Acid Rain Research Articles

Mathematical Modeling of the Process of Acid Rain Formation in Case of Emissions from Thermal Power Plants

Purpose. It is known that acid rain has a negative impact on the environment. The formation of acid precipitation in the atmosphere occurs as a result of the chemical interaction of fuel combustion products and atmospheric humidity. Acid rain leads to crop losses, deterioration of soil fertility, and acidification of water in reservoirs. The development of scientifically based methods for studying the intensity of such acidic pollution of the air and soil surface in regions with significant emissions from thermal power plants remains an urgent problem. To solve this problem, it is important to use mathematical modeling, since it is impossible to determine the impact of emissions from thermal power plants on the formation of acid rain experimentally. Therefore, the main goal of the work is to create a mathematical model for predicting the formation of acid rain in the event of emissions from thermal power plants. Methodology. To predict the process of acid rain formation, a three-dimensional equation of convective diffusion transport of a pollutant is used, which takes into account the wind speed profile, atmospheric stratification, emission intensity of an impurity, and wind direction. This equation is also used to describe the process of water vapor transport in atmospheric air. To describe the process of acid formation in atmospheric air, a stoichiometric relationship is used. The numerical integration of the modeling equation of transfer was carried out using the splitting method. Findings. A multifactorial numerical model was built that allows determining the zones where acid rain is formed. The problem of predicting the formation of acid rain in the case of emissions from thermal power plants on the basis of the constructed numerical model is considered. Originality. A numerical model is proposed to predict the occurrence of acid rain due to emissions from thermal power plants. The model is multifactorial and takes into account convection, atmospheric diffusion, and an uneven wind profile. A computer code has been created that allows for rapid assessment of acid pollution zones. Practical value. The developed computer code for analyzing the zones of acidic pollution of the environment in the case of industrial emissions makes it possible to predict the intensity of such pollution in various meteorological conditions.

Confining peroxophosphomolybdate within size-matched Zr-MOFs for extractive oxidative desulfurization

Deep desulphurization of diesel is essential because the sulfides from fuel combustion can cause acid rain, respiratory diseases and corrosion of industrial equipment. Peroxophosphomolybdate (BTA)3{PO4[MoO(O2)2]4}·3H2O, marked as PMo4, was confined in size-matched Zr-MOFs (UiO-66 and UiO-67) to prepared composites for extractive oxidative desulfurization. The composites underwent comprehensive characterization, including ICP-MS, FT-IR, XRD, SEM, XPS, TG and N2 adsorption–desorption analysis. Desulfurization test was conducted with PMo4 as homogeneous catalyst, and the reaction conditions were optimized. Then, the catalytic activity of the prepared composites was compared, and the result showed that the catalyst PMo4@UiO-67 can remove 94.1 % of the sulfides in the diesel within 100 min. After 15 consecutive tests, the total removal rate of sulfides still reached 88.5 %, thanks to the narrow window of carrier UiO-67 limited the leaching of the active component PMo4.

Effect of ph on migration patterns and degradation pathways of sulfamethazine in soil systems

Sulfonamide antibiotics (SAs) are widely used antimicrobial agents in livestock and aquaculture, and most of them entering the animal’s body will be released into the environment as prodrugs or metabolites, which ultimately affect human health through the food chain. Both acid deposition and salinization of soil may have an impact on the migration and degradation of antibiotics. Sulfamethazine (SM2), a frequently detected compound in agricultural soils, has a migration and transformation process in the environment that is closely dependent on environmental pH. Nevertheless, scarcely any studies have been conducted on the effect of soil pH changes on the environmental behavior of sulfamethazine. We analyzed the migration and degradation mechanisms of SM2 using simulation experiments and ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) techniques. The results showed that acidic conditions limited the vertical migration of sulfadimidine, and SM2 underwent different reaction processes under different pH conditions, including S-C bond breaking, S-N bond hydrolysis, demethylation, six-membered heterocyclic addition, methyl hydroxylation and ring opening. The study of the migration pattern and degradation mechanism of SM2 under different pH conditions can provide a solid theoretical basis for assessing the pollution risk of sulfamethazine degradation products under acid rain and saline conditions, and provide a guideline for remediation of antibiotic contamination, so as to better prevent, control and protect groundwater resources.

