Hello Ive been doing an online lab since my semester 2 so I havent gotten the chance to explore AAS. I understand that i need to prepare calibration from stock solution and digest the wastewater sample before analysing it. However, I am still confused on how to compare the result of heavy metal contains in the sample after i treated it using jar test. I will use 500ml in each beaker for jar test.
So do i just take the same amount i took for the untreated ww sample in the 500ml treated wastewater, digest it and then analyse ?
I'd take the sample and split it in two while mixing to maintain homogeneity. One you treat (treated sample) and the other don't treat (Control sample).
The untreated is your control to compare against.
If you are trying to precipitate metals with a polymer or other chemistry you need to remove the precipitate from your treated sample before checking metal content. Other wise the "digestion" (often and acid treatment) will cause the precipitated metal to become soluble once again.
Keep in mind that if the process to remove the precipitate removes some other organic matter that may contain metals you are removing the metal in the precipitate from your treatment plus metals in the organic matter.
For example if you allow the treated sample to settle and only test the liquid above, then you also must do the same for your control sample to compare the effect of the treatment.
Hello,
You need to use the standard addition method, when you are planing to analysis it on AAS. You could use different ratio of waste water with standard solution like 0,25, 50 and 100. After analysis you can make a linear curve in the excel file and and with correlation, you can find the concentration of heavy metals in your waste water.
Meanwhile, you have also mentioned the jar test, so you can choose the samples from the control and rest of different concentration jars and perform the heavy metal content analysis in AAS. If you can then you could also analysis metal content before the jar test. Then you could compare, before treatment, control and different treated samples (in the jar test).
Good Luck!
Statistical analysis can be used to compare the concentration of heavy metals in wastewater before and after treatment. Develop your hypothesis and use it to draw inferences if there are significant difference when compared.
Use this manual
https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=300036HL.TXT
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