541,249 research outputs found
Exploratory analysis of excitation-emission matrix fluorescence spectra with self-organizing maps as a basis for determination of organic matter removal efficiency at water treatment works
In the paper, the self-organizing map (SOM) was employed for the exploratory analysis of fluorescence excitation-emission data characterizing organic matter removal efficiency at 16 water treatment works in the UK. Fluorescence spectroscopy was used to assess organic matter removal efficiency between raw and partially treated (clarified) water to provide an indication of the potential for disinfection by-products formation. Fluorescence spectroscopy was utilized to evaluate quantitative and qualitative properties of organic matter removal. However, the substantial amount of fluorescence data generated impeded the interpretation process. Therefore a robust SOM technique was used to examine the fluorescence data and to reveal patterns in data distribution and correlations between organic matter properties and fluorescence variables. It was found that the SOM provided a good discrimination between water treatment sites on the base of spectral properties of organic matter. The distances between the units of the SOM map were indicative of the similarity of the fluorescence samples and thus demonstrated the relative changes in organic matter content between raw and clarified water. The higher efficiency of organic matter removal was demonstrated for the larger distances between raw and clarified samples on the map. It was also shown that organic matter removal was highly dependent on the raw water fluorescence properties, with higher efficiencies for higher emission wavelengths in visible and UV humic-like fluorescence centers
Evaluation of organic matter stability during the composting process of agroindustrial wastes.
Composting of wastes from citrus industrial processing (pastazzo and sludge) was studied in order to evaluate the evolution of organic matter during the process and to individuate chemical and/or biochemical techniques able to set the stability of the final product. Composts from two open-air piles of different composition were sampled every month during the whole period of composting (5 months) and the organic matter of each sample was characterised by chemical and biochemical techniques. Humification rate (HR%) and humification index (HI) were determined. Extracted organic matter of six samples collected for each compost was investigated by isoelectric-focusing technique (IEF). The biochemical analysis was based on the study of C-mineralisation after the addition of each collected sample to soil. Results obtained clearly demonstrated organic matter evolution during composting processes. Humification rates increased and humification indexes decreased over time, while extracted organic matter showed electrophoretic behaviour typical of stabilised organic compounds. Moreover, mineralisation patterns confirmed the increased level of organic matter stability during the composting process
New organic matter degradation proxies: Valid in lake systems?
We determined concentrations and diagenetic state of organic matter in two cores from Lake Zug, Switzerland. To obtain a general picture of organic matter decay in the lake, we measured bulk parameters such as total organic carbon, total nitrogen, and total hydrolyzable amino acids. In addition, we studied specific compound classes in detail—namely, amino acids and chlorins. From these data we obtained two recently proposed indicators for organic matter degradation state—the amino acid-based degradation index (DI) and the chlorin index (CI). The two indicators complement each other, with the CI being very sensitive during the initial stages of organic matter decay and the DI recording later stages of decay. Further differences are likely caused by nonlinear behavior during degradation. Nonetheless, the two proxies agree in the general picture of the degradation state. Despite higher concentrations of organic matter in the surface sediment at the deeper site, neither of the degradation state indicators showed much difference between the two sites. At depth, the degradation state at the two sites diverges, despite similar concentrations of organic matter. Although we cannot explain all differences between bulk parameters, amino acid composition, and chlorins conclusively, the results indicate a combined effect of different organic matter inputs (e.g., through sediment focusing) and different oxygen availability at the two sites since the onset of eutrophication
Nanoscale Infrared Imaging Analysis of Carbonaceous Chondrites to Understand Organic-Mineral Interactions During Aqueous Alteration
Organic matter in carbonaceous chondrites is distributed in fine-grained matrix. To understand pre- and postaccretion history of organic matter and its association with surrounding minerals, microscopic techniques are mandatory. Infrared (IR) spectroscopy is a useful technique, but the spatial resolution of IR is limited to a few micrometers, due to the diffraction limit. In this study, we applied the high spatial resolution IR imaging method to CM2 carbonaceous chondrites Murchison and Bells, which is based on an atomic force microscopy (AFM) with its tip detecting thermal expansion of a sample resulting from absorption of infrared radiation. We confirmed that this technique permits 30 nm spatial resolution organic analysis for the meteorite samples. The IR imaging results are consistent with the previously reported association of organic matter and phyllosilicates, but our results are at much higher spatial resolution. This observation of heterogeneous distributions of the functional groups of organic matter revealed its association with minerals at 30 nm spatial resolution in meteorite samples by IR spectroscopy
Organic and conservation agriculture, the best of both worlds?