The effect of heavy precipitation on the leaching of heavy metals from tropical coastal legacy tailings

The continued growth in demand for mineral resources has led to a large amount of mining wastes, which is a major challenge in the context of carbon neutrality and climate change. In this study, runoff migration, batch leaching, and column experiments were used to investigate the short-, medium-, and long-term leaching of heavy metals from legacy tailings, respectively; the cumulative metal release kinetic equations were established, and the long-term effects of tailings leaching were verified by HYDRUS-1D. In runoff migration experiments, surface dissolution of tailings and the co-migration of adsorbed soil particles by erosion were the main carriers in the early stages of leachate formation (Mn ∼ 65 mg/L and SO42- up to 2697.2 mg/L). Batch leaching tests showed that the concentration of heavy metals in soil leached by acid rain were 0.1 ∼ 22.0 μg/L for Cr, 0.7 ∼ 26.0 μg/L for Cu, 4.8 ∼ 5646.0 μg/L for Mn, 0.3 ∼ 232.4 μg/L for Ni, and 1.3 ∼ 448.0 μg/L for Zn. The results of column experiments indicated that some soluble components and metals with high mobility showed a significant decreasing trend at cumulative L/S ≤ 2. Additionally, the metals have higher leaching rates under TCLP conditions, as shown by Mn > Co > Zn > Cd > Ni > Cu > Pb > Cr. The fitting results of Langmuir equation were closer to the cumulative release of metals in the real case, and the release amounts of Mn, Zn, Co, and Ni were higher with 55, 5.84, 2.66, and 2.51 mg/kg, respectively. The water flow within tailings affects the spatial distribution of metals, which mainly exist in relatively stable chemical fractions (F3 + F4 + F5 > 90 %) after leaching. Numerical simulation verified that Mn in leachate has reached 8 mg/L at a scale of up to 100 years. The research results are expected to provide technical basis for realizing the resource utilization of tailings in the future.

Formulation and durability of slag/metakaolin-based geopolymers with 70 % municipal solid waste incineration fly ash (MSWI FA)

In this study, municipal solid waste incineration fly ash (MSWI FA) was used as an alternative to geopolymers for resource recovery. The 70 % MSWI FA mixing and durability of slag-metakaolin based geopolymer was assessed. The optimum formulation was determined based on MSWI FA mixing, silica-aluminum ratio (A), sodium-silica ratio (B), water-solid ratio, and slag content, and the solidification effect was analyzed in terms of compressive strength and heavy metal leaching concentration. The solidified products were tested by acid rain leaching, acid and alkali immersion, high-temperature calcination, and freeze-thaw cycles. The crystalline phases and structures of the solidified products were analyzed for stability using X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR) Spectroscopy , and Scanning Electron Microscopy (SEM). The experimental results revealed that when the mixing amount of MSWI FA was as high as 70 %, the compressive strength of the solidified products under the optimal formulation was 11.97 Mpa, and the solidification rate of heavy metals was greater than 92 %. The solidified products also exhibit good durability properties such as acid and alkali resistance, high-temperature resistance, and freeze-thaw resistance. Based on this study, the geopolymer possesses strong MSWI FA treatment capability.

Differential Responses of Soil Microbial and Carbon‐Nitrogen Processes to Future Environmental Changes Across Soil Depths and Environmental Factors

AbstractAccurately predicting carbon‐climate feedbacks relies on understanding the environmental factors regulating soil organic carbon (SOC) storage and dynamics. Here, we employed a microbial ecological model (MEND), driven by downscaled output data from six Earth system models under two Shared Socio‐economic Pathways (SSP1‐2.6 and SSP5‐8.5) scenarios, to simulate long‐term soil biogeochemical processes. We aim to analyze the responses of soil microbial and carbon‐nitrogen (C‐N) processes to changes in environmental factors, including litter input (L), soil moisture (W) and temperature (T), and soil pH, in a broadleaf forest (BF) and a pine forest (PF). For the entire soil layer in both forests, we found that, compared to the baseline period of 2009–2020, the mean SOC during 2081–2100 increased by 40.9%–90.6% under the L or T change scenarios, versus 5.2%–31.0% under the W change scenario. However, soil moisture emerged as a key regulator of SOC, MBC and inorganic N dynamics in the topsoil of BF and PF. For example, W change led to SOC gain of 5.5%–37.2%, compared to the SOC loss of 15.5%–18.0% under L or T scenario. Additionally, a further reduction in soil pH by 0.2 units in the BF, representing the acid rain effect, significantly resulted in an additional SOC gain by 14.2%–21.3%, compared to the LTW (simultaneous changes in the three factors) scenario. These results indicate that the results derived solely from topsoil may not be extrapolated to the entire soil profile. Overall, this study significantly advances our comprehension of how different environmental factors impact the dynamics of SOC and the implications they have for climate change.

