Utilization of palm oil mill effluent for polyhydroxyalkanoate production and nutrient removal using statistical design

The optimization for poly-β-hydroxyalkanoate production was carried out with nutrient removal efficiency for total organic carbon (TOC), phosphate, and nitrate from palm oil mill effluent waste. The experiment was conducted in a fabricated fed-batch reactor and the data obtained was analyzed using central composite rotatable design and factorial design for response surface methodology as a systematic approach for designing the experiment statistically to obtain valid results with minimum effort, time, and resources. The analysis of numerical optimization with propagation of error showed that 66 % of poly-β-hydroxyalkanoate production can be obtained with nutrient removal of TOC and nitrate by 19 and 3 %, respectively. However, phosphate removal efficiency was not found to be much effective. More over, the chemical oxygen demand: nitrogen phosphate (509 g/g N), chemical oxygen demand: phosphate (200 g/g P), air flow rate (0.59 L/min), substrate feeding rate (20 mL/min), and cycle length (20 h) were the optimized variables for maximum poly-β-hydroxyalkanoate production and nutrient removal.     

Nettle ash as a low cost adsorbent for the removal of nickel and cadmium from wastewater

This study was focused on nettle ash as an alternative adsorbent for the removal of nickel (II) and cadmium (II) from wastewater. Batch experiments were conducted to determine the factors affecting adsorption of nickel (II) and cadmium (II). The adsorption process is affected by various parameters such as contact time, solution pH and adsorbent dose. The optimum pH required for maximum adsorption was found to be 6. The experimental data were tested using Langmuir, Freundlich and Tempkin equations. The data were fitted well to the Langmuir isotherm with monolayer adsorption capacity of 192.3 and 142.8 mg/g for nickel and cadmium, respectively. The adsorption kinetics were best described by the pseudo second order model. The cost of removal is expected to be quite low, as the adsorbent is cheap and easily available in large quantities. The present study showed that nettle ash was capable of removing nickel and cadmium ions from aqueous solution.     

Two-stage reverse flotation process for removal of carbonates and silicates from phosphate ore using anionic and cationic collectors

Phosphate rock contains various gangue minerals including silicates and carbonates which need to be reduced in content in order to meet the requirements of the phosphate industry. Froth flotation has become an integral part of phosphate concentration process. In this study, double reverse flotation was applied to recover apatite from phosphate ore. H₃PO₄ and CaO were used as phosphate depressants, in acidic and alkaline conditions. Fatty acids and amines were added as carbonate and silicate collectors respectively. An experimental protocol devised to optimize the grade and recovery of phosphate using anionic–cationic method was found effective. Consequently, a required high quality of phosphate concentrate containing 30.1% P₂O₅ was obtained, with a recovery of 94%. X-ray diffraction and optical microscopy studies were performed to define the main minerals.     

Development and implementation of a new flowsheet for the flotation of a low grade nickel ore

Low grade nickel ores containing large amounts of serpentine minerals have historically been difficult to process efficiently. The Mt Keith ore was no exception with recoveries in the first five years of operation averaging just 60%.In this research, the factors limiting performance have been identified and a new process has been devised that raises recovery significantly. The process exploits the particle size dependence of nickel sulphide flotation and the different ways that pH change and pulp density influence the response of coarse and fine particles.Implementation of the new process at Mt Keith has raised nickel recovery by 10%. In turn, nickel production has increased by over 6000 t.p.a. and the net present value (NPV) of the operation has increased by over A$300 m. These outcomes illustrate the large commercial benefits that can be gained by understanding particle size effects in flotation.     

