Amount Of Organic Matter Research Articles

Abiotic chlorination of organic matter in the soil environment: A simulation study

Chlorination of organic matter occurs naturally and is an important part of the chlorine cycle. To investigate the likelihood that inorganic oxidants, (Fe(NO3)3, H2O2, and hydroxyl radicals (·OH), frequently present in soil environments, could promote the synthesis of chlorinated organic matter in the soil environment, litterfall, humus, and soil (0–20 cm) were collected and used in laboratory based simulation experiments. Results indicate that these inorganic oxidants might promote the synthesis of chlorinated organic matter, but their impact varied due to varying suitable reaction circumstances. Litterfall was the most sensitive to chlorination, likely caused by the presence of abundant amounts of labile organic matter, and the chlorination process was limited by its Cl− level. Hydroxyl radicals showed a dual effect (producing or degrading chlorinated organic matter) on the three materials assessed, which was controlled by both ·OH concentration and the stability of organic matter, and the dual effect was evident in order of litterfall > humus > soil. The Fe(NO3)3-mediated chlorination of organic matter was only significant in litterfall due to its labile organic matter composition, while the peroxidative reaction caused by H2O2 in the producing chlorinated organic matter was only obvious in soil, most likely due to the presence of metals, facilitating the process. Combined this study sheds light on the chlorine cycle by verifying that inorganic oxidants might mediate abiotic chlorination of organic matter in a natural soil environment.

Content and quality of soil organic matter in topsoils under different tundra vegetation in central Spitsbergen (High Arctic)

Permafrost-affected soils contain a large amount of soil organic matter (SOM) which may become easily available to microbial decomposition due to climate warming. Despite numerous studies conducted on SOM in permafrost-affected soils, our knowledge about its quantity and chemistry requires further enhancement in the central part of Spitsbergen, due to a lack of detailed studies in this area. Especially, very little is known about the link between soil and vegetation in the High Arctic region. The main aim of this study was to determine the quantity and chemistry of SOM in the topsoil horizons of permafrost-affected soils covered with different tundra vegetation types in the vicinity of Longyearbyen (central Spitsbergen). Four types of tundra (pioneer tundra, arctic meadow, wet moss tundra, and heath tundra) were selected for this study. The obtained results indicate that the highest mean content of total organic carbon (TOC, 24.22 %) and total nitrogen (TN, 0.79 %) occurred in topsoils covered with heath tundra, while clearly lower mean contents of TOC and TN were noted in topsoils under wet moss tundra (5.96 %, 0.37 %, respectively), arctic meadow (3.40 %, 0.19 %, respectively), and pioneer vegetation (2.56 %, 0.21 %, respectively). The obtained FTIR-ATR spectroscopy results indicated significant differences in the chemical composition of SOM under different types of tundra. The highest mean value of the aromatic C/aliphatic C ratio (1632/2928 ratio) was noted for topsoils covered with arctic meadow (2.82). On the other hand, the lowest mean value of aromatic C/aliphatic C ratio for SOM was obtained for topsoils covered with heath tundra (0.81). This indicated that SOM in topsoils under heath tundra vegetation is characterized by a higher content of aliphatic compounds in relation to aromatic compounds. Moreover, both soil texture and soil pH significantly affected the content and quality of SOM in the studied topsoils.

Organic Matter Composition as a Driver of Soil Bacterial Responses to Pig Carcass Decomposition in a Canadian Continental Climate

AbstractOrganic by‐products are released into the surrounding soil during the terrestrial decomposition of animal remains. The affected area, known as the Cadaver Decomposition Island (CDI), can undergo biochemical changes that contribute to landscape heterogeneity. Soil bacteria are highly sensitive to labile inputs, but it is unknown how they respond to shifts in dissolved organic matter (DOM) quantity and quality resulting from animal decomposition. We aimed to evaluate the relationship between soil DOM composition and bacterial activity/function in CDIs under a Canadian temperate continental climate. This was studied in soils surrounding adult pig carcasses (n = 3) that were surface deposited within a mixed forested environment (Trois‐Rivières, Québec) in June 2019. Using fluorescence spectroscopy and dissolved organic carbon analyses, we detected a pulse of labile protein‐like DOM during the summer season (day 55). This was found to be an important driver of heightened soil bacterial respiration, cell abundance and potential carbohydrate metabolism. These bacterial disturbances persisted into the cooler autumn season (day 156) and led to the gradual transformation of labile DOM inputs into microbially sourced humic‐like compounds. By the spring (day 324), DOM quantities and bacterial measures almost recovered, but DOM quality remained distinct from surrounding vegetal humic signals. All observed effects were spatially constrained to the topsoil (A‐horizon) and within 20 cm laterally from the carcasses. These findings provide valuable insight into CDI organic matter cycling within a cold‐climate ecosystem. Repeated CDI studies will however be required to capture the changing dynamics resulting from increasing global temperatures.

