磷灰石对湖泊沉积物中水铁矿稳定性的制约

doi:10.13745/j.esf.sf.2020.5.49

摘要/Abstract

摘要：

通过在滇池开展原位实验,研究探讨了湖泊沉积物中磷灰石制约水铁矿分解和转化的机制,以及二者共存时的环境效应。结果表明:将水铁矿放置到沉积物中1个月,矿物保持稳定;放置时间达到3个月时,添加磷灰石实验中水铁矿发生了显著物相转变。冬天(12—2月)实验中,转化产物随深度的变化趋势为针铁矿+磁(赤)铁矿→针铁矿+纤铁矿→针铁矿;夏天(6—9月)实验中,转化产物随深度的变化趋势为针铁矿+纤铁矿+磁(赤)铁矿→针铁矿+纤铁矿→未转化。透射电镜分析结果显示冬天实验中生成的磁性铁氧化物为纳米磁铁矿和磁赤铁矿,夏天实验中产生的则主要为纳米磁铁矿。X射线光电子能谱分析结果显示冬天表层实验样品具有较高P含量。分析表明的湖泊沉积物中磷灰石促进水铁矿转化的过程为:(1)微生物促进磷灰石溶解;(2)磷灰石溶解释放的P促进铁还原菌生长;(3)铁还原菌促进水铁矿还原;(4)水铁矿还原产生的溶解态Fe²⁺催化水铁矿向针铁矿、纤铁矿和磁铁矿转化。冬天及沉积氧化-还原界面最适宜磷灰石分解菌和铁还原菌生长,水铁矿的转化和P释放能力也更强,相应地内源磷释放的风险也更大。

关键词: 水铁矿, 磷灰石, 湖泊沉积物, 氧化-还原界面, 稳定性, 转化

Abstract:

In this study, we set out to investigate the mechanism of apatite-mediated dissolution and transformation of ferrihydrite in lacustrine sediments, and the synergic environmental effect of both minerals. We carried out in-situ ferrihydrite transformation experiments in the Dianchi Lake, Yunnan Province, China. The results show that ferrihydrite remained stable in 1-month cultured samples, whereas in apatite-added samples we observed obvious mineral phase transformation after 3-month culturing. The change of newly formed iron mineral assemblage composition with depth in the top 50 cm sedimentary layer were goethite+magnetite/maghemite → goethite+lepidocrocite → goethiten in the winter experiments, or goethite+lepidocrocite+magnetite/maghemite → goethite+lepidocrocite → no new mineral in the summer experiments. Transmission electron microscopy observations show that magnetic minerals formed in winter are nanosized magnetite and maghemite, while in summer they are mainly magnetite. X-ray photoelectron spectroscopy analysis only found P in 3-month cultured samples in winter at a sedimentary depth of no more than 20 cm. The experimental results suggest that the progressive steps in the apatite-mediated ferrihydrite transformation process in lacustrine sediments are as follows: (1) apatite is dissolved by microorganisms and P is released during dissolution; (2) dissolved P promotes iron-reducing bacterial growth; (3) iron-reducing bacteria promote ferrihydrite reduction and release of dissolved Fe²⁺; and (4) dissolved Fe²⁺ catalyzes the transformation of ferrihydrite to goethite, lepidocrocite, and magnetite. In winter at the sedimentary redox boundary, the functional microorganisms responsible for apatite dissolution and ferrihydrite reduction can grow better, thus the risk of endogenous phosphorus release is much greater.

Key words: ferrihydrite, apatite, lacustrine sediment, redox boundary, stability, transformation

中图分类号:

骆少勇, 周跃飞, 刘星. 磷灰石对湖泊沉积物中水铁矿稳定性的制约[J]. 地学前缘, 2020, 27(5): 218-226.

LUO Shaoyong, ZHOU Yuefei, LIU Xing. Effect of apatite on the stability of ferrihydrite in lacustrine sediments[J]. Earth Science Frontiers, 2020, 27(5): 218-226.

