Artigos Científicos

Aluminium Drinking Water Treatment Residuals and Their Toxic Impact on Human Health


Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7037863/

 

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. 2020 Feb; 25(3): 641.  Published online 2020 Feb 2. doi: 10.3390/molecules25030641  PMCID: PMC7037863 PMID: 32024220

Aluminium Drinking Water Treatment Residuals and Their Toxic Impact on Human Health

Izabela Krupińska

 

Abstract

Aluminium exerts undeniable human health effects, so its concentration should be controlled in water treatment plants. The article presents and discusses the results of studies on the influence of selected properties of aluminium coagulants on the concentration of aluminium remaining in the purified water. The coagulants used were classical hydrolysing aluminium salts: aluminium sulphate (VI) and sodium aluminate as well as pre-hydrolysed polyaluminium chlorides: Flokor 105B and PAX XL10 that had different the alkalinity coefficient r = [OH−]/[Al3+]. The Al species distribution in the coagulants samples were analysed by the Ferron complexation timed spectrophotometry. On the basis of their reaction rates with ferron reagent, the aluminium species were divided into three categories: monomeric (Ala), medium polymerised (Alb) and colloidal (Alc). The usefulness of the tested aluminium coagulants due to the concentration of residual aluminium and dissolved aluminium, which is easily assimilated by the human body, was increased according to the following series: sodium aluminate (Ala = 100%, Alb = 0) < aluminium sulphate (VI) (Ala = 91%, Alb = 9%) < PAX XL 10 (Ala = 6%, Alb = 28%, r = 2.10) < Flokor 105B (Ala = 3%, Alb = 54%, r = 2.55).

Keywords: water treatment plants, residual aluminium, coagulation, aluminium sulphate (VI), sodium aluminate, polyaluminium chlorides, monomeric Al species (Ala), medium polymerised Al species (Alb), colloidal Al species (Alc)

 

4. Conclusions

Data in the literature suggest that exposure to aluminium via drinking water may be a contributing factor in the development of Alzheimer’s disease and related disorders.

The chemical speciation of aluminium in drinking water is very important, as the form of aluminium regulates its solubility, bioavailability and toxicity. Water treatment using aluminium salts, can increase the percentage of dissolved, low molecular weight aluminium species that are chemically reactive and more readily absorbed by human body.

The analysis of test results showed that the pre-hydrolysed coagulants provided significantly lower concentrations of aluminium remaining in the treated water than non-prehydrolysed coagulants.

Because of the concentration of aluminium remaining in the purified water and the share of aluminium dissolved in the remaining aluminium, which is best absorbed by the human body, the usefulness of the studied aluminium coagulants was increased with an increase in the content of polycationic aluminium forms (Alb) and with an decrease in the content of monomeric aluminium forms (Ala) in the coagulants tested.

 



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