Importance of Environmental Education in the Context of Natural Sustainability

Anthropogenic activities are causing degradation in the environment at an alarming pace, which in turn causes a host of environmental challenges including acid rain, rising sea levels, incorrect monsoons, and global warming. There are many great things about science and technology, but we are paying an extremely high "price" for them. Industrialization alone is not enough to sustain economic growth. Scientific knowledge and technological advancement can only play a supporting role in the movement toward a more sustainable global environment; they cannot provide the solution on their own. Therefore, individuals need to be empowered with vital information and education if we are to attain an acceptable degree of global environmental sustainability. It is feasible to bring about tremendous changes in the public's thinking via educational institutions since they are the locations where society is most closely encountered. Encouraging learner awareness of ambient conditions in their area and their active engagement in fixing local issues makes environmental education a useful preventative measure to save youngsters living in polluted regions. The impact of environmental education on environmental sustainability is the focus of this study. The literature provides essential understanding into the ways in which Environmental Education (EE) might encourage pro-environmental behaviour via studies that concentrate on the link between various experiences and learning outcomes. In accordance with the importance of environmental education for sustainable development, this research aims to conduct a survey on the effectiveness of an intervention called EESD (Environmental Education Suitability Development) in improving students' environmental knowledge.

Low levels of Al stimulate the aboveground growth of Davidia involucrata saplings

Davidia involucrata is a woody perennial and the only living species in the Genus Davidia. It is native to southern China where it holds cultural and scientific importance. However, D. involucrata is now an endangered species and its natural range includes low pH soils which are increasingly impacted by acid rain, nitrogen deposition and imbalanced nutrient cycling. The combination of these stresses also poses the additional risk of aluminum (Al) toxicity. Since the responses of D. involucrata to low pH and aluminum toxicity have not been investigated previously, a hydroponic experiment was conducted to examine the growth of one year old D. involucrata saplings after 50 d growth in a range of pH and Al conditions. Plant biomass, morphology, antioxidant enzyme activity, mineral concentrations and plant ecological strategy were compared at pH 5.8 and pH 4.0 without added Al (AlCl3) and in 0.1, 0.2 and 0.5 mM Al at pH 4.0. Our results showed that compared with pH 5.8, pH 4.0 (without added Al) not only inhibited root and shoot growth but also limited accumulation of nitrogen (N) and phosphorus (P) in leaves of D. involucrate. However, low Al concentrations (0.1 and 0.2 mM Al) at pH 4.0 partially restored the aboveground growth and leaf N concentrations, suggesting an alleviation of H+ toxicity by low Al concentrations. Compared with low Al concentrations, 0.5 mM Al treatment decreased plant growth and concentrations of N, P, and magnesium (Mg) in the leaves, which demonstrated the toxicity of high Al concentration. The results based on plant ecological strategy showed that D. involucrate decreased the competitiveness and favored its stress tolerance as pH changed from 5.8 to 4.0. Meanwhile, the competitiveness and stress tolerance of D. involucrata increased and decreased at low Al concentrations, respectively, and decreased and increased at high Al concentration, respectively. These trade-offs in ecological strategy were consistent with the responses of growth and antioxidant enzyme activity, reflecting a sensitive adaptation of D. involucrata to acid and Al stresses, which may aid in sustaining population dynamics. These findings are meaningful for understanding the population dynamics of D. involucrata in response to aluminum toxicity in acid soils.

