Influence Of Acid Rain Research Articles

Effect of Acid Rain on Human Living Environment and Human Self

There have been countless scientists studying acid rain from the 1970s to the present, and of course, there have been reviews and studies of this kind, but these studies are not enough. The influence of acid rain on human beings, as well as the environment, is discussed in this paper. First, the production of acid rain is caused by a mix of human activities, as well as natural processes. Human activities like burning fossil fuels, industrial emissions, and transportation release pollutants such as sulfuric and nitric acid, as well as acid rain, are produced when sulfur dioxide (SO2) and nitrogen oxides (NOx) in the atmosphere combine with water vapor and oxygen. Acid rain creates a large bad effect to the ecosystem. It harms water bodies, soils, vegetation, and biodiversity. In addition, acid rain poses a threat to human health. Pollutants in acid rain can irritate the respiratory system and cause respiratory diseases. To combat the problem of acid rain, both individual and government efforts are critical. In the future, people need to develop technology and do more research to solve acid rain. The meaning of the essay is to let more people know about acid rain, how acid rain affect the world, and what human can do to solve acid rain.

Acid Rain and Seed Germination: A Predictive Model Using ML-based CART Algorithm

The impact of acid rain on the germination of seeds is a significant concern in agricultural and environmental studies. Acid rain, characterized by elevated acidity levels due to pollutants like sulfur dioxide and nitrogen oxides, can adversely affect the germination process of various plant species. The objective of this study was to evaluate the impact of simulated acid rain (SAR) on the germination of Brinjal (Solanum melongena Linn.) and Cowpea (Vigna unguiculata ssp. cylindrica L. Walpers) crops. The experiments were conducted using eight plastic trays of approximately 25 cm. x 30 cm dimensions. Four trays were used for experiments with brinjal seeds (Set I), while the other four were used for cowpea seeds (Set II). One tray from each set was used as positive control and treated with normal pH 5.6, while the other three trays from each batch were treated with SAR solutions of pH 4.5, 3.5, and 2.5. Brinjal seed germination percentage and seed vigor were inferior to Cowpea seeds. The seeds treated with SAR (pH 4.5, 3.5, and 2.5) showed hindered seed germination. Furthermore, a more significant inhibitory effect was observed at lower pH values. The mean germination percentage of seeds was highest for standard SAR (pH 5.6) in the case of Brinjal seeds, while it was recorded lowest for Cowpea seeds. The results indicate that plants do not respond uniformly to SAR. To investigate the behavior of the simulated acid rain data, a Machine Learning-based Decision Tree Algorithm was employed to identify and optimize conditions. Cowpea was predicted to get 95% seed germination, whereas brinjal would only be 64% in acid rain of pH value 5.05 for 36 hours. In conclusion, utilizing a Machine Learning-based CART algorithm has provided valuable insights into predicting the germination behavior of seeds under the influence of acid rain.

Effect of Acid Rain on Mechanical Properties and Aging Mechanism of Asphalt

Through the preparation of nitric acid–type acid rain, mixed acid rain, and sulfuric acid–type acid rain, an experimental method of periodic soaking of asphalt was developed. Then, using a four-component test, the four-component mass fraction of aging asphalt was obtained. The change characteristics of functional groups of aged asphalt were analyzed using infrared spectroscopy, and the aging mechanism of aged asphalt was analyzed using differential scanning calorimetry. Based on molecular dynamics theory, the bulk modulus and shear modulus of aged asphalt were calculated by establishing a molecular model of acid rain and a molecular model of aged asphalt. The diffusion coefficient, cohesive energy density, solubility, and other parameters of the aging asphalt molecular model were calculated. The influence of acid rain on the mechanical properties of asphalt was explored at the molecular level, and the mechanism of acid rain aging asphalt was explored. The results show that sulfuric acid–type acid rain has the greatest impact on the mechanical properties of asphalt and causes the most serious aging of asphalt, followed by mixed acid rain, and nitric acid–type acid rain has a relatively small impact on the mechanical properties of asphalt and the aging of asphalt.

Influence of acid rain and root reinforcement coupling factors on disintegration characteristics of expansive soil.

