まとめ
シリケート鉱物は,シリカを海水に素早く放出します. この研究は,一般的な鉱物でさえも迅速に反応することを示し,海洋化学システムにおけるゆっくりとした地質学的速度に関する以前の仮定に異議を唱える.
科学分野:
- 地質化学 地質化学
- マリン・ケミストリー (海洋化学)
- ミネラロジーは,鉱物学です.
背景:
- シリケート鉱物は海洋環境で豊富に存在する.
- 以前の理解では,シリケート鉱物と海水間の反応速度が遅いことが示唆されていた.
- イオン交換は,主な相互作用メカニズムと考えられました.
研究 の 目的:
- 様々なシリケート鉱物から海水へのシリカの放出率を調査する.
- 地質学的に遅いミネラル水と海水の反応の仮定に異議を唱えるために.
- デトリタルシリケートに対する海洋化学システムの反応性を評価する.
主な方法:
- 細粒子のシリケート鉱物サンプル (1グラム) を人工海水 (200ミリリットル) で発育した.
- 水中のシリカ濃度は6ヶ月間にわたって測定されました.
- 試験された特定の鉱物にはカオリニット,クロライト,イリライト,ムスコバイト,および2種類のモンモリヨニットが含まれていました.
主要な成果:
- すべての試験された鉱物から10日と6ヶ月以内に有意なシリカの放出が観察されました.
- モンモリヨナイトのサンプルは,最も高いシリカ濃度を示した (例えば,モンモリヨナイトB: 10日後に10ppm, 6ヶ月で21ppm).
- カオリナイトは,最も低い放出率を示した (10日後に0.6ppm,6ヶ月後に2.2ppm).
結論:
- シリケート鉱物は海水と素早く反応し,大量にシリカを放出します.
- 海洋は,添加されたデトリタルシリケートに素早く反応する化学システムとして見るべきです.
- 観測された速度は,海洋環境における地質学的にゆっくりとした鉱物の溶解の仮定と矛盾しています.
さらに関連する動画
11:50Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
09:39Proof-of-Concept for Gas-Entrapping Membranes Derived from Water-Loving SiO2/Si/SiO2 Wafers for Green Desalination
Published on: March 1, 2020
関連する概念動画
01:22Effect of Sea Water on Concrete
Concrete exposed to seawater can undergo degradation like the dissolution of ettringite and gypsum, increasing the material's porosity and decreasing its strength. In contrast, the crystallization of salts within the concrete's pores can cause expansion, particularly above the waterline where evaporation occurs. Nonetheless, this expansion only happens when seawater, enabled by the concrete's permeability, manages to infiltrate the structure.
Concrete in areas between tide marks, which undergo...
Concrete in areas between tide marks, which undergo...
01:26Alkali Aggregate Reaction in Concrete
The alkali-aggregate reaction in concrete involves natural siliceous minerals in aggregates reacting with alkaline hydroxides derived from cement alkalis. This reaction forms an alkali-silica gel that absorbs water, swells, and increases in volume, which is confined by the surrounding cement paste, creating internal pressures that crack and disrupt the concrete. The extent of expansion and damage can be partly attributed to the alkali-silica reaction's osmotic hydraulic pressure and the...
03:06Alkali Metals
Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the alkali metals are unusually low for metals and decrease going down the group, while the density increases going down the group with the exception of potassium (Table 1).
Table 1: Properties of the alkali metals
Table 1: Properties of the alkali metals
03:10Precipitation Reactions
In a precipitation reaction, aqueous solutions of soluble salts react to give an insoluble ionic compound – the precipitate. The reaction occurs when oppositely charged ions in solution overcome their attraction for water and bind to each other, forming a precipitate that separates out from the solution. Since such reactions involve the exchange of ions between ionic compounds in aqueous solution, they are also referred to as double displacement, double replacement, exchange reactions, or...
02:26Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
03:01Halogens
Group 17 elements, known as halogens, are nonmetals. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine a solid. Astatine is a highly unstable radioactive element, so currently, most of its properties are unknown due to its short half-life. Tennessine is a synthetic element also predicted to be in this group.