Recycling of Coal Fly Ash and Paper Waste to Improve Low Productive Red Soil in Okinawa,Japan

Coal fly ash (CFA) and paper waste (PW) related environmental problems and its recycling techniques have been a major challenge to society. Therefore, it is of crucial importance to develop new recycling methods for CFA and PW. This work proposes a potential new way of developing synthetic aggregates (SA) using CFA, PW, starch waste and ammonium sulfate (AS) as a granular nitrogen fertilizer medium, and their utilization as a soil amendment to improve crop production in the low productive acidic red soil of Okinawa, Japan. Three types of SA with three different nitrogen (N) percentages were produced and used to amend acidic red soil in a pot experiment for the cultivation of Komatsuna, which is also called as Japanese mustard spinach (Brassica rapa var. pervidis). SA had a low bulk density (0.58–0.62 g/cm³), high water holding capacity (0.60–0.64 kg/kg), high saturated hydraulic conductivity (2.34·10^–2 cm/s), high mean weight diameter (MWD) (4.32–4.48 mm), alkaline pH (8.58–8.61), high electrical conductivity (EC) (82.18–84.35 mS/m) and high carbon (C) content (68.71–70.07 g/kg) in comparison with the acidic red soil. The trace element concentrations of the developed SA were below the maximum pollutant concentration of individual metals for land application of sewage sludge given by the US Environmental Protection Agency. Scanning electron microscopic (SEM) studies showed the higher structural surface area of SA, where round shaped CFA particles were embedded into the fibrous PW matrix. Incorporation of SA into the acidic red soil not only enhanced soil fertility but also improved the physical and chemical properties of the soil compared to soil without SA addition. SA addition to the acidic red soil significantly increased the growth and yield parameters of Komatsuna compared to soil without SA addition.     

慢地震与深部不连续颤动和慢滑事件同时发生

我们对日本西南部南海俯冲板块界面过渡带发生的超低频地震进行报道。由矩震级为3.1～3.5的超低频地震引起的地震波显示其卓越长周期约为20s。超低频地震活动伴随深源低频颤动和慢滑事件同时发生,并随之移动。慢地震一直被认为会增加向上倾斜的大型逆冲地震断裂带上的应力,而这3种现象的同时发生提高了人们对慢地震的探测和特性鉴定水平。     

A Study on the Formation of Smectite in Silica Scales Precipitated from Geothermal Water: The Effect of Magnesium

Abstract. Silica scales containing large amounts of smectite were recently found in the pipelines for geothermal water at a geothermal power plant. To elucidate the mechanism of smectite formation, seven silica scale samples were characterized by powder X-ray diffraction, chemical analysis and ²⁷A1 MAS NMR. Smectite was present in samples with MgO levels above 10 wt% and Al₂O₃ levels below 10 wt%. In ²⁷A1 MAS NMR spectra, peaks assigned to both tetrahedrally and octahedrally coordinated aluminum (Al(4) and Al(6)) were observed for Mg-rich samples, whereas a peak due to Al(4) alone appeared in Mg-poor samples. From these observation and comparison between ²⁷A1 MAS NMR spectra for synthesized precipitates of Al₂O₃-SiO₂ containing MgO and not containing MgO, it is concluded that magnesium plays an important role in the stabilization of Al(6), and results in the formation of smectite     

Depositional and diagenetic history of limestones and dolostones of the Oligo‐Miocene Kujung Formation in the Northeast Java Basin,Indonesia

Lithological and geochemical features of platformal carbonates record the signatures of the global climates and the regional environmental settings and also reconstruct the diagenetic history and porosity evolution, which are essential to evaluate the potential of hydrocarbon reservoirs. This study investigates the platformal carbonates of the Oligo‐Miocene Krunji Formation of North East Java Basin, which are potentially significant hydrocarbon reservoirs. The carbonate sequence in a 283 m thick section at Kranji in East Java is subdivided into three lithological units: limestone unit 1, dolostone unit 2, and limestone unit 3, in ascending order. The strontium‐isotope ratios of well‐preserved calcite samples indicate the depositional period from Chattian (late Oligocene) to Burdigalian (early Miocene), which is consistent with ages of the foraminifer assemblages. Unit 1 consists of low‐porosity limestone, in which two horizons of subaerial exposure are recognized by the occurrence of red‐colored matrix and lower δ¹³C values. Unit 2 consists of dolomitic rock and exhibits coarse‐grained calcitic grains and cross‐stratified structure. Considering that this unit has been subject to dolomitization, the sediment of unit 2 was initially permeable and was likely deposited in a shoal setting. The overlying unit 3 of Aquitanian–Burdigalian age is characterized by a highly granular texture. High porosity and uniformly low δ¹³C and δ¹⁸O values indicate that Unit 3 was subjected to more intense meteoric diagenesis than the Chattian unit 1. This was likely a consequence of the Antarctic ice‐sheet expansion during the Oligocene/Miocene transition, which amplified sea level change. The unit 2 dolomite has high δ¹³C and δ¹⁸O values and a high ⁸⁷Sr/⁸⁶Sr ratio which resulted from the reflux of seawater into permeable the sediment body in middle‐late Miocene (Burdigalian Tortonian) following the deposition of unit 3. The porosity and permeability of the Kujung Formation were initially controlled by sedimentological processes, but largely modified by later diagenetic processes.     