Acid rain prediction in the Guangdong-Hong Kong-Macao Greater Bay Area using an explainable machine learning framework

Acid rain, characterized by pH values lower than 5.6, is a critical natural disturbance of ecosystems, which threatens the sustainability of ecosystems, agriculture, and human society worldwide. However, accurately quantifying the driving factors of acid rain remains challenging due to a changing environment of significant spatial heterogeneity. Here, we established an explainable machine-learning framework (MLF) using 19 meteorological, air pollutant, and land surface variables as model input to construct the pH values of acid rain across the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) during 2006–2021. The MLF includes Extreme Gradient Boosting (XGBoost) for acid deposition prediction and a SHapley Additive exPlanations method (SHAP) for interpreting factor importance. The results indicated that the observed increases in pH values of acid rain are predominantly controlled by the significant decreases in maximum daily sulfur dioxide (SO2) concentration of air across GBA, with its relative contribution ranging from 16.2% to 31.9% for each city. Changes in the urbanization rate and the proximity to the coast also play significant roles in predicting the pH values of acid rain. Meteorological variables typically have minimal impact on acid rain predictions, with their contribution generally being less than 5%, indicating the complex physical process of acid rain generation. This study enhanced our comprehension of the spatial variability of acid rain drivers across a highly developed region, providing valuable insights and case studies for regions worldwide that frequently experience acid rain.

Investigation of the pollutant load of artisanal-refined gasoline in the Niger Delta region of Nigeria and its implications on air quality

In order to examine the gaseous pollutants generated by artisanal refined gasoline and the contribution to air pollution associated with such combustion in the Niger-Delta region of Nigeria, this study collected a sample of indigenously refined gasoline product each from thirty (30) different randomly selected artisanal camps in the Niger-Delta region and subjected all the collected samples to combustion. Fifty (50) ml of each gasoline sample was combusted at controlled conditions, and the concentrations of gaseous emissions from the process were measured using a combustion emission analyser. Pollutants characterised by the Department of Petroleum Resources which include sulphur dioxide (SO2), carbon monoxide (CO), oxides of nitrogen (NOx), hydrocarbons (HC) and carbon dioxide (CO2) were characterised. The average concentrations of the emissions were 211.50 mg/m3, 7.18 mg/m3, 17.51 mg/m3, 3011.33 mg/m3, and 500.39 mg/m3 for CO, NOx, SO2, CO2, and HC respectively. The concentrations of SO2 and NOx measured were within the Federal Environmental Protection Agency (FEPA) set limits for combustion emissions from stationary sources but breached World Health Organization (WHO), World Bank and Environmental Guidelines and Standard for Petroleum Industry in Nigeria (EGASPIN) set limits. The concentrations of CO and HC exceeded FEPA, WHO, World Bank and EGASPIN set limits and hazardous on Air Quality Index (AQI) classification. Elevated concentrations of CO and HC in the atmosphere pose a major threat to ambient air quality and human health, especially in locations where artisanal-refined fuel is predominantly utilised. Associated risks include poor visibility, occurrence of acid rain, blood poisoning and cancer-related diseases. In addition to these effects are the worsening global warming crises associated with CO2 emission, a major product of fossil fuel combustion.

Fluorine-free approaches to impart photovoltaic systems with self-cleaning and anti-icing features

Dust deposition on photovoltaic systems has a significant impact on the transmittance, temperature, and roughness, causing reductions in their power generation efficiency and lifetime. A promising approach to deal with this problem relies on the use of superhydrophobic coatings to impart the surfaces of these devices with self-cleaning properties. In this work, materials with different chemistry and morphology were added to an acrylic dispersion to create hydrophobic surfaces using a non-fluorinated coating simple strategy for glass substrates. Results showed that materials with more complex morphology, namely the spherical shape of silica nanoparticles, and the needle-like and prism-like structures of zinc oxide, imparted the glass with higher water contact angles. All coatings prepared displayed self-cleaning features and good adhesion to the glass substrate. Coatings comprising silica nanoparticles, zirconia and alumina modified with HDMTS were the best ones to prevent ice formation. In terms of chemical stability, all the coatings resisted acidic conditions close to acid rain pH and solvents with mild polarity. Therefore, the coatings proposed hold great potential to expel dust contaminants and prevent ice formation of photovoltaic devices, increasing their lifetime and power generation efficiency.

