Acta Geochimica (v.32, #3)
Pollution of organic compounds and heavy metals in a coal gangue dump of the Gequan Coal Mine, China by Jingsen Fan; Yuzhuang Sun; Xinyu Li; Cunliang Zhao; Duanxin Tian; Longyi Shao; Jinxi Wang (241-247).
Samples around a coal gangue dump of the Gequan Coal Mine were collected in April 2009. GC (gas chromatography) and GC/MS (gas chromatography/mass spectrometry) were employed to analyze the composition of organic matter in the samples. ICP-MS (inductively coupled plasma mass spectrometry) was used to determine the concentrations of heavy metals. The contents of organic extracts are within the range of 140–750 mg/kg. Alk- and aro-ratios are relatively high. Compared to those of the background sample (GQ13), the contents of saturated hydrocarbon compounds in all the samples are relatively high. The contents of polycyclic aromatic hydrocarbons (PAHs) are relatively high with the distance getting closer to the coal gangue dump. These indicate that organic matter in the samples is from coal particles of the coal gangue dump. The distributions of heavy metals are very similar: the contents decrease with distance from the dump, which indicates that the harmful heavy metals from the coal gangue dump have polluted as thick as at least 500 m.
Keywords: coal gangue; environment; organic compound; heavy metal
Elemental characterization of black shales of Khyber Pakthunkhawa (KPK) region of Pakistan using AAS by Abdul Aziz; Muhammad Sajjad; Bashir Mohammad (248-251).
Black shale samples were collected from Chimiari Khyber Pakthunkhawa region of Pakistan and were analyzed for elemental compositions. Atomic Absorption Spectrophotometry (AAS) was utilized for the determination of elements in the digested solutions. The analysis of black shale was performed precisely with relative standard deviation (RSD) lower than 2%. Results showed that the samples contained high concentrations of Ca (11.98 %), Al (7.09%), Fe (3.03%), Mg (0.59%) and Ti (0.58%).
Keywords: Chimiari; black shale; Atomic Absorption Spectrophotometry (AAS); elemental characterization
A review on the aging phenomena of organic components and their mass transfer through the NAPL interfacial phase by Lihua Liu; Stefan Haderlein (252-260).
It occurs worldwide that the organic components of non-aqueous phase liquid (NAPL) enter the porous medium and become the source of contaminants in the subsurface. The transport of the organic components through NAPL interphase into the aqueous phase and the subsurface determines the extent of contamination, the persistence of residual NAPL phases and the techniques of remediation. During the transport process the NAPL interphase may experience “aging”, a physical and chemical change when NAPL is exposed to aqueous and or gaseous phases. This aging process alters vice versa the mass transfer behaviour of the organic contaminants in the porous medium.
Keywords: mass transfer; NAPL; interphase; contaminant
Development of Water Quality Index (WQI) model for the groundwater in Tirupur district, South India by P. J. Sajil Kumar; E. J. James (261-268).
Groundwater quality of the Tiruppur district in Tamil Nadu was investigated in this study to develop a Water Quality Index (WQI) model. Hydrochemical parameters showed tremendous variation in certain location over the seasons. Ionic chemistry of groundwater suggested that textile industries and rock-water interaction are major threats to the water quality. Analysis of Na and Ca concentration indicates that direct as well as the inverse cation exchange controls the natural cation chemistry. NO3 concentration shows that the pre-monsoon samples were affected by the fertilizer usage in agricultural fields. Na-Cl type of the water was dominant throughout the study area except few locations. WQI showed that 55% of the pre-monsoon samples and the 47% of the post monsoon samples were classified as poor/very poor/unsuitable for drinking category. Leaching of the textile waste and their transport to the downstream was well observed during the post-monsoon season. The specific contribution of river Noyyal in the transport of the solutes to the discharge zones was proved by the hydrochemistry of the samples.
Keywords: groundwater; hydrochemistry; Water Quality Index (WQI); Tiruppur
Extraction kinetics of strontium with SDS and Twain in celestine by Chenglun Liu; Zhimin Su; Longjun Xu; Li Zhang; Taiping Xie; Yuan Wang (269-272).
