A Novel Approach to Bioleach Soluble Phosphorus from Rock Phosphate

A novel approach to bioleach soluble phosphorus from rock phosphate,involving the bio-oxidation of pyrite by adaptated Acidithiobacillus ferrooxidans(At.f)and the product of sulfuric acid to dissolve rock phosphate,has been proposed in this paper.The soluble phosphorus could be leached more effectively in the presence of pyrite by At.f than that leached directly by sulfuric acid.The optimal technological parameters are presented.The highest phosphorus leaching rate is 9.00% when the culture substrate is the mixture of FeSO_47H_2O and pyrite,the phosphorus leaching rate is 8.00% when the initial pH and culture time are 2.5 and 5 d,respectively.The optimal rock phosphate particle size is 0.05 mm for the leaching of phosphorus.The bigger the grains of pyrite,the lower the phosphorus leaching rate.The bacterium At.f should be appropriately adaptated,which makes it easier to bioleach soluble phosphorus from rock phosphate.

Bioleaching of soluble phosphorus from rock phosphate containing pyrite with DES-induced Acidithiobacillus ferrooxidans

The effects of Acidithiobacillus ferrooxidans(At. f) mutated with diethyl sulfate(DES) as a mutagen on the bioleaching of soluble phosphorus(P) from rock phosphate(RP) were investigated. The results show that the oxidative activity of At. f is greatly improved by 1.0%(volume fraction) of DES. Correspondingly,the highest leaching rate of soluble P is also obtained to be 14.9% by the At. f mutated,which is 85.8% higher than that of the adapted At. f without mutation. In addition,the SEM images are significantly performed that the corrosion of RP residue surfaces leached by 1.0% DES-induced At.f is much worse than that of leached by the adapted At. f. All the above indicate that the leaching efficiency of soluble P from RP with pyrite can be greatly improved by using DES-induced At. f to a certain extent.

Rock Phosphate Solubilization Mechanisms of One Fungus and One Bacterium

Many microorganisms can dissolve the insoluble phosphates like apatite. However, the mechanisms are still not clear. This study was an attempt to investigate the mechanisms of rock phosphate solubiliza-tion by an Aspergillus 2TCiF2 and an Arthrobacter1TCRi7. The results indicated that the fungus produced a large amount of organic acids, mainly oxalic acid. The total quantity of the organic acids produced by the fungus was 550 times higher than that by the bacterium. Different organic acids had completely different capacities to solubilize the rock. Oxalic acid and citric acid had stronger capacity to dissolve the rock than malic acid, tartaric acid, lactic acid, acetic acid, malonic acid and succinic acid. The fungus solubilized the rock through excreting both proton and organic acids. The rock solubilization of the bacterium depended on only proton.

A New Example of Retrograde Solubility Model for Carbonate Rocks

Objective The dissolution and precipitation of carbonate during burial diagenetic process controls the reservoir property in deep buried strata. The geological process related with it has become a research focus during recent years. The most important dissolution fluids to carbonates are probably H2S and CO2 as byproducts of sulfate reduction in deep-buried setting with sulfate minerals, but carbonates are more soluble in relatively low temperature, which is the so-called retrograde solubility. Several geological processes can result in the decrease of temperature, including the upward migration of thermal fluids and tectonic uplift.

Phosphorus Solubility from Rock Phosphate Mixed Compost with Sulphur Application and Its Effect on Yield and Phosphorus Uptake of Wheat Crop

