Analysis necessary to reduce the concentration of PCBs

In summary, the conversation discusses a problem with PCB contamination in wastewater and the standard concentration limit of 5ppm. The factory has a policy to stop production if the average concentration exceeds 3ppm, and analysis of 50 random samples showed an average of 3.20ppm with a scattering of 0.23ppm. The question is whether the results are conclusive proof to stop production and if the concentration needs to be reduced. The calculations suggest that the results do not provide conclusive proof at a 95% confidence level, but they do at a 99% confidence level.
  • #1
jingjang
3
0
Hello

i have a problem with my homework and i hope someone can help me? because i really don't know how to calculate this
so its translated with google translate :blushing:

Major customer PCB (polychlorinated biphenyls, a hazardous substance used in
manufacture of transformers and capacitors), bring in small quantities PCBja
wastewater environment. Permissible concentration in water PCBja standard 5ppm
(Parts per million). Factory Administration issued internal instructions that must be stopped
production if the average concentration in the effluent PCBja exceed 3 ppm. Analysis
effluent in 50 random samples taken showed an average of 3.20 ppm PCBs, with
0,23 scattering ppm (squared).
Calculate:
A: are the results of the analysis is conclusive proof that it is necessary to stop production
B: is based on the analysis necessary to reduce the concentration of PCBs in the effluent
C: if you were the head of the factory, what would be your action on the basis of the analysis carried out
 
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  • #2


Please show us what work you have done on this problem, so that we can better help you. In particular, what do you think would constitute as conclusive proof?
 
  • #3


n=50
x=3ppm
xi=3.2ppm
s2=0.23ppm2
s=0.48ppm
λ=(3.2ppm-3ppm)/0.48ppm=0.42

hmmm...
 
  • #4


or is it like this
t=(3.2ppm-3ppm)/0.48ppm * √n =2.97
H(S=95%,n-1) x=μ--> t=2.0092
2.97<2.0092 (not true)
H(S=99%, n-1) x≠μ t=2.6802
2.97>2.6802 (true)
 

Related to Analysis necessary to reduce the concentration of PCBs

What is the main goal of analyzing PCBs?

The main goal of analyzing PCBs is to determine the level of contamination and identify potential sources in order to develop an effective plan for reducing their concentration.

What methods are commonly used for PCB analysis?

The most commonly used methods for PCB analysis include gas chromatography, mass spectrometry, and high performance liquid chromatography. These techniques allow for accurate and precise measurement of PCB levels in various samples.

Why is it important to reduce the concentration of PCBs?

PCBs are persistent organic pollutants that can have harmful effects on human health and the environment. Therefore, reducing their concentration is crucial in preventing further contamination and protecting human and ecological well-being.

What factors can affect the effectiveness of PCB reduction?

The effectiveness of reducing PCB concentrations can be affected by various factors such as the type and amount of PCBs present, the location and distribution of contamination, and the methods used for remediation. Other environmental factors, such as temperature and soil conditions, can also impact the success of reduction efforts.

How can the results of PCB analysis be used to develop a reduction plan?

The results of PCB analysis can provide important information about the extent and severity of contamination, as well as the potential sources. This data can be used to design a targeted and efficient remediation plan that addresses the specific PCB contamination present.

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