硫化物矿物溶解度与溶液pH值的关系   总被引：2，自引：0，他引：2  

贾建业  兰斌明  谢先德  吴大清  汤艳杰  王燕  王建成 《吉林大学学报(地球科学版)》2001,31(3):241-246

硫化物作为自然界常见的一大类矿物 ,由于溶解度很小 ,硫化物对水pH值的影响以及水对它的溶解度影响往往被人们所忽视。通过计算常见硫化物矿物的自由能ΔG0f、溶度积Ksp和溶解度S、绘制logS—pH曲线 ,得出硫化物矿物在不同 pH值条件下的溶解规律 ,水溶液的pH值受硫化物矿物的控制 ;反过来 ,水溶液的pH值也影响着矿物溶解度的大小。此外 ,对硫化物矿物饱和溶液的缓冲范围、缓冲容量和硫化物与溶液pH值相互作用的机理进行了探讨  相似文献   

Yearly changes in the seasonal frequency and duration of short-term acid pulses in some Nova Scotia, Canada streams   总被引：1，自引：0，他引：1  

T. A. Clair  A. Ghosh Bobba  Krista Miller 《Environmental Geology》2001,40(4-5):582-591

 The seasonal frequency and duration of low pH events at three sites located in southwestern Nova Scotia were analyzed using measured and synthetic daily pH data. The basins varied in size from 0.3 to 300 km² and were subject to frequent snowmelt events in winter and spring, as well as occasional runoff events during summer and fall. Results showed that, in order to fill in missing data from periods where collection was interrupted, statistical approximations using discharge were not totally acceptable, as generated data consistently missed the extreme values measured. Despite a lack of totally accurate event pH estimates for periods where daily data were missing, analysis showed that in this region, low pH episodes can occur year-round including summer. The highest probabilities of low pH episodes nevertheless occurred in the winter and spring when snowmelts were frequent. Received: 12 November 1999 · Accepted: 18 July 2000  相似文献   

广西巴里—龙头山100号锡多金属矿床成矿物理化学环境研究——氧逸度(f_(o_2))、CO_2逸度(f_(co_2))、硫逸度(f_(s_2))、mΣs     

邓金灿  李蘅  徐文炘  曾文高  韦少校  韦万川  马文来  苏亚汝  甘文志  左湛松  韦汉蒙 《矿产与地质》2001,(3)

根据已知的 10 0号矿体的成矿温度及成矿压力 ,并结合矿体的矿物组合推算出10 0号矿体是在相对低硫、氧和二氧化碳逸度 ,溶液为酸性至弱碱性的物理化学环境下形成的。  相似文献   

Partitioning of heavy metals on soil samples from column tests   总被引：3，自引：0，他引：3  

R. N. Yong  W. Z. W. Yaacob  S. P. Bentley  C. Harris  B. K. Tan   《Engineering Geology》2001,60(1-4):307-322

In this study, column tests were used to determine the retention capability of three types of estuarine alluvia collected adjacent to landfill sites in South Wales. Selective sequential extraction (SSE) was used to study the retention mechanisms of heavy metals in the soil columns obtained from leaching experiments. Acid digestion was later used to check the validity of the SSE results. Breakthrough curves show good retention of heavy metal ions (Pb, Cu, and Zn) by all soils, where almost 99% of heavy metals were retained with the C_e/C_o values in the order of 10⁻³. The retention strength of these soils was observed to be constant up to five pore volumes (PV). This corresponds with the pH of the effluents and pore water of soil slices, which also show good buffering capacity against very acidic leachate up to 5PV. The heavy metal extraction profiles from SSE show very similar trends with the retention profiles from the leaching experiments, where heavy metals were retained mainly at the top part where the leachate entered the column. SSE indicates qualitatively that heavy metals precipitated with carbonates and amorphous materials (oxides/hydroxides) are higher than heavy metal retention via exchangeable mechanisms. The mass balance calculation gives range of deviation of 1–16% of the total soil extraction. The distribution of the heavy metals with various soil constituents are ranked in the following order: Carbonates>Amorphous oxides hydroxides>Organic matter>Exchangeable phases.  相似文献   

湘西南石英脉型金矿矿物流体包裹体pH值和Eh值的估算   总被引：2，自引：0，他引：2  

吴湘滨  戴塔根  何绍勋 《大地构造与成矿学》1999,23(3):248-253

以湘西南石英脉型金矿床为例,研究ｐ Ｈ、Ｅｈ 估算值的结果表明利用围岩蚀变反应方程以及采用碱金属离子、卤素元素离子估算ｐＨ 值是不完善的。本文根据热力学原则（ 相平衡、电价中和） 提出了矿物流体包裹体成分体系计算ｐＨ 估算值的方法,并且讨论了测试包裹体时气体成分外逸是影响ｐＨ 和Ｅｈ 估算值的主要因素之一。  相似文献   