A field experiment was conducted to determine the effect of sulphur application with Rock phosphate mixed compost on phosphorus (P) solubility and its effect on yield and P uptake of wheat crop. The experiment was laid out in randomized complete block design (RCBD) with three replications at the research farm of The University of Agriculture Peshawar. The experiment was conducted during rabi 2015-16 with plot size of 3 m × 5 m. Nitrogen, phosphorus and potassium were applied at the rate of 120, 90 and 60 kg&#183ha-1 in the form of urea, compost, or single super phosphate and potassium sulphate, respectively. Elemental sulphur was applied at the rate of 10, 20 and 30 kg&#183ha-1 at the time of sowing. Results showed that sulphur applied with compost significantly improved wheat yield and yield components, soil organic matter, soil total N and AB-DTPA extractable P contents, plant N and P concentrations and their uptake, plant micronutrients concentration and their uptakes. No significant changes were noted in soil pH, ECe and lime contents. Maximum grain yield of 4076 kg&#183ha-1, total dry matter yield 9721 kg&#183ha-1, straw yield 5644 kg&#183ha-1, plant height 98.3 cm, spike length 11.2 cm, grain per spike 61.0, thousand grain weight 50.2 g were recorded on the application of S at the rate 20 kg&#183ha-1 with compost. The highest soil organic matter content of 1.41% was found for the application of S at the rate of 10 kg&#183ha-1 with compost. Maximum soil total N content of 1756 mg&#183kg-1 and P 5.7 mg&#183kg-1 were observed by the application of double recommended S with compost. Plant N uptakes of 125.7 kg&#183ha-1, and P uptake of 17.5 kg&#183ha-1, were maximum with application of compost and S @ 20 kg&#183ha-1. Highest plant uptake of Fe 0.56 kg&#183ha-1, Zn 0.41 kg&#183ha-1, Cu 0.16 kg&#183ha-1 and Mn 0.93 kg&#183ha-1 were found by the application of full recommended S with compost. Results suggested that S at the rate of 20 kg&#183ha-1 application with compost prepared from farm yard manure and rock phosphate proved better combination to enhance wheat yield, yield components and nutrients uptakes of wheat crop.

砂岩质文物内部毛细水运移过程微电极响应特征

盐结晶病害是砂岩质文物中最为常见的病害之一,可溶盐溶液在砂岩内部的毛细运移直接影响着文物保存的完整性。为了进一步了解不同因素影响下砂岩质文物内部中毛细水运移特征,以大足石刻砂岩材料为研究对象,自主设计了毛细吸水试验及微电极电阻率测试装置,定量分析孔隙结构、孔隙溶液、干湿循环及相对湿度对毛细运移和电阻率分布特征的影响。结果表明,松散的孔隙结构及较低的相对湿度对毛细运移有促进作用。毛细运移受可溶盐溶液表面张力影响明显,吸水量和运移速率随表面张力增加呈递增趋势。干湿循环作用导致内部孔隙扩张使毛细迁移速率加快,同时呈现出试样饱和度和砂岩电阻率的负相关性。可溶盐的存在极大降低了砂岩的电阻率,通过电阻率的时空分布特征,识别湿润锋的视电阻率范围与试样表层盐结晶劣化区域大致重合,整体趋势沿深度方向呈凹曲面变化。研究结果揭示了砂岩质文物内部毛细水运移规律,可为合理追踪盐害范围提供理论支撑。

加强油源岩沉积成岩成油模拟实验研究

干酪根热降解生油学说源于油页岩高温热解生成“人造石油”的生产实践,其理论内涵是凡富含干酪根的岩石,经高温热解后其所含的干酪根都可以生成“人造石油”。应用该学说的高温热解实验方法,可以评价油页岩的品质及其热解生成“人造石油”的潜力,因此仅适用于油页岩的评价研究。但该学说的倡导者却认为油页岩和油源岩都是能生成石油的岩石,如果埋藏较浅时就称为油页岩,如果埋藏较深时就是油源岩,因此干酪根热降解生油学说同样适用于油源岩。这种观点并没有被美欧等国家所认可,但遗憾的是,在改革开放之初不甚了解国外同行对该学说如何评价的情况下,中国的石油地质家不仅全盘接受了该学说,而且推广应用了40多年。为彻底改变这种被动局面,唯一可行的就是通过油源岩沉积成岩成油模拟实验,研究油源岩中可溶有机质的生油问题和评价方法。