Enhancing Soil Quality and Maize Yield with the Combination of Acacia-Biochar, NPK Fertilizer and Compost

<p style="text-align:justify; margin-bottom:13px"><span style="font-size:11pt"><span style="text-justify:inter-ideograph"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><span lang="EN-GB" style="font-size:12.0pt"><span style="line-height:150%"><span style="font-family:"Times New Roman",serif">Pakistan's agricultural soils exhibit a high tendency for leaching, low quantities of organic matter, and minimal microbial activity. The situation is aggravated by human activities such as bush burning, mining, sand extraction, and ongoing conventional methods of farming. These methods, together with the naturally low amounts of organic matter, result in the soil being deprived of essential nutrients. These nutrients are necessary for the optimal growth and yield of crops. Enhancing crop production such as maize and other crops on nutrient-deficient soils has the potential to improve household food security in Pakistan, necessitating the implementation of appropriate measures.</span></span></span> <span lang="EN-GB" style="font-size:12.0pt"><span style="line-height:150%"><span style="font-family:"Times New Roman",serif">Various techniques have been devised to mitigate the deleterious impacts on plants. The use of biochar, an organic substance produced through pyrolysis with limited oxygen supply, as a soil amendment is currently attracting significant attention globally.</span></span></span> <span lang="EN-GB" style="font-size:12.0pt"><span style="line-height:150%"><span style="font-family:"Times New Roman",serif">This study aimed to assess the effectiveness of a mixture of Acacia-biochar, NPK fertilizer, and compost in improving soil quality and boosting yields of crops.</span></span></span> <span lang="EN-GB" style="font-size:12.0pt"><span style="line-height:150%"><span style="font-family:"Times New Roman",serif">The first variable examined in the study was the biochar dosage, which was divided into four levels: no biochar, a biochar dosage of 5, 10, and 15 t ha<sup>-1</sup>. Additionally, it is important to take into account the selection of fertilizer, which consists of four different types: non-fertilizer, NPK, compost, and NPK + compost. The results showed that applying biochar at a rate of 10 t ha<sup>-1</sup>, along with NPK + compost, improved the availability of phosphorus and potassium, and significantly enhanced soil quality, as indicated by a soil quality rating value of 18. Applying a rate of 10 t ha<sup>-1</sup> of biochar, along with NPK + compost, led to the highest dry weight of seed maize, achieving 12.80 t ha<sup>-1</sup>. This represents a 40% augmentation in relation to the conditions without biochar and with the addition of NPK + compost. When the seed maize is weighed without any moisture content, the yield of 12.80 t ha<sup>-1</sup> results in the highest level of efficient agronomic value, which is 120.31%. Additionally, the feasibility value for growing maize in drylands is 1.28.</span></span></span></span></span></span></span></p>

Habitats, Plant Diversity, and Molecular Phylogeny of Endemic Relic Species Incarvillea semiretschenskia (Bignoniaceae)

Incarvillea semiretschenskia (B. Fedtsch.) Grierson is listed in the Red Data Book of Kazakhstan as a rare relic, narrowly endemic species of the Shu-Ile low mountains (Kazakhstan). The aim of this research was to advance our knowledge of the ecological conditions of its habitats, the floristic composition of plant communities, and molecular phylogeny, as well as to identify threats to the species’ existence. The ecological conditions of I. semiretschenskia habitats are rocky slopes and intermountain valleys of the low mountains in the altitude range from 812 to 1075 m asl with light chestnut mountain soils of little development, having a light granulometric composition and containing insignificant amounts of organic matter. We revealed 164 species of vascular plants in the communities of I. semiretschenskia, including five endemics and five species from the Red Data Book of Kazakhstan. Anthropogenic factors associated with grazing, fires, and limestone mining were identified as leading to a decrease in the number and density of populations. New insights into the relationship and time of diversification in the genus Incarvillea are gained through the use of several accessions of I. semiretschenskia and I. potaninii Batalin in the phylogenetic study. Preliminary fingerprint analysis shows relatively high genetic variability within populations of I. semiretschenskia. This unique relic species has survived since the Miocene epoch and exists to this day only in the Shu-Ile low mountains. To preserve this rare species, measures are proposed to create plant micro-reserves to provide ex situ collections and ensure future in situ restoration efforts.

