Aluminum and iron water treatment residuals and application in stormwater Revision as of 21:23, 28 December 2020 by Mtrojan (talk | contribs) (→Effects of feedstock and production temperature)
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.
Contents
- 1 Overview and description
- 2 Applications for aluminum and iron water treatment residuals in stormwater management
- 3 Sources of material, including variants
- 4 Properties of aluminum and iron water treatment residuals
- 5 Effects of aluminum and iron water treatment residuals on physical and chemical properties of soil and bioretention media
- 5.1 Effect of aluminum and iron water treatment residuals on retention and fate of phosphorus
- 5.2 Effect of aluminum and iron water treatment residuals on retention and fate of other pollutants
- 5.3 Effect of aluminum and iron water treatment residuals on soil physical and hydraulic properties
- 5.4 Effects of aluminum and iron water treatment residuals on soil fertility, plant growth, and microbial function
- 6 Standards, classification, testing, and distributors
- 7 Effects of aging
- 8 Storage, handling, and field application
- 9 Sustainability
- 10 References
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
Sources of material, including variants
WTR is a by-product generated from the addition of alum or ferric salts used in the coagulation–flocculation process during drinking water treatment, and contains minimal amount of toxic substance (Ippolito et al., 2011) Water treatment residuals are widely available and generally low cost. The use of WTR in bioretention media will prevent this material of ending up in a landfill. WTR was shown to efficiently remove more than 90% of phosphorus from wastewater (Lee et al., 2015) Different sources of WTR will have different adsorption levels due to the amount of Iron and Aluminum coagulants using. The adsorption of phosphorus in stormwater is correlated to the amorphous hydrous metal oxide content in the WTR due to their strong affinity for oxyanions like phosphate.
Phosphorus saturation index (PSI) of two WTRs were relatively low (Fe-WTR: 0.01 and Al-WTR: 0.02). When PSI was less than 1, there would be excess Fe and Al for binding of P or the presence of low P availability, which suggested that WTR has high P adsorption capacity (Elliott et al., 2002).
97% removal with WTR, 7-21% without WTR used in Babatunde et al. (2009)'s study had excellent P removal capacity (23.1 mg P/g)
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