Influence of Air Pollution and Humidity on Limestone Materials Degradation in Historical Buildings Located in Cities Under Tropical Coastal Climates

Climatic changes and the increased air pollution intensify the atmospheric degradation of stone, affecting the aspect and integrity of valuable historical buildings constructed using limestone and located in tropical coastal sites. This paper analyzes limestone degradation process due to air pollution and humidity in tropical humid conditions in historical buildings located in the cities of Havana, Cuba and San Francisco de Campeche, Mexico. Havana shows higher pollution level than San Francisco de Campeche, which presents pollution levels as a consequence of a multipollutant situation along with the presence of airborne salinity. Temperature and humidity data were recorded from the walls of historical buildings in the city of Havana: the Minor Basilica and the convent of San Francisco. Changes in dry/wet cycles due to the absence of direct sun radiation as well as a high level of SO₂ allow the formation of a black crust (mainly composed of gypsum) in the lower part of the surface of the facade of the Basilica Minor in Havana; however, crusts formed in historical buildings located in San Francisco de Campeche City are mainly composed of calcium carbonate, indicating the importance of natural degradation mechanisms mainly due to dissolution in water. In the last case, the influence of water plays an important role in the development of biodegradation, which induces the formation of calcium oxalates. Caves and cracks were found in the walls of military buildings caused by water infiltration. The influence of air contamination, humidity, and construction materials determine the type of degradation that historical buildings undergo.     

The effect of simulated runoff on the erosion of gypsiferous soils

The effect of runoff generation on the erosion of gypsiferous soils under different experimental conditions was investigated by applying simulated rainfalls of 48 and 58 mm h⁻¹ to experimental plots exhibiting representative characteristics of these soils. The 45 experiments indicate differing erosive behaviour as test conditions varied. Suspended gypsum yields ranged from 0-3.9 gm⁻² h⁻¹ the higher values occurring with the steeper slopes and dry soil conditions. The differences among the soils tested were mainly due to variations in underlying rock outcrop, whilst within each soil type, slope was the most important variable. Transport of suspended gypsum by runoff is inversely related to rock outcrop, and positively related to slope. The highest erosion rates are registered in Gypsic Calcisols, followed by Gypsic Calcisols (lithic phase), while production of suspended gypsum is not verified for Dystric Leptosols. By transporting gypsum particles down-slope, runoff is probably responsible for the dynamic evolution of gypsiferous hillslopes as well as the genetic evolution of the studied soils.     

Air Pollution Effect on the Decay of Carbonate Building Stones in Old Town of Tallinn

For a long time the local Ordovician carbonate rocks were widely used for the building of many historical buildings, churches and strongholds in Tallinn. The chemical and mineralogical composition of building stone and gypsum black crust from five historical objects of Old Town of Tallinn were examined in order to reveal the weathering behaviour of the limestone and estimate the influence of pollution on the decay processes. The ICP-MS analysis and X-ray difractometry were performed to provide a quantitative analysis of the processes, which are responsible for building stone decay. The enrichment factor and R-mode factor analyses were applied in order to improve the understanding the nature and sources of elements and assess the pollution effect. The obtained results confirmed a natural origin for Ca, Mg, Si, Al, Ti, K, Na and Fe. The black crust is elevated in Cu, Pb, Sb, Sn and Zn concentrations as a result of the pollution effect. The highest increase of Cu, Pb and Zn content was determined in the samples from gypsum crust at St. Olaf's church. The enrichment factors calculation and factor analysis confirm the input of these elements from anthropic sources. Sulphur isotope composition in damaged building stone and black crust was used to discriminate the anthropic and natural sources of sulphur. The impact of technogenous sulphur in the gypsum formation in the black crust was revealed. The contribution of sulphur dissoluted from limestone is reflected in the positive delta values of sulphur. Comparison of obtained data to those for similar objects in European cities was carried out.     

