Rain Solution Research Articles

Aging performance of high viscosity modified asphalt under complex heat-light-water coupled conditions

During the rapid development of sponge city construction in China, the porous asphalt pavement has been widely applied. The high viscosity modified asphalt that is used for producing porous asphalt experiences complex aging circumstances. In this study, the aging performance of high viscosity modified asphalt was evaluated based on the simulated heat-light-water coupled conditions, in which different aging effects and degrees were considered. The complex aging simulation method was innovated that mainly composed of an UV radiator and an environmental cabinet. The dynamic shear properties, high and low-temperature performance, and microstructural morphology of aged high viscosity modified asphalt binders were evaluated through the DSR (temperature-frequency sweep scan, LAS, MSCR), BBR, and ESEM tests, respectively. The results of DSR and BBR test demonstrated that the coupled aging effects should be considered during the service period, since acid rain solution and UV light also led to significant influences on the viscoelastic properties, high and low-temperature performance, and fatigue performance as similar as high temperature. The observation of the microstructures illustrated the aging mechanisms of different environmental factors and their combined effects. This study could provide a better protocol for aging performance examination of high viscosity modified asphalt binder used for porous asphalt pavement considering complicated environmental conditions.

Assessment of semi-dynamic leaching characteristics of lead and zinc from stabilized contaminated soil using sustainable phosphate-based binder after carbonation

Stabilized contaminated soils face long-term complex environmental effects in the process of sustainable resource reuse. Therefore, semi-dynamic leaching tests in this study were conducted to investigate the leaching characteristics of novel sustainable phosphate binder stabilized soil contaminated with lead (Pb) and zinc (Zn) after carbonation in various simulated acid rain solutions to verify the sustainability of stabilization. Immobilization mechanisms of Pb and Zn, carbonation impact, leaching concentrations, pH, electrical conductivity, desorption parameters, leaching mechanisms, observed/effective diffusion coefficient (Dobs/Deff), and leachability index were investigated. Complexation or adsorption of heavy metals can reduce the number of exchangeable ions, especially after carbonation. Carbonization showed a beneficial effect, indicating that the stabilized materials are a good carbon catcher. The leaching mechanism of Pb and Zn were all controlled by diffusion, which was caused by complex destruction and desorption. Dobs values for Pb ranged from 10−19 to 10−16 m2/s, and those for Zn from 10−17 to 10−13 m2/s. Therefore, the mobilization of Zn was more intense than that of Pb. Deff values, calculated through the desorption parameter, were ∼3–4 orders of magnitude larger than Dobs values. The leaching characteristics of Pb and Zn were influenced by leachant pH and carbonation, which were related to electrical conductivity and the cumulative leaching mass of magnesium. The effects had an influence on hydration products' chemical stability and buffering capacity. The stabilized materials can be used as recycled material in engineering, judging from the leachability index. This study can improve researchers' and engineers' understanding of the environmental leaching and toxicity of stabilized contaminated soil during reutilization, increasing reliability in reusing contaminated soil resources.

Desorption and Migration Behavior of Beryllium from Contaminated Soils: Insights for Risk-Based Management.

Factors influencing the desorption, distribution, and vertical migration behavior of Be in contaminated soils are not fully understood. This study examined the desorption and migration of Be in a soil profile from a legacy radioactive waste disposal site using different batch leaching [monofilled waste extraction procedure (MWEP); synthetic precipitation leaching procedure (SPLP); simulated acid rain solution (SARS); and toxicity characteristic leaching procedure] and sequential leaching [community bureau of reference (BCR)] methods for insights relevant to the application of risk-based management. The results showed that Be desorption was higher in the presence of organic than the inorganic leachate composition (MWEP < SPLP < SARS < TCLP < BCR first-step). The desorption followed three diffusion control mechanisms, which resulted in three desorption rate constant estimates of 157, 87.1, and 40.4 Be/kg.h0.5, and the estimated desorption maximum was 556 μg/kg. The desorption process was, spontaneous (ΔG > 0), enthalpically and entropically influenced. Increasing the incubation period and heat treatment resulted in a decrease of Be desorption and migration. The soil clay content and pH were the primary factors influencing Be desorption, and the results suggested that Be was desorbed from metal oxyhydroxides and surfaces of silicates (e.g., reactive surfaces of clay minerals), organic matters, and soil pores. Because of high Kd values, the mobility of Be was limited, and no exceedances of ecological or human health risk index or guidelines were determined for the current contamination levels at the site. However, Be released from the waste trenches has the ongoing potential to increase Be concentration in the soil.

