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Law in Place for Lead Regulation in Water

The Clean Water Act and Safe Drinking Water Act are in place for the regulation of lead in the water.

The Clean Water Act prohibits anyone from discharging pollutants, including lead, through a point source into a water of the United Sates unless they have a National Pollutant Discharge Elimination System permit.

In the Safe Drinking Water Act, lead in drinking water is regulated under the Lead and Copper Rule, that is if lead concentration exceed an action level of 15 ppl or copper concentrations exceed an action level of 1.3 ppm in more than 10 percent of customer taps sampled, the system must undertake a number of additional actions to control corrosion.

—Bruce

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What are the effects of mercury poisoning and how does it affect humans?

While mercury exposure in humans is not dangerous, a buildup of mercury causes mercury poisoning which has extremely negative impacts in human life and functioning. The major effects of mercury poisoning are shown in the nervous system which then causes neurological issues. These issues include memory problems, mood swings, and mental illness among many others. Mercury in human bodies greatly impacts the functioning of the brain, and can lead to physical deterioration. Humans can lose their ability to control their muscles, lose their inability to feel, struggle to breathe, and struggle to speak and even stand straight. The main reason for humans getting mercury poisoning is the consumption of fish due to fish ingesting mercury that has polluted bodies of water. For this reason, mercury pollution is an extremely important issue to address because it ends up in our systems and impacts our lives greatly.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3253456/

https://serc.carleton.edu/NAGTWorkshops/health/case_studies/mercury.html

- Anika

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A common way to remove arsenic is to irreversibly bind it to iron. What is done with this waste?

often, many scientists conclude that iron is a very good way to remove arsenic from groundwater or drinking water. the process involves treating the arsenic so that they adsorb onto iron oxides (Rust) and form larger chunk molcules/particles to be filtered. this works best or if only in lower pH.

One experiment used the Toxicity Characteristic Leaching Procedure (TCLP) to evaluate the stability of the spent adsorbent, iron. They found that the waste product was stable and met the EPAs conditions, allowing for the disposal of solid waste. However, many studies have found that TCLP has been guilty of severely undercutting the amount of arsenic actually still remaining in the water.

Many of the waste disposal methods are, “landfilling, stabilization, cow dung mixing, passive aeration, pond disposal, and soil disposal, (Rasken et. al)” and, while they have been effective, are prone to flaws. 

https://www.sciencedirect.com/science/article/pii/S2405653715300245

https://pubs.acs.org/doi/10.1021/es401749b

-aaron

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When Did the Flint River Crisis Actually Begin?

Many people believe the Flint River crisis began on April 25, 2014, when the city switched its water source from Detroit’s system, Lake Huron, to Flint’s own, Flint River. Upon looking back into the history of Flint, one begins to see a pattern of poor regulation of its river, specifically in the management of chlorine levels. 

Excessive bacteria found within a water source translates to extra chlorination to kill that bacteria. Throughout Flint’s usage, high levels of bacteria have required extreme chlorine treatment. The chlorine can produce carcinogens, corroded pipes, and unknown effects that scientists might not be able to study for decades. 

For most of its history, Flint did not seem to care about the pollution of its river. Lumber mill waste in the 1830s was followed by waste from paper mills and chemical processing, which could have increased the amount of bacteria as well as chlorine pollution. Road salt on the city’s bridges added to the amount of chlorine in and the corrosiveness of the water. In 1977, a crack in Lake Huron’s main water pipe caused Flint to switch to the Flint river, which required ten times the amount of chemicals to treat compared to Lake Huron. In 1990, a furniture salesman singlehandedly dumped entire drums of methylene chloride, toluene and xylene, lead and other chemicals onto his property on the banks of the river. His conviction mirrors the cases of dozens of others. 

The most frightening part is that the chlorine pollution continues (with much less abundance, however) today. Treating the city’s bridges with road salt continues to be a common practice. Here is a problem for the environmental engineers to solve: finding alternatives to road salt that do not pollute the surrounding environment. 