四川盆地金秋气田:一个典型以中生界沉积岩为氦源岩的含氦-富氦气田

氦气成藏长期以来研究较少,成藏条件与成藏机理还不十分清楚,氦源岩类型和形成条件争议较大。通过解剖含氦-富氦的金秋气田认为:(1)金秋气田氦气含量主要分布在0.05%~0.10%,平均为0.07%,部分井含量超过0.10%,最高为0.20%。同位素分析认为氦气为壳源成因,没有幔源的贡献。(2)金秋气田是一个典型以中生界沉积岩为氦源岩的含氦-富氦气田。上三叠统须家河组和侏罗系具有较高的铀、钍元素含量和较大的地层厚度,在金秋地区具有较高的氦气生气强度,是形成含氦-富氦气藏的氦源基础。氦气应该主要来源于侏罗系储层,而非上三叠统须家河组烃源岩层系。(3)金秋气田含氦-富氦气田的形成受3个主要因素控制,具有高氦气生气强度的氦源岩提供了很好的物质基础;具有适度充注强度的烃类气体的存在有利于氦气富集;地层抬升剥蚀温、压下降导致的原位溶解氦气脱溶作用是氦气富集的有益补充。

天然腐殖质材料对低品位磷矿粉水溶性磷的促释效果

低品位磷矿开发应用困难的关键问题在于其活化释放困难以及磷素在土壤中易被固定。将不同添加量的天然腐殖质材料及其衍生物作为促释材料,采用连续水浸提法、X-射线衍射以及红外光谱分析了促释材料对低品位磷矿粉的水溶性磷释放特性以及磷矿粉的结构与成键变化的影响,并通过盆栽试验进一步验证磷矿粉与促释材料在最优配比下的生物肥效。结果表明:随着促释材料添加量的提高,水溶性磷的释放也呈现增加趋势,当天然腐殖质材料和HNO3处理天然腐殖质材料分别与低品位磷矿粉混合的质量比为20︰80时,5次水溶性磷释放总量分别为对照处理的1.54倍和1.72倍。X-射线衍射分析结果表明,天然腐殖质材料或HNO3处理天然腐殖质材料混合低品位磷矿粉经过5次浸提后,P2O5和Ca(PO3)2对应的特征衍射峰出现显著下降。红外光谱分析结果表明,天然腐殖质材料或HNO3处理天然腐殖质材料混合低品位磷矿粉经过5次浸提后,可明显看到位于966 cm^(-1)3-处PO_(4)对称伸缩振动v1吸收峰消失,同时位于1127、673和612 cm^(-1)3-处PO_(4)非对称伸缩振-2-动v3吸收峰、H2PO_(4)相关吸收峰和HPO_(4)相关吸收峰强度均显著下降。盆栽试验进一步表明,天然腐殖质材料或HNO3处理天然腐殖质材料作为一种优质有机物料按照6 g·kg^(-1)或9g·kg^(-1)的施用量同时与低品位磷矿粉按照20︰80的质量比混合后可显著提升土壤的有效磷含量,同时可快速提升土壤有机质含量。天然腐殖质材料按9 g·kg^(-1)的施用量同时与低品位磷矿粉按20︰80的质量比混合,在播种后第14、30、60天土壤有效磷分别较对照处理增加了29.86%、29.47%、36.48%,土壤有机质分别较CK增加34.16%、8.05%、47.40%。HNO3处理天然腐殖质材料按9 g·kg^(-1)的施用量同时与低品位磷矿粉按20︰80的质量比混合,在播种后第14、30、60天土壤有效磷分别较CK增加了36.97%、94.44%、34.51%,土壤有机质分别较CK增加27.29%、14.57%、45.41%。天然腐殖质材料或HNO3处理天然腐殖质材料呈酸性、高比表面积、腐殖质含量高、活性官能团数量多等特性是提升低品位磷矿粉的水溶性磷和土壤有效磷含量的主要原因。