Effect of temperature on the corrosion behavior of a superplastic Zn–Al–Ag alloy in acid rain solution

Effect of temperature on the corrosion behavior of a superplastic Zn–Al–Ag alloy in acid rain solution

Study on the effect of Acid Rain erosion on the Road performance of Steel Slag Asphalt mixture

in order to study the influence rules of acid rain erosion on the road performance of steel slag asphalt mixture, the artificial acid rain solution of pH=2 and distilled water of pH=7 were used to carry out periodic immersion erosion test on asphalt mixture with different amount of steel slag (0, 30%, 50%, 70%), then rutting test, low temperature bending test and freeze-thaw splitting test were carried out on the asphalt mixture eroded by acid rain. The results show that after soaking in acid rain solution, the high temperature stability, low temperature crack resistance and water stability of each steel slag asphalt mixture decrease, and the decreasing range increases with the increase of soaking period. The high temperature stability, low temperature crack resistance and water stability of steel slag asphalt mixture soaked in distilled water also decreased, but the decrease was small.

Corrosion Behavior of Extruded AM60-AlN Metal Matrix Nanocomposite and AM60 Alloy Exposed to Simulated Acid Rain Environment

The present work compared the initial stages of corrosion process development on the AM60-AlN metal matrix nanocomposite surface and on AM60, during their exposure for 30 days to simulated acid rain solution (SAR). The AlN nanoparticles were observed as “attached” to those of Mn-rich AlMn intermetallic particles, forming clusters. The introduction of 1.0 wt.% AlN (≈ 80 nm) in the AM60 alloy carried a slight grain refinement and favored the formation of a denser and more protective corrosion layer, suggested by the electrochemical impedance spectroscopy (EIS) values of higher charge transfer resistance (R2) and capacitance, characteristic of the double layer in the presence of corrosion products, and also suggested by Rn (EN) values, compared to those of the AM60 alloy. Thus, the concentration of the released Mg-ions from the composite surface was lower. Due to the increase in time of the SAR solution pH, Al de-alloying may occur, as well as Al(OH)3 formation, as confirmed by XPS analysis. Due to the presence of Cl-ions in SAR solution, localized corrosion was observed, suggested as fractional Gaussian noise of a stationary and persistent process in time, according to the PSD of the corrosion current fluctuations (EN).

Degradation of Components in Cars Due to Bimetallic Corrosion.

This paper deals with the determination of the basic corrosion characteristics of metallic materials used as components in car construction to achieve a lighter vehicle with higher rigidity, a more complex “hybrid” of diverse materials is needed for the car body structure. Due to the different types of material used in the manufacture of components and their interactions, the issue of assessing the impact of bimetallic corrosion is currently relevant. Based on the potential difference at the end of the corrosion test, it was possible to determine the “anode index”, which determines the risk of degradation of materials due to bimetallic corrosion. In our case, a hot-galvanized steel sheet/Al alloy EN AW-6060 couple in deicing salt and hot-galvanized steel sheet/steel S355J0 couple in simulated acid rain solution (SARS) has proven to be “safest” and usable even for more aggressive environments. Hot-galvanized steel sheet/Al alloy EN AW-6060 in SARS solution is suitable for slightly aggressive environments. Stainless steel AISI 304/silumin A356 in deicing salt, stainless steel AISI 304/Al alloy EN AW-6060 in deicing salt, and stainless steel AISI 306/Al alloy EN AW-6060 in simulated exhaust gas environment (SEG solution) are not suitable for non-aggressive environments.

Deterioration of Portland Cement Pervious Concrete in Sponge Cities Subjected to Acid Rain.

The deterioration of Portland cement pervious concrete (PCPC) subjected to wet-dry cycles in the simulated acid rain solution was investigated; 4% silica fume (SF) and 8% fine aggregate (FAG) were used to replace part of cement and the coarse aggregates (weight by weight), respectively. The wear resistance, the compressive, and flexural strength of PCPC were measured. The results show that after 12 wet-dry cycles in acid rain solution the compressive strength and the flexural strength of control PCPC are decreased by 30.7% and 40.8%. The final compressive strength of PCPC with 4% SF and PCPC with 8% FAG is increased by 6.9% and 30.3%, and the final flexural strength is increased by 25.4% and 72.3%, respectively. The wear loss of PCPC is decreased by 58.8% and 81.9% when 4% SF and 8% FAG is added to PCPC, respectively. The microstructures of PCPC with wet-dry cycles are also discussed.

