# Chemical Measures of Environmental Indicators

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### Petrol vs. Ethanol to mitigate Greenhouse Gas Emission from Cars

Hello, I was wondering whether you would be able to complete my chemistry assignment that I have received. I have attached the task sheet, scaffolding for refuting the statement and scaffolding for supporting the statement (depending on which one you choose). The due date for this assignment is this Friday so I would prefer to

### Phytoremediation of lead in soil

Indian mustard (brassica juncea) can be used for phytoremediation of lead in soil because it has the ability to hyper accumulate lead by a factor of 17. The average crop yield is about 4.0 kg per square metre. a) Calculate the expected plant concentration of lead if the soil contains 280 ppm. b) What mass of lead would p

### BOD Concentration and Population Equivalent

A sample of wastewater contains 0.20 lbs of BOD per 120 gallons. Question #1: Calculate the BOD concentration in mg/l. Question #2: What is the equivalent population for a small town if the flow is 1.0 MGD with an average BOD of 450 mg/l?

### Aeration Time and BOD Loading

A conventional activated sludge secondary plant processes 7.7 MGD of wastewater with an influent BOD into the biological units of 170 mg/l. The total volume of the basins is 300,000 ft3 and the MLSS concentration is 2,700 mg/L. Question #1: The aeration period in hours. Question #2: BOD loading in lb/1000 ft3/Day

### A Trickling Filter Question

A trickling filter has the following: - Average Wastewater Flow: 500 gpm - Recirculation Ratio: 0.4 - Influent into the Primary Clarifier: 500 mg/l - The primary clarifier BOD removal efficiency: 80% - Filter Diameter: 54 feet - Depth of media: 6 feet Question #1: Calculate the BOD loading Qu

### BOD Load to the AST Tank & volume

A town in Virginia has a population of 50,000 people. The average flow for each person is 100 gpd. If the design were to use a detention time of 6 hours, and a recirculation rate of 0.5, WAS concentration of 9,000 mg/l, an F/M Ratio of 0.4, and a reactor loading rate of 30 lbs of BOD / 1000 cu.ft. Assume the BOD concentration

### Wastewater Treatment - Numerical Problem

Can you answer some more Q about the same problem and let me know the number of Credits you ask for please? And OK, next time I will post it in Engineering.. for the same problem: d-The theoretical chamber lenth,ft e-The design chamber lengh, ft, if the design length is 1.35 time the theoretical length and for ease of cons

### Environmental Science #5

Currently, I have an F average in this class and need assistance. Please assist me. If I receive a 100 this will bring my grade to at-least a C. My GPA 3.4 and it is important to me to maintain it. Please help

### Environmental Science #2

I need assistance with a project concerning demographic transition, which is little confusing to me. I am really concerned with this class as I have a failing grade. Any and all of your assistance will be greatly appreciated. I really need your help with this assignment Not all countries have moved through all four phase

### Effects of coal combustion

Coal combustion can affect freshwater or marine (saltwater) organisms in different ways. Describe the steps involved in one such way, from combustion to the effect(s) on one species or group of organisms. Which environmental sphere(s) is involved in each step, and how?

### environmental chemistry: water sample has a pH of 8.21 and a total calcium concentration of 143 ppm.

1. A water sample has a pH of 8.21 and a total calcium concentration of 143 ppm. (a) What are the molar concentrations of CO3 2- and HCO3- ? (b) What is the total alkalinity of the water?

### Calculation of Chlorine Ions Necessary for Charge Balance

See the attached file. Data: A chemical analysis of a surface water yields the following data: Ion Concentration mg/L Ca^(2+) 90 Mg^(2+) 30 Na^+ 72 K^+ 6 Cl^- 120 SO4^(2-) 225 HCO3^- 165 pH 7.5 Problem: The Cl^- concentration in the water analysis given has been questioned. What concentration

### Dissolved oxygen problem/ environmental engineering

Info: BOD: Biochemical Oxygen Demand BOD5 is the total amount of oxygen consumed by microorganisms during the first five days of biodegradation BOD5 = (DOi - Dof)/(P) this is the five-day BOD of a diluted sample Where DOi = the initial dissolved oxygen (DO) of the diluted wastewater DOf = the final DO of

### Calcium Carbonate Dissolved per Litre

The average pH of precipitation in rural areas is 5.80. Assuming that the pH is controlled by the carbonate system, i.e., no anthropogenic acid gases are present in the atmosphere, calculate the amount of calcium carbonate (mg) dissolved per liter of rainwater. pKa1=6.33, KCO2=3.388e-02 Hint: pCO2=3.162e-04

### General Chemistry / Environmental chem question

44) How many metric tonnes of 5%-S coal would be required to yield the H2SO4 needed to produce a 2.0-cm rainfall of pH 2.00 over an area of 100 square kilometers? HINT: Hint: Calculate vol rain, mol H+, mass of S, mass of coal

### Differences in Water Samples from the Same River

What reasons could there be for different water sample results at four sites along a river? (See files attached with data).