The effect of soil fixation and anti-scour instability of slope vegetation generally depends on the strength and anti-disintegration ability of slope soil due to increase of root system. Therefore, it is particularly necessary to study the disintegration characteristics of expansive soil related to slope instability under acidic conditions (simulated acid rain). In this paper, the response surface method (RSM) was used with the pH value, root diameter, root length, root coefficient, and distribution as independent variables, and the disintegration amount of root-soil (DARS) after 60min as the response value. Then X-ray diffractometer (XRD) was used to analyze the mineral composition changes of the sample under this environment. Simultaneously, the plasticity index of expansive soil at different values of pH was studied to discuss the disintegration mechanism of root compound expansive soil in an acid environments. The results show that the root system improves the anti-disintegration characteristics of the root-soil, and the effects of various factors on the amount of disintegration were as follows: root length > pH value > root distribution > root amount > root diameter. The DARS with a length of 20mm increased by 26.67% and 41.56% compared to the 30mm and 40mm. Compared to the horizontal distribution and horizontal + slant distribution, the DARS with slant distribution was increases by 11.39% and 20.24% respectively. The DARS with 2 roots is increased by 9.92% and 16.75% compared to 4 and 6 roots respectively. The 1mm diameter DARS is 6.65% and 15.49% higher than the 2mm and 3mm, respectively. In addition, an acidic environments can lead to an increase in the amount of disintegration or rate of disintegration. The disintegration at pH = 4.2 was increased by 11.4% and 22.4% compared to pH = 5.6 and pH = 7, respectively. The acidity affects soil disintegration is due to the hydrophilic minerals in the expansive soil react with H+ ion in the acid solution to form soluble salts. Due to the dissociation and leaching of free quartz and metal oxides in the soil to varying degrees, the ability of expansive soil to accumulate is reduced. The intensity of erosion and leaching decreases with increasing pH. In addition, the pH value can affects the plasticity index of the soil, which increases with the increasing pH, thus affects the disintegration properties of the expansive soil.

Mechanical behavior and constitutive model for loess samples under simulated acid rain conditions

Acid rain is mainly composed of sulfuric acid and nitric acid aqueous solutions, which can deteriorate the mechanical properties of soil and thus threaten the safety of soil engineerings. In this paper, the influence of sulfuric acid rain on mechanical properties of loess soil samples was studied. The diluted sulfuric acid solution has respectively pH 5.0, 4.0 and 3.0 to simulate the acid rain condition, and the triaxial compressional tests and scanning electron microscope were carried out to investigate the deteriorated properties and evolution of the microstructure of the saturated loess samples. The results demonstrated that acid rain made the porosity of loess samples larger, and changed the pore distribution and contacts of soil grains, so that the mechanical properties of loess samples varied in some degree. With the decrease of pH value, both the peak value of the deviatoric stress and volumetric contraction of loess samples decreased, which reduced the parameters of shear strength of loess samples. Furthermore, a framework of the chemical–mechanical model for loess under the action of acid rain was established, in which loess was considered as a porous medium material, and the influences of acid rain with different pH values were taken into account in the double-hardening constitutive model, and the model was also verified by the triaxial test results finally.

Influence of acid rain on slope instability mechanism—a case study in Sichuan provincial highway, China

Acid rain has important influences on the physical and mechanical properties of rock as a result of mineral conversion and dissolution of cement. There are clear spatial correlations between the occurrence of slope failure and rainfall pH value in acid-rain areas. Although some fatal landslides have been ascribed to acid rain, those landslides all consisted of sedimentary rocks that generally contained carbonate minerals, which are particularly susceptible to dissolution in acidic conditions. This paper describes the mechanical deterioration of the structural plane based on acid-rain simulation experiments on a slope cut in hard rock along Sichuan provincial highway S211, China. In the experiments, the cohesion and internal friction angle of the structural plane fell to 35.4% and 6.8% of their original values, respectively, and the strength deterioration exhibited a power-law relationship with the exposed area of the rock bridges. Mineralogical and hydrochemical analyses including polarising microscopy, X-ray diffraction, scanning electron microscopy, and inductively coupled plasma optical emission spectrometry were employed to describe the micromechanisms of weakening. Mechanical weakening of the structural plane is attributed to deterioration of both the composition and the structure. Transformation from hard essential minerals to clay minerals through pyroxene chloritisation, plagioclase illitisation, illite smectitisation, and chlorite dissolution reduced the strength properties of rock bridges. In addition, abundant secondary micro-cracks were formed by propagation of worm-like dissolution pits, thus disintegrating rock bridges and further reducing the strength of the structural plane. This paper provides a better understanding of slope failure mechanisms in areas affected by acid rain.

