activity is found to increase substantially during the foul weather condition (rain, fog/mist, hoarfrost), which further promotes the ageing of polymer insulators. Present work investigates the possible corona activity under fog/moist condition and its effects on the long term performance of polymer insulators in service. The spread of corona generated plasma is observed to be different under fog condition than in normal air condition. The concentrated streamers that are originated from the corona electrode during fog condition are believed to damage the polymer shed material locally and more intensely. This was confirmed by the scanning electron microscopy and Fourier infrared spectroscopy analysis carried out on the treated polymer samples, which showed more damage on the corona treated under fog than on the samples treated under normal air condition. Further TGA and EDAX studies have shown that loss of ATH occurs on the sample due to intense corona activity.

Corona degradation of the polymer insulator samples under different fog conditions

Corona discharges resulting from the metal parts of insulators and the line hardware affect the long term performance of the polymeric insulators used for outdoor application and can lead to its eventual failure. The authors previous work, involved in developing a new methodology to evaluate the performance of polymeric shed materials subjected to corona stresses in the presence of natural fog condition, results revealed more surface hydroxylation thereby resulting in more loss of hydropobhicity. With the increase in industrialization, there is an increase in acidic component of the rain as well as the fog (moisture). The present work, reports the effect of acid fog on the corona performance of the polymeric insulators for both AC and DC excitation, interesting results are obtained. A comparison of the experimental investigations revealed that the acidic fog has more effect than that of the normal fog. This fact has been confirmed by physico-chemical analysis like the scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) and contact angle measurement. The effect of DC corona is found to be lesser in comparison with the AC; however the hydroxylation induced by the DC corona under the presence of fog is similar with that of AC excitation.