可溶岩地区抽水蓄能电站主要工程地质问题探讨

为适应新型能源体系构建的需要,抽水蓄能电站规划和建设在全国普遍展开,有相当数量的站点布置在可溶岩地区。与常规水电站不同,抽水蓄能电站对水库渗漏、地下洞室围岩质量等要求更高,因而对工程地质勘察工作也提出了较高的要求。在总结抽水蓄能电站建设和工程地质勘察经验的基础上,针对可溶岩地区抽水蓄能电站建设面临的水库岩溶渗漏、岩溶库基稳定、地下水顶托、岩溶洞段地下洞室围岩稳定等主要工程地质问题进行了探讨,可供相关人员参考。

TSP结合TEM在风险围岩隧道超前地质预报中的应用

为了排查隧道施工过程中潜在的地质风险、指导隧道安全开挖掘进,针对某高速铁路风险围岩隧道浅埋段和可溶岩段,利用TSP和TEM两种方法开展超前地质预报。TSP预报可对掌子面前方围岩状况进行远距离宏观预测,能划定断层、破碎带、地下水等不良地质体的位置和大致规模;TEM预报可在掌子面附近开展多角度、多方位测量,能判定开挖面前方一定空间范围内不良围岩特征,特别是地下水、岩溶的分布及规模。研究表明,TSP震波对应的负反射和低速异常突出反映围岩岩性变化及岩体破碎程度,依据纵、横波速起伏特征可大致判定地下水发育情况;TEM低阻异常直观体现围岩富水状态,并可推测岩溶发育及分布状况,视电阻率阻值变化密集区对应了围岩岩体破碎。研究结果表明,采用两种或多种方法结合开展综合预报,可提升预报结论的准确度和可靠度,TSP结合TEM成功预报的应用实例可为类似风险围岩隧道的超前地质预报提供参考和借鉴。

穿越强富水可溶岩与非可溶岩接触带施工技术分析

以竹林湾隧道为案例,从施工的重难点入手,对穿越强富水可溶岩与非可溶岩接触带施工技术进行详细分析。研究表明,在穿越强富水可溶岩与非可溶岩接触带隧道施工时,利用超前地质预报技术,远距离预报采用隧道地震发射波法(TSP法),中距离预报采用地质雷达结合红外探测法,并采用超前探孔验证地质预报探明的岩溶的位置、形态和规模,通过不同超前预报形式的交叉运用,可准确掌握隧道施工前方存在溶洞、溶槽的位置和特点。针对施工中遇到的不同位置分布及特性的岩溶,采取对应的施工处置措施,并对穿越特殊地质强富水可溶岩和非可溶岩接触带施工工艺进行优化,可在保证施工质量的基础上,获得最佳效益。

山东省泰安市大汶口地区岩盐矿开发利用相关问题探讨

大汶口盆地内岩盐资源丰富,开发利用始于20世纪90年代,根据岩盐层赋存特征、矿石质量特征,盆地内岩盐采用钻井水溶法采矿。本次以岩盐开采方式为研究对象,基于岩盐开采现状调查,分析生产中卤水渗漏、堵井事故的产生原因及处理方式。通过分析,认为岩盐钻井水溶开采中,通过加强井组技术参数的研究可有效提高资源利用率,生产中通过选择高质量套管、提高固井质量、加强生产管理及监控等,可有效预防生产事故的发生。

凤凰盐矿高效开发实践

凤凰盐矿高浓度卤水已实现10年的稳定供给,为公司制盐创造了良好效益。为总结相关经验与技术方法,本文就凤凰盐矿资源特征、钻井工程、生产流程与防堵措施等方面开展梳理总结,为盐矿高效开发提供了技术手段,供同行借鉴。

Magnetic characteristics of insoluble microparticles in ice core (Nojingkangsang) from the southern Tibetan Plateau and its environmental significance