Strontium in celestine was activated in Twain-40 with the wetting and emulsifying methods. And strontium extract ratio increased providing that the negative effects of oxygen containing functional groups were eliminated on celestine surface. In the paper, the factors affecting the extraction of strontium in celestine were investigated with orthogonal experiments. The optimal conditions were described as follows: mass ratio of celestine to extracting aid=2.6:1, the solid-liquid ratio of extracting aid solvent composed was m(SDS): m(Twain 40): m(HCl)=6:1:2, when celestine was ground as small as less than 0.075mm in size, and extracted for 6 hours at 333K. The strontium extract ratio increased by 61.33% and reached 97.21%, while the ratio from the comparative experiment (without extracting aid agent) was only 35.88%. Extraction kinetics of strontium in celestine showed that the diffusion process was a controlling step, and the apparent active energy was about 14.1 kJ/mol. The research results were helpful to fully utilize strontium of celestine.
Keywords: strontium; extraction kinetics; SDS; Twain 40; celestine
Safety culture assessment of petroleum enterprises based on SMART by Kun Chen; Longjun Xu; Rui Yang; Zhiming Bi (273-280).
This paper introduces an improved fuzzy comprehensive evaluation model specially designed for the safety culture assessment of petroleum enterprises. The model is established based on the authors’ years of experience in this field. The index system of the safety assessment mentioned herein is based on SMART safety culture principles, covering safety material, safety behavior, safety system, safety belief, persistence of safety, and openness of safety. The proposed system also includes the safety material culture, in which on-the-spot analysis of the key factors of safety culture is conducted together with duty consultants. All the fuzzy membership indexes and their degrees were weighed and calculated with the final evaluation results, presented in accordance with the analytic hierarchy process. All the safety culture statuses of petroleum enterprises Z, S, and C were then incorporated into detailed analysis. The results of the application confirm that the levels of safety culture follow the order of Z petroleum enterprise
Keywords: safety control; SMART; assessment model; fuzzy comprehensive assessment
The petrographical and isotope geochemical tracers for deep ore-forming fluids from the Laowangzhai gold depoist in the northern part of the Ailao Mountains by Biping Deng; Xianfan Liu; Min Zhang; Qiuxia Lu; Fufen Zhao; Chunhui Li; Yating Chu; Yaoyao Xu; Xiaomin Tian; Hui Li (281-294).
Based on the petrological studies of wall rocks, mineralized rocks, ores and veins from the Laowangzhai gold deposit, it is discovered that with the development of silification, carbonation and sulfidation, a kind of black opaque ultracrystalline material runs through the space between grains and amphibole cleavages, which is the product of fast condensing consolidation with magma mantle fluids turning into hydrothermal crustal fluids in the process of mineralization and alteration. It is thought that the water in ore-forming fluids mainly derived from magmatic water through research on H-O isotopes, and C as well as S isotopic compositions, has clear mantle-derived characteristics, and rock (mine) stones contain high 87Sr/86Sr ratios, low 143Nd/144Nd ratios and high 206Pb/204Pb ratios, which also reflects the ore-forming fluids were derived from the metasomatically enriched mantle. In combination with the features of H-O-C-S isotopes and Sr-Nd-Pb isotopes described above, the ore-forming fluids of the Laowangzhai gold deposit in the northern part of the Ailao Mountains were derived mainly from the deep interior of the mantle, and their properties were transformed from magma fluids to hydrothermal fluids in the course of metasomatism and alteration, which initiated crust-mantle contamination simultaneously to be in favor of mineralization.
Keywords: micropetrography; isotope geochemistry; deep ore-forming fluid; crust-mantle mixing; Laowangzhai gold deposit
Uptake, accumulation and translocation of polycyclic aromatic hydrocarbons by winter wheat cultured on oily sludge-amended soil by Wenjuan Yu; Shaoping Kuang; Laishi Zhao (295-302).
