Introduction to Environmental Engineering

1
Introduction to Environmental Engineering

• Lecture 14
• Water Quality Continued
• Chapter 8

2
Solids

• The separation of solids is one of the primary
  objectives of wastewater treatment
• Solid
• Anything other than a liquid or gas
• Anything remaining after evaporation at 103 ?C

3
Solids

• Total Solids
• TS total solids, mg/L
• Wds weight of dish plus the dry solids, mg
• Wd weight of clean dish, mg
• V volume of sample, L

4
Solids

• Total Solids dissolved solids suspended
  solids
• Volatile Solids solids burned away _at_ 550 600
  ?C
• FS Fixed Solids remaining ash from burning _at_
  550 600 ?C

5
Nitrogen

• Remember, building blocks of life
• Carbohydrates, Protein, Fatty Acids, Nucleic
  Acids
• Nitrogen is a major component of Amino Acids,
  which are the building blocks of protein
• NH3 is an intermediate in biological metabolism
• Organic nitrogen and NH3 indicate recent
  pollution Kjeldahl Nitrogen test
• Nitrite and Nitrate indicate pollution some time
  ago
• Both are measured colorimetrically

6
Bacteriological Measurements

• Microbiology study of organisms that can not be
  seen with the naked eye
• Recall, before the late 1800s no one knew that
  they existed. Louis Pasteur
• Range in size from 1 mm to 10-5 mm
• From an environmental standpoint they are
  important in every compartment, Air, Water and
  Soil
• Most of the organic carbon available for life is
  in the form of microbes

7
Bacteriological Measurements

• It is really their world, from a population
  standpoint
• 1 gram of rich soil contains
• 2.5 billion bacteria
• 0.5 million fungi
• 50,000 algae
• 30,000 protozoa

8
Bacteriological Measurements

• An Environmental Engineer needs to have a
  knowledge of microbes
• to remove them in water treatment (filtration and
  chlorination)
• to support them in wastewater treatment (carbon,
  nitrogen and phosphorus removal from waste)

9
Bacteriological Measurements

• Only a small fraction cause disease
• Pathogens
• Typhoid and cholera killed millions around the
  turn of the century
• These two waterborne diseases drove technology
  advancement
• Today, Salmonella, Shigella, Hepatitis,
  Entamoeba, Giardia, Cryptosporidium are the main
  U.S. concerns

10
Bacteriological Measurements

• Epidemiology
• The connection between pathogens in water and
  human disease was made by Dr. John Snow
• Father of Epidemiology
• Determined that a Cholera outbreak was from water
  downstream of London
• Removed the water pump, ending the outbreak

11
Bacteriological Measurements

• Indicator Organisms
• Coliforms group of microbes used to show
  contamination of a source
• Qualities of a good indicator organism
• Inhabits the digestive tracts of warm-blooded
  animals
• Plentiful
• Easily detected
• Harmless
• Survive longer than most pathogens

12
Bacteriological Measurements

• Principal Methods of Measurement
• Filter Count
• Coliforms captured on a filter
• Filter placed in agar
• Colonies grown and counted
• MPN Test
• Diluted samples placed in broth
• Gas production indicates fermentation
• Count the positive reactions, statistics

13
Assessing Water Quality

• Standard Methods for the Examination of Water
  Quality (Standard Methods)
• Quantitative Measurement Techniques of everything
  that may be in water
• Drinking Water Standards
• EPA Primary and Secondary Standards
• MCL Maximum Contaminant Level
• Wastewater Effluent Standards
• NPDES Permit National Pollution Discharge
  Elimination System
• Surface Water Quality Standards
• A ? E levels