This page provides information on aluminum and iron in water treatment residuals. While providing extensive information on water treatment residuals, there is a section focused specifically on stormwater applications for aluminum and iron in water treatment residuals.

Overview and description

Water treatment residuals are the by-products of water treatment for drinking water. Drinking water treatment residuals are primarily sediment, metal (aluminum, iron or calcium) oxide/hydroxides, activated carbon, and lime removed from raw water during the water purification process (Agyin-Birikorang et al., 2009). Aluminum sulphate (commonly known as alum), ferric chloride and lime are added as flocculants in the water treatment process. This process results in the generation of vast quantities (generally between 10 and 30 mL of WTRs for every litre of water clarified) of a sludge-like waste (or by-product) known as water treatment residuals (WTRs), which require an outlet for their disposal or end use (Dassanayake et al. 2015). The most common method of disposing these WTRs is by sending them to landfills. However, WTRs have many physical and chemical properties that lend them to potential positive reuse routes.

Applications for aluminum and iron water treatment residuals in stormwater management

Effects of feedstock and production temperature

Effect of feedstock (source material)

Effect of production temperature

Properties of aluminum and iron water treatment residuals

Chemical-physical properties of aluminum and iron water treatment residuals

Potential contaminants in aluminum and iron water treatment residuals

Effects of aluminum and iron water treatment residuals on physical and chemical properties of soil and bioretention media

Effect of aluminum and iron water treatment residuals on retention and fate of phosphorus

Effect of aluminum and iron water treatment residuals on retention and fate of other pollutants

  • Nitrogen.
  • Metals.
  • Organics.
  • Bacteria and viruses.
  • Dissolved organic carbon.
  • Greenhouse gas emissions.

Effect of aluminum and iron water treatment residuals on soil physical and hydraulic properties

Effects of aluminum and iron water treatment residuals on soil fertility, plant growth, and microbial function

Standards, classification, testing, and distributors

aluminum and iron water treatment residuals standards

Distributors

Caution: The Minnesota Pollution Control Agency does not endorse specific distributors or products


Test methods

Effects of aging

Storage, handling, and field application

Sustainability

References