The purpose of this study is to comparatively investigate the plant uptake, accumulation and translocation behaviors of polycyclic aromatic hydrocarbons (PAHs) as priority pollutants in soil contaminated with oily sludge. The influence of different oily sludge application doses on the uptake of contaminants was studied together with the profile of individual PAH in roots, straws and leaves of winter wheat. Pot experiments were conducted using oily sludge application doses of 0, 5, 10, 15 and 20 percent, respectively. The total PAHs contents of control soil and oily sludge were 16.96 and 3504.66 µg/g, respectively. Analysis for the contents of the 16 PAHs was carried out with a HPLC-UV using plant tissue samples obtained at the 265th day of growth. The total PAHs contents in treated winter wheat were 9.02–334.81 ng/g for roots, 8.45–336.52 ng/g for straws and 10.70–406.32 ng/g for leaves. In addition to 5% of oily sludge dose, the total PAHs content in leaves was always highest under other doses of oily sludge application. With respect to individual PAH, the content did not show a significant plant tissue related trend. However, both the total content and individual content of PAHs in treated winter wheat tissues did increase with increasing oily sludge application dose. Another analysis for the control soil indicates that the degradation rate of PAHs was significantly enhanced by winter wheat after 265 days of growth based on the residual concentrations of PAHs in planted and unplanted soils.
Keywords: polycyclic aromatic hydrocarbon; oily sludge; winter wheat; soil; phytoremediation
Deep-penetrating geochemistry of the Tuwu copper deposit, northwestern China by Xueqin Wen; Shanding Zhao; Hong Zhang (303-312).
Desert terrains in northern China are covered by widespread regolith sediments which mask geochemical signals from ore bodies and are major obstacles to mineral exploration. There is a critical need to study the vertical distribution of elements in this regolith and to establish optimum sampling and analytical methods. The aim of this study is to understand the dispersion and variation of elements throughout the cover in a vertical profile. The results demonstrate that the main elements show a distribution pattern of enrichment in clay layers in the vertical profile, i.e., most elements tend to be enriched in the most upper part of the profile above the orebodies except for some elements like Cu, Ca and Ag. Meanwhile, both fine (−160 mesh) and coarse (+20 mesh) fraction samples from clay-rich horizons are favorable samples and selective leaching of the elements absorbed on clays or oxide coatings is effective for localizing buried deposits. The distribution of active Cu and Mo is quite different because chalcopyrite is weathered into Cu sulfate and CuCO3, and is precipitated in alkaline environments in a layer below close to the surface. Mo is soluble in the alkaline environment so it can penetrate the caliche layer and be enriched on the surface of soil enriched with weakly cemented clay.
Keywords: desert regolith; vertical variation; buried ore-body; mobile element: Tuwu copper deposit
Characteristics of biomarkers in source rocks of the Ganquan Formation in the Dahulishan region, Ejina Banner by Kui Su; Youjun Tang; Xingchao Jiang; Jianfa Chen (313-320).
Based on gas chromatography and gas chromatography mass spectrometry techniques, the authors examined biomarker characteristics of the Ganquan Formation source rocks in the area of Dahulishan, Ejina, and analyzed the information and petroleum geological significance that were indicated by the source of organic matter, sedimentary environment and maturity and so on. Gas chromatography peak of saturated hydrocarbons from the Ganquan Formation source rocks showed “the former peak” of the single peak distribution, the main peak of carbon being C18, indicating the main sources of organic matter with marine organic matter. Pr/Ph ranges from 0.3 to 0.6, indicating a strongly reducing sedimentary environment. Biomarker assemblages of the Ganquan Formation source rocks are abundant in tricyclic terpane with long side chains, with a high level of gammacerane, showing dominant distribution of C27 sterane. High contents of gammacerane in organic matter show organic facies of source rocks in the saltwater sedimentary environment. That average hopane/sterane ratio is 0.59, showing that algae have made more contributions to organic matter than bacteria. And the high level of C27 steranes shows that algae are the main source of hydrocarbon precursors. The Ganquan Formation’s methylphenanthrene index, which is an effective molecular parameter index to measure thermal evolution of organic matter, ranges from 0.35 to 0.50, and the conversion of vitrinite reflectance Rc from it is within the range of 2.00–2.09, indicating that the Ganquan Formation source rocks are in the over-mature stage of thermal evolution.
