- #1
sveioen
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[SOLVED] Removing Pb from water
Could anyone get me going with this?
Could anyone get me going with this?
Removing Pb2+ from Water: EPA Standards & NaCl Solution
- Thread starter sveioen
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Discussion Overview
The discussion revolves around the removal of Pb2+ ions from water, specifically in relation to EPA standards for drinking water. Participants explore the use of NaCl to precipitate lead as PbCl2 and the implications of this method, including potential environmental impacts and safety concerns.
Discussion Character
- Technical explanation
- Homework-related
- Debate/contested
Main Points Raised
- One participant states that the EPA recommends a maximum concentration of Pb2+ at 1.00 x 10-7 M in drinking water and questions the concentration of NaCl needed to achieve this.
- Another participant explains the relationship defined by the solubility product constant (Ksp) for PbCl2 and suggests that a significant amount of salt would be required, raising concerns about the ecological impact of high salinity in water sources.
- A participant emphasizes the need to avoid using hot water, as PbCl2 is more soluble at higher temperatures, which could pose health risks.
- There is a mention of other anions that could be problematic for drinking water, such as NO3-, when precipitating Pb with Cl-.
- Some participants express skepticism about the nature of the inquiry, suggesting it resembles a basic chemistry homework question rather than a practical issue faced by individuals with contaminated water.
Areas of Agreement / Disagreement
Participants do not reach a consensus on the appropriateness of using NaCl for removing Pb2+ from water, with multiple concerns raised about the environmental and health implications of this approach.
Contextual Notes
Participants highlight the need for careful consideration of the ecological consequences of creating saline environments and the potential health risks associated with the solubility of PbCl2 in hot water.
- #2
gravenewworld
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sveioen said:
Ksp=[Pb2+][Cl-]^2 by definition.
You are given the KSP and Pb2+ values, simply find the concentration of Cl-. You will notice that you will need a LOT of salt to do this, and creating highly saline environments in water sources kills a lot of plants and wildlife.
- #3
sveioen
- 14
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gravenewworld said:
Wow, so it is that easy. Thank you very much gravenewworld!
- #4
lightarrow
- 1,966
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Ok, however don't do it with hot water, or you'll kill people (PbCl2 is quite soluble in hot water).sveioen said:Wow, so it is that easy. Thank you very much gravenewworld!
Furthermore, precipitating Pb with Cl- obviously take in solution the anion and this one can be not appropriate itself for a drinking water: NO3- for example.
Last edited:
- #5
jim mcnamara
Mentor
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This sounds more like Chemistry 101 homework than somebody with bad well water. But, you never know.
- #6
lightarrow
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- 64
Agreejim mcnamara said:
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