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Silicified Microorganisms and Microorganism-Like Particles in the Groundwater of an Abandoned Coal Mine
Abstract
Relatively little research has been conducted on the preservation of microorganisms and microbial particles in the groundwater of abandoned mines (GAM). In this study, silicified microorganism-like particles, 50-450 nm in diameter, were found to commonly occur outside microbes and their associated extracellular polymers. These particles comprise a cellular core surrounded by a cortex essentially of silica and are similar in morphology to certainly known microorganisms. The studied samples suggest the preservation of microorganisms through silicification and add to understanding about how microorganisms in natural water systems undergo biomineralization. Finally, the silicified microorganism-like particles were surrounded by many silica nanoparticles. This study identified a new mode of silica transport in the GAM.
... In this study, the morphological structures of Fe-bearing nanoparticles resemble those commonly found in terrestrial bacteria, and some nanoparticles contain biophile elements such as S and N. One of the most noteworthy characteristics of Fe-bearing nanoparticles in hot springs is their bioavailability, as indicated by their resemblance to bacteria (McKay et al., 1996;Shao et al., 2023). Furthermore, the size and number of these nanoparticles generally increase in culture, suggesting that they might have an impact on the circulation and availability of elements in the environment (Young et al., 2009;Peng et al., 2011). ...
Iron is a critical redox-active element in geothermal water, and the presence of nanoparticulate Fe is essential in comprehending the intricate cycling of iron and related elements within the natural geothermal ecosystems. In this study, we investigated the mineral properties of Fe-bearing nanoparticles in a hot spring located in Shanxi Province. High-resolution transmission electron microscopy (HRTEM) is utilized for the examination of the morphology, chemical composition, and crystalline structure of Fe-bearing nanoparticles. The findings show that Fe-bearing nanoparticles can exist as single particles measuring 50–200 nm in size, as well as aggregate to form nanoparticle aggregations. The morphology of Fe-bearing nanoparticles mainly includes triangle, axiolitic, and irregular shapes. The selected area electron diffraction patterns reveal the crystal form, amorphous form, and the transition from amorphous to crystalline forms of these nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) analysis indicates that these nanoparticles primarily consist of O and Fe in composition, along with various trace elements including N, Al, Si, Ca, Zn, Cr, Ni, and Mo. These results reveal that goethite and hematite can occur in hot spring. Various in size and modality, tend to cluster into each other, and multiple crystalline states indicate that these iron-bearing nanoparticles are formed through natural processes. In addition, the iron-bearing nanoparticles with biomimetic morphologies (cell-like or microorganism-like shapes) may be produced through microbial activity. The biomimetic properties also imply that these nanoparticles may be readily available for biological processes. Significantly, our findings further validate that the shape of iron oxide nanoparticles can serve as an indicator of pH and temperature of the hot spring.
... Some of the nanoparticles (e.g., Ca-bearing nanoparticles and MnO 2 nanosheets) in the mineral water exited as irregular shapes. As the nanoparticles that are formed as biogenic products of microbial activity are usually regular shapes, such as a sphere with smoothed edges (e.g., [54]), nanoparticles with irregular shapes cannot be products of biogenesis. In addition, the concentration of microorganisms (e.g., coliform bacteria, Enterococcus faecalis, Pseudomonas aeruginosa, and Clostridium perfringens) in the mineral water was low [11]. ...
Environmental nanoparticles are known to be present in various aquatic environments, exerting significant influences on water quality, particularly in water distribution systems. However, there has been a notable dearth of research on the presence and impact of environmental nanoparticles in mineral water, a unique water resource. In this study, we employed Nanoparticle Tracking Analysis (NTA) and conducted High-Resolution Transmission Electron Microscopy (HRTEM) to address this research gap. This groundbreaking study represents the first comprehensive exploration of environmental nanoparticles within natural mineral water from Zibo City, Shandong Province, China. The results of the NTA showed that the concentration of the particles was 5.5 × 10 5 particles/mL and the peak diameter of the size distribution was 180 nm. The HRTEM showed that the nanoparticles were granular, pinniform, rodlike, and flakey in shape, and some of the nanoparticles existed in aggrega-tion. The energy-dispersive spectrometry results showed that most of the nanoparticles contained O, Mg, Ca, Si, Fe, Ti, and P, and some of them also contained F, V, S, and Mn. When combined with the characteristics of the selected area electron diffraction pattern, the nanoparticles were confirmed to be Ca-bearing nanoparticles, attapulgite nanorods, MnO 2 nanosheets, and TiO 2 nanoparticles. These findings shed light on a novel manifestation of elemental compositions in mineral water. Furthermore, considering the chemical and physical attributes of both the nanoparticles and mineral water, it is highly plausible that these environmental nanoparticles result from the weathering of minerals. The presence of these nanoparticles within mineral water offers a unique opportunity to advance our comprehension of nanoparticle behavior across diverse systems. Significantly, the realm of environmental nanoparticle science holds paramount importance for ongoing endeavors in ensuring water safety, enhancing treatment processes, and facilitating effective remediation procedures.
... In this study, the morphological structures of Fe-bearing nanoparticles resemble those commonly found in terrestrial bacteria, and some nanoparticles contain biophile elements such as S and N. One of the most noteworthy characteristics of Fe-bearing nanoparticles in hot springs is their bioavailability, as indicated by their resemblance to bacteria [32,33]. Furthermore, the size and number of these nanoparticles generally increase in culture, suggesting that they might have an impact on the circulation and availability of elements in the environment [34,35]. ...
