scholarly journals Footings of Residential Buildings, Erected on Clay Soils with Organic Content

2018 ◽  
Vol 196 ◽  
pp. 03015
Author(s):  
Dmitry Chunyuk ◽  
Olga Kopteva

In the proposed article the author examines issues determining physical and mechanical soils with organic matter content. Conditional definitions of organic soils depending on the value of the relative organic content matter are determined. The biogenic soils are examined using three groups - peat, blocked soils and sapropels. Depending on the relative content of organic substances, the author compares various peat types. The division of the soils with organic content is presented. A definition of sapropels is presented. The problem of complexity of determination of the amount of organic substances by calcination of samples is described. The current methods used to determine the amount of organic substances currently in Russia isexamined. The paper reviews physical and mechanical properties of organic soils. The on-site test-plate data is compared with laboratory test data. The problems of sapropel tests are described. The results of experimental studies, conducted at a construction site in the new suburban district of Moscow are shown.

2020 ◽  
Vol 195 ◽  
pp. 01020
Author(s):  
Leon A. van Paassen ◽  
Bruna R.F. Oliveira ◽  
Nor H.M. Zain ◽  
Cristina Jommi

Many low-lying peatlands in delta areas undergo significant subsidence due to drainage for agricultural purposes. Subsidence may be attributed to shrinkage, consolidation or oxidation. At the same time the canals and ditches are regularly dredged to maintain water quality and drainage capacity. Often these dredged sediments are placed on land, which may help to slow down subsidence. In this study subsidence of organic sediments was monitored for a period of three years. The sediments were dredged from lakes and canals in the peatlands of Wormer- en Jisperveld, in the Netherlands and placed in an on-land constructed depot. Samples were collected at regular time intervals to measure water content and organic content. Additionally, laboratory tests were performed to characterize the organic sediments and determine the compression, consolidation, shrinkage and water retention characteristics under various oxidizing conditions. The laboratory tests showed that oxidation can significantly affect the compression, consolidation, water retention and shrinkage characteristics of organic soils. However, monitoring results in the field showed that the major part of the subsidence, which occurred within the three years of this study, could be attributed to shrinkage of the dredged sediments and the remainder to consolidation of the underlying peat layers, while the organic matter content did not change significantly.


Lontara ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 82-88
Author(s):  
Rahmawati Rahmawati ◽  
Dewi Arisanti ◽  
Nurhidayat Nurhidayat

Gallons of refilled drinking water usually don't run out in a single use but run out in a few days or even up to 1 to 2 weeks, depending on usage, and stored at room temperature (27-29 °C). Drinking water that is stored for a long time will allow the growth of microorganisms which are influenced by environmental factors, namely temperature conditions and oxygen supply during storage. This affects the pH and total organic content of drinking water. Inspection of the quality of water products according to the Regulation of the Minister of Health of the Republic of Indonesia Number 492/MENKES/PER/IV/2010, which is a maximum organic matter content of 10 mg/L. According to chemical parameters, drinking water must not contain inorganic and organic substances exceeding the standard with a pH value between 6.5-8.5. The purpose of this study was to determine the levels of organic substances in RO (Reverse Osmosis) refill drinking water. This type of research is a laboratory experiment using purposive sampling technique. The results showed that the average organic content of refilled drinking water with a storage period of 0 days was 1.839 mg/L, 3 days was 2.57 mg/L, and 6 days was 5.28 mg/L. Thus, the levels of organic substances in drinking water are based on storage time of 0, 3, and 6 days using the spectrophotometric method according to the maximum drinking water quality standard.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Ahmad Shobib