Properties of solonetzes on terraces of salt lakes Bulukhta and Khaki in the Caspian Lowland

A comparative assessment of pedogenetic processes in solonetzes (Calcic Gypsic Salic Solonetzes (Siltic, Albic, Cutanic, Differentic)) developing on terraces of lake depressions within the Volga–Ural interfluve of the Caspian Lowland has been performed on the basis of data on their macro- and micromorphological features and chemical, physicochemical, and physical properties. The studied soils have number of common characteristics shaped by the humus-accumulative, solonetzic, eluvial–illuvial, calcification, and gypsification processes. However, it is shown that macro- and micromorphological indicators of solonetzic processes (the development of clay–humus coatings and the character of structural units in the solonetzic (B) horizon) do not always agree with the modern physicochemical conditions of the development of this process. This is explained by differences in the degree and chemistry of the soil salinization and the depth and salinity of the groundwater. Solonetzes developing on the second terrace of Playa Khaki are distinguished by the highest water content and maximum thickness of the horizons depleted of soluble salts. They are characterized by the well-pronounced humus-accumulative process leading to the development of the light-humus (AJ) horizon. In other solonetzes, the accumulation of humus is weaker, and their topsoil part can be diagnosed as the solonetzic-eluvial (SEL) horizon. Active solodic process and illuviation of organomineral substances with the development of thick coatings and infillings in the B horizon are also typical of solonetzes on the second terrace of Playa Khaki. Micromorphological data indicate that, at present, layered clayey coatings in these soils are subjected to destruction and in situ humification owing to the active penetration of plant roots into the coatings with their further biogenic processing by the soil microfauna. The process of gleyzation (as judged from the number of Fe–Mn concentrations) is most active in solonetzes developing on the first terrace of Playa Khaki. These soils are also characterized by the highest degree of salinization with participation of toxic salts. The maximum accumulation of gypsum is typical of the heavy-textured horizons.     

Genesis of gypsum enriched soils in north-west Isfahan,Iran

Most of gypsum-enriched soils in Isfahan and neighboring provinces occur on alluvial fans, dissected flood plains (old dissected alluvium)and piedmont plains. Herein we investigate the processes of formation and alteration of gypsic horizons and their pedofeatures. We described and sampled representative pedons on a transect from the mountain to the piedmont plain. In the study area, different gypsic pedofeatures have various kinds of internal lenticular cryslalitic fabrics. Micromorphologic observations confirmed that gypsic horizons have an evolutionary sequence across the different geomorphic surfaces from the upper fan to the piedmont plain. In primary stages (upper fan), gypsum crystals occur individually in the soil groundmass or as clusters in voids with idiotopic or xenotopic fabrics. Eventually, they form internal coatings or infillings and pendants (in middle and lower fans). In the more developed horizons (dissected flood plains or plateaus), the fibrous gypsum crystals are banded and perpendicularly distributed with reference to the gravels and soil surface. These loosely compacted fibers constitute the bulk of the soil materials, leaving non-gypsic particles as islands between crystals. In these pedofeatures, perpendicularly oriented fibrous crystals, with their lateral inter-connections give rise to a continuous three-dimensional firm structure.The fabric of these lenticular gypsum crystals is xenotopic or hyp-idiotopic. In the piedmont plain, the idiotopic crystals have no preferred orientation and have random distribution. Internal fabric of these pedofeatures is porphyrotopic. This study indicates that, physical environment plays a great role in formation of different gypsic pedofeatures.     

Origin and growth mechanisms of the sulfated crusts on urban limestone

Building stone surfaces exposed to the urban environment are subjected to rapid and differentiated deterioration, due to various chemical and physical attacks. Apart from a chemical deterioration below the sufated crusts, which mainly grow outwards at the unaltered gypsum/carbonatic rock interface, another physical deterioration was observed. The latter is, at times, even more important than the rapid chemical attack typical of the zones which are subjected to heavy washing by rainwater. The formation and growth of three different kinds of deterioration layers are discussed with reference to the main kinds of deterioration characterized by white, grey and black external appearance. Analyses of airborne particulate matter and of deterioration layers of urban monuments led to the conclusion that not all the gypsum of crusts which can be observed on marble monuments is derived from the transformation of the underlying rock, but it is also partially transported by aerosols.     