How the high chlorine levels affect the lead pipes in Flint’s water system: 

-Maeve

https://www.theverge.com/2016/2/26/11117022/flint-michigan-water-crisis-lead-pollution-history

https://cen.acs.org/articles/94/i7/Lead-Ended-Flints-Tap-Water.html

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Mercury in Fish

            Mercury, an element that is naturally present in the environment, is toxic to humans when ingested. One danger is through the consumption of fish. The root cause of mercury in fish is human industrial activities, such as waste incineration, burning of fossil fuels, mining, and even volcanic activity. This has driven mercury levels in the environment far past the natural amount. The toxic metal ends up in the water, forming methylmercury, which is absorbed by small aquatic organisms. Fish eat these organisms, and through the food chain the larger predators eventually accumulate high levels of mercury. There is no way to remove the mercury from the fish, as it binds to the protein in their muscles. As such, the consumption of bigger fish like walleye, albacore, and swordfish is limited by the Environmental Protection Agency. Overexposure to mercury can lead to health problems and complicate fetus development. 

- Jake

https://www.scientificamerican.com/article/how-does-mercury-get-into/

https://epi.dph.ncdhhs.gov/oee/mercury/in_fish.html

https://oehha.ca.gov/fish/mercury-fish-information-people-who-eat-fish

https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/MercuryFoodChain.svg/1200px-MercuryFoodChain.svg.png

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Lead and Arsenic Poisoning

Lead poisoning can be lethal depending on the amount of exposure. Lead can be found in old houses or buildings, specifically in the paint of those buildings. It can also be found in water that we drink and use everyday because of old pipes. Lead poisoning develops over months and even years. The first step is prevention, something that could help is making sure that you keep your house maintained. Keep it clean and freshly painted. As for treatments, there are two types of therapies, chelation therapy and EDTA chelation therapy. These therapies bind with the lead in your system so the lead can be excreted in urine. Both do the same thing but EDTA is for adults with a higher exposure. 

Arsenic poisoning is much more lethal. Arsenic can also be found in the water in our homes from groundwater. Arsenic can pile up over time or if the level of exposure is very high it can kill you in 24 hours. If the water in your area is declared unsafe do not drink the water and try to find a solution by getting a home water system to treat the water. If you have already been exposed one solution is a blood transfusion. Also keep a lookout for your kidney and heart function.

 If you have been exposed to Lead or arsenic at lethal levels please call a poison control center. 

Melanie

Articles:

https://www.medicalnewstoday.com/articles/241860.php

https://www.mayoclinic.org/diseases-conditions/lead-poisoning/diagnosis-treatment/drc-20354723

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Chemically, why did Flint, Michigan occur

Flint government decides to change the water source from the Detroit Water to the local Flint River. A few months later, the government informs the residents that there are high levels of trihalomethanes in the water. These molecules may pose severe threats to people’s health. Moreover, due to the massive usage of lead pipes in Flint, lead enters the water system. The government also fails to add phosphate, which can be used to protect the inside layer of the pipe, which makes it easier for lead ions to enter the water system. The high level of chloride ions in the water further exacerbate this problem; it leads to a faster corrosion rate of the pipe. Flint River also has a relatively low pH level, which damages the protective layer of the inside of the pipe. All these factors contribute to the increase in the concentration of lead in water.  

https://www.acs.org/content/acs/en/education/resources/highschool/chemmatters/past-issues/2016-2017/december-2016/flint-water-crisis.html

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How does increased corrosion of Iron impact the concentration of lead in water.

Brad.C

Metallic elements like zinc or iron with high reactivity are used in lead pipes to protect against corrosion. This method is called sacrificial protection. The more reactive metals act as cathodes where positive irons deposit on them and the cathode does not corrode.The less reactive anode will only corrode if the sacrificial layer is removed. If the Iron coating inside a lead pipe is removed, the anode(Lead) below will come into direct contact with water and creat free flowing Pb 2+ Ions. The production of lead ions will increase the lead concentration in water.

