Michele+Alshouli+-Log

Michele Alshouli - Log

==Final Research Project: Developing a monitoring program for the detection of Carbamazepine, Triclocarban, and Triclosan as wastewater tracers to assess the contribution of wastewater effluent to source water in the Philadelphia waterway.==
 * [That works - just expand or contract your focus as you need to meet the 3000 words JCB]**

**15. How to evaluate credibility of information when using internet sources.**
The World Wide Web is an excellent source for fast and updated information. However, it may be challenging to determine the authenticity of the information. At times, one may have to question the integrity and source of the information. “As numerous writers have pointed out, what chiefly distinguishes the web from traditional sources is that it lacks the filters, which promote reliability in numerous print sources” (1). Since the internet allows individuals to input information, and some sites like Wikipedia allow people to define and add information, people may begin to question if the information is valid. When an individual would like to do this, there are areas to observe when evaluating credibility, such as "peer review, credentials of the author, and writing style"(2). We will see later on if all this information is enough.

For peer review, it is important to denote the company that published the book, if the company is reputable, or if the source is from a well known journal or society. Anonymous internet writers can not be used as valid sources since it is unclear who they are or what company they work for. To test the credential of the author, while it may be unfair and unjust, some individuals may validate credibility if the author has achieved a high degree in that field. However, even though such a high degree is demonstrated, some individuals may tend to talk from a subjective point of view, which may have some bias, but this may not always be the case. Other authors may not have such high degrees but the sources for their information may be valid. But for the most part, if the author has expertise or a high degree and the quality of his writing is in a professional and in high academic standing, it may have more credibility than authors with low academic standing, but both would need further investigation. Another aspect to focus on is the way the information is presented, if it’s from a prestigious individual or company and presented in a clear objective and academic standpoint, it may as well seem credible, but also needs further invesigation. Lets do an example and see if the above mentioned criteria is suitable; lets look at flash point for carbamazepine (CBZ). Three data entries are obtained, one from a peer review journal (Asian Journal of Pharmaceuticals) and another from a chemical database (Wolfram Alpha) and one from an MSDS (Dorman Laboratories). The peer review journal shows the flash point of CBZ is 169 C, while the chemical database shows 202 C and the MSDS shows <204.4 C. The journal and chemical databases both fulfill the mentioned criteria above, and the MSDS probably takes the information from Sigma-Aldrich, but all have different values. How do we determine the correct value? Lets try another example from Reaxys, which is a chemical database. The melting point of CBZ is obtained from 3 sources, Nist, Sigma-aldrich, and Bioorganic and Medicinal Chemistry Letters, giving values of 189.5-191 C,191-192 C, and 191 C, respectively. All sources fill the criteria above and have a value of 191 C in common, so is it safe to assume the actual value is 191 C? Doing more examples and after checking the values are correctly depicted, it shows that seldom, one source may copy a value wrongly, and other sources copy from that wrong value, which would be appear to be accurate due to the value having precision, however it lacks accuracy. So, if a value is redundant, that does not necessarily mean that the value is correct. It can mean that the 'wrong value' was copied without validating with other sources and without validating where their sources are from.

In this class, we have learned a new approach to validate data. We have learned that even though a journal may have had peer review, the author has credentials, and the writing style is in a professional and academic standing, there is a further step that needs to be done to validate the data. This new strategy will give you a better chance to get an accurate result. If searching for a physical property from a database, such as Reaxys, the database will show values from different sources. If one were to choose a value from the list, the data source should be opened to verify that the value indicated is the one mentioned in the source, since typos or wrong values could be copied. A few things to look at however, is to make sure the units are all the same when comparing values from different sources. It has been shown that a lot of incorrect values occur due to neglected the denoted units. Other important things to look at are patterns in the molecule. If someone is looking at the melting point or boiling point for ethane, it would be essential to look at what is mentioned for methane, and propane, since the melting point should be in a decreasing pattern from methane to propane and increasing pattern of boiling point from methane to propane. So, if the trend is not there, most likely the source values are incorrect or has a typo in one of the values.

After obtaining several sources and after confirming the value's units, one should denote if the value was obtained at STP or at other conditions. It is also important to see if the value is the experimental or predicted. In addition, do further verification by looking at other available trends for the compound of interest against other compounds in the same family for valid correlations, as shown in the example above. "After this class, you should feel that you can never blindly trust chemical data sources again"(3). This statement is true, but through this class, we have learned approaches to have more confidence in obtaining accurate results.