Iron is a critical redox-active element in geothermal water, and the presence of nanoparticulate Fe is essential in comprehending the intricate cycling of iron and related elements within the natural geothermal ecosystems. In this study, we investigated the mineral properties of Fe-bearing nanoparticles in a hot spring located in Shanxi Province. High-resolution transmission electron microscopy (HRTEM) is utilized for the examination of the morphology, chemical composition, and crystalline structure of Fe-bearing nanoparticles. The findings indicate that Fe-bearing nanoparticles can exist as single particles measuring 50–200 nm in size, as well as aggregate to form nanoparticle aggregations. The morphology of Fe-bearing nanoparticles mainly includes triangle, axiolitic, and irregular shapes. The selected area electron diffraction patterns reveal the crystal form, amorphous form, and the transition from amorphous to crystalline forms of these nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) analysis indicates that these nanoparticles primarily consist of O and Fe in composition, along with various trace elements including N, Al, Si, Ca, Zn, Cr, Ni, and Mo. Combined with the mineral characteristics, we confirm that some iron-bearing nanoparticles belong to goethite and hematite. These mineral characteristics also indicate that these iron-bearing nanoparticles are formed through natural processes. The presence of biomimetic morphologies, such as cell-like or microorganism-like shapes, suggests that these nanoparticles may be produced through microbial activity. The biomimetic properties also imply that these nanoparticles may be readily available for biological processes. Our findings further validate that the shape of iron oxide nanoparticles can serve as an indicator of environmental conditions.
... Some of the nanoparticles (e.g., Ca-bearing nanoparticles and MnO2 nanosheets) in the mineral water exited as irregular shapes. As the nanoparticles that are formed as biogenic products of microbial activity are usually regular shaped, such as a sphere with smoothed edges (e.g., [54]), nanoparticles 10 with irregular shapes cannot be products of biogenesis. In addition, the concentration of microorganisms (e.g., coliform bacteria, Enterococcus faecalis, Pseudomonas aeruginosa, and Clostridium perfringens) in the mineral water was low [11]. ...
Environmental nanoparticles have been shown to exist in most aquatic environments, and environmental nanoparticles in water distribution systems significantly affect water quality. However, little research has been conducted on the environmental nanoparticles in mineral water, which is a special water resource. Nanoparticle tracking analysis (NTA) and high-resolution transmission electron microscopy (HRTEM) were conducted. This study was the first to identify many environmental nanoparticles in natural mineral water in Zibo City, Shandong Province, China. The results of the NTA showed that the concentration of the particles was 5.5 ×106 particles/mL and the peak diameter of the size distribution was 180 nm. The HRTEM showed that the nanoparticles were granular, pinniform, rodlike, and flakey in shape, and some of the nanoparticles existed in aggregation. The energy-dispersive spectrometry results showed that most of the nanoparticles contained O, Mg, Ca, Si, Fe, Ti, and P, and some of them also contained F, V, S, and Mn. When combined with the characteristics of the selected area electron diffraction pattern, the nanoparticles were confirmed to be Ca-bearing nanoparticles, attapulgite nanorods, MnO2 nanosheets, and TiO2 nanoparticles. These results indicate a new form of elements occurring in mineral water. In addition, based on the chemical and physical characteristics of the nanoparticles and mineral water, these environmental nanoparticles in the mineral water are likely to be the weathering byproducts of minerals. These nanoparticles within mineral water provide a good opportunity for understanding the behavior of nanoparticles in varied systems. Moreover, environmental nanoparticle science is important for continuing efforts in water safety, treatment, and remediation.
The role of viruses at different stages of the origin of life has recently been reconsidered. It appears that viruses may have accompanied the earliest forms of life, allowing the transition from an RNA to a DNA world and possibly being involved in the shaping of tree of life in the three domains that we know presently. In addition, a large variety of viruses has been recently identified in extreme environments, hosted by extremophilic microorganisms, in ecosystems considered as analogues to those of the early Earth. Traces of life on the early Earth were preserved by the precipitation of silica on the organic structures. We present the results of the first experimental fossilisation by silica of viruses from extremophilic Archaea (SIRV2 – Sulfolobus islandicus rod-shaped virus 2, TPV1 – Thermococcus prieurii virus 1, and PAV1 – Pyrococcus abyssi virus 1). Our results confirm that viruses can be fossilised, with silica precipitating on the different viral structures (proteins, envelope) over several months in a manner similar to that of other experimentally and naturally fossilised microorganisms. This study thus suggests that viral remains or traces could be preserved in the rock record although their identification may be challenging due to the small size of the viral particles.