Corrosion behavior of copper, tin, and bronze CuSn14 in acid rain solution

AbstractThe corrosion behavior of copper, tin, and bronze CuSn14 is studied in simulated acid rain (pH 4.5) by electrochemical techniques, cyclic voltammetry and electrochemical impedance spectroscopy. The potentiodynamic formation of anodic oxide film on copper and tin is described in terms of high‐field model. Cyclic voltammetry shows that dissolution of bronze is higher than of pure copper metal in acid rain. Electrochemical impedance spectroscopy data reveal that oxide films formed on copper and tin have a higher resistance and suppressed diffusion process through the surface layer than the oxide film formed on bronze CuSn14 at the same conditions.

Inhibition of Copper Corrosion in Acid Rain Solution Using the Imidazole Derivatives

Inhibition of Copper Corrosion in Acid Rain Solution Using the Imidazole Derivatives

Improved Acid Rain Resistance of High Calcium Fly Ash-sodium Hydroxide Geopolymer Mortar Cured at Ambient Temperature by Incorporating Rice Husk Ash

Geopolymer is an aluminosilicate material, synthesized from source materials rich in silica and alumina and alkali solution. This product provides similar strength to Portland cement concrete. Geopolymer exhibits a wide variety of properties and characteristics, including high compressive strength, low shrinkage, acid resistance, fire resistance and low thermal conductivity. In term of acid resistance, acid rain is an important consideration due to global warming. Structures deteriorate as a result of persistence contact with acid rain with of pH less than 5. Thus, this research aims to improve acid resistance of fly ash-NaOH geopolymer mortars by incorporating rice husk ash (RHA). Artificial acid rain solution was prepared by mixing nitric acid and sulfuric acid at the ratio of 70:30 v/v. The geopolymer mortars were immersed in 5% nitric acid, 5% sulfuric acid, and 5% synthetic acid rain solutions for 36 weeks. The evaluations of its resistance to acid solution was investigated with surface corrosion, compressive strength, and microstructure. The results showed that the incorporation of RHA improved the acid rain resistance of geopolymer mortar through pore refinement and increase in strength. The mortar with fly ash to RHA ratio of 90:10 provided the highest compressive strength and good resistance to acid rain.

Mechanism and erosion resistance of internally cured concrete including super absorbent polymers against coupled effects of acid rain and fatigue load

This study explored a novel method for inhibiting the effects of acid rain erosion and fatigue loading in concrete by incorporating super absorbent polymers (SAP). Three different dosages and four particle sizes of SAP were considered to evaluate the erosion resistance to a simulated acid rain solution (pH = 3.0) for eight test cycles. The mass loss, compressive strength, flexural strength, and erosion depth as well as the results of X-ray diffraction (XRD) and the mercury intrusion porosimetry (MIP) testing were employed to explore the erosion behavior and mechanism of the internally cured concrete with SAPs. The results show that the coupled effects of acid rain and fatigue loading has a remarkable influence on the performance degradation of concrete. The erosion of concrete by acid rain was delayed and weakened with the addition of SAP, particularly when 0.10% SAP was added with a particle size of 100–120 mesh. Moreover, the SAP promoted hydration, which lessened the deterioration caused by pore deformation and improved the internal pore structure.

Corrosion inhibiting effect of a green formulation based on Opuntia Dillenii seed oil for iron in acid rain solution

This study examines the development of a new green and eco-friendly formulation derived from Opuntia dillenii seed oil (labeled as FOD) and its application as a corrosion inhibitor to protect iron which is subject to corrosion phenomena that become important especially in acidic environments as acid rain.Physicochemical properties and fatty acid analysis of Opuntia dillenii seed oil were performed and they demonstrated that the oil is a major source of unsaturated fatty acids, in particular linoleic acid, with a percentage of 73.388%.Corrosion inhibition effect of FOD was studied by gravimetric methods, electrochemical measurements, and scanning electron microscopy coupled with elemental analysis (SEM/EDX). Obtained results confirmed that FOD behaves as a good mixed corrosion inhibitor with predominant anodic activity. Inhibition efficiency of FOD is more important when the concentration of FOD and the immersion time increase, reaching values up to 99%. FOD forms a barrier layer on the surface of the iron, and thereby minimizes the contact area between the metal surface and the corrosive solution. The adsorption behavior of FOD on iron surface obeys Langmuir adsorption isotherm with chemisorption and physisorption mechanism.

Experimental study of pore characteristics and radon exhalation of uranium tailing solidified bodies in acidic environments.