Biogenic and chemogenic calcium accumulations in Mollisols developed from loess in Argentina pampas

The morphology of pedogenic calcium accumulations, their distribution in the soil profile, and the mechanisms of their formation in Mollisols of Argentina pampas were studied in the southeast of the Buenos Aires province. The chemogenic collomorphic calcareous films and tubes and the biogenic (cyanobacterial) gypsum framboidal structures (spherulites) were detected with the use of electron microscopy. Two mechanisms of the formation of framboidal gypsum were identified: (a) the formation of crystalline gypsum crusts around less soluble minerals (calcite) by spherical colonies of cyanobacteria and (b) the inheritance of the spherical shape of gypsum pedofeatures from the framboidal pyrite concretions accumulated in marine deposits and subjected to decomposition by sulfate-reducing bacteria. It is probable that the cyanobacterial gypsum accumulations are only formed in the studied soils during the dry season and are dissolved during the wet season.     

Micromorphology and classification of Argids and associated gypsiferous Aridisols from central Iran

Gypsiferous Aridisols occupy the largest area within the Iranian Aridisols. Information on the genesis and classification of these soils is rather limited. Objectives of this research were to study the micromorphology of the gypsic, argillic, and calcic horizons, to understand the mode of formation of gypsic horizon in three different landscapes, and to test the criteria of the most recently revised Soil Taxonomy and FAO classification system in selected gypsiferous Aridisols occurring in central Iran. A total of 15 representative pedons occurring on three different landscapes (colluvial fans, plateaus, and alluvial plain) were studied. Evidence of illuviation in the colluvial soils is provided by the increase in the clay content and the fine to total clay ratio in the subsoil and by the well-developed, but considerably disrupted, clay coatings observed in thin sections. In addition to pendants, gypsum occurs as microscopic-sized particles, such as single and radiating fibrous shaped particles, random lenticular and granular crystals, along channels and planar voids with no apparent orientation to the associated surface. Gypsum also occurs as relatively larger interlocking plates. The horizon sequence, together with their chemical and micromorphological properties, reveals that gypsum accumulated in different landscapes has different modes of formation. The coexistence of argillic, calcic, and gypsic horizons in colluvial soils is a peculiar combination, suggesting a multistage pedogenesis in this landscape. Paleo-argillic horizons were likely developed under a moister environment than today. This study has also shown that the most recently revised version of the American Soil Taxonomy and FAO soil classification can reasonably well classify these soils. However, there is still a need to modify the criteria of both classification systems at the lower levels, particularly for the classification of the soils that are polygenetic.     

Slow-release urea fertilizer from sulfur,gypsum, and starch-coated formulations

To address nitrogen (N)-related environmental pollution, development of an economical, slow-release urea fertilizer is the need of the hour. A study was conducted on the reduction of nitrogen released from granular urea fertilizer by applying sulfur, gypsum, bentonite, and starch as coating material. Paraffin wax was used as a binder. The dissolution rates were studied by changing the composition of coating mixture using high-performance liquid chromatography. SEM was used to study the morphology of coated urea in terms of smoothness and uniformity. The ultraviolet spectroscopy analysis further authenticated the release behavior of coated urea in terms of nitrogen concentration. Coating material reduced the release rate of nitrogen from urea fertilizer, significantly. Mixture of sulfur and gypsum coating on urea gave slowest release rate of nitrogen from urea fertilizer, i.e., 37%, as compared to uncoated urea and thus seems to be the most promising binding material for product development.     

Study of Ammonium Contamination in Leachates from an Ultisol Following Application of Various Types of Amendment

The composition of leachates from an Ultisol reconstructed inlysimeters and amended with limestone, sugar foam waste and gypsum rock was studied. The typical rainfall of the area fromwhich the soil was collected was simulated under laboratory conditions over a five-month period. The soil samples treated with gypsum behaved markedly differently from the rest. Thus, the samples amended with gypsum gave leachates with substantially increased ammonium contents that might result in contamination of aquifers. The gypsum-treated samples alsoexhibited marked differences in pH, EC and the Ca, Mg, Na andK contents from the rest.     