The Crop Succession Systems Under No-Tillage Alters the Surface Layer Soil Carbon Stock and Stability

The main challenge of the no-tillage system (NTS) is to reconcile productivity, the maintenance of surface residues, and the stabilization of soil organic matter (SOM). To address this challenge, particularly in tropical regions, various cover crops have been tested. The objective of this study was to test the effects of agricultural crop succession systems on the stock and stability of soil organic carbon in different surface layers of the soils. The research was carried out in the state of Goiás, Brazil, in an experiment set up in 2016, designed in randomized blocks with a split-plot scheme (treatments and soil layers), comprising four repetitions (blocks). The treatments (plots) consisted of crops grown in succession to soybean, which were as follows: T1—soybean/corn (Zea mays); T2—soybean/pearl millet (Pennisetum glaucum); T3—soybean/Urochloa ruziziensis (brachiaria); and T4—corn + Urochloa ruziziensis. The subplots represented the following soil layers: 0–5, 5–10, 10–20, and 20–40 cm. We evaluated the biomass dry mass and the soil parameters such as soil density, total porosity, and light organic matter across all layers. The organic carbon, grain size fractionation (mineral-associated organic carbon—MOC; sand-sized carbon—POC), and isotopic composition (δ13C) were determined in the 0–5 and 5–10 cm layers. The highest biomass dry production was observed in the soybean/pearl millet succession, which reduced the soil density and increased the total porosity in the surface layer. The soybean/pearl millet treatment produced high amounts of light organic matter, particularly in the 0–5 cm layer, a result also found for the soybean/brachiaria and soybean/corn + brachiaria systems. The crop successions did not alter the soil carbon stock or stability; however, the surface layer stored the highest amount of carbon, with elevated total organic carbon values and carbon stocks and stability (MOC and POC). Overall, in this study, replacing corn with other crops in succession with soybean did not affect the stock or stability of soil organic carbon. The species grown in succession with soybean contributed to the higher surface carbon stock and stability, promoting the formation of more stable and recalcitrant carbon.

Effect of organic/inorganic separation on the adsorption performance of sludge-based activated carbon

Large amounts of organic matter of sewage sludge are enriched into the organic sludge (OS) by sludge organic/inorganic separation technology of acidification combined with multistage elution, which gives the OS the potential for preparing activated carbon. Hereinto, OS-based activated carbon (OAC) and raw sludge (RS)-based activated carbon (RAC) were prepared from OS and RS as raw materials at different carbonization temperatures and holding times. The results showed that compared with RS, the organic matter in OS increases by above 30 % including volatiles and fixed carbon. The optimal preparation conditions for RAC and OAC are to maintain a carbonization temperature of 800 ℃ for 1.5 h and 2 h, respectively. Under this condition, the specific surface area of OAC (296.8 m2/g) is higher than that of RAC (246.6 m2/g), and OAC has a richer mesoporous structure and a new functional group of N-H appears on the surface. Moreover, the batch experiments results show that compared with RAC, the adsorption capacity of Pb2+ by OAC increased from 3.12 to 4.92 mg/g and that of Cd2+ from 2.79 to 2.98 mg/g. Besides, the adsorption mechanism of OAC and RAC is the same, which is consistent with the Langmuir model and the pseudo-first-order kinetic type.

Spatial distribution studies on sedimentary organic matter along the shoreline of Arabian Sea: insights from Kollam, Southwest Coast, India.