It is generally accepted that silica (SiO2) is not toxic. But the increasing use of silica nanoparticles (SiO2NPs) in many different industrial fields has prompted the careful investigation of their toxicity in biological systems. In this report, we describe the effects elicited by SiO2NPs on animal and cell physiology. Stable and monodisperse amorphous silica nanoparticles, 25 nM in diameter, were administered to living Hydra vulgaris (Cnidaria). The dose-related effects were defined by morphological and behavioral assays. The results revealed an all-or-nothing lethal toxicity with a rather high threshold (35 nM NPs) and a LT50 of 38 h. At sub lethal doses, the morphophysiological effects included: animal morphology alterations, paralysis of the gastric region, disorganization and depletion of tentacle specialized cells, increase of apoptotic and collapsed cells, and reduction of the epithelial cell proliferation rate. Transcriptome analysis (RNAseq) revealed 45 differentially expressed genes, mostly involved in stress response and cuticle renovation. Our results show that Hydra reacts to SiO2NPs, is able to rebalance the animal homeostasis up to a relatively high doses of SiO2NPs, and that the physiological modifications are transduced to gene expression modulation.
Switching off the pumps of a mine is one of the last steps in the lifetime of a surface or underground mine. As the water in the open space rises, the water might become contaminated with different pollutants and eventually start to flow in the open voids. This book addresses the processes related to mine abandonment from a hydrogeological perspective. After an introduction to the relevant hydrogeochemical processes the book gives detailed information about mine closure procedures. Based on in-situ measurements the hydrodynamic processes in a flooded mine are described and some of the mine closure flow models exemplified. As all investigations are based on precise data, the book gives some key issues of monitoring and sampling, especially flow monitoring. Then the book presents some new methodologies for conducting tracer tests in flooded mines and gives some hints to passive mine water treatment. At the end of the book thirteen well investigated case studies of flooded underground mine and mine water tracer tests are described and interpreted from a hydrodynamic point of view.
Biofilms that grow around Gumingquan hot spring (T = 71 °C, pH = 9.2) in the Rehai geothermal area, Tengchong, China, are formed of various cyanobacteria, Firmicutes, Aquificae, Thermodesulfobacteria, Desulfurococcales, and Thermoproteales. Silicified virus-like nanoparticles, 40-200 nm in diameter, are common inside the microbial cells and the extracellular polymeric substances around the cells. These nanoparticles, which are formed of a core encased by a silica cortex, are morphologically akin to known viruses and directly comparable to silicified virus-like particles that were produced in biofilms cultured in the laboratory. The information obtained from examination of the natural and laboratory-produced samples suggests that viruses can be preserved by silicification, especially while they are still encased in their host cells. These results expand our views of virus-host mineral interaction in extreme thermal environments and imply that viruses can be potentially preserved and identified in the geological record.
Silica nanoparticle size distributions were measured from transmission electron micrographs of bacterial cells in thin-sectioned hot spring sediment samples, as well as specimens from laboratory experiments on bacterial silicification. Diameters of silica nanoparticles on bacterial cells were smaller than corresponding values of those occurring away from bacteria in the same fields of view. Regression analysis of the particle size data and application of the Lifshitz-van der Waals Acid-Base approach to evaluations of solid surface energy established that the size difference extends from a nearly 40% decrease in the mean interfacial energy of silica nanoparticles on bacteria (0.9 mJ/m 2 ) as opposed to free in aqueous suspension (1.2 mJ/m 2 ). In thermodynamic terms, the lower interfacial energy serves to reduce equilibrium solubility values, and enhance nucleation rates, of silica nanoparticles on bacteria cells. The well documented culmination of these events in hot spring sediments and experimental studies is rapid preferential silicification and structural preservation of bacterial cells.
Short-term geomorphic and hydrologic effects of subsidence induced by longwall mining under Burnout Creek, Utah were evaluated.
During the year after longwall mining, 0.3–1.5 m of subsidence was measured near impacted reaches of the mountain stream channel.
The major channel changes that occurred in a 700-m reach of Burnout Creek that was subsided from 1992 to 1993 were: (1) increase
in lengths of cascades and to a lesser extent glides; (2) increases in pool length, numbers and volumes; (3) increase in median
particle diameter of bed sediment in pools; and (4) some constriction in channel geometry. Most of the changes appeared short-lived,
with channel recovery approaching pre-mining conditions by 1994. In a 300-m reach of the South Fork that was subsided from
1993 to 1994, only channel constriction was observed, although any impacts on pool morphology may have been confounded by
heavy grazing in the riparian reaches during the dry summer of 1994. Similar near-channel sedimentation and loss of pool volume
between 1993 and 1994 were noted throughout Burnout Creek and in adjacent, unmined James Creek. Subsidence during the 3-year
period had no effect on baseflows or near-channel landslides.
Due to the rising use of nanomaterials (NMs), there is concern that NMs induce undesirable biological effects because of their unique physicochemical properties. Recently, we reported that amorphous silica nanoparticles (nSPs), which are one of the most widely used NMs, can penetrate the skin barrier and induce various biological effects, including an immune-modulating effect. Thus, it should be clarified whether nSPs can be a risk factor for the aggravation of skin immune diseases. Thus, in this study, we investigated the relationship between the size of SPs and adjuvant activity using a model for atopic dermatitis.
We investigated the effects of nSPs on the AD induced by intradermaly injected-mite antigen Dermatophagoides pteronyssinus (Dp) in NC/Nga mice. Ear thickness measurements and histopathological analysis revealed that a combined injection of amorphous silica particles (SPs) and Dp induced aggravation of AD in an SP size-dependent manner compared to that of Dp alone. In particular, aggravation was observed remarkably in nSP-injected groups. Furthermore, these effects were correlated with the excessive induction of total IgE and a stronger systemic Th2 response. We demonstrated that these results are associated with the induction of IL-18 and thymic stromal lymphopoietin (TSLP) in the skin lesions.