Cow manure can be used for making organic fertilizer because it contains nutrients such as Nitrogen (N), Phosphorus (P), and Potassium (K). Rice straw has a high C-Organic content. Adding straw compost will increase soil organic matter content. The study aims to determine the fermentation process that occurs so as to produce organic fertilize, know the effect of fermentation time and the effect of the composition of raw materials for cow manure and rice straw on the process of making organic fertilizer to the content of organic fertilizer according to SNI 7603 : 2018. The method use by aerobic fermentation is by mixing cow manure and rice straw and M-Dec bioactivators by comparison 3 : 1, 2 : 2,1 : 3 and fermentation time 7, 14, 21, 28 days. The parameters tested are C-organic, Nitrogen (N), C/N ratio, Phosphorus (P), and Potassium (K). The best quality organic fertilizer in the treatment of cow manure : rice straw with a ratio of 2 : 2 on the 28th day fermentation process namely C-organic content 34,63 %, C/N ratio is 25, macro nutrient content N+P2O5+K2O of 3,14 % that has met SNI 7763 : 2018. Keyword: M-Dec bioactivator, aerobic fermentation, cow manure, rice straw, C/N ratio


2005 ◽  
Vol 53 (1-2) ◽  
pp. 23-38 ◽  
Author(s):  
Rosebel C. Nalesso ◽  
Jean-Christophe Joyeux ◽  
Cintia O. Quintana ◽  
Evelise Torezani ◽  
Ana Clara Paz Otegui

The present work describes and analyses the structure of the macrobenthic epi- and infaunal assemblage of the estuarine system of Vitória Bay, South-eastern Brazil, from January 1998 to June 1999. Replicated sampling at intertidal and subtidal levels was conducted quarterly at ten stations. Intertidal and subtidal sediment composition was characterised. Water physico-chemical parameters were measured in situ. A total of 10,695 individuals, belonging to 144 taxa, were collected. Molluscs, crustaceans and polychaetes were the most abundant groups. The bivalves Anomalocardia brasiliana, Mytella guyanensis and M. falcata were the most abundant species. Locally, significant discharges of residential and industrial wastewater resulted in high organic content in the sediment (up to 30%) and low dissolved oxygen concentration in the water (< 1mg.l-1). Near the two entrances of the bay, high hydrodynamic activity and coarse sand reduced the detrimental effects of raw and treated sewage inputs. Species richness (S), diversity (H') and total abundance (A) decreased from outer-bay stations (22 < S < 72; 1.99 < H' < 2.85; 320 < A < 1737) towards inner-bay stations (2 < S < 45; 0.59 < H' < 2.67; 2 < A < 1317), where salinity and dissolved oxygen were lowest and organic matter content highest.


2019 ◽  
Vol 34 (3) ◽  
pp. 362-370
Author(s):  
Jose V. Fernandez ◽  
D. Calvin Odero ◽  
Gregory E. MacDonald ◽  
Jason A. Ferrell ◽  
Brent A. Sellers ◽  
...  

AbstractDissipation of S-metolachlor, a soil-applied herbicide, on organic and mineral soils used for sugarcane production in Florida was evaluated using field studies in 2013 to 2016. S-metolachlor was applied PRE at 2,270 g ha−1 on organic and mineral soils with 75% and 1.6% organic matter, respectively. The rate of dissipation of S-metolachlor was rapid on mineral soils compared with organic soils. Dissipation of S-metolachlor on organic soils followed a negative linear trend resulting in half-lives (DT50) ranging from 50 to 126 d. S-metolachlor loss on organic soils was more rapid under high soil-moisture conditions than in corresponding low soil-moisture conditions. On mineral soils, dissipation of S-metolachlor followed an exponential decline. The DT50 of S-metolachlor on mineral soils ranged from 12 to 24 d. The short persistence of S-metolachlor on mineral soils was likely attributed to low organic matter content with limited adsorptive capability. The results indicate that organic matter content and soil moisture are important for persistence of S-metolachlor on organic and mineral soils used for sugarcane production in Florida.