The present study was aimed at investigating the source, quality, and quantity of organic matter and labile fraction of biochemical constituents in the surficial sediments of Arabian Sea Shoreline at Kollam, India, which gives an input into the processes associated with the subsurface geochemistry pattern. About 15 surface sediment samples were collected from the five beaches for this study during January 2021. The samples were analyzed for CHN, total organic carbon (TOC), and labile fraction such as carbohydrates (CHO), proteins (PRO), and lipids (LIP). The TOC/TN ratio revealed that the source organic matter (OM) in the samples was primarily of marine origin and autochthonous, except TM3 at Thirumullavaram. Thirumullavaram is a sheltered beach, and it has low hydrodynamic process. The high organic matter content in TM3 (13.9) may be the originated from the terrestrial input. The hierarchical cluster analysis revealed that TM3 indicate that unique character to other stations. Principal component analysis revealed that three components accounted for 78% of the total variance. PC1 variance was associated with carbon-based organic compounds. PC2 was predominantly influenced by CHO and LOM, suggesting that PC2 may encompass variability associated with these nutritional profiles. PC3 was influenced by LIP and LIP/CHO, showing it may be a lipid-related component. The PRO to CHO ratio is < 1, exhibiting old aged organic matter deposited in sediments and the meso-oligotrophic status. The LIP to CHO ratio, recorded as < 1, exhibits the poor quality of energetic (food) OM in sediments. The sediment samples exhibit the following trend CHO > PRO > LIP.

Microstructures, crystallography and growth patterns of serpulid tubeworms (Class Polychaeta)

Serpulid polychaetes are marine worms that secrete calcium carbonate tubes in which they live. Despite extensive previous research on their microstructures, there are no crystallographic data and their biomineralization process remains unclear. Here, the microstructures of the tubes of seven serpulid species were studied, including their chemical composition, mineralogy and crystallography, using X-ray diffraction, Raman and Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, focused ion beam, electron backscatter diffraction, and thermogravimetric analysis. Generally, serpulid tubes have a high amount of organic matter (~ 7.5 wt%), consisting of chitin and proteins, and the calcite is always present as medium to high magnesium calcite. Three main microstructures were identified: granular-prismatic and lamello-fibrillar calcite, and fibrous aragonite. They all displayed an axial texture, which is stronger in the lamello-fibrillar calcite, with the c-axis aligned with the elongation axis of the crystals. These findings demonstrate that only some instances of the granular-prismatic and the lamello-fibrillar calcite are biogenic (primary) microstructures. Conversely, other instances of the granular-prismatic calcite and the fibrous aragonite are a consequence of a recrystallization process (i.e. secondary). Replacement may occur on either primary or secondary calcitic microstructures (replaced by aragonite). Secondary microstructures retain remnants of the previously replaced microstructures, such as vestigial crystals or major growth increments. The high-Mg nature of the calcite favors recrystallization. The plywood arrangement of the lamello-fibrillar calcite is hypothesized to result from the ordering of a chitin fibrillar precursor into a cholesteric liquid crystal phase, with the calcite subsequently growing by oriented nucleation onto the organic fibrils.

Optical Characteristics and Source Analysis of Dissolved Organic Matter in Hypersaline Lakes in Cold and Arid Regions

The composition and source information of the aquatic dissolved organic matter （DOM） in the Daihai Lake, a typical saline lake at the ecologically fragile agro-pastoral area, were explored with three-dimensional excitation and emission matrix fluorescence （3DEEM）, parallel factor analysis （PARAFAC）, and fluorescence peaks （B, T, A, M, C, D, and N）. Further, the relationship between aquatic DOM fluorescence characteristics and environmental factors were analyzed using correlation analysis in the Daihai Lake. The results showed that the water of Daihai was weakly alkaline, with high nutrient salt concentration and serious organic pollution. Two protein-like substances （C1 and C3） and one humic-like substance （C2） were identified using PARAFAC. The sum of C1 + C2 accounted for 80% of DOM. The results of fluorescence peaks showed that the total percentage of protein-like fluorescence absorption peaks （B, T, and N） was 49.67%. Aquatic DOM of Daihai demonstrated both terrigenous and endogenous characteristics. Terrestrial inputs were mainly from intensive agricultural activities and rapid ecological degradation of the watershed leading to large amounts of organic matter entering the lake. The environmental behavior of DOM was highly correlated with the metabolic activity of organisms and nutrient status of lakes. NH4+-N, DOP, TP, DO, and permanganate index characterized the effect of the lake trophic state on DOM composition. DO, SAL, and Chla were mainly related to microbial metabolic processes （P&lt;0.05）. This study provides basic data and insights for the improvement of inland lake environments in saline lakes.