The pore characteristics and radon exhalation of uranium tailings solidified in an acid environment were investigated in this study. Tailings from the beach of a uranium tailing reservoir in the acid rain area of Central China were selected as samples and solidified with cement, slag powder (GGBS), metakaolin (MK), or slag powder and metakaolin (GM), then immersed in simulated acid rain solution for 60 days. The transverse relaxation time T2 distribution and porosity of each solidified sample before and after immersion were measured by nuclear magnetic resonance (NMR) and the cumulative radon concentration before and after immersion was measured by a RAD7 radon meter. The experimental results show that the nuclear magnetic resonance T2 distribution curve shifts to the left, the peak amplitude decreases, and the pores in the sample gradually shrink as the admixture content increases. The porosity and radon exhalation rate of solidified samples also appear to decrease gradually as admixture content increases; a quadratic function relationship was observed between porosity and radon exhalation rate. The pore size and effective pore volume of solidified samples increase as immersion time increases, while the radon exhalation rate increases and the pore volume gradually increases. The results of this study may provide a sound theoretical basis for the solidification treatment of uranium tailings in engineering practice.

Experimental and theoretical studies of paracetamol as a copper corrosion inhibitor

The utilization of copper as a material in various fields is well known. In such environments as a synthetic acid rain solution, various aggressive ions can be found that negatively affect the characteristics of copper, i.e. lead to its dissolution. The most common way to protect copper from dissolving is to use inhibitors. Therefore, in this paper, the possibility of expired paracetamol for preventing the corrosion of copper in a synthetic acid rain solution was investigated. The results obtained by electrochemical methods showed the resistance of copper to corrosion in the presence of paracetamol. Additionally, binary system of paracetamol and potassium sorbate showed higher inhibition efficiency (97%) in regard to paracetamol (96.3%). Furthermore, the calculated quantum chemical parameters as well ae Gibbs free energy confirmed the inhibitory ability of paracetamol achieved by adsorption on the copper surface.

B-IMPACT project: eco-friendly and non-hazardous coatings for the protection of outdoor bronzes

Application of protective coatings is the most widely used conservation treatment for outdoor bronzes. Eco-friendly and non-hazardous coatings are currently needed for conservation of outdoor bronze monuments. To fulfil this need, the M-ERA.NET European research project B-IMPACT (Bronze-IMproved non-hazardous PAtina CoaTings) aimed at assessing the protectiveness of innovative coatings for historical and modern bronze monuments exposed outdoors.In this project, two bronze substrates (historical Cu-Sn-Zn-Pb and modern Cu-Si-Mn alloys) were artificially patinated, by acid rain solution using dropping test and by “liver of sulphur” procedure (K2S aqueous solution) to obtain black patina, respectively. Subsequently, the application of several newly developed protective coatings was carried out and their performance was investigated by preliminary electrochemical tests. In the following steps of the work, the assessment of the best-performing coatings was carried out and their performance was compared to Incralac, one of the most widely used protective coatings in conservation practice. A multi-analytical approach was adopted, considering artificial ageing (carried out in representative conditions, including exposure to rain runoff, stagnant rain and UV radiation) and metal release, as well as visual aspect (so as to include aesthetical impact among the coating selection parameters) and morphological and structural evolution of the coated surfaces due to simulated outdoor exposure. Lastly, also the health impact of selected coatings was assessed by occupational hazard tests. The removability and re-applicability of the best-performing coatings were also assessed. The best alternatives to the conventional Incralac exhibited were: (i) fluoroacrylate blended with methacryloxy-propyl-trimethoxy-silane (FA-MS) applied on patinated Cu-Sn-Zn-Pb bronze and (ii) 3-mercapto-propyl-trimethoxysilane (PropS-SH) applied on patinated Cu-Si-Mn bronze.

Influence of 5-Chlorobenzotriazole on Inhibition of Copper Corrosion in Acid Rain Solution.

This paper aims to examine the efficiency of 5-chlorobenzotriazole (5Cl-BTA) as a copper corrosion inhibitor in acidic rain solutions with a pH value of 2.42 by the electrochemical polarization method. 5-Chlorobenzotriazole acts similar to a mixed type inhibitor, according to the potentiodynamic polarization measurements. Results obtained in this research suggest that 5Cl-BTA is a good inhibitor; it decreases anodic and cathodic reaction rates, and the highest inhibition efficiency was 91.2%. The inhibitory effect of 5-chlorobenzotriazole is explained by the formation of the layer on the copper surface. Stability of the protective layer increased with inhibitor concentration. Scanning electron microscopy and energy-dispersive analysis of X-rays analysis confirmed that on the electrode surface, a protective layer was formed. Adsorption of 5Cl-BTA obeys the Langmuir adsorption isotherm. 5Cl-BTA showed good inhibitory characteristics even when the Cl– ions were present in examined solutions.