A particle size reduction in silica particles enhanced IL-18 and TSLP production, which leads to systemic Th2 response and aggravation of AD-like skin lesions as induced by Dp antigen treatment. We believe that appropriate regulation of nanoparticle physicochemical properties, including sizes, is a critical determinant for the design of safer forms of NMs.
Diatoms play a major role in carbon export from surface waters, but their role in the transport of carbon to the deep sea has been questioned by global analyses of sediment trap fluxes which suggest that organic carbon fluxes and transfer efficiencies through the mesopelagic are tightly correlated with CaCO3 (Klaas and Archer, 2002; François et al., 2002). Here we explore the role of diatoms in the biological pump through a study of Si and C interactions from the molecular to the global scale. Recent findings on molecular interactions between Si and C are reviewed. The roles of bacteria, grazers and aggregation are explored and combined, to account for the extent of Si and C decoupling between surface waters and 1000 m, observed to be very homogeneous in different biogeochemical provinces of the ocean. It is suggested that the mesopelagic food web plays a crucial role in this homogeneity: Sites of high export are also sites where diatom C is being either remineralized or channeled toward the long-lived carbon pool most efficiently in the mesopelagic zone. The amount of carbon participating in the biological pump but not collected in sediment traps remains to be explored. It is also demonstrated that statistical analyses performed at global scales hide spatial variability in carrying coefficients, indicating a clear need to understand the mechanisms that control spatial and temporal variations in the relative importance of ballast minerals and other export mechanisms such as particle dynamics.
With the increase in use of nanomaterials, there is growing concern regarding their potential health risks. However, few studies have assessed the role of the different physical characteristics of nanomaterials in allergic responses. Here, we examined whether intranasally administered silica particles of various sizes have the capacity to promote allergic immune responses in mice. We used nanosilica particles with diameters of 30 or 70 nm (nSP30 or nSP70, respectively), and conventional micro-sized silica particles with diameters of 300 or 1000 nm (nSP300 or mSP1000, respectively). Mice were intranasally exposed to ovalbumin (OVA) plus each silica particle, and the levels of OVA-specific antibodies (Abs) in the plasma were determined. Intranasal exposure to OVA plus smaller nanosilica particles tended to induce a higher level of OVA-specific immunoglobulin (Ig) E, IgG and IgG1 Abs than did exposure to OVA plus larger silica particles. Splenocytes from mice exposed to OVA plus nSP30 secreted higher levels of Th2-type cytokines than mice exposed to OVA alone. Taken together, these results indicate that nanosilica particles can induce allergen-specific Th2-type allergic immune responses in vivo. This study provides the foundations for the establishment of safe and effective forms of nanosilica particles.
The increasing use of nanomaterials has raised concerns about their potential risks to human health. Recent studies have shown that nanoparticles can cross the placenta barrier in pregnant mice and cause neurotoxicity in their offspring, but a more detailed understanding of the effects of nanoparticles on pregnant animals remains elusive. Here, we show that silica and titanium dioxide nanoparticles with diameters of 70 nm and 35 nm, respectively, can cause pregnancy complications when injected intravenously into pregnant mice. The silica and titanium dioxide nanoparticles were found in the placenta, fetal liver and fetal brain. Mice treated with these nanoparticles had smaller uteri and smaller fetuses than untreated controls. Fullerene molecules and larger (300 and 1,000 nm) silica particles did not induce these complications. These detrimental effects are linked to structural and functional abnormalities in the placenta on the maternal side, and are abolished when the surfaces of the silica nanoparticles are modified with carboxyl and amine groups.
Viruses of extreme thermophiles are of great interest because they serve as model systems for understanding the biochemistry and molecular biology required for life at high temperatures. In this work, we report the discovery, isolation, and preliminary characterization of viruses and virus-like particles from extreme thermal acidic environments (70-92 degrees C, pH 1.0-4.5) found in Yellowstone National Park. Six unique particle morphologies were found in Sulfolobus enrichment cultures. Three of the particle morphologies are similar to viruses previously isolated from Sulfolobus species from Iceland and/or Japan. Sequence analysis of their viral genomes suggests that they are related to the Icelandic and Japanese isolates. In addition, three virus particle morphologies that had not been previously observed from thermal environments were found. These viruses appear to be completely novel in nature.
Bioleaching of metal sulfides is caused by astonishingly diverse groups of bacteria. Today, at least 11 putative prokaryotic divisions can be related to this phenomenon. In contrast, the dissolution (bio)chemistry of metal sulfides follows only two pathways, which are determined by the acid-solubility of the sulfides: the thiosulfate and the polysulfide pathway. The bacterial cell can effect this sulfide dissolution by "contact" and "non-contact" mechanisms. The non-contact mechanism assumes that the bacteria oxidize only dissolved iron(II) ions to iron(III) ions. The latter can then attack metal sulfides and be reduced to iron(II) ions. The contact mechanism requires attachment of bacteria to the sulfide surface. The primary mechanism for attachment to pyrite is electrostatic in nature. In the case of Acidithiobacillus ferrooxidans, bacterial exopolymers contain iron(III) ions, each complexed by two uronic acid residues. The resulting positive charge allows attachment to the negatively charged pyrite. Thus, the first function of complexed iron(III) ions in the contact mechanism is mediation of cell attachment, while their second function is oxidative dissolution of the metal sulfide, similar to the role of free iron(III) ions in the non-contact mechanism. In both cases, the electrons extracted from the metal sulfide reduce molecular oxygen via a complex redox chain located below the outer membrane, the periplasmic space, and the cytoplasmic membrane of leaching bacteria. The dominance of either At. ferrooxidans or Leptospirillum ferrooxidans in mesophilic leaching habitats is highly likely to result from differences in their biochemical iron(II) oxidation pathways, especially the involvement of rusticyanin.