Source Rock Evaluation and Hydrocarbon Generation Potential of the Cretaceous (Dokan and Gulneri) Formations in Bai Hassan-13 Well Section, Kurdistan, North of Iraq

Eleven cutting rock samples from both Dokan and Gulneri formations (Cretaceous) in one subsurface section of Bai Hassan-13 (BH-13) well in northern Iraq were studied by using two techniques for hydrocarbon generation potentiality. The geochemical technique included Rock-Eval Pyrolysis analysis, The optical technique was achieved by studying palynological slides. The rock-Eval pyrolysis results showed that Dokan Formation has total organic carbon (TOC) wt.% ranging between 1.16 % and 2.3 % (good to very good), Gulneri Formation has a high TOC of 1.34 % and 4.64 % (good to excellent) quantity of organic matter. About the quality of organic matter, both Dokan and Gulneri formations are composed of kerogen types I and II. The organic matter of the Dokan Formation is not indigenous (migrated), one sample of the Gulneri Formation is indigenous the other one is located on the slanted line separating the Indigenous from non-indigenous organic matter. The organic matter within the two formations are thermally immature source rock, Therefore, they cannot generate oil and gas. The palynological study revealed that amorphous organic matter is the predominant organic matter component in both formations with more than 89%, whereas phytoclasts and palynomorphs comprised only a few percentages. There is no great variation in the percentages of the mentioned organic matter components, except a slight increase in the percentage of phytoclasts and palynomorphs in the lower part of the Dokan Formation, therefore one primary palynofacies type can be recognized, and divided into two secondary palynofacies. Through plotting Tyson's Amorphous, phytoclasts, and palynomorphs (APP) diagram, it is clear that the two formations are deposited in a distal suboxic to anoxic basin.

Changes in the structure of the microbial community within the phycospheric microenvironment and potential biogeochemical effects induced in the demise stage of green tides caused by Ulva prolifera.

Green tides caused by Ulva prolifera occur annually in the Yellow Sea of China, and the massive amount of biomass decomposing during the demise stage of this green tide has deleterious ecological effects. Although microorganisms are considered key factors influencing algal bloom demise, an understanding of the microbial-algae interactions within the phycospheric microenvironment during this process is still lacking. Here, we focused on the variations in phycospheric microbial communities during the late stage of the green tide in three typically affected areas of the Yellow Sea via metagenomic sequencing analysis. In total, 16.9 million reads obtained from 18 metagenome samples were incorporated into the assembled contigs (13.4 Gbp). The phycosphere microbial community composition and diversity changed visibly during the demise of U. prolifera. The abundances of algae-lysing bacteria, Flavobacteriaceae at the family level and Alteromonas, Maribacter, and Vibrio at the genus level increased significantly in the phycosphere. In addition, the levels of glycoside hydrolases (GHs) and polysaccharide lyases (PLs) enzymes, which decompose U. prolifera polysaccharides in the phycosphere, were greater. Therefore, the degradation of algal polysaccharides can increase the efficiency of carbon metabolism pathways in the phycospheric microenvironment. Most of the genes detected in the phycosphere, especially norC, nrfA, and nasA, were associated with nitrogen metabolism pathways and showed dynamics related to the demise of the large amount of organic matter released by a green tide. Therefore, the demise of green tide algae may affect the potential carbon and nitrogen cycles of the phycospheric microenvironment by driving changes in the structure and diversity of microbial communities. Our research provides a novel perspective to better understand the ecological impact of U. prolifera during the green tide demise stage.

Organic Coatings Reduce Dissolution Rate by an Order of Magnitude for Carbonate Minerals Produced by Marine Fish

AbstractMarine carbonate production and dissolution are important components of the global carbon cycle and the marine alkalinity budget. Global carbonate production by marine fish (ichthyocarbonate) has been estimated to be as high as 9.03 Pg CaCO3 yr−1; however, the fate of ichthyocarbonate is poorly understood. High magnesium concentrations in ichthyocarbonate would traditionally suggest rapid dissolution under current marine conditions, but a correlation between dissolution rate and mol%MgCO3 has not been observed. Here, we aim to determine the role of organic coatings on dissolution rates of ichthyocarbonate in marine environments. We applied a combination of petrographic, geochemical, and microCT approaches to assess the quantity and distribution of organic matter in ichthyocarbonate produced by two species of marine fish, the Gulf toadfish (Opsanus beta) and the Olive flounder (Paralichthys olivaceus). We show that organic matter, including external coatings and embedded organic material, is volumetrically significant, ranging from 8.5% to 32.3% of ichthyocarbonate by volume. Bleach oxidation of external organic matter coatings increased the dissolution rate of ichthyocarbonate by more than an order of magnitude, suggesting these coatings serve to reduce reactive surface area of the mineral fraction in ichthyocarbonate. Assuming that organic coatings do not influence sinking rates, external coatings extend the depth of ichthyocarbonate persistence in the water column by ∼12–15×. Therefore, organic coatings are an important determinant of the role of ichthyocarbonate in the marine carbon cycle.

