WATER POLLUTION-UEN008
Page 1: Overview of Water Pollution
Thapar Institute of Engineering & Technology
School of Energy & Environment (SEE)
Course: UEN008 - Energy and Environment
Topic: Water Pollution
Page 2: Water Cycle
Continuation of coursework regarding the water cycle as it pertains to water pollution.
Page 3: Water Pollution
Further detailing the issue of water pollution under the same course.
Page 4: Definition of Water Pollution
Definition: Water pollution is the contamination of water bodies mainly due to human activities.
Water Bodies Affected: Includes lakes, rivers, aquifers, and groundwater.
Cause: Results from excess concentrations of contaminants introduced into the environment, leading to a loss of beneficial uses of water caused by changes in its composition due to human activity.
Page 5: Characteristics of Water Pollution
Physical Characteristics:
Solids, temperature, color, odor, turbidity, oil and grease, conductivity.
Chemical Characteristics:
Organics: Proteins, carbohydrates, lipids, surfactants, phenols, pesticides, etc.
Inorganics: pH, chlorides, alkalinity, nitrogen, phosphorus, and heavy metals.
Gases: Oxygen, hydrogen sulfide, methane.
Biological Characteristics:
Pathogens, indicators, viruses, and invertebrates.
Page 6: Sources of Water Pollution
Point Sources: Single, identifiable sources of pollution.
Non-Point Sources: Diffuse source of pollution, such as:
General runoff of sediments.
Pesticide spraying.
Fertilizer runoff from farms.
Page 7: Point and Non-Point Sources
Overview of the classification and differences between point and non-point sources of water pollution.
Page 8: Major Water Pollutants and Their Sources
Identifying significant water pollutants and understanding their origin.
Page 9: Contaminants Affecting Water Bodies
Key Contaminants:
Biodegradable organic matter.
Suspended, colloidal, and dissolved solids.
Nutrients, pathogens, soaps, detergents, pesticides.
Acidic, basic, and ionic species; as well as thermal and radioactive materials.
Page 10: Categories of Pollutants
Fund Pollutants:
Those with some absorptive capacity in the environment.
Examples:
Degradable (organic residues) broken down by bacteria.
Thermal (heat injection) and Eutrophic (excess nutrients like nitrogen and phosphorus).
Stock Pollutants:
Have little or no absorptive capacity. Ex: Heavy metals, synthetic chemicals.
Page 11: Nature and Characteristics of Wastewater
Overview of wastewater characteristics.
Page 12: Dissolved Oxygen (DO)
Importance: A critical measure of water quality.
Key characteristics:
Oxygen solubility is inversely proportional to temperature; max DO at 16°C is 10 mg/L.
Obtained through diffusion from air, aeration, and photosynthesis.
Stress for aquatic life occurs below 5 mg/L.
Page 13: Dissolved Oxygen Levels
Classification of water quality based on DO levels:
8–9 mg/L: Good
6.7–8 mg/L: Slightly polluted
4.5–6.7 mg/L: Moderately polluted
4–4.5 mg/L: Heavily polluted
Below 4 mg/L: Gravely polluted
Page 14: Physio-Chemical Characteristics of Water
Aggregate organics including:
Total Organic Carbon (TOC)
Chemical Oxygen Demand (COD)
Biochemical Oxygen Demand (BOD)
Chemical and physical constituents affecting water quality:
Organics, Inorganics, Gases.
Page 15: Total Oxygen Demand (ThOD)
Total oxygen required to oxidize a known compound to CO2 and H2O.
Illustrated by stoichiometric calculations with organic compounds.
Page 16: Chemical Oxygen Demand (COD)
Measures the pollution potential of organic matter.
Higher COD values than BOD, as it does not differentiate between degradable and non-degradable matter.
Measured using potassium dichromate.
Page 17: COD Measurement Procedure
Procedure: Measured by the amount of potassium dichromate reduced during a controlled reaction.
Formula used for COD calculation:
COD(mg/l as O2) based on volumes of FAS in blank and sample samples.
Page 18: Example Problem on COD
Problem description involving estimation of COD in wastewater.