### Amount of Calcium Carbonate Dissolved

The average pH of precipitation in rural areas is 6.80. Assuming that the pH Is controlled by the carbonate system, i.e., no anthropogenic acid gases are present in the atmosphere; calculate the amount of calcium carbonate (mg) dissolved per liter of rainwater. pKa1=6.33, KCO2=3.388e-02 I've seen a couple different solutions

### Iron concentration given pH and pE values

At pH 6.00 and pE 2.90, what is the concentration of Fe2+ (mol/L) in equilibrium with Fe(OH)3?

### Calculating Ferric and Ferrous Concentrations

Calculating Ferric and Ferrous Concentrations - Please see the attachment.

### Pecent Contribution to Alkalinity from a Solution

For a solution having .0025 equivalents/liter total alkalinity (contributions from HCO3-, CO3-- and OH- (hydroxide)) at [H+] = 4.69E-11, what is the percentage contribution to alkalinity from CO3--? Hint: Calculate the bicarbonate concentration and the contribution of the bicarbonate to the total alkalinity.

### The consumption of dissolved oxygen in water by sugar.

A large pond is 300m by 95m with an average depth of 2.5m. Assuming that the pond is saturated with oxygen, calculate the amount of sugar (C12H22O11) in kg that would be sufficient to completely consume the dissolved oxygen.

### Not for OTA 102922 - Equil. ratios; pH; pE values, etc.

Deduce the equilibrium ratio of NH4+ to NO3- at a pH of 4.0 for aerobic water having a pE value of +9.0 and for anaerobic water for which the pE value is -7.0. (Provide the aerobic answer the anaerobic answer.) This is not for OTA 102922 as he has already tried this question once.

### PCB Concentration in Lake Michigan

The PCB concentration in Lake Michigan is declining according to a first-order rate law having a rate constant of 0.079 per year. If the PCB concentration in Lake Michigan averaged 0.47 ppt in 1991, what will it be in 2005? In what year will the concentration fall to 0.10 ppt? What is the half-life period of PCBs in this lake? (

### Deduce the Equilibrium Ratio of NH4+ to NO3-

Deduce the equilibrium ratio of NH4+ to NO3- at a pH of 4.0 for aerobic water having a pE value of +9.0 and for anaerobic water for which the pE value is -7.0. (Provide the aerobic answer in the first field and the anaerobic in the second).

### Titrations - rain water with NaOH

60. A 155 mL sample of rainwater is titrated using 0.0095 M NaOH solution. If 4.8 mL of the NaOH solution was required to reach the endpoint, what was the pH of the rainwater? The computer gave the following hint: Calculate the number of moles of NaOH to reach the endpoint. From this calculate the hydrogen ion concentration and

### pH of Rainwater and Diprotonic Acids

The pH of a sample of rain is found to be 3.3. Calculate the percentage of HSO4- that is ionized in this sample, given that the acid dissociation constant for the second stage of ionization of H2SO4 is 1.2E-2.

### Calculate Fraction of Cyanide Existing as the Anion

For HCN in water, Ka = 2.0E-10. Calculate the fraction of cyanide that exists as the anion rather than in the molecular form at pH values of 4, 7, and 10.

### Working with Concentration Conversion

44. The concentrations of lead in blood samples are often reported in units of micromoles of lead per liter of blood. Calculate the value of the concentration in these units of a blood sample containing 45 ppb lead, assuming that the density of blood is one gram per milliliter.

### Calculate the geologic sink and source of As (arsenic) at the lake bottom.

A situation with an industrial input of arsenic directly into the lake at 10kg/Day. The lake volume is 1.2 x 10^8 m^3, and the average depth is 10m. The river velocities are measured as 100 L/min at both the inflow and outflow points. Water samples taken from the rivers show incoming arsenic is 0.02mg/L and the outgoing arseni

### Calcium Carbonite in a Lake

If a piece of Calcite (Calcium Carbonate) is put into the lake, would it tend to dissolve? Calcium carbonate solubility is 10^-8.35 M2, and the measured concentration of calcium ion is 0.1mM (millimolar) Information received: Lake pH=4, and total carbonate concentration of 0.001M. Carbonate Equilibria: CO2 + H20 <-> H2