MINERALOGY, GENESIS AND CLASSIFICATION OF FERRUGINOUS SOILS OF THE EASTERN MYSORE PLATEAU, INDIA

The relationship of geomorphic and climatic history and formation of the ferruginous soils, formed on the acidic Peninsular Gneiss, of the Mysore Plateau, India, is discussed. The profiles studied are found on two different land systems. The soils of the older, fairly smooth landscape are composed of colluvium over truncated laterite profiles, with a gravel layer and a prominent kaolin layer over the weathered rock. These soils show an accumulation of pedogenic haematite grains in the sand fraction and have considerable kaolinite and amorphous ferri-aluminosilicate minerals in the clays. The soils of the younger, rugged landscape have similar clay mineralogy, but do not have a gravel layer, or haematite grains. The influence of the coarse-grained parent rock is seen in the large amounts of quartz gravel. The absence of granulation is attributed to lack of accumulation of iron. The soils have been formed in an earlier, more humid climate than prevails today. The original laterite profiles were formed on a plane surface, and subsequent change in climate has led to change in the land forms and dissection. Truncation of the profiles was followed by deposition of red colluvium over the resistant ferruginous layer. These ancient soils do not fit the criteria for Oxisols in the U.S. classification, but fit well in the French system as ‘Sols Ferrallitiques’, subclass ‘fiablement désatures en (B)’. The soil from a low lying area, formed from colluvium under hydromorphic conditions. is classified as‘Vertisols et Paravertisols'.     

Clay minerals in chernozem-like soils of mesodepressions in the northern forest-steppe of European Russia

In the northern forest-steppe of European Russia, under the conditions of surface waterlogging (freshwater) and a stagnant-percolative regime, gleyic podzolic chernozem-like soils with thick light-colored eluvial horizons are formed. These horizons are close or similar to the podzolic horizons of bog-podzolic soils in many properties of their solid phase. They are bleached in color and characterized by the removal of Ca, Mg, Fe, Al, and Mn and the relative accumulation of quartz SiO₂. These soils differ from leached chernozems in their acid reaction and very low CEC, the presence of Fe-Mn concretions and coatings, and the significant decrease in the clay content in the A2 horizon as compared to the parent rock. The soils studied differ significantly from loamy podzolic and bog-podzolic soils by the composition of the clay minerals in the A2 horizons: (1) no essential loss of smectite minerals from this horizon was found as compared to the rest of the solum, (2) pedogenic chlorites (HIV and HIS) are absent, and (3) the distinct accumulation of illites is observed as compared to the subsoil and parent material, probably, due to the process of illitization.     

Gypsum applications to aggregated saline—sodic clay topsoils

Gypsum application was highly efficient as a treatment for reducing amounts of exchangeable sodium and inhibiting clay dispersion in highly structured saline-sodic clay topsoils. Phosphogypsum, applied to the surfaces of aggregates in soil columns treated with simulated rainfall, was dissolved efficiently by frequent intermittent ‘rainfall’. The calcium released by dissolution displaced sodium on the exchange complex within soil aggregates ranging from 7.5 mm to 45 mm in diameter. Of the applied calcium, 64–74% was transferred to ion exchange sites; however, almost one-third of this adsorbed calcium displaced exchangeable magnesium. Comparison of three gypsum treatments, phosphogypsum, rock gypsum, and a saturated gypsum solution (representing a top dressing of highly soluble gypsum), showed that the effectiveness of calcium uptake on the exchange complex followed the order: rock gypsum < saturated solution < phosphogypsum, but differences were small. Application of phosphogypsum caused a 90% reduction in the total amount of dispersed clay released in column leachates, and decreased the maximum clay concentration in the effluents by at least 80%, when compared to soils leached without gypsum treatment.     