Mechanical behavior degradation of recycled aggregate concrete after simulated acid rain spraying

To understand the degradation of mechanical properties of recycled aggregate concrete(RAC) after acid rain exposure, the effect of recycled coarse aggregate (RCA) replacement ratios, the acidity (pH value) of the simulated acid rain solution and mineral admixtures on compressive strength and elastic modulus of RAC are investigated in this study. The test results showed that elastic modulus and the compressive strength of RAC specimens may increase slightly at the beginning of acid rain spraying, then decreases gradually with the continuous erosion of acid rain. The greater the acidity of acid rain solution is, the more obviously the mechanical properties of RAC decreases. Appropriately adding fly ash and silica fume separately or together will effectively improve the strength and the acid rain resistance of RAC, whereas higher replacement rate of RCA may be unfavourable for RAC to resist acid rain. SEM/EDS observation and analyses also further illustrated that the impact of acid rain and mineral admixtures on the microstructures of ITZ in RAC.

Growth and Leaf Chlorophyll Content of Eucalyptus grandis W. Hill ex Maiden are Adversely Affected by Simulated Acid Rain

The study assessed the effects of different pH values of simulated acid rain on growth and leaf chlorophyll content of Eucalyptus grandis.&#x0D; The treatments comprised of two simulated acid rain solutions of pH 4.0 and 3.5, and unacidified water at pH 6.5.&#x0D; Place and Duration of Study was the National Forestry Development Agency, Humid Savannah Zone, Bamenda I Sub-Division, North West Region, Cameroon, between June and September 2019, respectively.&#x0D; The experiment was conducted under field conditions. Thirty 3-month-old seedlings were exposed to each pH level at 7-day intervals using a spray bottle. While two sets of thirty seedlings were administered sulphuric acid calibrated tap water with pH values of 4.0 and 3.5, the third set that constituted the control was sprayed with normal tap water. Data were collected on morphology, biomass, and leaf chlorophyll content at the end of the study and subjected to analysis of variance and Scheffé’s test.&#x0D; Results: The pH 3.5 treatment resulted in significantly lower responses of height (12.95 cm), number of leaves (15.28), leaf area (23.96 cm2) and total biomass (0.61 g) than the other two pH levels that did not differ for any of the traits. Average values between pH 4.0 and control were 20.39 cm, 22.00, 45.66 cm2 and 1.77 g. Stem diameter and root collar diameter declined from 2.87 mm and 4.14 mm at the control to 2.54 mm and 3.78 mm at pH 3.5, respectively. Leaves at pH 3.5 showed signs of necrosis, drying and curling. Leaf chlorophyll content was significantly greater in the control (45.30 SPAD units) than in the pH 4.0 (40.01 SPAD units) and pH 3.5 (39.82 SPAD units) treatments that displayed similar responses.&#x0D; Conclusion: The study reveals that simulated acid rain at pH 3.5 can have a harmful effect on chlorophyll content and growth of Eucalyptus grandis.

Comparative Effects and Phytotoxicity of Photo Fenton Solutions and Acid Rains on Cucumber (Cucumis Sativus) Plants: Treats and Console

The Eco-physiological assessments of variable parameters known to be essential for proper plant growth and health were determined in cucumber plants exposed to short term treatments in 42 days using two broad classification types; Photo Fenton solution generating OH radicals and simulated acids. Solutions containing different classification of scavengers of OH radicals and mannitol were employed as Controls. Results indicated that the acid rain and photo Fenton solution both decreased the photosynthetic rate (Amax), stomatal conductance (gs), photochemical efficiency of PSII in the dark (Fv/Fm), SPAD chlorophyll and they imparted severe foliar injuries on cucumber leaves. The acids treatments have the highest negative impact followed by the photo Fenton Solution. The mechanisms of phytotoxicity of the two solutions may be through OH radical and other Reactive Oxygen Species (ROS) generation. The addition of mannitol, catechin hydrate and tea solutions to the acids and photo Fenton solution mixtures all mitigated the negative effects of the duo on the cucumber plants. Mannitol at dosage applied in the present study can be adjudged to be the best in the amelioration of the negative effects of the fumigants. Future plant protection from deleterious impacts of atmospheric and hydrospheric pollutants can employ mannitol as scavengers of ROS.