Study of Macro‐ and Mesodamage of Remolded Loess under Alternating Dry and Wet Conditions in an Acid Rain Environment

As a national development plan, ecological protection of the Yellow River Basin has attracted extensive social attention in recent years. Considering the influence of acid rain on the engineering characteristics of loess in this area, we investigated changes in the physical and mechanical characteristics of remolded loess under the combined action of acid rain and dry‐wet cycles by means of triaxial tests, nuclear magnetic resonance spectroscopy, and scanning electron microscopy. The results are as follows: in the acidic environment, the stress‐strain relationship of remolded loess undergoes stress hardening after dry‐wet cycling. The cohesion and internal friction angle of remolded loess are negatively correlated with the number of cycles. From the multiscale analysis of the dry‐wet cycle process under acid rain condition, the T2 spectrum of the test soil has three peaks at the micropore level. With the increasing number of cycles, the spectral area increases gradually, and the sample transitions from small pores to large‐ and medium‐size pores. At the microscopic level, the clay mineral particles among soil particles decrease in size, the contact mode between soil particles develops from stable to unstable, the particles are gradually rounded, and the fractal dimension decreases. Chemical erosion and physical erosion are special features of this experiment. Physical erosion causes particle erosion and pore growth, while chemical erosion includes reactions by feldspar. Together, physical and chemical reactions aggravate the soil deterioration process. These research results have laid a good experimental foundation for the ecological protection of the Yellow River Basin.

Transport and transformation of uranium and heavy metals from uranium tailings under simulated rain at different pH

Uranium tailings are radioactive and toxic solid wastes that could contaminate waters, soils and sediments. Actually the risk of contamination is poorly known due to the lack of knowledge on the mobility of contaminants, especially the influence of acid rain on leaching, transformation and speciation of contaminants. Here, we studied the effect of simulated rain at different pH on the transport and transformation of Mn, Sr, Pb and U from uranium tailings. Semi-dynamic leaching tests and sequential extraction were conducted for Mn, Sr, Pb and U to determine their leaching patterns and to determine their speciation in uranium tailings. Results show that Mn, Sr, Pb and U become more leachable with decreasing rain pH. The release of these metals is initially rapid and then reaches a near steady state. After leaching with simulated rain, concentrations of metal-exchangeable and metal-carbonate fractions in tailings are highly reduced. The process governing the leaching of Mn and U is mainly wash-off, whereas the leached Sr and Pb are dissolution-controlled.

Effects of sulfuric, nitric, and mixed acid rain on Chinese fir sapling growth in Southern China

The influence of acid rain on plant growth includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in root growth. In addition, the concentration of NO3- in acid rain increases along with the rapid growth of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO42-/NO3- (S/N) ratios, which were 1:0, 5:1, 1:1, 1:5 and 0:1, on Chinese fir sapling growth from March 2015 to April 2016. Results showed that Chinese fir sapling height growth rate (HGR) and basal diameter growth rate (DGR) decreased as acid rain pH decreased, and also decreased as the percentage of NO3- increased in acid rain. Acid rain pH significantly decreased the Chlorophyll a (Chla) and Chlorophyll b (Chlb) content, and Chla and Chlb contents with acid rain S/N 1:5 were significantly lower than those with S/N 1:0 at pH 2.5. The chlorophyll fluorescence parameters, maximal efficiency of Photosystem II photochemistry (Fv/Fm) and non-photochemical quenching coefficient (NPQ), with most acid rain treatments were significantly lower than those with CK treatments. Root activities first increased and then decreased as acid rain pH decreased, when acid rain S/N ratios were 1:1, 1:5 and 0:1. Redundancy discriminant analysis (RDA) showed that the Chinese fir DGR and HGR had positive correlations with Chla, Chlb, Fv/Fm ratio, root activity, catalase and superoxide dismutase activities in roots under the stress of acid rain with different pH and S/N ratios. The structural equation modelling (SEM) results showed that acid rain NO3- concentration and pH had stronger direct effects on Chinese fir sapling HGR and DGR, and the direct effects of acid rain NO3- concentration and pH on HGR were lower than those on DGR. Our results suggest that the ratio of SO42− to NO3− in acid rain is an important factor which could affect the sustainable development of monoculture Chinese fir plantations in southern China.