图/表 8

图1 实验装置及样品 a—实验装置; b—实验样品;c—样品袋结构示意图。

Fig.1 Photo showing the experimental setup (a) and samples (b) and schematic cross-section of the sampling bag (c)

图2 冬天3个月实验后水铁矿的XRD结果 Gt:针铁矿;Lp:纤铁矿;Mt:磁铁矿;Qz:石英。

Fig.2 XRD patterns of ferrihydrite samples after 3-month culturing in winter

图3 夏天3个月实验后水铁矿的XRD结果 Gt:针铁矿;Lp:纤铁矿;Mt:磁铁矿。

Fig.3 XRD patterns of ferrihydrite samples after 3-month culturing in summer

表1 水铁矿磁化率

Table 1 Magnetic susceptibilities of ferrihydrite samples

实验编号	距水-沉积物界面不同深度处水铁矿磁化率/ (10^-8 m³·kg^-1)
实验编号	10 cm	20 cm	30 cm	40 cm	50 cm
A11	201	198	189	178	205
A12	407	501	477	638	325
A21	190	191	191	188	190
A22	18 478	23 664	6 282	3 579	8 565
B11	287	254	246	247	257
B12	245	242	239	239	250
B21	429	953	1203	408	559
B22	22 632	19 926	879	4 046	696

表2 部分水铁矿样品Fe2+/总Fe比值

Table 2 Fe2+ to total Fe ratio for some ferrihydrite samples

实验编号	距水-沉积物界面不同深度处样品Fe²⁺/总Fe比值
实验编号	10 cm	20 cm	30 cm	40 cm	50 cm
A22	3.4	2.7	0.3	0.4	0.6
B22	3.1	3.0	—	—	—

图4 3个月实验水铁矿中P的XPS结果

Fig.4 XPS patterns of P in ferrihydrite samples after 3-month culturing

图5 A22-10样品中磁选物质TEM结果 a—磁性铁氧化物及针铁矿的低倍TEM成像;b—磁性铁氧化物的低倍TEM成像;c—磁赤铁矿电子衍射花样;d—磁赤铁矿高分辨晶格像。Mh:磁赤铁矿,Gt:针铁矿。

Fig.5 TEM patterns of particles magnetically separated from sample A22-10

图6 B22-10样品中磁选物质TEM结果 a—磁性铁氧化物低倍TEM成像;b—磁铁矿电子衍射花样;c—磁赤铁矿和纤铁矿高分辨晶格像;d—磁铁矿和纤铁矿高分辨晶格像。Mt:磁铁矿,Mh:磁赤铁矿,Lp:纤铁矿。