Evidence of positive tectonic inversion in the north-central sector of the Sicily Channel (Central Mediterranean)

In order to unravel the tectonic evolution of the north-central sector of the Sicily Channel (Central Mediterranean), a seismo-stratigraphic analysis of single- and multi-channel seismic reflection profiles has been carried out. This allowed to identify, between 20 and 50 km offshore the central-southern coast of Sicily, a ~80-km-long deformation belt, characterized by a set of WNW–ESE to NW–SE fault segments showing a poly-phasic activity. Within this belt, we observed: i) Miocene normal faults reactivated during Zanclean–Piacenzian time by dextral strike-slip motion, as a consequence of the Africa–Europe convergence; ii) releasing and restraining bend geometries forming well-developed pull-apart basins and compressive structures. In the central and western sectors of the belt, we identified local transpressional reactivations of Piacenzian time, attested by well-defined compressive features like push-up structures and fault-bend anticlines. The reconstruction of timing and style of tectonic deformation suggest a strike-slip reactivation of inherited normal faults and the local subsequent positive tectonic inversion, often documented along oblique thrust ramps. This pattern represents a key for an improved knowledge of the structural style of foreland fold-and-thrust belts propagating in a preexisting extensional domain. With regard to active tectonics and seismic hazards, recent GPS data and local seismicity events suggest that this deformation process could be still active and accomplished through deep-buried structures; moreover, several normal faults showing moderate displacements have been identified on top of the Madrepore Bank and Malta High, offsetting the Late Quaternary deposits. Finally, inside the northern part of the Gela Basin, multiple slope failures, originated during Pleistocene by the further advancing of the Gela Nappe, reveal tectonically induced potential instability processes.

     

Scaling relationships between sizes of nucleation regions and eventual sizes of microearthquakes

We investigate the initial rupture process of microearthquakes to reveal relationships between nucleation region sizes and eventual earthquake sizes. In order to obtain high quality waveform data, we installed a trigger recording system with a sampling frequency of 10 kHz at the base of a deep borehole at the Nojima Fault, Japan. We analyze waveform data of 31 events around the borehole, with seismic moment ranging from 4.2 × 10⁹ Nm to 7.1 × 10¹¹ Nm. We use both a circular crack model with an accelerating rupture velocity (SK model) [Sato, T., Kanamori, H., 1999. Beginning of earthquakes modeled with the Griffith's fracture criterion, Bull. Seism. Soc. Am., 89, 80-93.], which generates a slow initial phase of velocity pulse, and a circular crack model with a constant rupture velocity (SH model) [Sato, T, Hirasawa, T., 1973. Body wave spectra from propagating shear cracks, J. Phys. Earth, 21, 415-431.], which generates a ramp-like velocity pulse. Source parameters of these two models are estimated by waveform inversion of the first half cycle of the observed velocity pulse applying both a grid search and a non-linear least squares method. 14 of 31 events are never reproduced by the SH model with a constant Q operator. But SK model with a constant Q operator provides a size of the pre-existing crack, corresponding to the size of the nucleation regions, and a size of the eventual crack. We recognize that (i) the eventual seismic moment is approximately scaled as the cube of the size of pre-existing cracks, (ii) the eventual seismic moment is scaled as the cube of the size of eventual cracks, and (iii) the size of eventual cracks is roughly proportional to the size of pre-existing cracks. We, thus, conclude that the size of eventual earthquakes is controlled by the size of the nucleation regions.     