Adsorption of estrogen contaminants (17β-estradiol and 17α-ethynylestradiol) by graphene nanosheets from water: Effects of graphene characteristics and solution chemistry

In this research, adsorption of two estrogens, namely, 17β-estradiol (E2) and 17α-ethynylestradiol (EE2), by graphene nanosheets with different reduction degrees (rGOs) were investigated; and the effects of solution chemistry, such as natural organic matter (NOM), pH and ionic strength (IS), on the E2 and EE2 adsorption behaviors were also examined. Results indicated that adsorption abilities of estrogens increased with increasing the reduction degree of rGOs; the π–π stacking interaction could be considered as a predominant interaction to the enhanced adsorption capacities of rGOs. Among the solution chemistry, NOM exhibited the significant influence on estrogens adsorption, which suggested that once released into water environments, graphene materials will adsorb estrogens but with a lower adsorption ability than that in ultrapure water due to the ubiquitous presence of NOM in aquatic environments. Besides, estrogens adsorption on rGOs was pH-dependent, but the influence of acid rain would be insignificant due to slight change in low pH range. However, IS within the typical range in natural waters did not exhibit significant influence on the uptake of estrogens by rGOs. Above findings of this work might have significant implications for the fate and transport of estrogens with graphene materials in the environment.

Comparative effects of simulated acid rain of different ratios of SO42 − to NO3− on fine root in subtropical plantation of China

The influence of acid rain on forest trees includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in fine-root growth. In addition, the concentration of NO3− in acid rain increases with the rapidly growing of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO42−/NO3− (S/N) ratios, which were 5:1 (S), 1:1 (SN) and 1:5 (N), on fine-root growth from March 2015 to February 2016. Results showed that fine roots were more sensitive to the effects of acid rain than soils in the short-term. Both soil pH and fine root biomass (FRB) significantly decreased as acid rain pH decreased, and also decreased with the percentage of NO3− increased in acid rain. Acid rain pH significantly influenced soil total carbon and available potassium in summer. Higher acidity level (pH=2.5), especially of the N treatments, had the strongest inhibitory impact on soil microbial activity after summer. The structural equation modelling results showed that acid rain S/N ratio and pH had stronger direct effects on FRB than indirect effects via changed soil and fine root properties. Fine-root element contents and antioxidant enzymes activities were significantly affected by acid rain S/N ratio and pH during most seasons. Fine-root Al ion content, Ca/Al, Mg/Al ratios and catalase activity were used as better indicators than soil parameters for evaluating the effects of different acid rain S/N ratios and pH on forests. Our results suggest that the ratio of SO42− to NO3− in acid rain is an important factor which could affect fine-root growth in subtropical forests of China.

Desorption of 137Cs from Brachythecium mildeanum moss using acid solutions with pH 4.60–6.50

