Since the beginning of industrial revolution, pollution and damage to buildings in urban areas is very real. The cause is often due to the impact of air pollution. Pollution, acid rain is sulfur dioxide and nitrogen oxides, both published in the burning of fossil fuels such as coal and oil. Since industrial revolution, the two types of emissions. English, sulfur dioxide (SO2) peak in 1960, but has increased more than 80%. In 1999, emissions of sulfur dioxide in the amount of approximately 1.2 million tons. With emissions of nitrogen dioxide and nitrogen oxides, collectively known as Nox decreased since 1990, emissions in 1999 is around 1.6 million tons.
Although the fact that emissions reduction is not clear that air quality, which resulted in a decrease of decomposition. In fact, buildings that are thousands of years aging in the last 25 years and has quickly worsened. This can still show the changes on the surface of the stone Sulphation, a process that visible surface layer of the rain dissolves limestone sulphated wins.
Only in the last ten years, or the efforts that have been conducted to determine the amount of material damage due to acid. With concerns about the impact of acid rain on building materials has been raised in the Chamber of Local Authorities, Report of the Committee in September 1984. As part of the response from the government, the impact of Group (Berg) has been considered as a recommendation to the effect on the acid. It was not until relatively recently that the spatial concentration of pollution, acid rain and mechanisms for transport, to understand, so that more accurate estimate of the damage that occurred, Mai Mai in the design are made.
Materials Affected:
List of raw materials, a very long acids, as most materials are certain degrees of damage. The most vulnerable are: limestone, marble, steel, zinc, nickel, paint and plastic. Stone deterioration May many forms, including details of the stones and the introduction of black crusts from stone in the protected area. Metal corrosion is determined by oxygen and moisture, that the SO 2 accelerates. Most of the buildings that came from some acidic to which, therefore, that certain materials that are free from the effects. In addition to the atmospheric structure of the attack, cream butter in water, such as foundations and pipes are corroded.
The Chemistry of Corrosion:
Dry and wet deposition on the corrosion of materials. Secs deposits consist of gas and particles that fall to the ground near the source of emissions causing the damage. That sulfur dioxide is often deposited in secs 30 kilometers from the source. The wet deposition of pollution, if everywhere in the atmosphere reacts with moisture in clouds to the diluted acid. Effect also occurs, and the deposit of wet area may contain several dozen kilometers from the source.
Although the fact that emissions reduction is not clear that air quality, which resulted in a decrease of decomposition. In fact, buildings that are thousands of years aging in the last 25 years and has quickly worsened. This can still show the changes on the surface of the stone Sulphation, a process that visible surface layer of the rain dissolves limestone sulphated wins.
Only in the last ten years, or the efforts that have been conducted to determine the amount of material damage due to acid. With concerns about the impact of acid rain on building materials has been raised in the Chamber of Local Authorities, Report of the Committee in September 1984. As part of the response from the government, the impact of Group (Berg) has been considered as a recommendation to the effect on the acid. It was not until relatively recently that the spatial concentration of pollution, acid rain and mechanisms for transport, to understand, so that more accurate estimate of the damage that occurred, Mai Mai in the design are made.
Materials Affected:
List of raw materials, a very long acids, as most materials are certain degrees of damage. The most vulnerable are: limestone, marble, steel, zinc, nickel, paint and plastic. Stone deterioration May many forms, including details of the stones and the introduction of black crusts from stone in the protected area. Metal corrosion is determined by oxygen and moisture, that the SO 2 accelerates. Most of the buildings that came from some acidic to which, therefore, that certain materials that are free from the effects. In addition to the atmospheric structure of the attack, cream butter in water, such as foundations and pipes are corroded.
The Chemistry of Corrosion:
Dry and wet deposition on the corrosion of materials. Secs deposits consist of gas and particles that fall to the ground near the source of emissions causing the damage. That sulfur dioxide is often deposited in secs 30 kilometers from the source. The wet deposition of pollution, if everywhere in the atmosphere reacts with moisture in clouds to the diluted acid. Effect also occurs, and the deposit of wet area may contain several dozen kilometers from the source.
Calcium carbonate in certain stones dissolves in dilute sulphuric acid to form calcium sulphate:
CaCO3 + H2SO4 + H2O ® CaSO4.2H2O + CO2
This has two consequences. First, make sure that the surface of the stone to break the two black gypsum (calcium sulfate) to the formation of vesicles, which consists of more than a stone. When the stone's crystal can be in the stone, and in May to 50 years. This is called the memory effect.
Sulfur dioxide is a pollutant with corrosion, but also with the delivery, including Nox, carbon dioxide (CO2), ozone (on organic materials) and sea salt spray. Research has shown that nitrogen dioxide (NO2), represented by SO2, the increase in the level of corrosion can occur. This is because the oxide NO2-SO2 Sulfite (SO3), which is more than SO2 absorption. Acid rain in the panel report in 1990 noted that in remote areas where the majority of deposits in the wet east England, while the deposits are in the majority secs. This conclusion is supported by studies in the southeast of England, which showed that 40% of the damage caused by debris secs.
Interaction between materials and substances that are complex and many variables involved. Deposit of pollution to the surface depends on the concentration of air pollution and weather and micro-climate on the surface. Once on the surface of the substance, the interaction may vary depending on exposure, the response capacity of different materials and the amount of moisture. Important factor that is very important as SO2, which is proposed oxidized in dry sulfuric acid in the presence of moisture on the surface.
Examples of damage:
The influence of acid on the modern buildings that are far less damaging impact on ancient monuments. Lime and limestone in most buildings open to the monument, "the most corrosion resistant and is a renewal.
Evidence of harmful effects on the acid all over the world. For example, as the world-famous Taj Mahal, Cologne Cathedral, Notre Dame, the Colosseum and Westminster Abbey are also affected.
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