2020 ◽  
Author(s):  
Belén Oliva-Urcia ◽  
Ana Moreno ◽  
Blas Valero-Garcés

&lt;p&gt;Paleoenvironmental reconstructions from three mountaineous lakes located in northern Iberia are compared and completed with classical magnetic analyses in order to detect the influence of different processes on the record and preservation of magnetic properties. The lakes are located in the Cantabrian Mountains, Enol Lake, and in the Pyrenees, the Marbor&amp;#233; Lake and Basa de la Mora Lake and share a similar composition of their catchment areas, dominated by limestones. They present other different characteristics, such as in the organic matter content, being Enol the one with the highest organic carbon values. Redox indicator (Mn/Fe) is higher and more variable in Basa de la Mora Lake, whereas in Enol and Marbor&amp;#233; Lakes steadily increases towards the top of the sequences. New and revisited results from sedimentary cores unravel the significance of the magnetic changes respect to the geochemical and sedimentological variations found in the geological record.&lt;/p&gt;&lt;p&gt;The magnetic mineralogy present after analyses done in discrete samples (less than 500 mg) is magnetite in all samples, due to a sharp decrease at 120 K (Verwey crystallographic transition) and 580&amp;#186;C (Curie temperature of magnetite) in the thermomagnetic curves performed in the MPMS and the Curie balance respectively. No indication of neither pyrrhotite (phase transition at 35 K) nor siderite is observed. The high temperature thermomagnetic analyses show the presence and creation of magnetite during heating, see an increasing of induced magnetization forming a broad peak above 450&amp;#186;C in the heating curve. In addition, a subtle change in the induced magnetization is observed at around 300&amp;#186;C. All analyses related with coercivity indicate the predominance of low coercitive minerals (&amp;#8220;soft&amp;#8221;) as magnetite is.&lt;/p&gt;&lt;p&gt;The combination of geochemical, sedimentological and magnetic proxies suggest that in Enol Lake the magnetic signal may be dominated by the formation of new minerals in relation to redox processes favored by the higher presence of organic matter (6%organic content), whereas in Marbor&amp;#233; Lake, the increase of the magnetic signal toward the top of the sequence seems related to the oxic environment and the preservation of magnetite, since this lake is ultra-oligotrophic. In Basa de la Mora Lake, the source rock seems to play a role in the magnetic signal of the sequence.&lt;/p&gt;&lt;p&gt;These results indicate that diagenesis and changes in the redox conditions alter the concentration of magnetic minerals during the Late Pleistocene and Holocene and underlines their value as environmental and paleoclimate archives.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgements&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Funding for this research was provided by the Spanish Inter-Ministry Commission of Science and Technology through MEDLANT (CGL2016-76215-R) and DINAMO 3 (Ref CGL2015-69160-R) projects and by the European Commission (EFA056/15 REPLIM). The Institute for Rock Magnetism (IRM), the Instrumentation and Facilities program of the National Science Foundation of the Earth Science Division and the University of Minnesota are acknowledged for supporting visits and the free use of the facilities at the IRM, together with the both easy-going and expert guidance from the IRM staff.&lt;/p&gt;


2006 ◽  
Vol 63 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Marcos Gervasio Pereira ◽  
Gustavo Souza Valladares ◽  
Lúcia Helena Cunha dos Anjos ◽  
Vinícius de Melo Benites ◽  
Ademar Espíndula Jr. ◽  
...  

Soil taxonomy systems distinguish mineral soils from organic soils based on the amount of soil organic carbon. Procedures adopted in soil surveys for organic carbon measurement are therefore of major importance to classify the soils, and to correlate their properties with data from other studies. To evaluate different methods for measuring organic carbon and organic matter content in Histosols and soils with histic horizons, from different regions of Brazil, 53 soil samples were comparatively analyzed by the methods of Walkley & Black (modified), Embrapa, Yeomans & Bremner, modified Yeomans & Bremner, muffle furnace, and CHN. The modified Walkley & Black (C-W & B md) and the combustion of organic matter in the muffle furnace (OM-Muffle) were the most suitable for the samples with high organic carbon content. Based on regression analysis data, the OM-muffle may be estimated from C-W & B md by applying a factor that ranges from 2.00 to 2.19 with 95% of probability. The factor 2.10, the average value, is suggested to convert results obtained by these methods.