The desorption of 137Cs from the moss Brachythecium mildeanum (Schimp.) was performed using the following solutions: H2SO4 (I), HNO3 (II), H2SO4 + HNO3 (III) with pH values of 4.60, 5.15, and 5.75, respectively, as well as distilled water (D) with pH 6.50. After five successive desorptions, each lasting 24 h, 20.5–37.6% 137Cs was desorbed from the moss using these solutions, while 30.7% of the starting content was desorbed using distilled water. The first desorption removed the highest percent of the original content of 137Cs in the moss (11.3–18.4%). This was determined by measuring 137Cs activity. If the current results are compared with those obtained earlier it may be concluded that 137Cs desorption from mosses is not species-dependent. The obtained results indicate the necessity of investigating the influence of acid rain, or rather, of H+ ions, on desorption of other ions from biological systems, i.e., the role of H+ ions in spreading other polluting compounds and thus producing secondary environmental pollution. From the results of this study it follows that acid rain will lead, through H+ ion action, to a similar increasing pollution of fallout waters with other ionic compounds which may not be present in the water before the contact with the plants and thus enable the pollution spreading. In the investigated system, the replacement of H+ ions from acid rains by more dangerous radioactive ions occured, increasing the concentration of the radioactive ions in the water, which demonstrates that the same process takes place in fallout water.

Numerical Simulation on U(VI) in Uranium Tailing Impoundment Affected by Acid Rain

As acid rain getting more and more serious, increasing attention is given to environmental effect assessment of uranium tailings under the condition of acid rain. In the paper, influence of acid rain to partitioning coefficient (Kd) of U(VI) in soil was studied, and migration of radionuclide uranium in soil was simulated by computer. The static experiment results showed that the Kd value of U(VI) in soil reaches minimum value when pH is 2.0. When 2.0<pH<3.5, the Kd showed a rising tendency;The Kd in soil reaches maximum value when pH is 3.5. And when 3.5<pH<8.0, the Kd showed a decreasing tendency. This paper has taken a large uranium tailings impoundment in South China as an example studied by VisualModflow. After setting up models of groundwater movement and radionuclide migration in the study area, migration tendency of radionuclide U(VI) was simulated and pollution of radionuclide to environment was predicted. The results of simulation show that the migration of uranium speed to be the slowest when pH = 2.0, and the figure to be the fastest when pH = 3.5. Furthermore, maximum speed is about 1.24 times of minimum speed.

Research on Physical-Mechanical Property of Reshaped Loess Contaminated by Acid

With the rapid development of process of industrialization in Inner Mongolia, the environmental pollution, such as phenomenon of regional acid rain is gradually increasing. The Quaternary loess spread widely in Inner Mongolia. The ecological environment must be affected the intrusion acid rain. Meanwhile the physical-mechanical properties of original loess also are significantly influenced by the acid rain. To investigate the influence of acid rain on the physical-mechanical properties of loess, a series of triaxial tests in laboratory are carried out. The results showed that changes of PH value has significant effect on the specific gravity of soil grain, the limit moisture content , maximum dry density, and strength characteristics of loess.

Intercompartmental differences between cytosol and mitochondria in their respective antioxidative responses and lipid peroxidation levels in acid rain stress

Relatively little is known about the direct influence of acid rain (AR) on pro- and antioxidative changes in plant cells. Intercompartmental differences between cytosol and mitochondria have not been studied before. Aboveground parts of plants were treated with different pH variants of AR and oxidative damages (lipid peroxidation) as well as antioxidative enzyme activities (superoxide dismutase, SOD; ascorbate peroxidase, APx; glutathione peroxidase, GSH-Px) in the cytosolic and mitochondrial fractions were examined. The character of changes in antioxidative enzyme activities and of oxidative damages was closely connected with the cell compartment as well as with pH and time after treatment. The activity of both APx and GSH-Px increased more intensively in cytosol. Contrastingly, strong induction of lipid peroxide formation was observed in the mitochondrial fraction. In both cell compartments SOD activity did not change significantly. The results suggest that cucumber mitochondria are more susceptible to oxidative damage caused by AR than cytosol. Antioxidative defence of cytosol appeared to provide sufficient protection against the oxidative stress imposed by AR.