深基坑开挖中桩墙体系支护的结构优化设计

针对桩墙加内支撑这种支护型式在常规支护结构设计中所存在的不足,提出了一种优化设计方法,通过决策变量、约束条件、目标函数、优化算法的确立以及计算机程序的编制,成功实现了桩墙体系支护结构的参数优化设计。     

Effect of nitrogen loading rates on nitrogen removal by using a biological filter proposed for ventilated improved pit latrines

Pit latrines are the most frequently used sanitation systems in developing countries because of weak infrastructure and poor economic wealth. A modified ventilated improved pit latrine, with a biological filter beneath is proposed to stabilize and to remove the bulk of the nitrogen from the liquid phase. Although the hydraulic loading rate in the proposed biological filter system was calculated to be ca 36 L/m²/d, significantly lower than the rates that are typical applied in standard rate biological filters (in the range of 1000–4000 L/m²/d) used to treat domestic wastewater; the total Kjeldahl nitrogen and chemical oxygen demand concentrations are significantly higher in faecal sludge, namely 3–5 g /L and 20–50 g /L, respectively compared to ca 60 mg/L and 500 mg/L in standard rate biological filters. The biological filter was operated at nitrogen loading rates of 72, 145, 290 and 435 g/m²/d, respectively, until stable state conditions were obtained. The biological filter showed effective nitrogen removal between 72 and 434 g/m²/d and the best total nitrogen removal was obtained at 145 g/m²/d, namely 92 %. These results suggest that it should be possible to remove nitrogen effectively using a biological filter beneath a modified ventilated improved pit latrine.     

High-precision Pb isotope analysis by multicollector-ICP-mass-spectrometry using 205Tl/203Tl normalization: Optimization and calibration of the method for the studies of Pb isotope variations

The development of the MC-ICP-MS method, which was launched about one decade ago and was largely stimulated by the need to solve geological problems, has opened a new avenue in isotope mass spectrometry. One of the advantages of this method is the possibility of applying a newly developed approach to the correction of analytical results for the effect of mass discrimination by normalizing the measured isotope ratios of an element to a reference (standard) isotope ratio of another element. This makes it possible to overcome the main disadvantage of conventional thermal ionization mass spectrometry (TIMS), in which the effect of mass discrimination cannot be fully taken into account during isotope analysis, and thus to implement a highly accurate method for the analysis of Pb-isotope composition. In application to the capability of the NEPTUNE MC-ICP mass spectrometer, we optimized and calibrated a method for high-accuracy Pb isotope analysis in solutions spiked with Tl, with all currently measured Pb-isotope ratios normalized to the standard ²⁰⁵Tl/²⁰³Tl ratio (TLN-MC-ICP-MS). The factors affecting the random and systematic analytical errors were examined, and the optimal operating regime and analytical conditions were determined. Much attention was paid to the correlation of the measurement results and the mass discrimination effect determined from the ²⁰⁵Tl/²⁰³Tl ratio. The value of the ²⁰⁵Tl/²⁰³Tl normalizing ratio was analytically determined through isotope analyses of the NIST SRM 981, and SRM 982 standard samples of Pb-isotope composition. The data obtained for two mixtures Tl + Pb (SRM 982) and Tl + Pb (SRM 981) in ten replicate analyses were 2.38898 ± 12 and 2.38883 ± 20, respectively. These results are in good mutual agreement, and their general mean ²⁰⁵Tl/²⁰³Tl = 2.3889 ± 1 coincides (within the error) with the recently published values of 2.3887 ± 7 [Collerson et al., 2002] and 2.3889 ± 1 [Thirlwall, 2002]. The precision of the method (±2SD), which was assayed by the long-term reproducibility of the results of replicate analyses of SRM 981 and seven galena samples (90 analyses) was 0.016–0.018% for the ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb, and ²⁰⁸Pb/²⁰⁴Pb ratios and 0.005 and 0.009% for the ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb ratios, respectively. The precision of the isotope analysis of common Pb was significantly improved (by factors of 6–10 for various isotope ratios) compared with the precision of TIMS techniques acceptable in isotope studies during three decades. The described method was applied to examine the Pb-isotope composition of approximately 250 samples of galena, scheelite, and pyrite from a number of well known (including large) gold, sulfied, and base-metal deposits. The precision of the method (0.01–0.02%) makes it possible to study small inter-and intra-phase differences in Pb-isotope ratios in hydrothermal and magmatic rocks, to assay the scale of regional and variations in the isotope composition of ore Pb, and to correlate the Pb-isotope composition of rocks and ores and reveal its evolutionary trends.     