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How does a home water filter work?

How does a water filter in your house work (ie. Brita, etc.)? What can it filter and not filter? Most water filters have one major feature in common: activated carbon. Activated carbon, normally made of charcoal, is used for adsorption. Adsorption is great for trapping liquids and gases, so this technique is quite functional when capturing aqueous solutions (drinking water with impurities). However, heavy metals and substances that are solid and not in an aqueous solution can not be captured. Adsorption is possible due to a property of activated carbon that is reminiscent of something very near and dear to our hearts (nanoparticles) — high surface area to volume ratio. The porous surface creates more opportunities for chemicals and other impurities to be adsorbed. Charlotte https://www.google.com/search?q=brita+filter+diagram&safe=active&rlz=1CDGOYI_enUS843US843&hl=en-US&prmd=sivn&source=lnms&tbm=isch&sa=X&ved=2ahUKEwi5weiP4ZvjAhVxUd8KHfP_C5IQ_AUoAXoECA4QAQ&biw=375&bih=638#imgrc=yy2uxffzuGsrcM https://www.explainthatstuff.com/howwaterfilterswork.html https://www.pur.com/the-lab/water-filters-how-do-they-work

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Why is arsenic in water still a problem?

Despite methods like reverse osmosis and other forms of filtration to remove arsenic, methods like adding chlorine and boiling water doesn’t remove arsenic. Arsenic is often in water as a result of burning coal, as it is a byproduct that comes off of the coal. If disposed improperly, it can end up in water or the ecosystem. Because we still burn coal, and not every country has full safety measures to account for proper arsenic disposal, arsenic can still find its way into water. More so, arsenic can be naturally found in groundwater sources, so it will always be present. Therefore, scientists are consistently looking for better methods of removing arsenic and preventing it from harming others. -Ethan https://www.who.int/news-room/fact-sheets/detail/arsenic

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Low-Cost Way for Water Testing

The cheapest water testing methods are using test strips: pH paper strips, water hardness strips, and salinity test strips. pH paper strips indicate the pH level of the sample by the color of the tip of the strip. It changes color when the sample accepts or donates a proton. If the sample accepts a proton, the strip will turn to a color that indicates that it’s basic. If the sample donates a proton, it will indicate that it is acidic. Water hardness strips indicate the level of calcium and magnesium in water. The strip is impregnated with chemicals to react to indicate the level of hardness. Finally, the salinity test strip measures the chloride ions present in the solution.

On top of test strips, using a turbidity tube shows how clear or cloudy the water is. 

-Louis

Sources:  https://www.quora.com/What-are-some-cheap-solutions-for-testing-water-quality https://blogs.worldbank.org/water/how-test-water-quality-here-are-some-low-cost-low-tech-options

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Effects Of Lead On Children

Lead poisoning occurs when there is too much lead in the body through breathing, drinking, or eating. Lead is toxic to everyone, but babies and young children (from 6 months to 3 years) are at the greatest risk, leading to serious health problems quickly. Children absorb lead quicker than adults, leading to more serious results. Symptoms advance as lead levels rise. Children may complain of general symptoms such as headaches, abdominal pain, constipation, loss of appetite, which could then move on to clumsiness, agitation, and drowsiness, and then vomiting and convulsions. 

Lead can reorientate basic nervous system functions and alter development in children. Images have also shown a decrease in brain volume and changes in its microstructure, along with an impact in the reorganization of the brain. Lead can also critically impact kidneys, and make it difficult for the body to receive vitamins and minerals.

- Danya 

https://www.aap.org/en-us/advocacy-and-policy/aap-health-initiatives/lead-exposure/Pages/Lead-Exposure-in-Children.aspx

https://kidshealth.org/en/parents/lead-poisoning.html

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Cyclic Voltammetry

A

Cyclic Voltammetry is a technique used to study electron transfer reactions. Voltage is increased until electron transfer is favourable. The increase in voltage is seen on the x-axis and the rise in current, on the y-axis, shows the transfer of electrons, as current is the movement of electrons. There is a movement of electrons when the potential energy for an electron on the lowest free orbital in a species is lower than the potential the electron has. The potential of the electron is increased until it is higher than the potential of the electron on the lowest free orbital, the electron then moves inducing a current. 