In millions of years huge amounts of organic matter were stored in the soil as organic matter or fossil energy carriers as oil, gas and coal. We make use of these stocks to supply us with energy and to be able to grow plants for our needs. However what has been stored in our soils for millions of years we now are depleting in a few hundred years. The amount of organic matter we return back to the soil is in general too low to maintain its capacity for plant production on the long term. Various studies show there is a decrease of organic matter in arable soils all over the world
Nutrient Digestibility and Productivity of Bali Cattle Fed Fermented Hymenachne Amplexiacalis Based Rations Supplemented with Leucaena Leucocephala
An experiment was conducted to study the effects of lamtoro (Leucaena leucocephala) leaf supplementation in fermented kumpai grass (Hymenachne amplexiacalis) based rations on the productivity of Bali cattle. Variables measured were dry matter and organic matter intakes, nutrient digestibility (dry matter, organic matter, crude protein, and crude fiber), body weight gain, and feed efficiency. The types of rations were: Ration A= 45% fermented kumpai grass + 40% benggala grass + 15% concentrate + 0% lamtoro leaf, Ration B= 45% fermented kumpai grass + 30% benggala grass + 15% concentrate + 10% lamtoro leaf, Ration C= 45% fermented kumpai grass + 20% benggala grass + 15% concentrate + 20% lamtoro leaf, and Ration D= 45% fermented kumpai grass + 10% benggala grass + 15% concentrate + 30% lamtoro leaf. The supplementation of lamtoro leaf up to 30% into the ration could increase (P<0.05) dry matter and organic matter intakes, and crude protein digestibility. The highest body weight gain and feed efficiency were found in Bali cattle fed ration with 20% lamtoro leaf supplementation. The level of lamtoro leaf supplementation in the ration did not affect the digestibility of dry matter, organic matter, and crude fiber. It was concluded that the supplementation of lamtoro leaf in the ration could increase dry matter, organic matter, and crude protein intakes. Addition of 20% lamtoro leaf gave the best effect on the increased body weight gain and feed efficiency in Bali cattle
Chemical and spectroscopic analysis of olive mill waste water during a biological treatment
The treatment of olive mill waste water was studied on the laboratory scale. Physico–chemical analyses showed the final products had a mean pH of 5.4 without neutralisation and 5.7 when lime was added to the process. Raising the pH by adding lime had a positive outcome on the degradation of phenols, whose levels were reduced by over 76%. The lime also changed the structure of the organic matter, as seen in the infra-red spectra. Combining the FT-IR and 13C NMR data showed that with addition of lime, the density of aliphatic groups decreased to the benefit of aromatic groups, indicating that polymerisation of the organic matter occurred during the bioprocess. Under our experimental conditions, the biotransformation of olive mill waste water appears to favour the stabilisation of the organic matter through mechanisms analogous to those that lead to the formation of humus in the soil
The White Stone Band of the Kimmeridge Clay Formation, an integrated high resolution approach to understanding environmental change
The Kimmeridge Clay is a Jurassic mudrock succession that shows Milankovitch Band climatic cyclicity. A key issue is to determine how the subtle changes that define this cyclicity result from climatic change. Using material from the Natural Environment Research Council Rapid Global Geological Events (RGGE) Kimmeridge Drilling Project boreholes, the White Stone Band was investigated at the lamination scale using backscattered electron imagery and quantitative palynofacies. Fabric analysis shows the lamination to represent successive deposition of coccolith-rich and organic-matter-rich layers. Individual laminae contain unsorted palynological debris with a consistent ratio of marine and terrestrial components. Such mixed organic matter input is interpreted as the result of storm transport. Linking water column processes to laminae deposition suggests seasonal input with a coccolith bloom followed by a more diverse assemblage including dinoflagellates and photosynthetic chlorobiacean bacteria. As the photic zone extended into the euxinic water column organic matter export to the sea bed underwent minimal cycling through oxidation and subsequently became preserved through sulphurization with greatly increased sequestration of carbon. This was significantlyincreased by late season storm-driven mixing of euxinic water into the photic zone. Increased frequency ofstorm systems would therefore dilute the coccolith input to give an oil shale. Hence climatically induced changes in storm frequency would progressively vary the organic content of the sediment and generate the climate cycle signal. Keywords: Milankovitch theory, Kimmeridge Clay, organic matter, high-resolution methods, climate change
Dutch (organic) agriculture, carbon sequestration and energy production
Carbon sequestration in soils is often mentioned in the discussions about climate changes. In this paper the opportunities for carbon sequestration in Dutch agriculture are discussed at farm and national level. Farm internal carbon sources are already completely used in livestock farming. The effect under arable conditions is limited in time and very limited compared to national CO2 emission. External sources are scarce. Energy production out of crop residues and manure via biogas installations is possible but the overall impact is again very limited. The effect of this biogas pathway on soil organic matter quantity and quality is not yet known. Organic arable farmers do already have a higher soil organic matter content than conventional farmers, partly due to external carbon sources. This puts them in a leading position. The disadvantage is that it is more difficult for them to do a next step in increasing soil organic matter
Particulate Organic Matter as a Soil Quality Indicator of Sugarcane Plantations in East Java
This study is aimed to test the hypothesis that the soil quality of sugarcane plantations closely linked to the particulate organic matter (POM) and earthworm's populations. The research was conducted at five sites in Malang, East Java. The sites were selected based on differences in average annual rainfall and two types of soil management : with and without organic input. Soil samples taken from a depth of 0-20 cm were analyzed total organic C (TOC), total N, POM-C, and POM-N and earthworm's population density and biomass. The TOC were corrected by the clay content using pedotransfer equations so obtained TOCref. The interaction between differences in annual rainfall and two types of the treatments significantly (
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