ENVM COMPREHENSIVE EXAM RISK MANAGEMENT 10/19/17 NAME: Sheetal M Patel STUDENT NUMBER: 540249 ENVM 665 Risk Management: Question 1 What are the two major general types of chemical sources that result in human exposure to those chemicals and provide a simplified “total” human exposure model showing the pathways that determine the total human dose from those chemicals. The total Human exposure model Source: http://exposurescience.org/a-total-human-exposure-model-them Chemical sources Lead…
What is acid rain? Acid rain is a form of deposition in which chemicals with an acidic pH level are taken out of the atmosphere through precipitation. When we pollute the air by burning fossil fuels, we create different chemicals that end up in our atmosphere. A few of these have chemical reactions with the water in clouds, and form (depending on the chemical) sulfurous and nitrous acids. When it rains, this acid is taken back to the ground. While pure water has a neutral pH level of 7,…
nature, it was possible to utilize it as an acid catalyst for the dehydration reaction.4 The use of Montmorillonite K10 is an excellent example of green chemistry as it not only shows the use of catalysts to increase efficiency but also displays a less hazardous form of chemical synthesis. The cyclohexene collected from the first experiment served as the starting material for the next reaction of the cycle in which, hydrogen peroxide (H2O2) and hydrobromic acid (HBr) were combined to generate…
Posttreatment of anaerobically treated DWW by aerobic activated sludge using SBR and membrane UF was investigated. The aim of this study was to reduce the organic loading (COD and BOD), nutrients (TKN, NO2, NO3 and TP) and total suspended solids (TSS) of anaerobically treated DWW effluent first by the activated sludge system using SBR and further treated by ceramic tubular membrane UF separately to investigate the possibility of the reusing the effluent for different purposes depending on the…
CHAPTER 4 RESULTS AND DISCUSSION 4.1 Extraction using Different Solvents The grounded Ixora coccinea and Beta vulgaris plant samples were extracted using the following solvents: Acetone, ethanol, methanol and ethyl acetate. The absorbance was noted to select the best choice of solvent for extraction. Inference Acetone, ethanol and methanol showed higher values. But, the dye extracted from acetone and ethanol did not fix to the fabric properly. So, methanol was selected as solvent for…
DM and GalA content were determined according to the method reported by Aina et al., [32] and Food Chemical Codex 1996 [33]. 0.1g of pectin was weighed into a 250 mL conical flask, then wetted with 5mL ethanol. 100mLof deionized water was added, then six drops of phenolphthalein (0.1% in ethanol) indicator to each sample. Pectin dispersions were stirred until it was fully dissolved, thereafter, the solution was titrated slowly with 0.1N NaOH until the colour of the indicator just changed to…
stability of the soap. Glycerin was added to increase the solubility of the solution and add moisture to one’s skin. Irgasan was added to the solution as an effective and safe antibacterial ingredient against microbial infections. A pinch of citric acid was added to the solution which lowered the initially measured pH of 10 down to 7.9 using the pH meter. It also provided better foam and water-softening in the liquid hand soap. The safe range of pH for soap is between 6 and 9 according to…
1-pyrenehexanoic acid was used as the 5-carbon linker and fluorescent component of the target molecule "PYRET-5". This molecule was purchased pure along with the sugar Trehalose, the molecule to which the pyrene was to be attached. Other reactants and solvents include HATU, HBTU, N, N-Diisopropylethylamine (DIPEA), sodium azide, Dimethylformamide (DMF), and Diphenyl phosphoryl chloride and were bought pure or used as received. All reactions were run at room temperature (298.15 K) and standard…
1.1 Overview: In a research lab, Mr. Z trying to formulate a colloidal dispersion system with sodium lauryl sulphate. What type of colloidal system is suitable for sodium laurly sulphate and also we have to discuss the different stability factors for sodium laurly sulphate dispersion. 1.2 Solution to the question: Introduction of colloids: Colloids are homogeneous non-crystalline substances. Here one substance is divide into more minute particles called colloidal particles and then it…
6. The first step in metabolism of ethanol in humans is the oxidation of ethanol to acetyldehyde by the enzyme alcohol dehydrogenase (ADH). At 298 K and pH=7.0, ethanol is incubated with ADH and the concentration of ethanol and acetyldehydee is measured over time. a. Using the results above, calculate the standard free energy change (ΔGº’) for this reaction. Explain your calculations. The standard free energy change can be expressed through the formula ΔGº’=-R(gas constant) T(temp in Kelvin)…