Organic Sulfur Markers as Proxies of Depositional Paleoeenvironments Related to Recôncavo and Amazon Basins, Brazil.

This study employed organic sulfur markers (S-markers) associated with geochemistry parameters to evaluate the paleoenvironment of different depositional settings in 24 samples collected in vertical sections of outcrops of the Candeias and Barreirinha Formations in Recôncavo and Amazon basins, respectively. A total of twenty-one S-markers from benzothiophene (BT), dibenzothiophene (DBT), and benzonaphtothiophenes (BNT) classes were optimized and quantified by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). S-markers efficiently evaluated and differentiated the depositional paleoenvironment in the source rocks based on the individual compound, in cross-validation with saturated biomarkers, and associated with parameters such as total organic carbon (TOC) and Rock-Eval pyrolysis. Samples from the lacustrine environment presented low concentrations of BT, DBT, and BNT, and samples from the marine environment showed high BT, DBT, and BNT concentrations. The variations in ∑DBT and TOC indicated that the quantity and/or the type of organic matter exert some control over the distribution of DBTs. Although the formations are from different paleoenvironments, the organic matter input was similar, as indicated by high proportions of 1,2-BNT and 2,1-BNT relative to 2,3-BNT, thus characterizing the algal input with a microbial contribution for both sites. The sum of the BNTs was directly related to the amounts of amorphous organic matter (AOM) in the vertical distribution of outcrops. These results are in accordance with the finding that BNTs may originate from the microbial activity. The DBT/Phen vs pristane/phytane (Pr/Ph) relationship attested to differences in the redox conditions of the depositional paleoenvironments of the formations under study. The 4,6-DMDBT/2,4,6-TMDBT and 2,4,6-TMDBT/(2,4,7 + 2,4,8)-TMDBT ratios indicated immaturity for hydrocarbon generation.

Hydrocarbon generation potential of South Geisum Oilfield, Gulf of Suez, Egypt: Source rock evaluation and basin modeling for unconventional hydrocarbon prospects

This study aims to define the hydrocarbon generation potential of source rocks by assessing various factors including quantity of organic matter, types of kerogen, thermal maturity, and source of organic matter input. Depositional conditions of source rocks from Thebes, Brown Limestone, and Matulla formations in Well G-9, Well GA-2 and Well GW-6, are assessed through pyrolysis, vitrinite reflectance and 1D basin modeling. Results show the source rocks of Thebes and Brown Limestone formations exhibit favorable to excellent source rock characteristics with Type I–II kerogen and have the capacity to generate oil. Conversely, the source rocks of the Matulla Formation show fair to good source rock characteristics with Type II–III kerogen and have the capacity to produce both oil and gas. Thermal maturity shows the source rocks are at an immature stage. A 1D basin model is constructed for Well G-9 to simulate multi-tectonic episodes, burial events, and the history of thermal maturity. Sedimentation rates of Cretaceous to Eocene deposits are characterized by a low burial rate, which contrasts with the high burial and sedimentation rates for Miocene and post Miocene (Pliocene–Recent) strata. Overall, the South Geisum oilfield petroleum system is found to be immature based on integration of source rock evaluation and petroleum basin modelling.