Hourly near-ground NO2 concentration retrieval from geostationary satellite observations

Abstract. Nitrogen dioxide (NO2) is an important contributor to the formation of acid rain, photochemical smog and aerosol particles, which seriously endangers public health. At present, remote sensing of polar-orbiting satellites is a conventional means to obtain large-scale NO2 distribution, but it cannot capture the rapid change because of long revisit periods. The Advanced Himawari Imager (AHI) on the Himawari-8 geostationary satellite has the advantage of high time resolution, which makes it possible to realize near-real-time atmospheric monitoring. Here, based on the absorption characteristics of NO2 in infrared radiation, hourly near-surface NO2 concentrations are retrieved based on the brightness temperature from AHI and auxiliary information such as meteorology and aerosol. The results of 10-fold cross-validation show that NO2 estimations from satellite are in good agreement with in-situ measurements, and their determination coefficient (R2) can reach 0.79. Due to different emission and atmospheric diffusion conditions at different time, the model performance presents a diurnal variation of high accuracy in the noon and afternoon but low accuracy in the morning. Based on the retrieval dataset, it is found that high NO2 concentrations are mainly concentrated in the densely populated and industrial areas such as the North China area. In addition, NO2 pollution mainly occurs in autumn and winter, and the average NO2 concentration in winter is about 1.63 times that in summer in 2021. This study provides a new insight for satellite retrieval of NO2, which is of great significance for real-time pollution monitoring and public health protection.

Considering the bioavailability and bioaccessibility of metal(loid)s for risk assessment of soils affected by different non-ferrous metal activities in Southwest China

Toxic metal(loid)s released into the soil by non-ferrous metal mining and smelting activities pose a serious threat to residents and the surrounding ecosystem. Considering only total metal(loid) concentrations likely overestimates routine (eco)toxicological risk assessment of soil. We hypothesize that considering metal(loid) bioavailability/accessibility will improve the accuracy of risk assessment. To test this hypothesis, four mining areas in Southwest China, including mining and surrounding sites, were studied. Bioavailability was determined considering metal(loid)s leached by a simulated strong acid rain (SSAR) treatment. In the four areas, the mining site showed higher cumulative releases of metal(loid)s under SSAR treatment than the agricultural field located in the surrounding sites. Thus, the bioavailable metal(loid)s contents were continuously being released during SSAR treatment and likely increased the environmental risk. Ecological and health risk assessment of soil, calculated using total metal(loid)s content, was corrected considering bioavailable/accessible metal(loid)s, which was determined by the heavy metal(loid)s forms and in vitro simulated intestinal stages. Although the corrected indices indicated that the risk of metal(loid)s-contaminated soil was reduced, unfavorable ecological and health risks remained in the four areas. Our study provides new perspectives to better predict the risk of bioavailable/accessible metal(loid)s in non-ferrous metal contaminated and surrounding soils.

Soil Erosion Risk Estimation by using Semi Empirical RUSLE model: A case study of Maniyari Basin, Chhattisgarh

Soil is the protective skin of our earth's surface, but today’s numerous population pressures on land, along with industrialization, climatic variability such as a vigorous increase in temperature, acid rain, and deforestation, definitely degrade the quality of land. It should have to evaluate the quality of the land and find out the nutrition status as well as the soil health. The present study is employed in a Geographic Information System (GIS) environment to predict erosion risk using the Semi-Empirical Revised Soil Loss Erosion Model (RUSLE). The physiographic soil map has been prepared by visual interpretation of the Sentinal 2 satellite image, from which the soil erodibility factor has been derived. The digital elevation model (DEM) has been prepared from a contour map and used as the base map for the topographic-related analysis. In this model, the slope length (LS) factor has been prepared from the DEM. The crop conservation and management factor (C) and support practice factor (P) factors have been derived from the LULC map. It has been found that 4.45% of the watershed comes under very high erosion, 3.50% under high erosion, 7.80% under moderate erosion, 11.37% under low erosion, and 51.36% under a very low erosion-prone zone.