Weathering geochemistry of a paleudult in tropical Surinam

Chemical analyses and mineral norm calculations of a Paleudult, situated on a dolerite dike, revealed that the soil was not derived from the dolerite but from schistose material that is found in adjacent areas and which has been deposited over the dolerite.Thin-section micromorphology of the argillic horizon indicates that clay illuviation is now not an active process. With respect to the clay mobility the soil is paleosolic.The weathering of the quartz-dolerite rocks under the deposit of schistose material was studied by analyzing the spheroidal weathering layers of the rock. It appeared that most minerals of the rock dissolve completely and that only little clay has been formed during the early stages of weathering.     

Exchange-induced dissolution of gypsum and the reclamation of sodic soils

A study was undertaken to define the dissolution kinetics of gypsum in the presence of ion exchange resins and to study sodic soil reclamation in laboratory soil columns.
Gypsum pellets were prepared at 1.5 MPa pressure and the time course of their dissolution followed by measuring the electrical conductivity of the solution. Dissolution experiments were carried out in distilled water with and without Na- and Cl-saturated exchange resins or a combination of the two. The results indicate that in the presence of resin the reaction is first order as calcium and/or sulphate are removed from solution by the resin driving the reaction to completion. In water alone the reaction follows second-order kinetics and depends on the rate of mixing as the reaction is transport controlled.
The effect of gypsum placement (uniformly mixed with the entire soil, mixed with the top third of the soil, applied to the soil surface or applied as a saturated gypsum solution) on the efficiency of exchangeable sodium removal, leaching of soluble salts and soil hydraulic conductivity was studied. In addition, the effect of various flow rates on reclamation efficiency was investigated.
The amount of leachate required for reclamation was found to be dependent on gypsum placement, tending to decrease in the order mixed < top third mixed < saturated gypsum solution < gypsum surface application < water. Soil hydraulic conductivity was much higher in the mixed gypsum column than in the gypsum applied on the surface; a result of the higher effective gypsum solubility. Sodic soil electrical conductivity in the presence of solid-phase gypsum is linearly related to the total amount of exchangeable sodium expressed in mol dm⁻³.     

Weathered pumice influence on selected alluvial soil properties in west Nayarit, Mexico

Parent material and pumiceous alluvial soils, located in a tropical region of Mexico, were studied to supply information on soil suitability for agricultural production in the context of sustainable agriculture. In recent alluvial soils, an understanding of how soil characteristics vary with parent material and topography provides a basis for determining land utilization type, land suitability as well as land quality. The main objective of this study was to establish the relationship of soil properties to parent material in west Nayarit, Mexico. Field studies were initiated in 1993 by a request for technical assistance from the Comision Federal de Electricidad. The studied soils were derived from pumice that has been reworked and mixed with detrital material from other sources. We found that such soils have unique physical, chemical and mineralogical characteristics that are rarely found in soils derived from other parent materials. Data for two selected alluvial soil profiles are presented. These soils were developed on Holocene volcanogenic pumiceous alluvial river terraces and river floodplains, under current udic-isohyperthermic soil-climate conditions. The agronomic properties, tillage influences and fertilizer requirements of these soils have been studied extensively. To maximize their productivity and minimize deterioration, proper management must be based on an understanding of the unique physical, chemical and mineralogical properties. Results indicate that such soils have physical properties that provide a good environment for deep rooting and can supply the water necessary for vigorous plant growth. In both soils, water retention at 33 and 1500 kPa, particle surface area, calculated clay, cation exchange capacity, Al exchangeable percentage and P retention, and the occurrence of isotropic coatings on rock fragments and peds tend to increase in the presence of the large amounts of hydrolyzed pumice that are found in the 0.02–2.0 mm fraction. Scanning electron microscope–energy dispersive X-ray analyses demonstrate that the coatings dominantly consist of noncrystalline material, probably allophanic-like material as suggested by the Si/Al molar ratio of 1.0. Selective dissolution analysis reveals that these abundant noncrystalline materials consist of ferrihydrite and allophane with an atomic ratio (Al_o−Al_p)/Si_o of approximately 1.4. Both ferrihydrite and allophane have very large specific surface area and absorptive capacity that make a significant contribution to the overall properties of these soils. X-ray diffraction analysis and transmission electron microscope observation show that the major group of crystalline clay minerals in the upper section of studied soils are tubular and spheroidal halloysite. These soils were classified as Vitrandic Udifluvents according to Soil Taxonomy.     

