Environmental Chemistry

By Prof. Bhanu Prakash Vellanki   |   IIT Roorkee
Learners enrolled: 379
The course deals with the fundamentals and critical analysis of chemical processes one encounters in the field of Environmental Engineering. The course deals with:
• Application of equilibrium equations and material balance equations to calculate conditions in environmental systems at equilibrium using the concept of components.
• Use of chemical equilibrium programs such as VMINTEQ to calculate conditions in environmental systems at equilibrium
• Application of kinetic equations, stoichiometric relationships and material balances to calculate conditions in environmental systems in which reactions occur that are not at equilibrium.
• Application of fundamental aspects of thermodynamics to describe equilibrium conditions in environmental systems. 
• Defining equilibrium and kinetic limitations as relating to environmental systems and the relative importance of each for chemical processes in environmental systems. 
• Knowledge of important terminology for chemical processes occurring in environmental systems

Environmental engineering professionals and students pursuing a degree with emphasis in Environmental engineering
PREREQUISITES Entry level chemistry course
INDUSTRIES  SUPPORT     : CPCB, SPCB, Degremont, ERM, Ramky Enviro Engineers, Veolia Water, SFC Environmental Technologies Pvt. Ltd., Nalco Water, VA Tech Wabag, Ther
Course Status : Upcoming
Course Type : Core
Duration : 12 weeks
Start Date : 26 Jul 2021
End Date : 15 Oct 2021
Exam Date : 23 Oct 2021
Enrollment Ends : 02 Aug 2021
Category :
  • Civil Engineering
  • Environment
Credit Points : 3
Level : Postgraduate

Course layout

Week 1
I. Introduction
II. Fundamentals of chemical processes
A. Introduction 
   1.      Terminology
   2.      Fundamental Aspects of Chemical Processes
      a) Equilibrium
      b) Kinetics
   3.     Relationships between Equilibrium, Kinetics, steady-state
     B.      Equilibrium 
   1.     Introduction (importance, definitions)
   2.     Gibbs free energy 
      a) Definition
      b) Process feasibility (criteria, driving forces)
      c) Application to reactions
            (1) Mixtures
            (2) Reactions
      d) Calculate Gibbs Energies
            (1) Standard conditions
            (2) Non-standard conditions
                    (a) Concentration/activity (concept of activity; effect of activities, reaction quotient, equilibrium coefficient, relationship of activities and concentrations, determining activity coefficients, corrected equilibrium coefficients)
                    (b) Temperature (van't Hoff equation)
                    (c) Pressure (effect of change in volume)
   3.    Phase Equilibrium
     a) Introduction
     b) Gas-Liquid
     c) Fluid-Solid
     d) Multiphase
  4.   Equilibrium Models 
     a) Introduction
     b) Chemical Equilibrium models
       (1) Structure
       (2) Example

Week 2
       (3) Generalized Approach
            (a) Species
            (b) Components
            (c) Formation equation
            (d) Tableau
            (e) Component balance equations
            (f)         Equilibrium equations
            (g) Solutions
    C. Kinetics 
  1.    Reactions
      a) Introduction (importance, terminology)
      b) Factors affecting rates of reactions
        (1)   Concentrations of reactants
        (2)    Temperature
      c) Stoichiometry
  2.    Reactors
     a) General approach (rate equation, material balance)
     b) Material balances
       (1) Batch reactor (assumptions, material balances, stoichiometry examples)
       (2)  Plug flow reactor (assumptions, material balances, stoichiometry examples)
       (3) Completely mixed reactor (assumptions, material balances, stoichiometry examples)
     c)    Examples

Week 3:
     d) Reaction Kinetics for Reversible Reactions
 3. Determination of rate equation
     a) Requirements
            (1) Form of equation (rates, graph, regression for n)
            (2) Values of coefficients
     b) Approaches
            (1) Rate-based (rates, regression, linear or nonlinear, one-point)
            (2) Concentration-based (concentration model, regression, one-point)
     c) Regression
            (1) Linear
            (2) Linearized
            (3) Non-linear
III. Acid/Base Reactions 
A. Introduction (importance, terminology)
B. Kinetics
C.  Equilibrium
   1.     Single Reaction
     a) Henderson-Haselbach Equation
          (1)         Acid dissociation constant
  (2) pKa
  (3) Strength of Acid
  (4) Example

Week 4
     b) Ionization Fractions
  2.       Models (multiple reactions)
     a) Recipe problems
            (1) Single acid in water
            (2) Single base in water
            (3) Mixture of acid and base
            (4) Titrations
            (5) Buffering
     b) Inverse Problems
     c) Computer solutions (VMINTEQ)

Week 5
  1.      Log C-pH Graphs
     a) Introduction
     b) Preparation
     c) Example
  2.      Carbonate System
     a) Introduction
     b) Closed system
     c) Open system
  3.      Equivalence Point
  4. Buffer
     a) Introduction
     b) Application by VMINTEQ

