Untitled Quiz

Water Quality Parameters

• Color:

  • True color: Measured in samples without turbidity (after filtration or centrifugation).
  • Apparent color: Measured in samples with turbidity (containing colloidal or suspended material).
  • Measured using spectrophotometers, colorimetric methods, or colorimetric discs.
  • Potability standard: Portaria de consolidação Nº 5, 28 September 2017, with apparent color <15uH.
  • Water body classification: CONAMA Resolution 357, March 17, 2005.

• Turbidity:

  • Unit of Measurement: Turbidity Units (uT) or nephelometric turbidity unit (unT).
  • Defined as the reduction in light intensity as light passes through water.
  • Caused by suspended particles (e.g., clay, silt, algae).
  • Factors affecting turbidity: Sedimentation, aquatic insect habitat, nutrient and pesticide transport, and heat absorption.
  • Potability standard: Portaria de consolidação Nº 5, 28 September 2017, with turbidity < 5 uT. Water body classification: CONAMA Resolution 357, March 17, 2005.
  • Measured using a turbidimeter.

• Taste:

  • Interaction of substances (e.g., salts, methane, chlorine, organic matter) affecting taste.
  • Referenced to taste descriptors (e.g., salty, sweet, sour).

• Odor:

  • Olfactory sensation.
  • Caused by gases like hydrogen sulfide (H2S), chlorine (Cl2) or methane (CH4).
  • Measured using the Odor Threshold method.
  • Determined using successive dilutions in a water sample until odor is nearly unnoticeable (LPO calculation involved).
  • Correction of taste and odor uses methods like activated carbon, chlorine dioxide, chlorine, and aeration.

• Temperature:

  • Measurement of heat intensity.
  • Units: °C.
  • Source: Natural (convection, conduction, radiation) and anthropogenic (cooling towers, industrial discharge).

• Biological Parameters (e.g., Coliforms):

  • Total coliforms: Includes non-fecal origin organisms (e.g., soil/water).
  • Fecal coliforms: Primarily intestinal bacteria from warm-blooded animals (e.g., humans).
  • Escherichia coli (E.coli): A specific fecal indicator from warm-blooded animals.
  • Detection method: Multiple Tube Method, calculating the most probable number (NMP).
  • Potability standard: Portaria de consolidação Nº 5, 28 September 2017.
  • Water body classification: CONAMA Resolution 357, March 17, 2005.

• Chemical Parameters (e.g., pH):

  • pH: Potential of Hydrogen measuring the concentration of hydrogen ions (H+).
  • Represents acidity, neutrality, or alkalinity of water, measured using a scale from 0 to 14.
  • Measurement Tools: pH meter.
  • Potability standard: Portaria de consolidação Nº 5, 28 September 2017, with system distribution pH between 6.0 and 9.5.
  • Water classification: CONAMA Resolution 357, March 17, 2005.

• Chemical Parameters (e.g., Nitrogen and Phosphorus):

  • Nitrogen compounds: Exists as molecular nitrogen (N2), organic nitrogen (dissolved and suspended), ammonia, nitrite and nitrate.
  • Phosphorus: Mostly as orthophosphate, polyphosphate, and organic phosphorus.
  • Measurement Tools: Spectrophotometer.

• Chemical Parameters (e.g., Biochemical Oxygen Demand - BOD):

  • Amount of dissolved oxygen required to oxidize organic matter in water through aerobic decomposition.
  • Indicates organic matter content and pollution level in a water body.
  • Higher values indicate greater organic pollution.
  • Measured indirectly by determining the oxygen consumption.

• Eutrophication:

  • A process where a water body experiences excessive growth of plants (algae) due to high concentrations of nutrients.
  • This is caused by high amounts of organic matter, nitrogen, and phosphorus.

• Dissolved Oxygen (DO):

  • Essential for aquatic life, particularly fish.
  • Low levels of DO can cause fish kills.
  • Measurement: A key parameter to assess the water quality.

• Hardness:

  • Measure of the concentration of divalent metal cations (calcium and magnesium).
  • Classification: Soft, Moderately hard, Hard and Very Hard based on CaCO3.
  • Impacts factors like soap use, incrustation of pipes.