Stable carbon and oxygen isotopes in pedogenic carbonate coatings of chernozems in the Southern Cis-Baikalia as indicators of local environmental changes

Carbonate coatings formed on the lower surfaces of pebble inclusions in the Holocene-Late Pleistocene sediments on the Irkutsk-Cheremkhovo Plain have been studied. The coupled analysis of the carbon isotope composition of the soil organic matter and carbonate coatings has indicated the formation of coatings under conditions of phytocenoses with the predominance of C3 plants. A significant effect of the atmospheric CO₂ on the carbon isotope composition in the coatings has been noted, which could be related to their formation under low soil respiration rates. The latter was apparently due to the periodic freezing of the soil, which affected the structure of the coatings and was most manifested in the formation of spherulites in their outer layers. The carbonate coatings consist of two laminae significantly differing in their structure and stable isotope composition, which allows separating two main stages of their formation. The lightening of the carbon isotope composition in the outer (younger) layers of the coatings compared to their inner (older) ones coincides with the increase of the δ¹⁸O values, which points to changes of the environmental conditions in the studied area during the formation of the coatings.     

Evaluating the land use potential of gypsiferous soils from field pedogenic characteristics

Abstract. Although gypsiferous soils cover approximately 100 million ha in the world, it is only in the past two decades that their pedogenic and agronomic properties have been better understood and their classification improved. There is still no method to assess adequately their production potential.
This paper focuses on gypsum accumulation forms as diagnostic criteria for a rapid soil suitability appraisal in the field. Pseudomycelia, gypsum spots, powdery coatings and other localized in situ precipitations usually indicate soils with less than 15% gypsum. Depending on their intensity and depth of occurrence in the root zone, they define a soil environment which is suitable for semi-sensitive and semi-tolerant crops. Continuous gypsum accumulations characterize soils or horizons with high (e.g. more than 25%) gypsum contents, and these can be used only for tolerant crops.
The land use potential of gypsiferous soils is primarily determined by: (a) the depth of the impermeable layer, (b)the gypsum content within the root zone, and (c) the crop tolerance level. A method is proposed to assess the land suitability of gypsiferous soils on the basis of these criteria.     

Monitoring aldehyde production during frying by reversed-phase liquid chromatography.

Acrolein (2-propenal) and other low molecular weight aldehydes (LMWAs) formed by degradation of the frying medium (triglycerides) were monitored by liquid chromatography (LC) during preparation of fried items. LMWA contents of coatings from codfish and of doughnuts and their volatiles that codistill with steam are monitored by trapping the vapors and distillate from the food matrix in a 2,4-dinitrophenylhydrazine solution. The resulting hydrazones are partitioned from the aqueous phase, first into isooctane and then into acetonitrile for LC analysis. The hydrazones are separated and quantified on a C18 reversed-phase column with acetonitrile-water as the mobile phase. LMWAs are confirmed by gas chromatography/mass spectrometry. No difference was found in LMWA content in coatings from fish fillets fried at 182 or 204 degrees C. Cake doughnuts were higher in acrolein content than yeast-raised doughnuts prepared under similar conditions. Freshness of the frying medium, frying time, and batch size did not seem to influence LMWA production from doughnuts. Results indicated that most of the LMWAs formed codistilled with steam during frying rather than remaining with the food item.     

A survey of lead pollution in Baghdad

Lead pollution in Baghdad City was studied. Several potential sources of Pb pollution were investigated, among which are leaded gasoline, battery manufacturing, and printing press type. The study included the analysis of blood samples from males and females of different ages and professions. Particular attention was given to workers who are in direct contact with Pb materials in order to discover whether local contamination is taking place or not. In addition, samples of palm leaves were collected from about twenty five different parts of Baghdad in 1978 and again in 1980 in order to study the distribution and relative increase in Pb deposition caused by vehicles using leaded gasoline. The results were compared with similar samples from less crowded cities. The results of this survey have shown that Pb pollution exists; its scale, however, can not be determined accurately until more data are obtained.