Recent Patents on Particle Wettability Measurement and Improvement

Background: As the coal mining industry becomes more mechanized, it leads to a large number of coal dust particles suspended in the air, polluting the surrounding environment, accompanied by an increase in fine-grained low-rank coal particles and a low recovery rate of a large amount of organic matter in the particles, wasting resources. Objective: The study of particle wettability can have an impact on spray dust reduction and particle flotation efficiency. By adjusting the hydrophilicity of coal powder particles, the generation of suspended coal dust can be effectively suppressed. By adding surfactants, the flotation separation efficiency of coal particles can be improved. Method: This article introduces the measurement method of particle wetting properties and methods to improve the wetting properties of particles, providing a reference for studying the wetting properties of particles Results: The measurement of particle wetting properties is more accurate, simple, and convenient. Improving the wetting properties of particles by adding additives has significant implications for later dust reduction and particle flotation. Conclusion: This thesis provides an important basis for studying the wettability of particles, modifying the wettability and hydrophilicity of particles, providing specific guidance for improving the wettability of particles for spray dust reduction and particle flotation, and greatly improving industrial production efficiency.

Efficient treatment of printing and dyeing reverse osmosis concentrate by a Ti‐NTA/SnO2‐Sb2O3 electrocatalytic membrane

AbstractBACKGROUNDPrinting and dyeing reverse osmosis concentrates (ROC) contain large amounts of salts and organic matter, which is a major environmental issue. The unique composition of such wastewater makes the use of traditional physicochemical techniques challenging.RESULTSIn this paper, titanium dioxide nanotube arrays/SnO2‐Sb2O3 (Ti‐NTA/SnO2‐Sb2O3) electrodes were prepared by anodizing–cathodizing and sol–gel method for the electrocatalytic degradation of printing and dyeing ROC. Organic matter removal under different situations was examined, and the best treatment parameters were identified.CONCLUSIONFollowing treatment, organic matter concentration dropped from 1600 to 50 mg L−1, or even less. The outstanding removal performance of the Ti‐NTA/SnO2‐Sb2O3 electrode was validated by full‐scan ultraviolet spectra, gas chromatography–mass spectrometry and three‐dimensional fluorescence. Evaluation of the dissolved heavy metals and halogenated degradation process byproducts revealed that the electrocatalytic membranes were environmentally safe. These findings highlight the enormous potential of electrocatalytic membranes for the treatment of high‐salt ROC when equipped with a Ti‐NTA/SnO2‐Sb2O3 electrode. © 2024 Society of Chemical Industry (SCI).

Linking fish bioturbation to life history in a eutrophic wetland: An analysis of fish contributions to internal nutrient loading

Abstract Bioturbation (sediment disturbance by animal actions) effects on nutrient cycling and nutrient levels in surface waters are difficult to quantify, in part because the diversity and magnitude of species‐specific influences are poorly understood. These influences may have consequences for the management of the trophic state of freshwater ecosystems. Fish cause bioturbation in freshwater and marine ecosystems by digging in benthic sediments, manipulating periphyton mats while searching for prey and scraping hard substrates while feeding. We used experimental enclosures (2.25 m2) to quantify bioturbation‐mediated phosphorus (P) and nitrogen (N) regeneration from sediment by three species of fish that differ in interactions with the benthos (largemouth bass, Micropterus salmoides; tilapia, Oreochromis spp.; and sailfin catfish, Pterogoplichthys spp.) in shallow eutrophic wetlands in Southern Florida. Tilapia are omnivores that include detritus in their diet (winnowing or ingesting sediments) and dig nests in soft sediments year round, sailfin catfish actively burrow into substrate and consume detritus (digging and ingesting sediments), and largemouth bass are piscivores that do not routinely interact with the benthos when feeding but may dig nests in soft sediment in spawning season (January–April). We quantified the amount of suspended flocculent organic matter and changes in water column nutrients (total phosphorus [TP] and total nitrogen [TN]) in 2‐week trials for each species and estimated the portion of nutrient increases relative to fishless controls that could be attributed to bioturbation‐mediated internal nutrient loading through suspension of organic matter (as opposed to excretion or other sources of nutrient loading). Water column nutrient concentrations increased with increasing biomass for all species, but the bioturbation contribution differed by species. Largemouth bass increased water column nutrient concentrations (TP: 86% and TN: 5% relative to controls) but did not influence water column suspended particulate matter through bioturbation of sediment. Tilapia increased water column nutrients a modest amount (TP: 8%; TN: 15%), of which a small portion was attributed to bioturbation (c. 18% of TP). Sailfin catfish raised water column nutrients substantially (TP: 105%; TN: 46%) and up to 100% of the increased TP was attributed to bioturbation. Sailfin catfish also suppressed algal growth and TP accumulation on the sides of the enclosures and reduced nutrient concentrations of the flocculent sediments. Our results were consistent with our hypothesis that behaviour and foraging traits affect bioturbation contributions to nutrient loading. The results also demonstrated that species with similar net effects like largemouth bass and sailfin catfish, added nutrients via different mechanisms (i.e. excretion vs. bioturbation). Considering the feeding strategies and interactions with the substrate of common fish species may assist managers in meeting nutrient reduction goals for eutrophic wetlands and managed freshwater systems.