Evaluation of low-rank coals as raw material for Fe and Ca organomineral fertilizer using a new EDXRF method

A rapid and reliable method for analyzing Fe and Ca in low-rank Greek coals was developed. The presence of Fe and Ca is of importance regarding the potential use of these coals as raw material for organomineral fertilizers. Samples were collected from the main Greek lignite deposits and standards were prepared using Atomic Absorption Spectroscopy (AAS), which were also employed in the Energy Dispersive X-ray Fluorescence (EDXRF) method. The new method offers the advantages of being timesaving, non-destructive and can be easily incorporated in a fertilizer production line. Analysis of low-rank Greek coals demonstrated a significant Fe and Ca content ranging from 0.15 to 1.97 wt.% for Fe and from 0.04 to 2.51 wt.% for Ca. When both EDXRF and AAS techniques were applied, the Fe and Ca concentration values differed less than 5%, demonstrating that both techniques are reliable for low-rank coals in the above concentration range. These EDXRF results may be used as a preliminary test regarding the application of Greek coals in organomineral fertilizer production, given that in these coals iron and calcium are the most abundant metals.     

TG/plus—a pyrolysis method for following maturation of oil and gas generation zones using Tmax of methane

Thermogravimetric Fourier transform infrared spectroscopy (TG-FTIR) analyses were carried out on two sets of isolated kerogens covering a wide maturity range from low mature (0.46% R_o) through the end of oil and gas generation (maximum R_{o = 5.32%}). Data onweight percent and T_max for evolution of methane, volatile tars, ethylene, SO₂, NH₃, CO₂, and CO are reported. The T_max of methane shows the most consistent response to increasing maturation in both sets of samples. Results are comparable to those of whole rocks from an Alaskan North Slope well analyzed previously. The collective data for both whole rocks and isolated kerogens shows a generally linear correlation between %R_o and T_max of methane, with the exception of R_o of about 2.0% where a dip in the curve occurs. The slope of the correlation line was steeper for the predominantly terrigenous Wilcox kerogen than for more marine Colorado kerogen or for the Alaskan North Slope whole rock samples, probably reflecting differences in the chemical nature of various kerogen sets, which is also reflected by differences in the shapes of the pyrolysis curves of SO₂, CO₂, CO, H₂O, and ethylene. These preliminary data indicate that T_max of methane is a good maturation indicator for whole rocks and isolated kerogens up to an R_o of about 4%, which includes all of the wet gas and a considerable portion of the dry gas generation zones. This correlation was also observed for samples containing migrated bitumen, where it was not possible to obtain a reliable T_max for the volatile tar (S2) peak. The more terrigenous Wilcox kerogens also showed a good correlation of the T_max of ethylene with %R_o. T_max of ammonia evolution did not correlate with maturity and occurred 100–200°C lower than previously found for whole rocks, consistent with a whole-rock source of pyrolytic ammonia for Alaskan whole rock samples. HI and OI indices were calculated in several ways and plotted to reflect kerogen type as well as both the residual oil and gas generation potential. The ratio of pyrolyzable to combustible sulfur (evolved as SO₂) was independent of maturity and showed a clear difference between the more terrigenous Wilcox kerogens and the more marine Colorado kerogens.     

Experimental study of the stability of sudoite and magnesiocarpholite and calculation of a new petrogenetic grid for the system FeO–MgO–Al2O3–SiO2–H2O

