Nutrient

"Nutrients" in wastewater are nutrients or chemical elements contained in wastewater, mainly nitrogen (N) and phosphorus (P). These nutrients generally come from:

• Domestic waste: used water from laundry, kitchen, toilet (urine contains urea → nitrogen).

• Industrial waste: e.g. from food, fertilizer or livestock factories.

• Agricultural runoff: fertilizers carried by rainwater.

Main Nutrient Types

1. Nitrogen (N)

   • Forms: ammonia (NH₃/NH₄⁺), nitrite (NO₂-), nitrate (NO₃-), and urea.

   • Sources: human/animal urine, fertilizers, food waste.

2. Phosphorus (P)

   • Forms: orthophosphate, polyphosphate, and organic phosphorus.

   • Sources: detergents, fertilizers, organic waste.

3. Potassium (K) (of lesser concern, but still present in wastewater).

Impact of Nutrients in Wastewater

• Eutrophication: if nutrients enter rivers/lakes, aquatic plants & algae overgrow → dissolved oxygen decreases → fish die.

• Water quality degrades: odor, color, and taste of water become unacceptable.

• Health problems: e.g. high nitrate in drinking water can cause blue baby syndrome in infants.

Nutrient Management

In wastewater treatment, there are specific processes to reduce nutrients:

• Biological Nutrient Removal (BNR) → utilizing bacteria to remove nitrogen & phosphorus.

• Chemical precipitation → adding chemicals (e.g. alum or iron) toprecipitate phosphorus.