Week 6
     c) Buffer Intensity at various pH ranges 
     d) Design of Buffers
  5.   Alkalinity, acidity
(1) Definitions
            (a) Theoretical
    (b) Operational
(2) Acidity
    (a) Mineral Acidity
            (b) Phenolphthalein Acidity
            (c) Total Acidity 
        (3) Multiple Equivalence Points

Week 7
(4) Relationship among ALK,ACD, Ct,co3
(5) Mixing Problems
(6) Conservative quantities
(a) Introduction
(b) Alkalinity due to Carbonate and Non- Carbonate Species
(7) Example: Complex Acid/Base Problems

Week 8
IV. Aqueous Complex Formation 
     A. Introduction
1. metals as acids
2. examples
3. terminology
4. importance
     B. Kinetics
     C. Equilibrium
        1. Equilibrium Coefficients
       a)  stepwise
       b) one-step
        2. Strength of complexes
        3. Models
V. Precipitation 
           A.     Introduction
1. Terminology
2. Applications
   B.     Kinetics
        1. Relative Importance

Week 9
        2. Steps
             a) Nucleation
             b) Crystal Growth
             c) Agglomeration
             d) Ripening
                    (1) Definition
                    (2) Types
(a) Ostwald
(b) More crystalline, less soluble
     3. Controlling precipitation
  a)     Promoting precipitation
  b)     Inhibiting precipitation
C.   Equilibrium
     1. Coefficients
     2. Important concepts
     3. Models
a) General approach
b) Problem types
(1) Recipe
(2) Solubility
(3) Inverse recipe

Week 10
  4.     Competitive Precipitation
  5.     Predominance Area Diagram
  6.     Calcium carbonate precipitation
 a) Saturation indexes
VI. Oxidation/Reduction 
     A. Introduction
     1.  Terminology
     2.  Applications
     3.  Balancing Redox Reactions
             B. Kinetics
     1. Importance
     2. Models

Week 11
    C. Equilibrium
     1. Introduction
     2. Alternatives for reaction feasibility
      a) Q/K approach 
b) pe approach
(1) Definitions of pe, pe0
(2) Reaction feasibility 
(3) Models

Week 12
c) Eh approach
(1) Galvanic cell
(2) Nernst equation
(3) Relationship of Eh, pe 
    3.     Oxidation-Reduction Potential (ORP) Measurement
a) Introduction
b) Advantages
c) Limitation
    4.     Predominance Area Diagrams
a) Introduction
b) Examples
    5.     Corrosion
                a) Introduction
b) Corrosion Cell
c) Types
d) control methods

Books and references

1. Water Chemistry, M. Benjamin, Waveland Press, Long Grove, Illinois, 2010 (ISBN 1577666674) ,
2.Water Chemistry: An Introduction to the Chemistry of Natural and Engineered Aquatic Systems, Patrick L. Brezonik, William A. Arnold, Oxford University Press, New York, 2011,
3. Aquatic Chemistry, 3rd Edition, W. Stumm, J.J. Morgan, John Wiley and Sons, New York, 1996. 4- Aquatic Surface Chemistry, W. Stumm (Ed), John Wiley and Sons, New York, 1987.

Instructor bio

Prof. Bhanu Prakash Vellanki

IIT Roorkee
Dr. Bhanu Prakash Vellanki, is an Assistant Professor at IIT Roorkee. He holds a PhD in Civil Engineering with a specialization in Environmental Engineering from Texas A&M University. During the course of his doctoral work, Dr. Vellanki developed a new class of treatment processes, called the Advanced Reduction Processes. His research interests include Advanced Redox Processes, industrial/hazardous waste treatment, and emerging contaminants.

Course certificate

The course is free to enroll and learn from. But if you want a certificate, you have to register and write the proctored exam conducted by us in person at any of the designated exam centres.
The exam is optional for a fee of Rs 1000/- (Rupees one thousand only).
Date and Time of Exams: 23 October 2021 Morning session 9am to 12 noon; Afternoon Session 2pm to 5pm.
Registration url: Announcements will be made when the registration form is open for registrations.
The online registration form has to be filled and the certification exam fee needs to be paid. More details will be made available when the exam registration form is published. If there are any changes, it will be mentioned then.
Please check the form for more details on the cities where the exams will be held, the conditions you agree to when you fill the form etc.


Average assignment score = 25% of average of best 8 assignments out of the total 12 assignments given in the course.
Exam score = 75% of the proctored certification exam score out of 100

Final score = Average assignment score + Exam score

YOU WILL BE ELIGIBLE FOR A CERTIFICATE ONLY IF AVERAGE ASSIGNMENT SCORE >=10/25 AND EXAM SCORE >= 30/75. If one of the 2 criteria is not met, you will not get the certificate even if the Final score >= 40/100.

Certificate will have your name, photograph and the score in the final exam with the breakup.It will have the logos of NPTEL and IIT Roorkee.It will be e-verifiable at nptel.ac.in/noc.

Only the e-certificate will be made available. Hard copies will not be dispatched.

Once again, thanks for your interest in our online courses and certification. Happy learning.

- NPTEL team

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