Keywords: Ejina Banner; Ganquan Formation; biomarker; methylphenanthrene index
Discovery of an abnormally high-δ34S barite deposit and a new understanding of global sulfur isotope variation during geological history by Junbo Gao; Ruidong Yang; Ping Tao; Wei Cheng; Huairui Wei (321-325).
The evolution of the global sulfur isotope curve was plotted based on the δ34S values of evaporates resultant from oceanic evaporation. In the long period of geological history the δ34S values showed obvious peaks for three times during the process of ancient oceans’ sulfur isotope evolution, namely the Early Cambrian (+30‰), the Late Devonian (+25‰) and the Permian-Triassic transition interval (+17‰), but the causes of the abnormal rise of sulfur isotopic values during the geological period are still in question. In this paper, 18 samples collected from a large Devonian barite deposit from Zhenning County were analyzed to determine their δ34S values, revealing that the 18 samples have very high δ34S values (δ34S=41.88‰–+68.39‰), with an average close to 56.30‰, which are higher than the isotopic values of contemporary sulfates (+17‰–+25‰). A comparative analysis was conducted of the emerging of high δ34S barite deposits (from Cambrian and Devonian) and the δ34S variation curves of the ancient oceans. The results indicate that the time when the obvious peaks of δ34S values appeared and the time of massive sedimentation of high δ34S barite deposits are very close to each other, which, in our opinion, is not a coincidence. There may exist some correlations between the sulfur isotope evolution of ancient oceans during the diverse periods of geological history and the massive sedimentation of high δ34S barite deposits. Therefore, it is inferred that perhaps it was the massive sedimentation of high δ34S barites that caused the sharp rise of δ34S values in a short period of time.
Keywords: global sulfur isotopic variation; δ34S value; barite; Devonian; Guizhou
Research on application of kyanite in plastic refractory by Wei Zhang; Qian Meng; Wenyong Dai (326-330).
Effect of kyanite addition on properties of plastic refractories that based on Chinese calcined flint clay were investigated with the Chinese calcined flint clay as raw materials, aluminum sulfate and fireclay as binding systems. After 24 h curing after demoulding and another 24 h curing at 110°C, the specimens were heat-treated at 1000, 1300 and 1500°C for 3 h, respectively. The permanent linear change, bulk density, modulus of rupture, clod crushing strength, thermal expansion coefficient and thermal shock resistance were examined. The results show that the shrinkage of plastic refractory decreased with increasing kyanite addition after heat-treated at 1000 and 1300°C, and its expansivity increased with increasing kyanite addition after heat-treated at 1500 °C. The strength can be increased when kyanite was added into the plastic refractory. The thermal expansion coefficient and the expansivity were increased, and the shrinkage can be reduced at high temperature when kyanite addition was more than 10%. On the condition of this experiment, the thermal shock resistance of plastic refractory was the best when kyanite addition is w(kyanite)=10%.
Keywords: plastic refractory; kyanite; permanent linear change; thermal expansion coefficient; thermal shock resistance
Leaching of manganese residue for the preparation of trimanganese tetroxide with a high surface area by Tiefeng Peng; Longjun Xu; Xingmin Wang (331-336).
The accumulation of electrolytic manganese residue (EMR) has become a serious problem and its recycling will be of great benefit to protect the environment and assist sustainable development. The reusing method was conducted by leaching EMR with sulfuric acid and the optimal leaching condition was 1:3 (g/g) as the ratio of solid to liquid with 20% (g/g) H2SO4, heating at 90 °C for 3 hours, which aims at extracting Mn in a sulfuric acid medium. The produced MnSO4 solution was precipitated by adding alkali and oxidized in aqueous phase. The oxidized products were characterized by various techniques, including X-ray powder diffraction (XRD), Fourier transform infrared (IR) spectrometry, vibrating sample magnetometry (VSM), with Brunauer-Emmett-Teller (BET) specific surface area instrument and laser particle size analyzer. The final products were confirmed to be a single-phase Mn3O4.
Keywords: manganese residue; hydrometallurgy; leaching; oxidation; Mn3O4