Insoluble microparticles in ice cores are related closely to the transportation of eolian dust,and thus are important natural media to reconstruct climate change.In this study,we conducted a systematic mineral-magnetic investigation of insoluble microparticles in the Nojingkangsang ice core (29°2.1'N,90°11.88'E,5950 m) from the Southern Tibetan Plateau.Results indicate that the dominant magnetic mineral is magnetite,and its concentration has grown significantly since the 1980s,which coincides with trends in climate warming of the Tibetan Plateau.Influenced by regional warming,the glacial recession around Nojingkangsang shortens the distance between the dust source and glacial areas and thus increases the concentration of coarse-grained magnetic minerals in ice cores.However,the frequency of dust storms,associated with annual precipitation,could play only a regulatory role on the magnetic content over yearly (or seasonal) time scales.Therefore,using a new approach,the magnetic index of insoluble microparticles in ice cores of this region is seen as mainly reflecting trends in climate warming.

Quantification and implications of two types of soluble organic matter from brackish to saline lake source rocks

Two types of soluble organic matter, the free and adsorbed, were obtained and quantified from the brack- ish to saline lake source rocks. The adsorbed type was ex- tracted with chloroform, solvent mixtures of methanol: acetone:chloroform (MAC) and CS2:N-methyl-2-pyrroli- dinone (CS2/NMP). The total amounts of the two types of soluble organic matter from some immature source rocks are >830 mg/g TOC, more than 63% of the total organic matter in these samples. This result indicates that the majority of the organic matter in the immature source rocks in the brackish to saline lake basin is soluble, and is significant for study of petroleum formation and helpful for petroleum exploration in the brackish to saline lake basin.

广州市岩溶塌陷发育特征

根据地质灾害调查资料,岩溶塌陷已成为制约广州市社会经济发展的主要地质灾害之一。文章在详细阐述广州市可溶岩空间分布及岩溶发育特征的基础上,系统地分析了广州市岩溶塌陷的分布特征、形态特征和岩溶塌陷发育的控制因素。研究结果表明,广州市岩溶塌陷主要受隐伏岩溶发育程度、覆盖层岩土体结构特征、地质构造、水文地质环境及人类工程活动强度的控制;岩溶塌陷的直接触发因素主要为采矿和基础工程施工抽排地下水、过量开采岩溶地下水、钻探施工、地面振动加载、采矿坑道突水突泥、强降雨入渗及旱涝交替效应等。研究结果可为广州市岩溶塌陷防治提供翔实的地质依据。

沉积岩中不同形态氮的提取方法及其在古环境研究中的意义

近年来,沉积岩中的氮同位素组成(δ^(15)N)已成为生命起源和古环境研究的有效地球化学指标,并为这些领域的原创性发现提供了重要科学证据。沉降的有机质在经过生物地球化学过程和地质作用的改造后转化为不同形态的含氮物质(如干酪根结合氮、可溶性有机氮以及NH^(+)_(4)等),并保存于沉积岩中。不同形态氮可能具有独特的古环境意义,有必要进行单独的分离和提取,丰度较低的氮组分(如固定铵)也逐渐得到重视。当前,学者们主要利用全岩和干酪根的氮同位素组成开展相关研究工作,但由于地质过程复杂,特定含氮物质提取同位素测试和解译难度较高,何种形态的氮能代表原始的古海水信号尚不明确。在前人研究的基础上,归纳了含氮物质在不同地质作用中的演化历程,系统总结了沉积岩中不同形态氮的提取方法,阐明了它们的古环境意义,并对不同形态氮应用于古环境研究存在的问题进行了讨论;同时,提出古海洋氮循环研究亟需开展的工作,为推动氮同位素的高精度测试及古环境研究提供参考。

可溶岩路基顶板稳定性研究

文中以某公路路基顶板稳定性分析为例,在多种方法进行地质勘察的基础上,采用半定量评价分析法、结构近似分析法、三维数值模拟等对路基顶板抗弯、抗剪计算分析,综合评价路基顶板整体稳定性。结果表明,在工程实践中,采用多种方法对可溶岩溶洞顶板进行定性分析和定量计算,可进一步分析可溶岩的发育规律等,充分保证路基安全稳定。