Land use has generally been considered a local environmental issue, but it is becoming a force of global importance. Worldwide
changes to forests, farmlands, waterways, and air are being driven by the need to provide food, fiber, water, and shelter
to more than six billion people. Global croplands, pastures, plantations, and urban areas have expanded in recent decades,
accompanied by large increases in energy, water, and fertilizer consumption, along with considerable losses of biodiversity.
Such changes in land use have enabled humans to appropriate an increasing share of the planet's resources, but they also potentially
undermine the capacity of ecosystems to sustain food production, maintain freshwater and forest resources, regulate climate
and air quality, and ameliorate infectious diseases. We face the challenge of managing trade-offs between immediate human
needs and maintaining the capacity of the biosphere to provide goods and services in the long term.
The net inputs of silicic acid (dissolved silica) to the world ocean have been revised to 6.1 +/- 2.0 teramoles of silicon per year (1 teramole = 10(12) moles). The major contribution (about 80 percent) comes from rivers, whose world average silicic acid concentration is 150 micromolar. These inputs are reasonably balanced by the net ouputs of biogenic silica of 7.1 +/- 1.8 teramoles of silicon per year in modern marine sediments. The gross production of biogenic silica (the transformation of dissolved silicate to particulate skeletal material) in surface waters was estimated to be 240 +/- 40 teramoles of silicon per year, and the preservation ratio (opal accumulation in sediment/gross production in surface waters) averages 3 percent. In the world ocean the residence time of silicon, relative to total biological uptake in surface waters, is about 400 years.
Much attention is currently being paid to the behaviour and effects of engineered silica particles, but there is only limited information available on the natural silica particles. In this study, we have found for the first time that natural silica can occur as spherical amorphous nanoparticles and silica fine disperse particles in the soil aerosol after studying nine areas from northern to southern China. These particles are usually 10 to 600 nm in diameter and contain a high content of impurities. Amorphous nature of the particles has been proved by the electron diffraction images. These findings indicate that nanoparticles and fine disperse particles in vapour phase could be an important transport form for natural silica and during the transportation in the vapor phases many elements could also accompany nanoparticles and finely disperse particles. The aggregative growth of SiO 2 nanoparticles is also observed for the first time in the natural system. In addition, these particles may be a perfect candidate to prospect blind ore.
Filling a long-standing need for a desk reference that synthesizes current research, Land Use Effects on Streamflow and Water Quality in the Northeastern United States reviews and discusses the impact of forest management, agriculture, and urbanization. The book provides a gateway to the diverse scientific literature that is urgently needed to understand and solve ubiquitous watershed management problems. The authors use an in-depth approach that focuses on the science behind sound management principles and practices. The book begins with a summary of the scientific principles and processes that define and govern the interactions between activities on land and conditions in streams, lakes, and estuaries. Building on these principles, later chapters progress from basic science to small-scale, controlled field experiments to landscape-scale studies and their watershed management implications. This nested format parallels the development of watershed management projects and solutions. The deliberate integration of land use history, ecology, hydrology, chemistry, and resource management avoids the artificial separation of inter-related watershed characteristics and tracks causes and effects over realistic time scales. The authors present the hydrologic and water quality principles on which to construct management plans for water supply watersheds across a wide range of sizes, configurations, and time scales. Rigorously reviewed by a distinguished panel of scientists and watershed managers, the book benefits from their collective experience across the full range of watershed science and management. It provides a diverse audience with the opportunity to update and expand their knowledge in critical areas of watershed science and management.
The composition, diversity and distribution of algae in Malaysian mining areas contaminated with potentially toxic trace heavy metals are described. One Site in Peninsula Malaysia (Sungai Luit) is an operational alluvial gold mine, Penjom is a mining area undergoing redevelopment, and Mengapur is a mineral prospecting area. Four abandoned mining areas studied in Sarawak (Jugan, Lucky Hill, Bidi, Tai Ton) had been mined for gold, antimony and mercury. Algal Samples were collected at 31 sites ranging from small drainage areas on a sulphide outcrop to streams, ponds and soil-free rock surfaces. The pH was measured at most sites and water analysed for trace heavy metals (principally copper, iron, arsenic). One hundred and forty-two algal species (75 genera) were recorded and 272 taxa if included are those grouped into size categories ('morphotypes') and doubtful species. Diatoms and chlorophytes were the two most diverse algal groups, with 70 and 57 species recorded respectively. High flushing rates, substrate instability, intermittent flow regime, and differences in pH and potentially toxic metals are thought to be implicated in low algal diversity. Diversity was highest in ponds whose pH was above 5.7 and where a wide range of microhabitats were present. The algal assemblage at a Jugan stream site was similar to an assemblage described from Europe and North America that is known to be indicative of acid mine drainage; several of these algae are new records for Malaysia. The widely distributed filamentous green alga Klebsormidium rivulare was the most characteristic alga of acid drainage areas on the sulphide-ore outcrop at Jugan. One new chlorophyte species is described, the desmid Closterium penjomium D. Williamson sp. nov.