The solid-solid reaction magnesiocarpholite = sudoite + quartz has been bracketed between 350 and 500°C, 6.3 and 7.8 kbar. Because it is impossible to synthesize end-member sudoite, all experiments were carried out using natural minerals as starting materials. Although mineral compositions were very close to those of the end-members, the effect of the fluorine content in carpholite was significant. Particularly in those experiments where sudoite grows at the expense of carpholite, electron microprobe analysis of the run products shows that a more stable F-rich carpholite crystallizes too, and consumes the fluorine released in solution by the breakdown of the original carpholite.
Our experimental results are combined, through a thermodynamic analysis, with a previous data set and with previous experimental data concerning the relative stability of chlorite, talc and magnesiocarpholite with excess of quartz and water as a function of P–T and AlAl(SiMg)_-1 substitutions in phyllosilicates. This allows us to constrain the feasible thermodynamic parameters (H°_f, sud; S ° sud) and (H°_f,car; S °_car) for the Mg end-members. Using the partition coefficients calculated from natural parageneses, we have computed a petrogenetic grid for the system FeO–MgO–Al₂O₃–SiO₂–H₂O. It demonstrates that parageneses involving sudoite and carpholite can be used as indicators of P–T conditions, up to 600° C, 8 kbar for sudoite, and at higher pressure for carpholite.     

Sediment yield and soil erosion assessment by using empirical models for Shazand watershed,a semi-arid area in center of Iran

Natural Hazards - In Kuwait, the transport sector is facing a daily traffic congestion pandemic. The traffic congestion is significantly influencing the economy and obstructing the development and...     

A new method for identification of protocatagenesis, mesocatagenesis, and apocatagenesis zones in a terrigenous sedimentary cover by applying layer seismic velocities

This method pertains to oil and gas geology and to geology of sedimentary basins prospective for oil and gas. It includes identifying catagenesis zones in drilled areas within the sedimentary cover of the basin based on assay results for drill cores and cuttings using the standard methods. Analysis is primarily made in order to determine rock catagenesis based on the optical characteristics of vitrinite. A correlation between catagenesis zones and layer seismic velocities obtained from regional and exploration seismic data is made for a drilled area. Both the layer seismic velocities and the degree of rock catagenesis increase with depth under the influence of increasing rock density. Correlations between layer velocities and the degree of rock catagenesis have been established. The following ratios have been determined for the Scotian shelf, Canada, and the Barents shelf, Russia: a protocatagenesis zone (the cap) corresponds to layer seismic velocities (V _lay) of 1.5–3.3 km/s, a mesocatagenesis zone (the principal hydrocarbon generation area) corresponds to V _lay of 3.3–5.0 km/s, and an apocatagenesis zone (an area with a very low hydrocarbon potential) corresponds to V _lay of over 5.0 km/s. An advantage of the new method of identification of catagenesis zones is that it can be used prior to drilling. Its conceptual originality and cost efficiency lie precisely in this.     

Regressions and transgressions of the Baltic basin reflected by a new high-resolution deglacial and postglacial lithostratigraphy for Arkona Basin sediments (western Baltic Sea)

Seismoacoustic profiles from the Arkona Basin show a late Pleistocene and Holocene succession of several distinct reflectors. The physical, sedimentological, mineralogical and geochemical properties of more than 30 sediment cores were analysed in order to assign these reflectors to specific sedimentary discontinuity layers. Additionally, AMS ¹⁴C data and biostratigraphic information were gathered. Based on this multi‐proxy approach, seven lithostratigraphic units (AI, AII, B to F) were distinguished. These consist of fine‐grained clay, silt and mud, and are separated from each other by thin basin‐wide traceable sandy layers (S_ab‐S_ef). The most sensitive parameter to mark the lithostratigraphic boundaries is the weight percentage of the grain‐size fraction >63μm. In addition, some of the quartz‐grain‐dominated sandy layers cause the strong reflection lines recorded in seismoacoustic profiles. The sandy layers are interpreted to reflect enhanced hydrodynamic energy induced by episodes of basin‐wide water‐level low‐stand conditions. These low stands resulted from water‐level drops that occurred frequently during the Baltic Sea's history and presumably affected the entire Baltic basin. The thick fine‐grained units AI, AII to F, in which coarser material is absent, represent water‐level high‐stands. We conclude that the units AI and AII are Baltic Ice Lake sediments deposited before and after the Billingen‐1 regression, respectively. We assign the most prominent sandy layer S_ab to the final drainage of the Baltic Ice Lake (Billingen‐2), whereas the sandy layers between units B, C., D and E are related to the Yoldia Sea and Ancylus Lake regressions of the Baltic Sea's history. The uppermost fine‐grained unit F with its high organic carbon content contains marine sediments deposited after the Littorina Transgression. The macroscopically well‐visible sediment colour change from reddish/brown‐to‐grey, previously interpreted as a regional stratigraphic boundary, varies from core to core. It has been shown by our new data that this colour change has a diagenetic origin, and thus does not represent a stratigraphic boundary. Previous subdivisions therefore have to be revised.     