So is it better to stick to textbooks? Textbooks may also have the same issues as using the web. There are differnt pros and cons of using the text versus the web, but both are susceptible to the same errors. One advantage of a text, however, is that its information cannot be lost since it is provided in a hard copy format, but if there are any adjustments in data or information, revisions have to be made to new versions of the text. When using internet, the site may have the URL changed or mistyped due to rearrangements of the site by the domain, so it will be difficult to find, but if there are updates or adjustments, the revisions are much faster and just as easily accessible. However, it is important to denote that texbooks are not favorable, since many of their assertions are not referenced. Therefore, the sources of data can not be verified and textbooks should be avoided.

1) [] 2) Tony Doyle, John L. Hammond, (2006) "Net cred: evaluating the internet as a research source", Reference Services Review, Vol. 34 Iss: 1, pp.56 – 70 [|Link] DOI 10.1108/00907320610648761 3) Dr. Bradley []
 * References**

(Completed Michele Alshouli)

__**Assignment 2:**__ Article: Evaluation of micropollutant tracers. II. Carbamazepine tracer for wastewater contamination from a nearby water recharge system and from non-specific sources. G. Gasser, M. Rona, A. Voloshenko, R. Shelkov, O. Lev, S. Elhanany, F.T. Lange, M. Scheurer, I. Pankratov doi:10.1016/j.desal.2011.01.058
 * [Full Marks JCB]**

Abstract This is an approach presented for detection of wastewater that contaminates water wells. Carbamazepine (CBZ) is a stable antiepileptic drug that is suitable for use as a quantitative tracer to help estimate how much wastewater has been influenced into water wells.

Intro: Due to the realization that waterborne diseases lead to production of microorganism, ideas soon emerged to use this microorganisms as indicators to trace the source of wastewater intrusion.Tracers now are being used more frequently as a precaution for invasive treated effluents unintentionally contaminating source water.

One method to quantify wastewater intrusion using a tracer study is to observe qualitatively levels of chloride and CBZ relative to wastewater-pristine water mixing predictions. This method also allows for analysis to quantify how much wastewater invaded the water wells.

Amoungst the increasing amount of available tracers, Chloride seems to be the most used wastewater tracer. For sewage contamination, waste specific contaminants are more rather used as markers. Other molecules of interest are compounds that are consumable by humans as well as exhibiting properties of being biorefractory. This article will evaluate wastewater-pristine mixing as well as to evaluate the uncertainty of the method.

In locations such as Israel, chloride and other molecules, particularly inorganic molecules, cannont be used as wastewater tracers, due to low background levels as well as not having exclusive origin. In pristine Israel, wastewater has much higher chloride concentrations in wastewater than it pristine water, but the levels are so variable that it would not be suitable for this kind of study. Since CBZ is exclusively of domestic origin, such as human waste, it is a more favorable tracer. Even though it is possible for CBZ to be contaminated into compost and agricultural soils, studies show the leaching of CBZ from soils is very small. CBZ is present is such a high abundance, that dilution by rain still allows for its detection. Other factors for the favoring of CBZ is that the concentration is not so variable, is non-volatile, and is very stable.

Materials and Methods The detection of CBZ was through GC/MS, as per EPA method 8270.D, as well as LC/MS/MS, as per EPA method 1694. 1000ml samples were taken through SPE using and Oasis HLB cartridge then elution with 4mL Methanol, followed by concentration to a final volume of 1mL. 1uL of sample was taken through GC/MS using full scan or SIM.

The study location revolved around the wells near the wastewater treatment plant, which consists of permeable sand aquifer on a marine clay aquitard.

Water wells that were in the area of the petroleum basin, such as Rishon 5, was ceased due to salination processes. Another water well, Yavetz, is another study location, followed by Soreq 1, which had high CBZ levels.

Wastewater treatment plants around Israel have been looked into. One of the largest treatment plant, Shafdan, uses conventional treatment followed by nitrification and denitrification processes, while the sludge is discarded to the Mediterranean Sea. The west Jerusalem WWTP is the second largest plant but not using nitrification-denitrification processes, while the sludge is treated by anaerobic digestion, rather than discharged to sea. The third treatment plant is Ayalon, similar to west Jerusalem WWTP except it does not involve a final flow into the river.

