Fill in Order Details

  • Submit paper details for free using our simple order form

Make Payment Securely

  • Add funds to your account. There are no upfront payments. The writer will only be paid once you have approved your paper

Writing Process

  • The best qualified expert writer is assigned to work on your order
  • Your paper is written to standard and delivered as per your instructions

Download your paper

  • Download the completed paper from your online account or your email
  • You can request a plagiarism and quality report along with your paper

Q1. Given that daily cancer death rate (CDR) is calculated using (Equation 1):CDR= (Carcinogenicity potency of radon)×(Radonconcentration)×(Exposuretime)……….. (1) If radon concentration in a

Q1. Given that daily cancer death rate (CDR) is calculated using (Equation 1):

CDR= (Carcinogenicity potency of radon)×(Radonconcentration)×(Exposuretime)……….. (1)

If radon concentration in a village varies between 0.28 pCi/L and 2.72 pCi/L values, calculate range of CDR values for residents exposed to it for 20 hours/day? (Radon cancer potency = 10-8 Cancer deaths per hour of exposure at1 pCi/L).(10points)

Answer: 

CDR= (Carcinogenicity potency of radon)×(Radonconcentration)×(Exposuretime)

Q2. What do you understand by threshold response and non-threshold response? Explain this concept taking chemicals as example contaminants and by plotting on the “risk” vs “dose” plane?          (10 points for write up + 5 points forplot)

Q3. Suppose a 50-kg individual drinks 2 L day of chloroform and 0.1 mg L1 phenol.What is the hazard index? Is there cause for concern? (10 points) 

Q4. Estimate the cancer risk for 70-kg individual consuming 1.5 liters of water containing trichloroethylene (TCE) per day for 70 days. (10 points) 

Q5. Using the U.S. Environmental Protection Agency IRIS database (www.epa.gov/iris), find the critical effect, uncertainty factor, and NOAEL, LOAEL, and RfD for mercury, chromium, and chloroform. In drinking water, which one would be the most toxic? (10 points)

Q6. A small stream with a flow rate of 0.1m3/sec empties into a river that has a flow rate of 2m3/sec. The stream is affected by mining operations and is contaminated with arsenic at a concentration of 50mg/L. The river is not affected by mining and has arsenic concentration of 0.03mg/L upstream from the small stream. What is the arsenic concentration in the river downstream from the stream? Provide the conceptual model to support your solution.

(15 points for calculation + 5 points for conceptual model)

Q7. Consider the electroplating facility that discharges to a river liquid wastes containing chromium. The effluent flow rate is 0.05m3/sec and the river flow rate is 5m3/s. if the concentration of chromium in the river is not allowed to exceed 100microgram/L, what is the maximum allowable concentration of chromium in the effluent?

(10 points for calculation + 5 points for conceptual model)

Q9. Consider a contaminant having a concentration C0= 10mg at t=0 which undergoes firstorder decay with k=0.4min-1. Generate a table of C as a function of time upto a maximum time of 10 minutes in step of 2 min. Plot this C v/s TIME on a sheet of paper (preferably graph paper) with proper labels and titles. Sample graph sheet is provided below, you can paste your excel plot directlytoo.(15 points for calculation + 5 points forplot)

TIME (Min.)

Concentration (mg)

0

10

2

4

6

8

10

Q10. If 3.0 g of substance AA decomposes for 36 minutes the mass of unreacted A remaining is found to be 0.375 g. What is the half life of this reaction if it follows first-order kinetics? (5 points)

Q11. A tank aboard a barge traveling along the Chicago Ship Canal suddenly collapses, releasing its benzene content (C6H6, density = 0.879 g/cm3), of which 100 liters find their way quickly to the water. The rest of the benzene remains contained on the barge. Assuming rapid mixing across the canal section (8.07 m deep and 48.8 m wide) and estimating the turbulent diffusion coefficient at 3.0 m2/s. The canal has the Peclet number << 1, which means that the flow rate of canal water is negligible and Diffusion is the only force acting in spreading thecontaminant.