Petrogenesis and geochronology of Mishao peraluminous I-type granites,Shalair valley area,NE Iraq

The Shalair area, which is located in northeastern Iraq, is considered to be part of the northern Sanandaj-Sirjan Zone (SaSZ) and contains several granitoid bodies. One of these bodies, the Mishao porphyritic-granite (MG), was crystallized at 111.6?±?2.4 Ma, based on its zircon U-Pb age. Its geochemical characteristics suggest that the MG rocks are calc-alkaline, peraluminous, I-type granites with microgranular mafic enclaves. They are enriched in SiO₂, Na₂O, Al₂O₃ and Zr and depleted in MgO, Fe₂O₃, Nb and Ti; in contrast, the enclave sample records lower SiO₂ content and higher contents of MgO and Fe₂O₃. These rocks show an enrichment of LREE relative to HREE, and pronounced negative Eu anomalies implying feldspar fractionation. The isotopic and geochemical characteristics of the MG samples suggest that these rocks are evolved through fractional crystallization. In the La/Nb-Nb diagram and Sm/Nd ratios, the MG rocks and the enclave samples exhibit strong evidence for crustal contamination. The MG rocks record high initial ⁸⁷Sr/⁸⁶Sr (0.70625–0.70740) and low ¹⁴³Nd/¹⁴⁴Nd(i) (0.51235–0.51274) ratios. These Sr-Nd isotopic data, combined with the presence of high Th/U and Rb/Sr ratios and significant depletions of Nb, Ta and Ti, show a relation of these bodies to an active continental margin regime. Based on the age and geochemical data of the MG, this study presents new information about the occurrence of Middle Cretaceous magmatic activities, which are related to the active continental margins in the SaSZ that run parallel to the Zagros Fold-Thrust Belt.     

Submarine flank eruption preceding caldera subsidence during the 2000 eruption of Miyakejima Volcano, Japan

During the early part of a seismic swarm preceding eruption and caldera formation at Miyakejima Volcano, discoloured sea surfaces were observed 1.5 km off the western coast of Miyakejima on 27 June 2000. A later survey of the area using a multi-beam side scan sonar and a remotely operated small submarine revealed four craters of 20–30 m diameter aligned east-west in a 100×10–30 m area on the seafloor, with hot water at 140°C being released from one of the centres. Each crater consists of submarine spatter overlain in part by scoria lapilli. Dredged spatter from the craters was fresh, and there was no evidence of activity of marine organisms on the spatter surface, indicating that the discoloured sea surface resulted from magmatic eruption on the seafloor. This eruption occurred when a westward-propagating seismic swarm, initiated beneath Miyakejimas summit, passed through the area. Finding new magma on the seafloor demonstrates that this seismic swarm was associated with intruding magma, moving outward from beneath Miyakejima. Submarine spatter shows flattened shapes with a brittle crust formed by cooling in water, and its composition is aphyric andesite of 54 wt% SiO₂. The spatter is similar in whole rock and mineral composition to spatter erupted in 1983. However, the wide range of Cl in melt inclusions in plagioclase of the 27 June submarine spatter shows that it is not simply a remnant of the 1983 magma, which has only high Cl melt inclusions in plagioclase. The mixed character of melt inclusions suggests involvement of a magma with low Cl melt inclusions. The magma erupted explosively on 18 August from Miyakejimas summit, considered as the second juvenile magma in this eruption, contains low Cl melt inclusions in plagioclase. Based on these observations and the eruption sequence, we present the following model: (1) A shallow magma chamber was filled with a remnant of 1983 magma that had evolved to a composition of 54–55 wt% SiO₂. (2) Injection of the 18 August magma into this chamber generated a mixed magma having a wide range of Cl in melt inclusions contained plagioclase. The magma mixing might have occurred shortly before the submarine eruption and could have been a trigger for the initiation of the removal of magma from the chamber as an extensive dyke, which eventually led to caldera subsidence.Editorial responsibility: S Nakada, T Druitt     

Nitrate pollution from agriculture in different hydrogeological zones of the regional groundwater flow system in the North China Plain