Acid Rain and Environmental Problems: Implications for the Teaching of Biology in Schools in Riverine Communities

This study was conducted to investigate the influence of acid rain and environmental problems on the teaching of Biology in schools in the riverine communities of Akwa Ibom State - Nigeria. One hundred and eighty (180) Biology teachers were selected using the stratified sampling technique. A questionnaire titled “Acid rain and Teaching of Senior Secondary Biology” (ARTSSB) was used to collect data for testing the four null hypotheses of the study at .05 level of significance. Data analysis was done using the t-test statistics. Findings were made that the damage of buildings by acid rain, the destruction of forest by acid rain, the devastation of arable land by acid rain and the acidification of surface and domestic waters by acid rain all had a significant influence on the study of senior secondary Biology. Recommendations were made among others that: the ecology component of the Biology curriculum for secondary schools should be effectively taught; important environmental issues including acidification of environment by acid rain should be incorporated into the senior secondary curriculum and be carefully thought by teachers of Biology. DOI: 10.5901/ajis.2013.v2n12p101

模拟酸雨对小麦产量及籽粒蛋白质和淀粉含量及组分的影响

以宁麦13和徐麦31两种小麦(<em>Triticum aestivum</em>)品种为材料,通过盆栽试验研究了不同pH值酸雨对小麦产量和籽粒品质的影响。结果表明:模拟酸雨抑制了小麦的生长,减少了生物量的积累。pH值2.0酸雨处理后宁麦13的单穗粒数和单茎产量分别较对照下降了48.6%和56.7%,徐麦31则分别下降了31.2%和39.7%,差异显著。小麦籽粒主要营养成分对酸雨胁迫响应不同,酸雨处理提高了籽粒氨基酸、蛋白质含量,pH值2.0酸雨处理后,宁麦13和徐麦31小麦籽粒中氨基酸含量分别比对照高36.6%和30.9%,总蛋白含量分别比对照高20.6%和15.1%,均与对照差异显著。而小麦可溶性糖、淀粉和脂肪含量较对照降低,且总体表现为酸度增强变化幅度增大。不同蛋白组分也对酸雨胁迫反应不同,酸雨处理提高了籽粒中清蛋白和球蛋白含量,而降低了谷蛋白含量和谷/醇。pH值2.0的酸雨处理后,宁麦13和徐麦31的清蛋白含量较对照分别增加了13.1%和23.9%,但与对照差异不显著。酸雨胁迫降低了总淀粉和支链淀粉含量,宁麦13和徐麦31的pH值2.0酸雨处理总淀粉含量分别较对照下降了11.8%和20.2%,与对照差异显著,但对直链淀粉含量影响不明显。可见酸雨不仅影响小麦的产量,而且对品质也有明显影响。酸雨处理尽管提高了籽粒总蛋白含量,但降低了谷蛋白和谷/醇,降低了其加工品质。;Acid rain is a worldwide important environmental problem, and might be a long-term trouble due to the rapid development of industry. The south area of Yangtze River is one major acid rain region in China, where crop production is severely limited by acid rain interacted with acid red soil. Wheat is the third largest crop in China and the second largest crop in Jiangsu province. Both yield and quality of wheat are of importance to food security. Wheat may suffer from acid rain stress during the whole stage, but the later growth stage of grain filling is more critical in determining grain yield and quality. Although the growth and physiological characteristics of crops exposed to acid rain have been broadly studied, little is known about the effect of acid rain on wheat quality. Here, effects of acid rain on wheat yield and quality in wheat were investigated. Two wheat (<em>Triticum aestivum</em>) cultivars of Ningmai 13 and Xumai 31 were selected in a pot experiment in Pailou experiment station in Nanjing Agricultural University, Jiangsu Province, China. Two acid rain treatments, i.e. by spraying solution of pH 2.0 and pH 4.0 were implemented, and that at pH 6.0 was set as control. Acid rain inhibited the growth of wheat. The dry weight of leaf, stem and ear under both acid rain treatments all were reduced as compared with the control. Grain number per spike and yield per shoot of Ningmai 13 was significantly reduced by 48.6% and 56.9% due to acid rain of pH 2.0 as compared with pH 6.0, respectively, and those of Xumai 31 was significantly reduced by 31.2% and 40.1%. As to wheat grain quality, the influence of acid rain was more complicated. Contents of amino acids in wheat grain of Ningmai 13 and Xumai 31 under acid rain of pH 2.0 increased 36.6% and 30.9%, respectively, as compared with control. The content of total protein in grains of Ningmai 13 and Xumai 31 under acid rain of pH 2.0 increased 20.6% and 15.1%, respectively. Acid rain increased contents of albumin and globulin, while decreased content of glutenin and the ratio of glutenin to gliadin. Compared with the control, the albumin content at pH 2.0 in Ningmai 13 and Xumai 31 increased 13.1% and 23.9%, respectively, and the globulin content at pH 2.0 in Ningmai 13 and Xumai 31 increased 35.7% and 100%, respectively. The other protein was also increased by acid rain. While glutenin content at pH 2.0 in Ningmai 13 and Xumai 31 decreased 4.4% and 15.2%, respectively, as compared with the control. Acid rain decreased contents of soluble sugar, starch and fat in wheat grain. The total starch content of Ningmai 13 and Xumai 31 under acid rain of pH 2.0 decreased 11.8% (<em>P</em><0.05) and 20.2% (<em>P</em><0.05), respectively. Acid rain also reduced amylopectin content, but has little effect on amylose content. As a result, the ratio of amylopectin to amylose was also decreased, although the difference was not significant. It is concluded that acid rain influenced both wheat yield and quality. Although acid rain enhanced protein content, grain quality was negatively affected as exemplified by the decreased glutenin content and ratio of glutenin to gliadin and amylopectin to amylose.

