Key Difference – Alkalinity vs Hardness
Although water covers 71.1% of the earth’s crust, water everywhere is not the same. However, water is the onlyinorganic substance这可以在所有三个物理状态下自然地作为液态水,冰或水蒸气存在。这是由于温度的变化。根据溶解在其中的成分,从一个地方到另一个地方的颜色,味道或化学成分可能不同。例如,海水与井中的水样完全不同。因此,为了测试水质,已经引入了水测试参数。碱度和硬度是这样的参数,这些参数是在食用水之前应测试的非常重要的因素。碱度和硬度之间的关键区别在于alkalinity measures the total amount of bases present in waterwhereas硬度测量二价盐的总量(浓度)。
内容
1.Overview and Key Difference
2.What is Alkalinity
3.What is Hardness
4.碱度与硬度之间的相似之处
5.Side by Side Comparison – Alkalinity vs Hardness in Tabular Form
6。概括
什么是碱度?
碱度是水保持水的能力ph稳定的。换句话说,碱度是水中和的能力酸. The degree of alkalinity is mostly dependent on the soil or rocks it passes through. Alkalinity mainly occurs due to the presence of碳酸盐水中存在的物种。它与basicityof water. Alkalinity comes mainly fromhydroxidesor bases. Carbonate species contribute to the alkalinity than other basic species does because considerable amounts of carbonate species are found in water naturally.
碱度是一个重要的参数,因为它可以直接影响水生寿命。水生寿命正常运作的最佳pH范围是6.0-9.0 ph。碱度有助于维持水体的pH值。它是通过使用acid-base titration. In this titration, the amount of an acid that can be neutralized by a water sample is measured. The carbonate species will neutralize the acid and the end point is obtained when all the carbonate species are consumed.
What is Hardness?
Water hardness is the measurement of the concentration of total divalent ions present in water. Examples of some divalent ions present in water are calcium ion, magnesium ions, and Fe2+ion. However, calcium and magnesium are the most common sources of water hardness. The unit for hardness is ppm per CaCO3等效物。There are two types of water hardness:
Temporary Hardness
Temporary hardness occurs due to the presence of calcium hydrogencarbonate (Ca (HCO3)2) and magnesium hydrogencarbonate (Mg (HCO3)2). Both species decompose when heated and CaCO3or MgCO3precipitation occurs. Therefore, temporary hardness can be removed by boiling water.
Permanent Hardness
永久性水硬度由于存在硫酸钙。不能通过开水去除它。
碳酸钠可用于临时硬度和永久硬度,以软化硬废物。Sodium carbonateis dissolved in water and provides enough carbonate ions to react with calcium ions in the water. This helps to soften the hard water.
The hardness of water can easily be estimated by an EDTA titration. EDTA will bind with both calcium and magnesium ions; hence, it can determine the amount of those ions present.
What are the Similarities between Alkalinity and Hardness?
由于它们共享的几个相似之处,碱度和硬度通常会感到困惑。一种相似之处之一是,两个参数的测量单位相同,即CACO中的PPM(每百万)3等效物。
另一个相似之处是,水的硬度和碱度主要来自limestone or dolomite在自然来源。这发生在当不是水ses through rocks and uptake minerals which cause alkalinity and hardness., When limestone and dolomite dissolve in water, calcium ions, magnesium ions, and carbonate species are mixed with water. Calcium and magnesium ions cause water hardness and the alkalinity occurs due to the presence of carbonate species.
碱度和硬度有什么区别?
Alkalinity vs Hardness |
|
碱度是水抵抗由于酸而发生的pH变化的能力。 | Hardness is the measurement of total amount of divalent ions present in water. |
Causative Species | |
Alkalinity is mainly caused by the presence of carbonate species. | Hardness is caused by divalent ions such as calcium, magnesium or iron ions. |
Determination | |
Alkalinity can be determined by acid-base titrations. | 硬度可以通过EDTA滴定确定。 |
Reactions in Titrations | |
引起碱度的碳酸盐物质可以在苯甲胺蛋白和甲基橙色指示剂存在下与强酸反应,以在所有碳酸盐离子消耗时会变化。 | 引起硬度的钙和镁离子可以与EDTA结合,并且通过找到EDTA的量,可以找到水样的硬度。 |
概括– Alkalinity vs Hardness
Alkalinity and hardness are found in natural water in different degrees. Those are parameters used to determine the water quality. The main difference between alkalinity and hardness is that alkalinity measures the total amount of bases present in water whereas hardness measures the total amount (concentration) of divalent salts.
Download PDF Version of Alkalinity vs Hardness
You can download PDF version of this article and use it for offline purposes as per citation notes. Please download PDF version hereDifference between Alkalinity and Hardness.
参考:
1.“生产池塘的碱度和硬度。”池塘中的碱度和硬度。N.P.,N.D。网络。Available here. 05 June 2017.
2. “Water Treatment .” Lenntech . N.p., n.d. Web.Available here.2017年6月5日。
3. “What is Alkalinity?” Water quality information – What is alkalinity? | APEC Water. N.p., n.d. Web.Available here. 05 June 2017.
Image Courtesy:
1. “Mono-lake-tufa-1981-003” By Richard E. Ellis(CC BY 3.0)viaCommons Wikimedia
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