Recent research has emphasized the importance of terrestrial ecosystems in the global biogeochemical cycle of silica (Si). The production, retention, and dissolution of amorphous silica of biological origin in soils and vegetation effectively control terrestrial Si fluxes. However, surprisingly little is known about the role of wetlands in these processes. Wetlands are known hotspots for both nitrogen and phosphorus cycling, and there have been countless studies and numerous reviews on these nutrients worldwide. By bringing together previously scattered results, we show that wetland ecosystems may be as important for Si transport and processing as they are for other important biogeochemical cycles. Yet, the range of studied systems is small and incomplete. This constitutes a serious gap in our understanding of both coastal eutrophication and climate change, issues that are strongly linked to Si biogeochemistry. Ecosystem scientists and wetland biogeochemists around the world need to begin addressing these issues.
Discharges from some underground flooded coal mines have exhibited increases in pH and reductions in contaminant loadings with time. Data from a study of mine water quality evolution in interconnected, flooded mines of the Uniontown syncline, Southwestern Pennsylvania were evaluated with the aid of modeling to elucidate the hydrologic and geochemical factors responsible for such changes. Coal barriers left in place from mining operations define three hydraulically distinct but interconnected zones: the southern, central, and northern pools. Assuming each mine pool to behave as a completely mixed tank reactor, a steady-state, tanks-in-series model was developed to describe system hydraulics. Chemical modeling components were coupled with the tank reactor hydraulic model to simulate inputs to the mine voids, acid generation from pyrite dissolution, and discharge water quality. Empirical in-mine chemical production terms were estimated for each of the mine pools based on discharge data from 1974 to 1975 and 1998 to 2000. The production terms were then used to simulate discharge water quality for each of the mine pools over a 50 year period. Simulated water quality in the northern and central mine pools reached steady-state conditions approximately 25-30 years after the mine pools flooded, evolving over time to reflect the recharge water quality. The simulation results indicate that the evolution of mine water quality in the flooded mine voids has been governed by alkaline recharge water slowly displacing acidic "first flush" water. Journal of Environmental Engineering
The natural occurring tendancy of high concentrations of tobacco mosaic virus (TMV) particles to associate into a nematic liquid crystals was described. The preparation of interior design of silica mesophases and nanoparticles was also demonstrated using tobacco mosaic virus (TMV) liquid crystals as templates. It was suggested that a wide range of inorganic oxides, semiconductors and metal-based mesophases can be prepared using TMV liquid crystals.
This case history provides information on the ground-water system and presents the results of an analysis of present and future hydrologic effects of coal mining in the Appalachian coal basin. Although emphasis is on the probable hydrologic effects due to subsurface mining, examples and discussions are equally applicable to surface mine problems. The case history is based on an ongoing study in Greene County which will be completed in 1983. Cooperators in this project were the Pennsylvania Geologic and Topographic Survey and the Greene County Commissioners. The study stemmed from local interest in the rural water supply of the county which is predominantly groundwater.
An on-site continuous-flow trough mesocosm was used to examine changes in the composition and abundance of periphytic algae and benthic invertebrates from additions of a solution of treated acid mine drainage (AMD). Five control and five treatment troughs supported an assemblage of periphyton and invertebrates that colonized from water withdrawn from Foxy Creek, a stream that receives limed AMD from the Equity Silver Mine, central British Columbia, Canada. A water intake for the mesocosm was located upstream of the AMD discharge. The treated AMD was delivered to the apparatus through a pipeline laid in a canal that carried the AMD to Foxy Creek. After three weeks of colonization in the troughs, additions of one part AMD to 10 parts Foxy Creek water was delivered to the treatment troughs and continued for three weeks. Analyses of variance of measurements of abundance and biomass indexes contained high power values and indicated that the AMD addition did not significantly change the algal and insect composition and abundance. Advantages and disadvantages of the mesocosm with regard to the relative sensitivity of the measured parameters for use in examining effects of the AMD additions are discussed. The conclusion was that quantitative on-site experimentation using the mesocosm apparatus is a powerful approach in setting guidelines for AMD discharge mainly due to its capability of integrating ecosystem processes in experiments where hypothesis testing is possible.