Answer following –

i)           what are the concentrations of benzene 2, 6, 12 and 24 hours after the accident, at the site of the spill and 300 m away? Fill your answers for 5 blanks in thetablebelow.                                                                  (15pts)

Time

Conc. at spill (mg/L)

Conc at 300m(mg/L)

2 hours

0.428 mg/L

?

6 hours

?

?

12 hours

0.175 mg/L

?

24 hours

?

0.113mg/L

ii)        calculate the exact time at which the concentration reaches its maximum (answer in hr:min)      (5pts)

iii)      what that maximum concentration is? (answerinmg/L)                                          (5pts)

iv)      Comment on the concentration profile at 300m. Is it dropping continuously or increasing or both,andwhy?     (5pts)

Important conversions: gms/cm3 = kg/L; 1Kg = 1000 mg

HINT: – Mass = density * Volume; so mass of spill is = 0.879 g/cm3* 100L = 0.879kg/L*100L

= 87.9KG

Equations to be used when advection is negligible –

C(x,t) =

WHAT OUR CURRENT CUSTOMERS SAY

  • Google Rating
  • Sitejabber
  • Trustpilot
Cindy L
Cindy L
You can't fault the paper quality and speed of delivery. I have been using these guys for the past 3 years and I not even once have they ever failed me. They deliver properly researched papers way ahead of time. Each time I think I have had the best their professional writers surprise me with even better quality work. Elite Academic Research is a true Gem among essay writing companies.
Samuel Y
Samuel Y
I really appreciate the work all your amazing writers do to ensure that my papers are always delivered on time and always of the highest quality. I was at a crossroads last semester and I almost dropped out of school because of the many issues that were bombarding but I am glad a friend referred me to you guys. You came up big for me and continue to do so. I just wish I knew about your services earlier.
Mindi D
Mindi D
Brilliant writers and awesome support team. You can tell by the depth of research and the quality of work delivered that the writers care deeply about delivering that perfect grade.
Stuart L
Stuart L
Thanks for keeping me sane for getting everything out of the way, I’ve been stuck working more than full time and balancing the rest but I’m glad you’ve been ensuring my school work is taken care of. I'll recommend Elite Academic Research to anyone who seeks quality academic help, thank you so much!
Zahraa S
Zahraa S
Absolutely spot on. I have had the best experience with Elite Academic Research and all my work have scored highly. Thank you for your professionalism and using expert writers with vast and outstanding knowledge in their fields. I highly recommend any day and time.

ORDER NOW

Consider Your Assignments Done

“All my friends and I are getting help from eliteacademicresearch. It’s every college student’s best kept secret!”

Jermaine Byrant
BSN

“I was apprehensive at first. But I must say it was a great experience and well worth the price. I got an A!”

Nicole Johnson
Finance & Economics

Our Top Experts

————-

See Why Our Clients Hire Us Again And Again!


OVER
10.3k
Reviews

RATING
4.89/5
Avg Rating

YEARS
12
Experience

Elite Academic Research Promises You:


Always on Time

If we are a minute late, the work is on us – it’s free!

Plagiarism-free

If the work we produce contains plagiarism we’ll pay out a £5,000 guarantee.

Quality

Providing quality work is core to our beliefs, which is why we will strive to give you exactly that, and more!

Written to Standard

All of our assignments go through a stringent quality checking process from start to finish.

Success Guarantee

When you order form the best, some of your greatest problems as a student are solved!

Reliable

Professional

Affordable

Quick

Short Answers To Common Questions

[ultimate-faqs]

YOUR EDUCATION ON AUTOPILOT

Pay an expert to take your online class and say goodbye to poor grades, missed deadlines, and the struggles
of balancing your education with other work/life responsibilities. Life Is too Short to Spend on Classes
You Have No Interest In. Focus on what is really important in your life. Let our professional handle your class.

    Guaranteed A or B

    100% Confidential

    Experienced Tutors

    24/7 Support

Fill in free quote request

Tell us about your online class and what help you need. Try to give us the maximum information.

Agree on price

Our representative will contact you to discuss the details of your order and the rates for our assistance.

Pay and get help

When everything is agreed, you will receive an email with the invoice. After you pay, we start working on your task.

error: Content is protected !!