Effect of Simulated Acid Rain and Rare Earth Contamination on Soil Enzyme Activities in Rare Earth Ming Area, South Jiangxi, China

This study focus on the influence of acid rain, single and combined contamination of La and Ce, rare earth leachate of tailings on urease and catalase activities with the methods of leaching experiment and indoor thermostatic incubation. The results indicated that acid rain and rare earth contamination caused the change of soil enzyme activities. The change of urease activity accorded with hormesis effect of rare earth; at the preliminary stage of incubation, urease activity began to heighten and reached maximum value at 10th day; after being incubated for 15 days, urease activity initiated to reduce remarkably, and continued to 30th day. Accordingly, catalase activity was inhibited, then promoted slightly, the minimum value appeared in different time incubated by different solution: 15th day (La, Ce), 10th day(La + Ce), 5th day (rare earth leachate).

Artificial weathering of granite under earth surface conditions - the influence of acid rain on rocks and minerals (Part 3).

Artificial weathering of granite under earth surface conditions - the influence of acid rain on rocks and minerals (Part 3).

Artificial chemical weathering of gabbro under earth surface conditions- - : The influence of acid rain on rocks and minerals (part 4)

In order to predict the effect of acid precipitation on building stone, artificial chemical weathering of polished plates of Muroto Gabbro from Kochi, Shikoku Island, Japan, was conducted. An improved Soxhlet extraction apparatus was used with distilled water and HNO 3 , H 2 SO 4 and HCl solutions at pH 4 at 55°C for different periods of time up to 780 days. The gabbro was composed mainly of olivine (Fo 66 Fa 34 ), plagioclase (Ab 33 An 66 Or 1 ), and clinopyroxene (En 47 Fs 13 Wo 40 ). Morphological and chemical changes of each mineral surface were studied by SEM, EPMA and optical microscopic techniques. Alteration products were collected from the surface of each mineral on the polished plates by hand picking and examined using XRD. The leached sample solutions were analyzed for major and minor elements using ICP-AES, ICP-MS and ion-chromatography. It is evident that olivine changed into smectite, chlorite and talc by exposure to the various acid solutions used in the experiment. Smectite appeared to be formed from plagioclase during the artificial chemical weathering. However, altered products from clinopyroxene were not detected. Molar ratios of each element in the leached solutions to those in the fresh gabbro varied depending on the experimental period. The ratios of elements such as Mg, Mn, Fe, Ni, Zn and Co, which reflect the dissolution of olivine, were relatively high. Similarly, the ratios of Ca, Na, Sr, Ce, Sm and La, which reflect the dissolution of plagioclase, were relatively high. It seems, therefore, that olivine and plagioclase are easily weathered. It was also estimated from the molar ratios that the reactivity order of the acid solutions for olivine and plagioclase is H 2 SO 4 , HNO 3 and HCl.