Sargassum beaching on mangrove sediments shifts microbial and crab metabolisms and enhances blue carbon storage

AbstractBenthic metabolism and net carbon accumulation in mangroves sediments strongly depend on the quantity and quality of organic matter (OM) supplied, including material brought by coastal waters such as the macroalgae Sargassum spp. Mesocosms were used to assess the effect of eutrophication by Sargassum on mangrove sediments. The concentration of fatty acids (FAs), organic carbon and its carbon isotopic signature, and the sediments–air CO2 fluxes were used to follow the evolution of sedimentary OM in surface and subsurface sediments for 60 d. Sargassum beaching shifted microbial and crab metabolism, leading to a preferential degradation of the labile fraction of OM from both Sargassum (δ13C = −17.7‰ and high concentration of essential FAs) and mangrove leaves (δ13C: −28.9‰ and high concentrations of 18:2ω6 and 18:3ω3). Fatty acids composition of crabs hepatopancreas revealed they preferentially fed on Sargassum and these invertebrates also increased the particulate OM tidal export. In addition, microbial activity at the sediment surface was enhanced, as revealed by strong production of branched FAs and higher CO2 fluxes in mesocosms containing Sargassum. However, Sargassum beaching also increased the transfer and preservation of more refractory OM from mangrove leaves found in higher quantity in subsurface sediments (6–8 cm) after 60 d. Inputs of macroalgae induced a negative priming effect and enhanced the preservation of blue carbon in the sediments. This negative priming effect was enhanced by crab activities. These biotic interactions that include microbial communities apparently make mangrove efficient in storing carbon in a context of growing eutrophication of the tropical ocean.

Organic petrographic and geochemical insights into organic matter derived from land plants and marine algae in the Lark Formation, Danish North Sea

Climatic fluctuations from the Eocene to the Miocene highlight the importance of investigating the paleoenvironment of the latest Eocene to the Middle Miocene Lark Formation in the Danish North Sea. This study investigates immature sedimentary organic matter in the Lark Formation using 54 cuttings samples and one core sample collected from seven wells in the eastern North Sea Basin. Organic petrography and molecular geochemistry analyses were performed to determine the variations in the quantity and origin of allochthonous and autochthonous organic matter. Additionally, the study assesses the impact of climate fluctuations on marine productivity in the eastern North Sea Basin and land plant vegetation at the basin margins during the latest Eocene to the Middle Miocene.The organic matter in the Lark Formation originated from mixed sources, primarily land plants, with a secondary contribution from marine algae. This is indicated by the maceral composition and the types and abundance of aliphatic and aromatic hydrocarbon biomarker compounds. Moreover, the presence of diterpenoids (gymnosperm biomarkers) and non-hopanoid triterpenoids (angiosperm biomarkers) reveals that the allochthonous organic matter originated from conifers and angiosperms.Climatic impacts on land plants and marine algae during the latest Eocene to the Middle Miocene are revealed by several parameters: the Averaged Chain Length (ACL) of land plant waxes, the proportion of coniferous contribution (C/(C + A)), and the whole rock volume percentages of huminite, inertinite (H + I, vol%) and liptinite (L, vol%). The shifts to cooler and drier climates highlighted the cold adaptation of onshore conifers and resulted in the input of higher molecular weight waxy components into the sediments. However, under these conditions, reduced precipitation and runoff resulted in lower amounts of terrigenous organic matter supplied to the basin. Additionally, the drop in water temperature and the warm-affinity of local algae assemblage led to reduced marine productivity. Together, these factors contributed to an overall decrease in organic richness. In contrast, during shifts to warmer and more humid climates, the trend reversed. The contribution of conifers to the floral assemblage diminished, but higher amounts of terrigenous organic matter were transported to the basin due to increased precipitation and runoff. This was accompanied by warmer water temperatures, boosting the productivity of organic-walled microplankton in the marine environment and contributing to greater organic richness.