Weed Science ◽  
1981 ◽  
Vol 29 (6) ◽  
pp. 667-671
Author(s):  
Song-Wu Li ◽  
Max M. Mortland

The newly developed herbicide buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadizol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone} was studied with respect to its interaction with soils and homoionic clay minerals and its response to irradiation with ultraviolet light. Results showed that it could enter the interlamellar spaces of swelling clays such as smectite. Isothermic adsorption studies indicated that Cu+2-smectite adsorbed more buthidazole than Cu+2-kaolinite. The Cu+2-clay adsorption isotherm fitted the Langmuir model. The effect of exchangeable cations on adsorption was not significant in soils of high organic matter content. Bioassay studies indicated that buthidazole's phytotoxicity was not decreased in either clays or in organic soils. Infrared spectroscopic studies showed the coordination of buthidazole with Cu+2through C=O Cu interaction with buthidazole resulted in a ligand-to-metal ratio to 1:1. Protonation of buthidazole occurred in Al+3-and H+-smectite. The herbicide was labile to UV-light irradiation at 254 nm but not at 366 nm. The photoconversion indicated a first-order reaction. The photolytic product(s) included the –N=C=O structure. Copper(II) ions, which form complexes, retarded photolysis of buthidazole in UV-light, but the Ca+2ion, which is unable to form complexes, did not.


Author(s):  
Dace Kļaviņa ◽  
Anita Osvalde

Abstract The main aim of the study was to evaluate the soil chemical characteristics of Cypripedium calceolus sites in Latvia for understanding of the species ecology, and its conservation problems and possibilities. Soil for 27 C. calceolus sites in Latvia was analysed during 2007-2015. The concentration of plant available essential nutrients (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B), soil pH, electrical conductivity and concentration of organic matter were determined. Nutrient concentration of C. calceolus leaf samples from six sites were determined. The results demonstrated high heterogeneity in soil chemical composition with high variation for Ca, Mg, and Mn. The results suggest some relationship between soil organic matter content and size of the orchid population. Soil pH and Ca concentration did not affect the size and vitality of C. calceolus populations in Latvia. There was no significant correlation between nutrient concentration in soil and C. calceolus leaves suggesting strong impact of other soil-related factors in determining the availability of nutrients. In general, the levels of N, P, K, Ca, Mg, Fe, Mn, and Zn concentrations in C. calceolus leaves were adequate or slightly decreased for successful orchid growth. The study showed deficiency of S, Cu, and B in the vast majority of leaf samples. C. calceolus sites in Latvia occur mainly on organic soils or mineral soils with high content of organic matter. There was a weak positive correlation (r = 0.21) observed only between total number of ramets of C. calceolus in site and Ca concentration in the soil, suggesting that soil properties are not a main factor affecting species abundance in the site.


1967 ◽  
Vol 47 (2) ◽  
pp. 83-88 ◽  
Author(s):  
S. K. Rana ◽  
G. J. Ouellette

Studies on thirty mineral soil series and five organic soils from the broad cultivated areas of Quebec indicated that total cobalt, extracted with 70% perchloric acid digestion, ranged from 1.1 to 21.6 ppm and 2.5% acetic acid-extractable cobalt from 0.3 to 0.83 ppm. Extractable cobalt in the surface soils was significantly correlated with total cobalt, which in turn was highly dependent on the clay content of the soil. The soil pH or the organic matter content did not seem to have any influence on the cobalt content in the cultivated soils. Light-textured and podzolized soils are likely to be low m cobalt, while soils with richer clay content are higher. Organic soils, in general, were found to be lower in cobalt content than mineral soils. Nineteen out of the thirty mineral soils studied and all the organic soils contained less than 0.25 ppm of extractable cobalt and may be considered as critical or deficient because forage grown on such soils is likely to cause cobalt deficiency in livestock.


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