Discharges of contaminated groundwater from abandoned deep mines are a major environmental problem in many parts of the world. While process-based models of pollutant generation have been successfully developed for certain surface mines and waste rock piles of relatively simple geometry and limited areal extent, such models are not readily applicable to large systems of laterally extensive, interconnected, abandoned deep mines. As a first approximation for such systems, hydrological and lithological factors, which can reasonably be expected to influence pollutant release, have been assessed by empirically assessing data from 81 abandoned deep coal mine discharges in the UK. These data demonstrate that after flooding of a deep mine is complete and groundwater begins to migrate from the mine voids into surface waters or adjoining aquifers, flushing of the mine voids by fresh recharge results in a gradual improvement in the quality of groundwater (principally manifested as decreasing Fe concentrations and stabilisation of pH around 7). Alternative representations of the flushing process have been examined. While elegant analytical solutions of the advection–dispersion equation can be made to mimic the changes in iron concentration, parameterisation is tendentious in practice. Scrutiny of the UK data suggest that to a first approximation, the duration of the main period of flushing can be predicted to endure around four times as long as the foregoing process of mine flooding. Short- and long-term iron concentrations (i.e. at the start of the main period of flushing and after its completion, respectively) can be estimated from the sulphur content of the worked strata. If strata composition data are unavailable, some indication of pollution potential can be obtained from considerations of the proximity of worked strata to marine beds (which typically have high pyrite contents). The long-term concentrations of iron in a particular discharge can also be approximated on the basis of the proximity of the discharge location to the outcrop of the most closely associated coal seam (MCACS) and, thus, to zones of possible ongoing pyrite oxidation. The practical application of these simple predictive techniques is facilitated by means of a flowchart.
In high-temperature geothermal fields, precipitation of amorphous silica from solution to form silica scales is the main obstacle to efficient heat extraction from the hot fluids. The silica deposits cause operational problems and may even clog pipelines and injection drillholes. The rate of silica-scale formation can be reduced by ageing amorphous silica super-saturated waters, thus allowing the aqueous silica in excess of saturation to polymerize. Polymeric silica shows less tendency to precipitate from solution than monomeric silica. Studies of separated water from the Nesjavellir geothermal power station, Iceland, indicate that silica-scale formation can be avoided during heat extraction by rapid cooling of the water in “capillary heat exchangers”, followed by ageing the water for 1–2 h and subsequently mixing it with condensed steam. It is thus possible to avoid scale formation during injection of the amorphous silica super-saturated water leaving the heat exchanger.
We previously reported that well-dispersed amorphous nanosilicas with particle size 70 nm (nSP70) penetrate skin and produce systemic exposure after topical application. These findings underscore the need to examine biological effects after systemic exposure to nanosilicas. The present study was designed to examine the biological effects. BALB/c mice were intravenously injected with amorphous nanosilicas of sizes 70, 100, 300, 1000 nm and then assessed for survival, blood biochemistry, and coagulation. As a result, injection of nSP70 caused fatal toxicity, liver damage, and platelet depletion, suggesting that nSP70 caused consumptive coagulopathy. Additionally, nSP70 exerts procoagulant activity in vitro associated with an increase in specific surface area, which increases as diameter reduces. In contrast, nSP70-mediated procoagulant activity was absent in factor XII-deficient plasma. Collectively, we revealed that interaction between nSP70 and intrinsic coagulation factors such as factor XII, were deeply related to nSP70-induced harmful effects. In other words, it is suggested that if interaction between nSP70 and coagulation factors can be suppressed, nSP70-induced harmful effects may be avoided. These results would provide useful information for ensuring the safety of nanomaterials (NMs) and open new frontiers in biological fields by the use of NMs.
Currently, nanomaterials (NMs) with particle sizes below 100 nm have been successfully employed in various industrial applications in medicine, cosmetics and foods. On the other hand, NMs can also be problematic in terms of eliciting a toxicological effect by their small size. However, biological and/or cellular responses to NMs are often inconsistent and even contradictory. In addition, relationships among NMs physicochemical properties, absorbency, localization and biological responses are not yet well understood. In order to open new frontiers in medical, cosmetics and foods fields by the safer NMs, it is necessary to collect the information of the detailed properties of NMs and then, build the prediction system of NMs safety. The present study was designed to examine the skin penetration, cellular localization, and cytotoxic effects of the well-dispersed amorphous silica particles of diameters ranging from 70 nm to 1000 nm. Our results suggested that the well-dispersed amorphous nanosilica of particle size 70 nm (nSP70) penetrated the skin barrier and caused systemic exposure in mouse, and induced mutagenic activity in vitro. Our information indicated that further studies of relation between physicochemical properties and biological responses are needed for the development and the safer form of NMs.
Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses have not. Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained, and a clear elemental signature of phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDS).
Ion microprobe measurements of carbon isotope ratios were made in 30 specimens representing six fossil genera of microorganisms petrified in stromatolitic chert from the approximately 850 Ma Bitter Springs Formation, Australia, and the approximately 2100 Ma Gunflint Formation, Canada. The delta 13C(PDB) values from individual microfossils of the Bitter Springs Formation ranged from -21.3 +/- 1.7% to -31.9 +/- 1.2% and the delta 13C(PDB) values from microfossils of the Gunflint Formation ranged from -32.4 +/- 0.7% to -45.4 +/- 1.2%. With the exception of two highly 13C-depleted Gunflint microfossils, the results generally yield values consistent with carbon fixation via either the Calvin cycle or the acetyl-CoA pathway. However, the isotopic results are not consistent with the degree of fractionation expected from either the 3-hydroxypropionate cycle or the reductive tricarboxylic acid cycle, suggesting that the microfossils studied did not use either of these pathways for carbon fixation. The morphologies of the microfossils suggest an affinity to the cyanobacteria, and our carbon isotopic data are consistent with this assignment.