CBZ was sampled at Shafdan plant, the Jerusalem wastewater system, and the Ramat Hasharon plant, all giving positive values of CBZ, as depicted in the following table in the paper.

Results

A model is used to calculate the steady state dilution. This consists of wastewater effluent combining with and [X]ef of the tracer to a stream from a pristine aquifer, have a concentration of [X]b, giving a final concentration of [X]i. Mixing Ratio= [X]i-[X]b / [X]ef -[X]b

When Mixing ratio = 1, this shows there is pure wastewater effluents, while Mixing ratio=0 shows pure pristine water.

For uncertainty measures, relative error applies to all three variables. Each variable is is multiplied by an amplification factor growing hyperbolically.

[X]i and delta[X]i are determined by averaging the tracer level and calculating the variance.

[X]b and delta[X]b is difficult to calculate the background and uncertainty since chloride is so variablee. However, CBZ's concentration in pristine water is zero with an uncertainty depending on the analytical uncertanty.

For [X]ef and delta[X]ef, the average wastewater CBZ determination is a little challenging since the sources are not known. CBZ varies due to populations and areas, so by doing a survey of the level is a more approachable way to determine the CBZ source level in Israel.

The survey done involves eleven wastewater treatment plants, and the sludge retemntion time, nitrate and ammonia levels were denoted.

The performances of the treatment plant were evaluated; the plants that involve nitrification-denitrification might effect CBZ levels, since CBZ is an amide its removal efficience maybe altered.

Since the population of Israel is a mix of Jewish to Arab and Rich to poor, respectively, these factors were considered when evaluating socioeconomic background. To deter over-influence of the WWTPs, tertiary effluent of CBZ was used to evaluate the average CBZ level and calculation of variance.

CBZ levels remain constant through the wastewater treatment plants, with the exception of the airport wastewater treatment plant, possibly due to 50% waste contribution leading to industrial waste. There is also variability in treatment methods. It is shown that the CBZ level at the source can be estimated without knowing where the oriin is.

Calculations show that all three wells are contaminated by WW effluents. For two wells, the contamination source was the nearby recharge system. For the third well, the source is yet unknown.

The uncertainty levels for the mixing ratios were calculated and conclude that the unspecified domestic source is highly possible to be influenced from the Shafdan SAT. Very low mixing ratios exist, due to the very low background level of the tracer.

To determine the standard deviation of the mixing ratio, we can assume [X]i<<[X]ef and know that [X]b=0, this gives the following equation: delta E= [ (delta[X]i/[X]i) ^2 + ( delta[X]b/[X]i )^2 + (delta[X]ef/[X]ef )^2 ]^1/2

Since delta[X]i>> delta[X]b, then : delta E= [ (delta[X]i/[X]i) ^2 + (delta[X]ef/[X]ef )^2 ]^1/2

For nonspecific tracers (chloride) [X]b becomes large and the uncertainty levels grow hyperbolically.

Conclusion For two of the three contaminated wells, Yavetz and Rishon 5, the contamination originates to the nearby wastwater recharge facility. For the Silicate, the source of contamination is from another source which gives a minimal amount of contamination and is most probably from the SAT effluents.

It has been shown that CBZ is conservative in its level under SAT by Gasser et al [7] and supported by Arye et al [32]. The mixing ratio is calculated with high certainty based on nil degradation assumptions.

This method and its implications show how useful CBZ is as a tracer, due to its biorefractoryness and abundance. The constant level can be due to the sociological and cultural uniformity. Although CBZ levels are not constant throughout the country, its average level in the watershed can be determined. The mixing ratio uncertainty level is a useful tool to use to quantify uncertainty level of CBZ variance as well as the calculation of the mixing ratio.

Final:

You must write a 3000 word paper on a research topic of your choosing but approved by the instructor. Use the bibliographic search techniques you learned in this course to prepare the cited reference list in your paper. You should include at least 20 references in your bibliography. Hyperlinks to references available electronically through the Hagerty library must be included using the digital object identifier (DOI). For articles that are not available directly electronically (such as those received via interlibrary loan) a password protected server will be provided to allow direct linking to the pdf.