Page 19: COD Solution Example
Calculated COD based on given data and formula:
Result: 12000 mg/L.
Page 20: Biochemical Oxygen Demand (BOD)
Definition: Indicator of organic matter concentration in wastewater.
Determined based on aerobic biological decomposition of organic waste.
Known as BOD5, measures DO before and after 5 days incubation at 20°C.
Page 21: Factors Affecting BOD
Not a specific pollutant measure but a gauge of oxygen needed by microorganisms.
Influences include temperature, time, and light conditions.
Page 22: BOD Exponential Decay Curve
Illustration of BOD decay over time.
Page 23: BOD Testing Procedure
BOD determination using initial and final DO measurements, dilution factor applied.
Page 24: Dilution Factor Explained
The dilution factor used in BOD calculations.
Page 25: BOD Calculation Method
Formula to calculate BODt over time based on decay.
Page 26: BOD Numerical Problem
Example problem involving calculations of BOD at different temperatures.
Page 27: Temperature Correction for BOD
Discussion on correcting BOD values based on temperature variations.
Page 28: BOD and COD Relationship
Relationship noted: COD > BOD, indicating biodegradable versus non-biodegradable particles present.
Page 29: Total Organic Carbon (TOC)
Indicates pollution load through carbon content.
Tested using TOC analyzers.
Page 30: Physical Parameters of Water
Overview of solids in water including TSS, TDS, TVS, and their measurement methods.
Page 31: Further Physical Parameters
Additional categories of suspended and dissolved solids.
Page 32: Turbidity Measurement
Definition: Light transmission property of water.
Measurement technique: Nephelometry; units are NTU.
Page 33: Additional Physical Parameters
Colour: Measured by spectrophotometer in PCU.
Temperature: Key in chemical reactions.
Electrical Conductivity: Indicates water's capacity to conduct electricity related to TDS.
Page 34: Physico-Chemical Characteristics Summary
Summary of chemical constituents affecting water quality including alkalinity, nitrogen, phosphorus, etc.
Page 35: Importance of Alkalinity and Nitrogen in Water
Alkalinity from hydroxides, crucial for biological treatment.
Nitrogen compounds measured include NH3, NO3, etc.
Page 36: Phosphorous and Metallic Constituents
Importance of phosphorus as a nutrient and effects of metals like cadmium, mercury as priority pollutants.
Page 37: Wastewater Treatment Overview
Stages of treatment:
Primary: Removes solids.
Secondary: Targets organics.
Tertiary: Nutrient removal.
Page 38: Unit Operations in Wastewater Treatment
Overview of typical operations within a treatment plant.
Page 39: Primary and Secondary Treatment
Focus on the suspended growth process in these treatments.
Page 40: Screening Process
First operation in treatment focused on removing objects that may damage equipment.
Types of screens included: coarse, medium, and fine.
Page 41: Primary Clarification/Sedimentation
Process of gravity separation to remove suspended solids and organic material.
Page 42: Sludge Removal Techniques
Use of scrapers in circular clarifiers.
Page 43: Biological Treatment Fundamentals
Basics of enzymatic reactions involved in biological treatment.
Environmental factors affecting microbial growth described.
Page 44: Activated Sludge Process (ASP)
Description of ASP as an aerobic treatment method utilizing biomass to degrade organic matter.
Page 45: ASP Continued
Further details on the functioning of activated sludge processes (ASPs).
Page 46: Trickling Filters
Explanation of trickling filters as aerobic treatment systems for biodegrading organic matter.
Page 47: Trickling Filter Overview
Summary and visual representation of the trickling filter process.
Page 48: Additional Trickling Filter Information
Further information detailing the trickling filter treatment process.
Page 49: Anaerobic Fluidized Bed Process
Combination of suspended and attached growth processes in a treatment method.
Page 50: Disinfection Process
Describes the partial destruction of pathogens, key characteristics of ideal disinfectants.
Page 51: Disinfection Methods
Overview of physical and chemical methods used for disinfection in water treatment.
Page 52: Mechanism of Disinfectant Action
Describes how different disinfectants interact with pathogens and factors affecting their efficacy.
Page 53: Acknowledgement
Closing slide thanking the audience.