Unlike the familiar Phanerozoic history of life, evolution during the earlier and much longer Precambrian segment of geological time centred on prokaryotic microbes. Because such microorganisms are minute, are preserved incompletely in geological materials, and have simple morphologies that can be mimicked by nonbiological mineral microstructures, discriminating between true microbial fossils and microscopic pseudofossil 'lookalikes' can be difficult. Thus, valid identification of fossil microbes, which is essential to understanding the prokaryote-dominated, Precambrian 85% of life's history, can require more than traditional palaeontology that is focused on morphology. By combining optically discernible morphology with analyses of chemical composition, laser--Raman spectroscopic imagery of individual microscopic fossils provides a means by which to address this need. Here we apply this technique to exceptionally ancient fossil microbe-like objects, including the oldest such specimens reported from the geological record, and show that the results obtained substantiate the biological origin of the earliest cellular fossils known.
Prevention of acid mine drainage at surface coal mines in the Appalachian region relies to an extent on minimizing ground water contact with acid-forming materials, and maximizing ground water contact with alkalinity-yielding materials. Acid-forming materials are often selectively handled to minimize or prevent contact with ground water. Controlling ground water contact with acidic or alkaline materials depends on forecasting the level and range of fluctuation of the postmining water table within the mine backfill. Physical measurements and aquifer testing of more than 120 wells from 18 reclaimed mines in Kentucky, Ohio, Pennsylvania, and West Virginia have led to improved forecasting of the postmining ground water system. Factors that influence the ground water regime include spoil lithology and particle size, age of reclamation, spoil thickness, distance from the final highwall, and pit floor dip angle and direction. Spoil hydraulic conductivity (K) exhibits a 95% confidence interval range of six orders of magnitude about a mean K of 1.7 x 10(-5) m/sec. Spoil aquifer saturated thickness is related to the overall thickness of the spoil, the lithology of the spoil, dip of the pit floor, and distance to the highwall. Saturated spoil thickness has a 95% confidence interval of 2.2 to 3.6 m about the mean of 2.9 m. The predicted saturated zone averages 19% of the total spoil thickness.
A novel virus, termed Pyrobaculum spherical virus (PSV), is described that infects anaerobic hyperthermophilic archaea of the genera Pyrobaculum and Thermoproteus. Spherical enveloped virions, about 100 nm in diameter, contain a major multimeric 33-kDa protein and host-derived lipids. A viral envelope encases a superhelical nucleoprotein core containing linear double-stranded DNA. The PSV infection cycle does not cause lysis of host cells. The viral genome was sequenced and contains 28337 bp. The genome is unique for known archaeal viruses in that none of the genes, including that encoding the major structural protein, show any significant sequence matches to genes in public sequence databases. Exceptionally for an archaeal double-stranded DNA virus, almost all the recognizable genes are located on one DNA strand. The ends of the genome consist of 190-bp inverted repeats that contain multiple copies of short direct repeats. The two DNA strands are probably covalently linked at their termini. On the basis of the unusual morphological and genomic properties of this DNA virus, we propose to assign PSV to a new viral family, the Globuloviridae.
A new virus-like particle TTSV1 was isolated from the hyperthermophilic crenarchaeote Thermoproteus tenax sampled at a hot spring region in Indonesia. TTSV1 had a spherical shape with a diameter of approximately 70 nm and was morphologically similar to the PSV isolated from a strain of Pyrobaculum. The 21.6 kb linear double-stranded DNA genome of TTSV1 had 38 open reading frames (ORFs), of which 15 ORFs were most similar to those of PSV. The remaining 23 ORFs showed little similarity to proteins in the public databases. Southern blot analysis demonstrated that the viral genome is not integrated into the host chromosome. TTSV1 consisted of three putative structural proteins of 10, 20, and 35 kDa in size, and the 10-kDa major protein was identified by mass spectrometry as a TTSV1 gene product. TTSV1 could be assigned as a new member of the newly emerged Globuloviridae family that includes so far only one recently characterized virus PSV.
Global consequences of land use
- J A Foley
- R Defries
- G P Asner
- C Barford
- G Bonan
- S R Carpenter
- F S Chapin
- M T Coe
- G C Daily
- H Gk
- H Joseph
- H Tracey
- A H Erica
- J K Christopher
- Chad M Jonathan
- Colin Ip
- R Navin
- P K Snyder
Foley JA, DeFries R, Asner GP, Barford C, Bonan G, Carpenter
SR, Chapin FS, Coe MT, Daily GC, Gk H, Joseph H, Tracey
H, Erica AH, Christopher JK, Chad M, Jonathan AP, Colin IP,
Navin R, Snyder PK (2005) Global consequences of land use.
Science 309:570-574
- C H House
- J W Schopf
- K D Mckeegan
- C D Coath
- T M Harrison
- K O Stetter
House CH, Schopf JW, McKeegan KD, Coath CD, Harrison TM, Stetter KO (2000) Carbon isotopic composition of individual Precambrian microfossils. Geology 28:707-710
Available options for the bioremediation and restoration of abandoned pyritic dredge spoils causing the death of fringing mangroves in the Niger Delta
- E I Ohimain
Ohimain EI (2003) Available options for the bioremediation and restoration of abandoned pyritic dredge spoils causing the death of
fringing mangroves in the Niger Delta. Proc, International Biohydrometallurgy Symp, pp 475-481
Hydrologic effects of strip mining west of Appalachia
- D J Cederstrom
- DJ Cederstrom