A survey of the quality of groundwater across a broad area of the North China Plain, undertaken in 1998 to 2000, indicates that nitrate pollution is a serious problem affecting the drinking water for a vast population. The use of nitrogen (N)-fertilizer in agriculture has greatly increased over the past 20 years to meet the food needs of the rapidly expanding population. During the study, 295 water samples were collected from wells and springs to determine the water chemistry and the extent of nitrate pollution. High concentrations of nitrate, especially in a recharge area along the western side, but also in the vicinity of Beijing and locally in other parts of the plain, pose a serious problem for the drinking water supply. In places, the nitrate concentration exceeds the maximum for safe drinking water of 45 mg/L. The intense use of N-fertilizer and the widespread use of untreated groundwater for crop irrigation contribute greatly to the problem, but no doubt the disposal of industrial and municipal waste into streams and infiltrating the aquifer also contribute to the problem; however, the lack of data prevents evaluation of those sources. In the recharge area, nitrate is found at depths of as much as 50 m. Near Beijing, relatively high concentrations of nitrate occur at depths of as much as 80 m. In the discharge area, in the vicinity of the Yellow River, high concentrations of nitrate occur at depths of <8 m.

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Electronic Supplementary Material Supplementary Material is available in the online version of this article at

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Resumen Contaminacíon de nitratos a causa de prácticas agrícolas en diferentes zonas hidrogeológicas del sistema de flujo regional de aguas subterráneas en la planice del norte de China. Un estudio de la calidad del agua subterránea en una zona amplia de la planice del norte de China se llevó a cabo entre 1998 y el año 2000. Este estudio indica que la contaminación de nitratos es un problema grave que afecta el agua potable de una vasta población. El uso de fertilizantes a base de nitratos en la agricultura ha aumentado considerablemente durante los últimos 20 años para satisfacer las necesidades alimentices de la creciente población. Durante el estudio, se tomaron 295 muestras de pozos de agua y manantiales para determinar la química de las aguas y el grado de contaminación por nitratos. Altas concentraciones de nitratos, especialmente en una zona de recarga a lo largo del lado oeste, asì como en la cercanía a Pekín y en zonas locales en otras partes de la planicie, presentan un problema serio al sumunistro de agua potable. En ciertos lugares, la concentracióon de nitratos excede el nivel máximo de seguridad para el agua potable 45 mg NO₃/L. El intenso uso de fertilizantes de nitratos y el abundante uso de agua subterránea sin tratamiento para la irrigación de cultivos contribuyen sustancialmente al problema. Sin embargo, sin lugar a dudas, la descarga de deshechos industriales y municipales en arroyos y en el acuífero también contribuyen al problema. La falta de datos impide la evalución de dichas fuentes. En la zona de recarga se encuentran nitratos hasta los 50 m de profundidad. Cerca a Pekín, concentraciones relativamente altas de nitrato ocurren hasta los 80 m de profunidad. En las zonas de descarga afectadas por el Río Amarillo las concentraciones altas de nitrato se encuentran solamente a menos de 8m de profundidad.

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Resumé Une campagne dévaluation de la qualité de leau souterraine entreprise entre 1998 et 2000 à travers une vaste étendue de la plaine du nord en Chine indique que la pollution par les nitrates est un problème sérieux qui affecte la qualité de leau souterraine pour une abondante population. Lutilisation de fertilisants azotés pour lagriculture a augmenté considérablement durant les 20 dernières années afin de rencontrer les besoins alimentaires dune population à forte croissance. Lors de cette étude, 295 échantillons deau ont été prélevés dans des puits et sources naturelles afin de déterminer la composition chimique de leau souterraine ainsi que létendue de la pollution par les nitrates. Des concentrations élevées de nitrates, en particulier dans une zone de recharge le long de la limite ouest de la plaine, mais aussi dans la région de Beijing et sporadiquement dans la plaine, posent de sérieux problèmes à la consommation de leau souterraine. A certains endroits, la concentration en nitrates excède la valeur maximale acceptée pour la consommation qui est de 45 mg NO₃/L. Lutilisation intensive de fertilisants azotés ainsi que lutilisation répandue deau souterraine non traitée pour lirrigation contribuent pour beaucoup au problème, mais il ne fait pas de doute que le rejet des déchets municipaux et industriels dans les rivières et aquifères y est aussi pour quelque chose. Par contre, le manque de donnés ne permet pas dévaluer la contribution de chacune de ces sources. Dans la zone de recharge, les nitrates se retrouvent à des profondeurs allant jusquà 50 m. Près de Beijing, des concentrations relativement élevées de nitrate ont été mesurées à des profondeurs allant jusquà 80 m. Enfin, dans la zone démergence affectée par la rivière Jaune, les fortes concentrations se retrouvent à une profondeur maximale de 8 m.