87Sr/86Sr in waters from the Lincolnshire Limestone aquifer,England, and the potential of natural strontium isotopes as a tracer for a secondary recovery seawater injection process in oilfields

The Sr isotope composition of formation waters is a sensitive indicator of diagenetic processes in the host sediments, mixing processes between different bodies of water, and the connectivity of hydrological systems. The⁸⁷Sr/⁸⁶Sr ratio of present seawater is constant worldwife, while formation waters in hydrocarbon reservoirs have various values, depending on the aforementioned effects, in most cases different from modern seawater. This forms the basis of anatural tracer technique for seawater injection projects, involving characterization of the⁸⁷Sr/⁸⁶Sr ratios and Sr contents of formation waters in the reservoir before injection commences, followed by monitoring of these parameters in the produced water as injection proceeds. This method is best suited to reservoirs in which the formation waters have low Sr concentrations and⁸⁷Sr/⁸⁶Sr ratios much higher or lower than seawater. Available data for reservoir formation waters suggest that breakthrough recognition could be expected at <10% seawater in many sandstone reservoirs, while the method would be less sensitive in carbonate reservoir or situations where the formation waters had interacted with evaporites, as the associated waters tend to have high Sr contents. In heterogeneous but well-mapped reservoirs, it may be possible to obtain information about flow paths/mechanismsbefore breakthrough. Combination with other chemical and isotopic tracers creates a very powerful tool, the Sr method acting as a safeguard should the batch of water containing the conventional tracers be overtaken by subsequently injected seawater. The Sr method could also be used for injection projects that were begun without the addition of tracers. A natural analogue of a water injection process is found in the Jurassic Lincolnshire Limestone aquifer in England, where rapidly moving fresh meteoric water mixes progressively with an older saline formation water. The⁸⁷Sr/⁸⁶Sr data enable quantitative modelling of this mixing process. The infiltrating fresh water becomes progressively modified by dissolution of detrital carbonate and calcite cement in the limestone, with depth becoming increasingly dominated by Sr derived from the more soluble detrital components. The saline formation water contains water molecules of meteoric origin and an⁸⁷Sr/⁸⁶Sr ratio much higher than Jurassic seawater or marine carbonate; the solute content has been influence by interaction of the water with non-carbonate phases.     

Determination of earthquake-risky areas in Yalova City Center (Marmara region,Turkey) using GIS-based multicriteria decision-making techniques (analytical hierarchy process and technique for order preference by similarity to ideal solution)

Disaster mitigation as a pre-disaster measure within the scope of disaster risk management is significant in the sense of reducing the adverse effects of earthquakes in the context of earthquake-sensitive risk planning. In the urban planning context, the existence of numerous decision makers and alternatives, which are depending on many criteria, makes decision-making process difficult. This difficulty was overcomed through geographical information systems (GIS). In the context of GIS-based multicriteria decision-making (MCDM) analysis, we used analytic hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) to determine earthquake-risky areas in Yalova City Center. First, AHP analysis related to geological and superstructure/infrastructure criteria was conducted and two separate AHP maps were obtained. Then, we conducted TOPSIS analysis to consider both criteria in the sense of earthquake risk-sensitive planning. Then, overall earthquake risk map obtained which could be used as an input for disaster mitigation processes.