Nitric Acid Rain Decreases Soil Bacterial Diversity and Alters Bacterial Community Structure in Farmland Soils

Being regarded as one of the environmental problems endangering biodiversity and ecosystem health, acid rain has attracted wide attention. Here, we studied the effects of nitric acid rain (NAR) on the structure and diversity of microbial communities in agricultural soils by laboratory incubation experiments and greenhouse experiments. Our results indicated that NAR had an inhibitory effect on soil microorganisms, showing a significant reduction in the Chao1 index and Shannon index of soil bacteria. Proteobacteria, Acidobacteriota, Actinobacteriota, and Chloroflexi were the dominant bacterial phyla under NAR stress in this study. NAR significantly reduced the relative abundance of Proteobacteria and Actinobacteria, but significantly increased the relative abundance of Acidobacteriota and Chloroflexi, suggesting that NAR was unfavorable to the survival of Proteobacteria, and Actinobacteria. It is worth noting that the inhibitory or promoting effect of NAR on the dominant bacterial phyla gradually increased with increasing NAR acidity and treatment time. In addition, the study observed that the change in soil pH caused by NAR was the main reason for the change in soil bacterial community structure. In summary, the effects of NAR on soil microorganisms cannot be underestimated from the perspective of sustainable agricultural development.

Deterioration of dynamic fracture properties of granite under the coupled effects of hydrochemical solutions and freeze-thaw cycles

Fractured rock mass is a kind of complex rock mass widely existing in engineering projects, which is often subjected to erosion by different pH hydrochemical solutions such as surface water, acid rain, acidic and alkaline wastewater discharge, and deicing salts. When the rock project in a cold region suffers from the coupled effects of hydrochemical solutions and freeze-thaw (FT) cycles, the frost-heave-thaw-shrinkage characteristics of rocks are different from ordinary FT under dynamic loads, and the effect of FT cycles may be enlarged or reduced in different hydrochemical solutions. How to determine the effect of FT cycles on the expansion and changes of rock fractures, which is related to the safety and stability of many engineering rock masses in cold regions. In this study, the microstructure changes of specimens induced by hydrochemical solutions and cyclic FT were measured using nuclear magnetic resonance (NMR) and X-ray diffraction (XRD). The dynamic fracture tests were conducted using single cleavage triangle (SCT) granite specimens. Crack propagation gauge (CPG) was applied to examine crack propagation speed (CPS). The findings indicate that the mineral composition of the granite did not vary large with the hydrochemical solutions and FT cycles, but the maximum diffraction intensity of each mineral composition changed. For the granite under the coupling effect of hydrochemical solutions and FT cycles, the granite specimen in NaOH solution with 100 FT cycles has the highest dynamic fracture toughness and is 10.76 MPa·m1/2, dynamic fracture toughness of H2O, HNO3 and Na2SO4 solutions are only 0.94, 0.91 and 0.93 of that of NaOH solution. With increasing FT cycle times, the dynamic fracture toughness and crack speed decrease, whereas the porosity increases. For the specimen in NaOH solution and 100 FT cycles, dynamic fracture toughness decreased by 18.12 % without FT cycles and crack speed decreased by 34.18 %, the porosity increases by 26.42 %.

HYBRID MODEL AND FRAMEWORK FOR PREDICTING AIR POLLUTANTS IN SMART CITIES

The pollution index of any urban area is indicated by its air quality. It also shows a fine balance is maintained between the needs of the populace and the industrial ecosystem. To mitigate such pollution in real-time, smart cities have a significant role to play. It's common knowledge that air pollution in a city severely affects the health of its dependents. More alarmingly, human health damage and disease burden are caused by phenomena like acid rain, and global warming. More precisely, lung ailments, CPOD, heart problems and skin cancer are caused by polluted air in congested urban places. Amongst the worst air pollutants, CO, C6H6, SO2, NO2, O3, RSPM/PM10, and PM2.5 cause maximum havoc. The climatic variables like atmospheric wind velocity, direction, relative humidity, and temperature control air contaminants in the air. Lately, numerous techniques have been applied by researchers and environmentalists to determine the Air Quality Index over a place. However, not a single technique has found acceptance from all quarters as being effective in every situation or scenario. Here, the main aspect relates to achieving authentic prediction in AQI levels by applying Machine Learning algorithms so worst situations can be averted by timely action. To enhance the performance of Machine Learning methods study adopted imputation and feature selection methods. When feature selection is applied, the experimental outcomes indicate a more accurate prediction over other techniques, showing promise for the application of the model in smart cities by syncing data from different monitoring stations.