The shape of the cyclic voltammetry graph is due to there being two scans. There is a scan that goes form low to high potentials and another from high to low potentials as illustrated bellow. The direction is switched at point D. 

https://pubs.acs.org/doi/full/10.1021/acs.jchemed.7b00361

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HPLC

high performance liquid chromatography analyzes chemical mixtures by separating a specific product from a reaction mixture. It also measures the relative amounts of different compounds in a mixture.

The mechanism by which it functions is that a sample will interact with a mobile phase or a liquid solvent (typically composed of polar and nonpolar molecules). the sample is then separated as it passes through the stationary phase: a solid (there is a difference in affinity for each constituent to both phases).

because the HPLC consists of a column, the sample and mobile phase are pushed through this column by a multi-piston pump, where it will interact differently with the columns’ packings (thus giving us our readings). at the end of the column is a detector. the tool used for detection varies depending on the sample and the mobile phase because its role is to both detect the sample’s parts while also ignoring the solvent. Typically, scientists use a range of tools from UV absorption detectors to nuclear magnetic resonance to detect particles.

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X-Ray Diffracrtion

X-Ray Diffraction analysis the molecular structure of crystalline materials. X-ray diffraction is the elastic scattering of x-ray photons by atoms in a periodic lattice. The measurements are made by the constructive interference made by the scattered monochromatic x-rays that are in phase. By measuring the angle of the X-ray reflection from the interplanar spacing of every single crystallographic phase can be determined.

It is typically performed on powder samples. However, for solid samples, with a surface of interest of up to a maximum size 25mm* 12mm and no more than 11mm thick will be able to determined by XDR.

-Bruce

Source: https://www.sciencedirect.com/topics/materials-science/x-ray-diffraction

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Chemical Vapor Deposition (CVD)

Chemical vapor deposition is not an instrument, but, rather, the most common method of coating a thin layer of one substance over a ceramic or metallic compound through a thermally driven chemical reaction. The outcome is, regardless of other factors, a solid, though it takes the form of a powder, film or crystal. This subsequent solid tends to be uniformly thick with low porosity. 

A gaseous substance is deposited (turned directly from gas to solid) upon another solid, or, in some cases, liquid precursor. The result is a chemical reaction that leads to a solid powder.

Despite the fact that deposition is mainly supplied by heat, other resources, such as electrons, ions and photons, have also been utilized in this way. In addition, the reactor for CVD can be either hot or cold walled, despite the fact that the substrate temperature is critical for what reaction occurs.

CVD is a blanket term for several processes, including chemical reactions and plasma-based reactions. 

(Source: Science Direct)

- Becca

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Liquid Cell TEM

Liquid Cell Tem is very similar to TEM which we recently learned about in class. In normal TEMs, no liquid can stay on the grid or can survive in the high-vacuum conditions in the machine. Scientists need a way to separate the liquid from the high vacuum while still allowing the electrons to go through the material. The cell also needs to be air tight so liquid does not leak as that would ruin the TEM. 

LCTEM uses two membranes made out of silicon nitride which the liquid can flow between. The machine can scan many things such as different nanoparticles through a 50 μm window. Different nanoparticle growth include Pt3Fe nanowires, ZnO, and more. Not only that but LCTEM is also used for nanoparticle assembly, manipulation of nanoparticles, tracking particle motion, nanoparticle shape evaluation, and synthesis evaluation. Liquid cell TEM has grown tremendously and is very useful for many different types of research in the present. 

By Melanie 

Articles:

https://www.annualreviews.org/doi/full/10.1146/annurev-physchem-040215-112501

https://www.azonano.com/article.aspx?ArticleID=5040