     

FY-3 A/MERS I积雪制图中NDS I指标建立及积雪判识模型研究 ——以祁连山区为例

我国新型自主的极轨气象卫星风云3号A星（简称FY-3A）上搭载的中分辨率光谱成像仪（MERSI）为大面积雪监测提供了新的遥感数据源。以中国西北祁连山区为例,分析FY-3A/MERSI传感器积雪与其它地物的图谱特征差异,建立了适用于FY-3A/MERSI的归一化差分积雪指数（NDSI）,以此为基础,构建了综合利用多光谱判别指标及土地覆盖类型（LULC）定类辅助的积雪判识模型,生成250 m分辨率的日积雪制图产品。模型通过逐步逼近的树状判别结构,去除了易和积雪混淆的部分乔木林、云、云阴影、水体、湖冰、沙（盐）地等地物,并提出应考虑积雪下覆地表特性的影响,调整设定不同LULC类型的积雪判别阈值约束,实时结合区域LULC影像进行积雪的最终判定与优化。对祁连山区2010-2011年积雪季FY-3A/MERSI影像的积雪制图应用结果表明,该资料能够客观精细地反映积雪的空间分布与动态发展过程。同时利用气象台站积雪观测记录及Terra/MODIS积雪判识结果进行对比验证,结果表明基于FY-3A/MERSI建立的积雪判识模型具有较高的精度和稳定性,特别是提高了云雪区分的效能。     

A virtual voyage through 3D structures generated by chaotic mixing of magmas and numerical simulations: a new approach for understanding spatial and temporal complexity of magma dynamics

In this contribution, we present a virtual voyage through 3D structures generated by chaotic mixing of magmas and numerical simulations with the aim to highlight the power of 3D representations in the understanding of this geological phenomenon. In particular, samples of mixed juveniles from Salina island (Southern Italy) are reconstructed in 3D by serial lapping and digital montage and numerical simulations are performed by using a 3D chaotic dynamical system. Natural and simulated magma mixing structures are visualized by using several multimedia tools including animations and “virtual reality” models. It is shown that magma interaction processes can generate large spatial and temporal compositional heterogeneities in magmatic systems. The same topological structures are observed in both 3D reconstructed rock samples and chaotic numerical simulations, indicating that the mixing of magmas is governed by chaotic dynamics. The use of 3D multimedia models gives the opportunity to penetrate into magma mixing structures and to understand their significance in the context of magma dynamics. Such an approach is very powerful since multimedia tools can strongly capture the attention of the reader bringing him/her into an interactive and memorable geological experience. Electronic supplementary material  enclosed:     

Determination of Sr and Ba partition coefficients between apatite and water from 5°C to 60°C: a potential new thermometer for aquatic paleoenvironments

Apparent partition coefficients of Sr and Ba between calcium phosphate and water were measured experimentally for temperature ranging from 5°C to 60°C. Calcium phosphates were precipitated from an aqueous mixture of Na₂HPO₄ · 2H₂O (10⁻² M) and CaCl₂ · 2H₂O (10⁻² M). Spiked solutions of Sr or Ba were introduced into the CaCl₂ · 2H₂O solution at Sr/Ca and Ba/Ca ratios of 0.1. The experiment consisted in sampling the liquid and solid phases after 1, 6, 48, and 96 h of interaction. The amorphous calcium phosphate (ACP) precipitated early in the experiment was progressively replaced by hydroxylapatite (HAP), except at 5°C where brushite (di-calcium phosphate di-hydrate or DCPD) was formed. We observed that the crystallinity of the solid phase increased with time for a given temperature and increased with temperature for a given time of reaction. With the exception of the experiment at 5°C, yield (R%) and apparent partition coefficients (K_a-w^Sr/Ca and K_a-w^Ba/Ca) both decreased with increasing reaction time. After 96 h, R%, K_a-w^Sr/Ca and K_a-w^Ba/Ca were observed to be constant, suggesting that the solid phases were at steady-state with respect to the aqueous solutions. The thermodependence of Sr and Ba partitioning between apatite and water at low temperature could therefore be calculated: