Alexis Breeze , Ishimwe Masozera Determination of the Most Efficient Material (Charcoal or Bentonite Clay) for PAH Absorption Chemistry 112 Section 573 April 21, 2016 Abstract Both charcoal and bentonite clay are currently used to remove PAHs from water sources. This experiment was conducted to determine which material was the more effective sequestering agent of PAHs through the use of Procion Red Dye. A spectrometer was used to create a calibration curve to which the absorption of both the charcoal and clay could be compared. Ultimately, the charcoal proved to be the most effective PAH adsorbent. Introduction PAHs, or Polycyclic Aromatic Hydrocarbons, are a group of organic compounds, generally created by incomplete combustion or pyrolysis of organic matter1. PAHs are a growing environmental concern due to their toxicity to wildlife and …show more content…
To do this, a hot water bath was prepared and by placing 250 mL of deionized water into a 600 mL beaker and heating it to 70˚C using a hotplate. An Erlenmeyer flask with 70 mL of deionized water was placed into the hot water bath. When the temperature of the hot water bath was at a constant 70˚C, 0.000 g of FeCl3 and 0.000 g of FeSO4· 7 H2O were added to the Erlenmeyer flask. The flask was swirled around in order to dissolve any solid compounds before being removed from the hot water bath. 20 mL of 2.5 M NaOH was then added drop wise to the solution, so that a black precipitate formed. The solution was allowed to cool before being placed in a centrifuge for 5 minutes at 4000 rpm. The supernatant was then removed, and deionized water was poured over the precipitate to fill the centrifuge tube. Once again, the solution was centrifuged for 5 minutes at 4000 rpm, and the supernatant was removed. The remaining solid, which would ultimately harden to form clay, was removed from the centrifuge tube using a spatula and placed in a beaker to dry for 7
Carefully add 20mL of aqueous sodium hydroxide to the filtrate, with external cooling (ice-water bath) and continuous stirring. Re-filter the solution under vacuum and collect the resulting yellow precipitate using Buchner funnel. Dissolve the product under 50mL of boiling water, filter while hot and allow the mixture to cool. Collect the crystals obtained and dry them by
The solution was removed from the heat and allowed to cool at room temperature for 20 minutes, then the solution was placed in an ice bath and allowed to cool for an additional 20 minutes. During this cooling process the alum crystals began to form.
You test the procedure by dissolving 10.00 g of ore in an aqueous acidic solution and diluting the solution with water, so that the final volume is 1.0 L. To the solution of dissolved ore, 1.0 L of a 0.025 M NaCl solution is added, to precipitate silver chloride. The mixture is then filtered and the solid washed with 1.0 L of water.
PAH have toxicity potential, environmental persistence, ubiquity and tendency to bioaccumulation, reasons why they are viewed
From the solid mixture, the iron filling was separated by using the property of iron fillings that they were attached together. The solid mixture was then spread over the surface of a sheet of white paper, then the magnet was covered with another sheet of paper and moved closely over the solid mixture. Then iron filling was then attached to the magnet and was separated and gathered in the weighing dish. The same procedure was done three times, to separate any remaining iron fillings. When the procedure was performed three times, the collected iron fillings mass was them discovered by used the digital scale. After I removed the iron filling, the sand was removed by using the property of sand that the sand was totally insoluble in the waste. The iron free solid mixture was dissolved in the solution, and was mixed with the benzoic acid along with the salt and that allowed it to dissolve was enhanced by the heating of the solution. The solution was the sent to another beaker. The leftover sand was rinsed out with a few millimeters of hot water about three times to remove any leftover salt and benzoic acid. The sand itself was dry and the mass of the sand was measured by using the dish. The benzoic acid and salt solution was
To remove the supernatant liquid from the evaporating dish they decant as much of the liquid as possible into beaker 1 and the evaporating dish was placed on top of a beaker of boiling hot water until the SiO2 was completely dry. Chemical 2M K2CO3 was added to the supernatant liquid after it was decant into the beaker and boiled for 5 minutes. This chemical was added to CaCl2 because the residue it leaves behind is CaCO3. CaCl2(aq) + K2Co3(aq) = 2 KCl(aq)
The most common point-of-use filtration media is activated carbon. Activated carbon is able to absorb organic and inorganic contaminates and are more commonly used to reduce any flavor or odor in the water2, 27, 28. In addition to the high surface area, activated carbon can chemically interact with heavy metals in the water. Most carbon materials like activated carbon are known to have high adsorption capabilities towards metal ions24. The pores of the carbon allow for trapping of large particles as well as increasing the available surface for contaminates to interact. Table 1 shows the overall size distribution of the activated carbon grains, average pore diameter and elemental composition of the activated carbon used for experimentation. The carbon has a rough exterior with many cavities and pathways for particles and ions in the water to filter (Figure 1).
The solution was created by mixing potassium hydroxide pellets (Sigma-Aldrich, Saint Louis, MO), deionized water, and fumed silica (Cab-o-sil, Cabot Corp., Boston, MA) in a stainless steel Bain Marie using a magnetic stir plate and polytetrafluoroethane magnetic stir bar. After fully dissolving the potassium hydroxide pellets in the deionized water, the fumed silica was slowly added to ensure full dissolution. The solution was allowed to mix covered for 24 h, after which any water content that was lost due to the exothermic reaction of the water and potassium hydroxide or evaporation was replaced to maintain the proper chemical composition.
Then add about 50cm³ of distilled water ensuring you continue to stir until crystals have dissolved. Then transfer the solution into a 100cm³ volumetric flask
Polycyclic Aromatic Hydrocarbons (PAHs) are 16 different pollutants together. Eight of these are considered carcinogenic, while others can lead to mutations of wildlife that encounter them. Humans can come into contact by swimming in water where they are present because of pollution, but mostly it is from drinking water, which has PAH
The swelling agent used in this case is 1,2,3-Trimethyl benzene and the mineralizing agent is ammonium fluoride. The silica source used is tetra ortho silicate (TEOS) and these mixture is used in acidic conditions. In this method the surfactant P-123 was diluted by a strong acid i.e. 1.6M HCL and was stirred in a stirrer for 1 hour at 40oC followed by the addition of swelling agent and the mineralizing and this mixture was further stirred for 20 hours under the same condition. Then the silica source i.e. TEOS was added and this mixture was stirred for another 24 hours under the same operating condition and the solid that was obtained at the end of the process was then filtered, then washed with de-ionized water followed by calcination at 500oC for another 8 hours to remove the organic component. Hence, MCF silica was
The remaining NaCl and SiO2 will be combined with H2O, where NaCl will be extracted. The residue will be SiO2, where it will be heated.
Filter off the precipitate when solution reached room temperature. Wash precipitate with 10 – 15mL hot distilled water. Transfer filtrate to large evaporation dish.
According to the Canadian Council of Ministers of the Environment (CCME) [28], the contamination of soil by PAHs is widespread in Canada due to the near ubiquitous nature of its major sources: namely, the release of various petroleum hydrocarbon or coal-derived products and the production of PAHs through a variety of combustion processes or types such as vehicle exhaust or a wide variety of industrial processes. Crude oil and refined product spills commonly found at oil and gas well sites are the major overall source of thermodynamically-favoured (petrogenic) PAHs to soils and sediments, especially in urbanized and industrialized areas of Canada [15]. Naphthalene, fluorene, chrysene, phenanthrene, and pyrene are particularly common PAHs in
In a study carried out by Y. Lev et al, it is seen that the concentration of total PAH is around 0.25 ng to 1 ng per µg of total particulate matter depending on the number of rings, which is a very small quantity of the total hydrocarbon emission from automotive.