Fig.6 TEM patterns of particles magnetically separated from sample B22-10

参考文献 51

[1]	SULLIVAN K A, ALLER R C. Diagenetic cycling of arsenic in Amazon shelf sediments[J]. Geochimica et Cosmochimica Acta, 1996, 60(9):1465-1477.
[2]	CUMMINGS D E, MARCH A W, BOSTICK B, et al. Evidence for microbial Fe (III) reduction in anoxic, mining-impacted lake sediments (Lake Coeur d’Alene, Idaho)[J]. Applied Environmental Microbiology, 2000, 66(1):154-162.
[3]	ROZEN T F, TAILLEFERT M, TROUWBORST R E, et al. Iron-sulfur-phosphorus cycling in the sediments of a shallow coastal bay: implications for sediment nutrient release and benthic macroalgal blooms[J]. Limnology and Oceanography, 2002, 47(5):1346-1354.
[4]	LOVLEY D R. Microbial Fe (III) reduction in subsurface environments[J]. FEMS Microbiology Reviews, 1997, 20(3/4):305-313.
[5]	CROWE S, ROBERTS J, WEISENER C, et al. Alteration of iron-rich lacustrine sediments by dissimilatory iron-reducing bacteria[J]. Geobiology, 2007, 5(1):63-73.
[6]	ROBERTS A P. Magnetic mineral diagenesis[J]. Earth-Science Reviews, 2015, 151:1-47.
[7]	LOVLEY D R, WMTE D C, PYE K. Reduction of Fe (III) in sediments by sulphate-reducing bacteria[J]. Nature, 1993, 361:436-438.
[8]	CANFIELD D E. Reactive iron in marine sediments[J]. Geochimica et Cosmochimica Acta, 1989, 53(3):619-632. DOI URL
[9]	ZHOU Y, GAO Y, XIE Q, et al. Reduction and transformation of nanomagnetite and nanomaghemite by a sulfate-reducing bacterium[J]. Geochimica et Cosmochimica Acta, 2019, 256(1):66-81. DOI URL
[10]	奚姗姗, 周春财, 刘桂建, 等. 巢湖水体氮磷营养盐时空分布特征[J]. 环境科学, 2016, 37(2):542-547.
[11]	余丽燕, 杨浩, 黄昌春, 等. 夏季滇池和入滇河流氮, 磷污染特征[J]. 湖泊科学, 2016, 28(5):961-971.
[12]	朱广伟, 许海, 朱梦圆, 等. 三十年来长江中下游湖泊富营养化状况变迁及其影响因素[J]. 湖泊科学, 2019, 31(6):1510-1524.
[13]	ZHU G, QIN B, GAO G. Direct evidence of phosphorus outbreak release from sediment to overlying water in a large shallow lake caused by strong wind wave disturbance[J]. Chinese Science Bulletin, 2005, 50:577-582.
[14]	RUTTENBERG K C. Development of a sequential extraction method for different forms of phosphorus in marine sediments[J]. Limnology and Oceanography, 1992, 37(7):1460-1482. DOI URL
[15]	HUPFER M, GÄCHTER R, GIOVANOLI R. Transformation of phosphorus species in settling seston and during early sediment diagenesis[J]. Aquatic Sciences, 1995, 57:305-324. DOI URL
[16]	RYDIN E. Potentially mobile phosphorus in Lake Erken sediment[J]. Water Research, 2000, 34(7):2037-2042. DOI URL
[17]	于子洋, 杜俊涛, 姚庆祯, 等. 黄河口湿地表层沉积物中磷赋存形态的分析[J]. 环境科学, 2014, 35(3):942-950.
[18]	骆少勇, 周跃飞, 刘星. 滇池内源磷释放潜力的区域差异: 来自沉积物磷形态的证据[J]. 矿物学报, 2019, 39(1):15-22.
[19]	TRAINA S J, LAPERCHE V. Contaminant bioavailability in soils, sediments, and aquatic environments[J]. Proceedings of the National Academy of Sciences, 1999, 96:3365-3371. DOI URL
[20]	LEYVAL C, BERTHELIN J. Interactions between Laccaria laccata, Agrobacterium radiobacter and beech roots: influence on P, K, Mg, and Fe mobilization from minerals and plant growth[J]. Plant and Soil, 1989, 117:103-110. DOI URL
[21]	WELCH S, TAUNTON A, BANFIELD J. Effect of microorganisms and microbial metabolites on apatite dissolution[J]. Geomicrobiology Journal, 2002, 19(3):343-367. DOI URL
[22]	HUTCHENS E, VALSAMI J E, HAROUIYA N, et al. An experimental investigation of the effect of Bacillus megaterium on apatite dissolution[J]. Geomicrobiology Journal, 2006, 23(3/4):177-182. DOI URL
[23]	FENG M H, NGWENYA B T, WANG L, et al. Bacterial dissolution of fluorapatite as a possible source of elevated dissolved phosphate in the environment[J]. Geochimica et Cosmochimica Acta, 2011, 75(19):5785-5796. DOI URL
[24]	吴峰炜, 汪福顺, 吴明红, 等. 滇池,红枫湖沉积物中总磷, 分态磷及生物硅形态与分布特征[J]. 生态学杂志, 2009, 28(1):88-94.
[25]	JAMBOR J L, DUTRIZAC J E. Occurrence and constitution of natural and synthetic ferrihydrite, a widespread iron oxyhydroxide[J]. Chemical Reviews, 1998, 98(7):2549-2586.
[26]	REVESZ E, FORTIN D, PAKTUNC D. Reductive dissolution of arsenical ferrihydrite by bacteria[J]. Applied Geochemistry, 2016, 66:129-139. DOI URL
[27]	SCHWERTMANN U, CORNELL R M. Iron oxides in the laboratory, preparation and characterization[M]. Weinheim: Wiley-VCH Publisher, 2000: 1-188.
[28]	郑大中, 郑若峰. 岩石、土壤、沉积物中氧化亚铁与氧化高铁的分离与测定[J]. 岩矿测试, 1988, 7(1):28-31.
[29]	丁仕兵, 刘稚. 重铬酸钾滴定法测定铁矿石中铁含量不确定度的评价和计算[J]. 冶金分析, 2002, 22(1):63-65.
[30]	CHEN T, XU H, XIE Q. Characteristics and genesis of maghemite in Chinese loess and paleosols: mechanism for magnetic susceptibility enhancement in paleosols[J]. Earth and Planetary Science Letters, 2005, 240(3/4):790-802. DOI URL
[31]	JOHNSTONE R, KOOP K, LARKUM A. Physical aspects of coral reef lagoon sediments in relation to detritus processing and primary production[J]. Marine Ecology Progress Series, 1990, 232(1):273-283.
[32]	CUDENNEC Y, LECERF A. Topotactic transformations of goethite and lepidocrocite into hematite and maghemite[J]. Solid State Sciences, 2005, 7(5):520-529. DOI URL
[33]	GALVEZ N, BARRON V, TORRENT J. Effect of phosphate on the crystallization of hematite, goethite, and lepidocrocite from ferrihydrite[J]. Clays and Clay Minerals, 1999, 47(3):304-311. DOI URL
[34]	GOLTERMAN H. Phosphate release from anoxic sediments or “What did Mortimer really write?”[J]. Hydrobiologia, 2001, 450:99-106. DOI URL
[35]	LI Q M, ZHANG W, WANG X X. Phosphorus in interstitial water induced by redox potential in sediment of Dianchi Lake, China[J]. Pedosphere, 2007, 17(6):739-746.
[36]	BEROVIČ M. Scale-up of citric acid fermentation by redox potential control[J]. Biotechnology and Bioengineering, 1999, 64(5):552-557.
[37]	DONG H, FREDRICKSON J K, KENNEDY D W, et al. Mineral transformations associated with the microbial reduction of magnetite[J]. Chemical Geology, 2000, 169(3/4):299-318. DOI URL
[38]	NEWMAN D K, KOLTER R. A role for excreted quinones in extracellular electron transfer[J]. Nature, 2000, 405:94-97.
[39]	STRAUB K L, BENZ M, SCHINK B. Iron metabolism in anoxic environments at near neutral pH[J]. FEMS Microbiology Ecology, 2001, 34(3):181-186. DOI URL
[40]	MARSILI E, BARON D B, SHIKHARE I D, et al. Shewanella secretes flavins that mediate extracellular electron transfer[J]. Proceedings of the National Academy Sciences, 2008, 105(10):3968-3973.
[41]	SHI L, DONG H, REGUERA G, et al. Extracellular electron transfer mechanisms between microorganisms and minerals[J]. National Reviews Microbiology, 2016, 14:651-662.
[42]	CHEUNG K H, GU J D. Reduction of chromate (CrO^2-₄) by an enrichment consortium and an isolate of marine sulfate-reducing bacteria[J]. Chemosphere, 2003, 52(9):1523-1529. DOI URL
[43]	CUDENNEC Y, LECERF A. The transformation of ferrihydrite into goethite or hematite, revisited[J]. Journal of Solid State Chemistry, 2006, 179(3):716-722. DOI URL
[44]	CORNELL R M, SCHWERTMANN U. The iron oxides: structure, properties, reactions, occurrences and uses[M]. Weinheim: Wiley-VCH Publisher, 2000: 1-664.
[45]	LIU H, LI P, ZHU M, et al. Fe(II)-induced transformation from ferrihydrite to lepidocrocite and goethite[J]. Journal of Solid State Chemistry, 2007, 180(7):2121-2128. DOI URL
[46]	BOLAND D D, COLLINS R N, MILLER C J, et al. Effect of Solution and solid-phase conditions on the Fe(II)-accelerated transformation of ferrihydrite to lepidocrocite and goethite[J]. Environmental Science & Technology, 2014, 48(10):5477-5485.
[47]	SHENG A, LIU J, LI X, et al. Labile Fe(III) from sorbed Fe(II) oxidation is the key intermediate in Fe(II)-catalyzed ferrihydrite transformation[J]. Geochimica et Cosmochimica Acta, 2020, 272:105-120. DOI URL
[48]	HANSEL C M, BENNER S G, FENDORF SCompeting Fe(II)-induced mineralization pathways of ferrihydrite[J]. Environmental Science & Technology, 2005, 39(18):7147-7153. DOI URL
[49]	STEWART B D, NICO P S, FENDORF S. Stability of uranium incorporated into Fe (hydr)oxides under fluctuating redox conditions[J]. Environmental Science & Technology, 2009, 43(13):4922-4927.
[50]	YANG L, STEEFEL C I, MARCUS M A. Kinetics of Fe(II)-catalyzed transformation of 6-line ferrihydrite under anaerobic flow conditions[J]. Environmental Science & Technology, 2010, 44(14):5469-5475. DOI URL
[51]	CHEN C, KUKKADAPU R, SPARKS D L. Influence of coprecipitated organic matter on Fe²+(aq)-catalyzed transformation of ferrihydrite: implications for carbon dynamics[J]. Environmental Science & Technology, 2015, 49(18):10927-10936.