Preparation of a nano aluminum phosphate enhanced hydroxyapatite coating for marble conservation

Open-air marble relics in Beijing are experiencing degradation due to sugaring, dissolution and other illnesses. Therefore, it is necessary to apply a protective and reinforcing coating to the weathered surface. Hydroxyapatite (HAP) has significantly lower solubility and dissolution rate compared to calcite. Additionally, HAP has similar lattice parameters with calcite, suggesting that a cohesive layer of HAP can be formed over calcite. In fact, HAP exhibits a lattice mismatch of 5 % with calcite, which might potentially lead to stress if the layer exceeds a few nanometre in thickness. On the other hand, aluminum phosphates (ideally, B-AlPO4) only exhibit a 1 % mismatch with calcite and have a solubility lower than that of calcite. In this study, in order to improve the property of HAP in marble conservation, sol–gel method was employed to synthesize nano AlPO4, which were then incorporated into the phosphate solution to produce protective coating on the stone surface. The coatingʼs morphology and the structure were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), high capacity 3D X-ray microscopy (XRM), optical microscope, and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). Moreover, the color, the contact angle, the three-point bending strength measurements, as well as the simulated acid rain test and freeze–thaw treatment were performed to assess the chromatic aberration, hydrophilicity, reliability, and durability of the coating. Results indicated that the nano AlPO4, with its matched lattice parameters and nucleation site provision, facilitated the formation a coherent HAP layer of crystal flakes. Subsequently, the anti‑corrosion property, freeze-thaw resistance and consolidation property of the coating were improved, demonstrating the potential application the hybrid of HAP with nano AlPO4 in the preservation of marble.

Petroleum Exploration in the Niger Delta Region and Implications for the Environment: A Review

Petroleum exploration and production in the Niger Delta, Nigeria, has been a significant source of revenue and foreign exchange for the country. Nevertheless, this industry has also been blamed for serious environmental pollution in the region. This review aims to shed light on the implications of petroleum exploration in the Niger Delta region and the resultant environmental damage it has caused. One of the most severe consequences of petroleum exploration in the Niger Delta is the frequent occurrence of oil spills. Due to aging infrastructure, poor maintenance, and criminal activities such as oil theft, pipeline spills have become a recurrent problem. Oil spills lead to the destruction of farmland, loss of biodiversity, poisoning of water sources, and widespread contamination of ecosystems. Petroleum exploration and production activities release substantial pollutants into the atmosphere, posing a significant threat to both human health and the environment. The burning of natural gas during oil production, also known as flaring, is particularly prevalent in the Niger Delta. This practice results in the emission of toxic gases such as carbon dioxide, methane, and sulfur dioxide, contributing to climate change, respiratory diseases, and acid rain. Petroleum exploration in the Niger Delta has led to significant damage to forests and mangrove ecosystems. The destruction of these vital habitats has serious implications for species survival. Oil exploration activities often release harmful chemicals and wastes into the region's water bodies. These pollutants infiltrate the groundwater and surface water, leading to contamination that poses severe risks to human health and aquatic life. Contaminated water supplies have been linked to increased instances of skin diseases, as well as liver and kidney problems among the local population. The negative environmental implications of petroleum exploration in the Niger Delta also have severe socioeconomic consequences. Displaced fishermen and farmers face declining livelihoods, while sporadic employment opportunities generated by the oil industry do not compensate for the long-term damage inflicted on the region.

Development of Measures to Reduce Air Pollutants As Much As Possible

The papers include contemporary ecological challenges, steps taken to reduce artificial pollution, and environmental issues relating to the atmosphere's circulation through natural and artificial processes. A major threat to world health, air pollution can have a range of negative consequences on the environment, such as haze, eutrophication, acid rain, and harm to animals. The combustion of fossil fuels for energy production and transportation is the main cause of air pollution. The effects of air pollution on human health are significant, with millions of people affected by respiratory and cardiovascular diseases, reproductive and central nervous system dysfunctions, and cancer. The articles emphasize the importance of reducing air pollution through various measures, such as improving energy efficiency, promoting renewable energy sources, reducing emissions from transportation, and implementing policies and regulations to control air pollution. The articles also highlight the need for public awareness and a multidisciplinary approach to tackle the problem of air pollution and its impact on climate change and public health.