Wastewater characterisation

Why might you characterise wastewater?

• design treatment plan

• monitor and control operations

• meet legal requirements

• detect long-term trends

What sort of things are being tested in gross pollution measures?

BOD, COD, grease, suspended solids, NH3

What sort of things are being tested for aesthetic appeal?

Colour, turbidity, taste, odour

What sort of tests can be done for the presents microbiological behaviour?

indicator organisms

What sort of things are being tested in tests for toxins?

pesticides, heavy metals, radioactivity

What sort of things are being tested in test for health-risk materials?

fluoride, nitrate

What sort of things are being tested in tests to determine suitability for other incidental uses?

Corrosion effects, Fe, Mn and hardness salts Ca and Mg

What sort of things are being tested in operational tests?

monitor plant performance

What are the pollution measures?

• gross pollution measures

• aesthetic appeal

• microbiology

• toxins

• incidental use - suitability

• determine process suitability

What is DO?

Dissolved O2

essential to aquatic life, minimum ~5 mg/L needed to sustain a balanced population of aquatic flora and fauna

saturation - at 15 degrees - 10.2 mg/L (~10ppm)

pollutant addition - decreases available DO - may render life unsustainable

What measures are done for solids?

• suspended solids - SS

dry weight retained on filter

classified as fixed and volatile (organic)

• dissolved solids

  remains after SS test

  salinity indicator - can be measured by EC

• settleable solids

  volume of settleable solids

  imhoff cone

Nutrients - N & P

NH3-N

Most reduced from

composed of NH3 and NH-4 - unionised form most toxic

NO3-N

promotes excess growth

nitrite combines with haemoglobin - methemoglobin - blue baby in humans and brown blood disease in fish

Microbial measures and toxins

microorganisms

Key winery waste characteristics

BOD - explain