Multi-proxy data from Kaksoislammi Lake in Finland: dramatic changes in the late Holocene cladoceran assemblages     

Kaarina Sarmaja-Korjonen 《Journal of Paleolimnology》2002,28(3):287-296

A small lake, Kaksoislammi (60° 3830N, 24° 4550E), in southern Finland was studied for Cladocera, diatoms and pollen from a core which covers the entire Holocene. The diatom remains indicate a steady development from alkaliphilous taxa towards the dominance of acidophilous forms and lowering pH in the late Holocene. About 1800–1700 BP, dramatic changes took place in the microfauna, mainly the planktonic Cladocera. Bosmina longirostris, the dominant species, suddenly disappeared, and Daphnia, Chydorus sphaericus and Chaoborus increased. The change is simultaneous with a decline of the diatom-inferred pH to 4.8. It is probable that there was a sudden, profound change in predator-prey relationships. The acidity of the lake water probably increased to such a low level that it led to the disappearance of even the most acid-tolerant fish. Consequently invertebrate predators increased and quickly altered the species composition in the lake. There is also pollen evidence of the onset of Iron Age cultivation and grazing almost simultaneously with the faunal change. Therefore, it cannot be ruled out that the sudden lowering of pH was indirectly caused by prehistoric human activity; possibly the acidic peatland surrounding the lake was disturbed.  相似文献   

长三角经济高速发展地区土壤pH时空变化及其影响因素   总被引：13，自引：0，他引：13  

邵学新  黄标  顾志权  钱卫飞  金洋  毕葵森  严连香 《矿物岩石地球化学通报》2006,25(2):143-149

通过调查和分析长三角地区张家港市2004年和第二次土壤普查时(1980)的土壤pH,探讨了该市近20年来基于经济高速发展影响下的土壤pH变化及影响因素。结果表明,自第二次土壤普查以来,该市土壤pH变化明显。南部人为土地区绝大部分土壤pH值都下降了一个单位,平均值由7.39降至6.33;北部雏形土区,两个时期的土壤pH值分别为7.92和7.98。土壤pH的降低可能同该地区长期施用化学肥料、酸雨及工业酸性“三废”排放的增加有关。此外,土地利用和田间管理也对土壤pH变化起着较为重要的作用,而土壤地球化学性质差异则是导致南北地区土壤pH变化不同的内在因素。  相似文献   

pH值对红土粒度成分影响的分形几何研究     

马琳  王清  原国红 《水文地质工程地质》2007,34(2):41-44

红土是一种特殊土,其成分和结构决定了红土本身具有不同于一般粘性土的工程地质性质。红土中游离氧化铁的存在使土颗粒之间产生胶结,是土具有“假粉性”和“假砂性”特征的主要原因。研究发现,游离氧化铁含量和形态的改变,将直接影响红土颗粒的粒度分布。通过对不同pH值红土试样的颗粒成分进行测试,借助分形理论得到不同pH值红土粒度成分分维值。计算发现,不管是否在测试过程中采用分散剂,土粒度分维曲线上都存在两个无标度区。pH值的改变引起了土粒度分维的变化,随pH值的增大,土粒度分维值也变大,反应出土的细颗粒含量增加,土颗粒所形成的集合体越分散。土pH值的大小与粒度成分分维、游离氧化铁含量之间的内在联系,揭示出了红土中游离氧化铁对土颗粒胶结的本质。  相似文献   

FRESH SNOW CHEMISTRY FROM HIGH MOUNTAIN REGIONS IN CENTRAL HIMALAYAS     

KANG Shi chang  QIN Da he  YAO Tan dong  PAUL A. Mayewski  SALLIE Whitlow 《中国地理科学(英文版)》2000,10(3):218-225

Investigations of atmospheric composition in the Himalayas has been limited in both temporal and spatial scales, mainly due to difficult logistics. Ideal sites for monitoring atmospheric composition and its evolution should be free from local pollution and representative of the remote troposphere (HUEBERT et al., 1980). As the Himalayas are far removed from highly industrialized regions they provide suitable locations to monitor the chemistry of the remote troposphere and to study the evolu…  相似文献   

Grey relational analysis on the relation between marine environmental factors and oxidation-reduction potential   总被引：2，自引：0，他引：2  

刘学庆  王佳  张盾  李言涛 《中国海洋湖沼学报》2009,27(3):583-586

The effects of marine environmental factors-temperature(T),dissolved oxygen(DO),salinity(S) and pH-on the oxidation-reduction potential(ORP) of natural seawater were studied in laboratory.The results show an indistinct relationship between these four factors and the ORP,but they did impact the ORP.Common mathematical methods were not applicable for describing the relationship.Therefore,a grey relational analysis(GRA) method was developed.The degrees of correlation were calculated according to GRA and the va...  相似文献