Sammanfattning

Drinking water treatment residual (DWTR) derived from flocculation and sedimentation of raw water using aluminum coagulants is a valuable environmental remediation byproduct capable of inactivating phosphorus (P). However, no generalizable model exists in the literature to describe reduction of releasable (mobile) P in lake sediment as a result of DWTR addition. The reduction of mobile P (sum of labile P and reductant soluble P) was investigated in over 100 sub-samples using five sediment samples from two lakes and three DWTRs from different water treatment plants. A consistent relationship was determined across a range of mobile P contents (0.23 g/ m2/cm to 0.92 g/m2/cm, or 15.8 to 186.1 mu g/g DW) and DWTRs. The relationship was best described as a function of the mobile P content of the sediment and the oxalate-extractable aluminum content of the DWTR. An empirical model was developed to predict the immediate reduction in mobile P following the addition of DWTR containing aluminum. This model was validated using two additional lake sediments and one additional DWTR (R2 = 0.995). Thus, the immediate inactivation of P in lake sediment following DWTR addition can be predicted with this model, which can be used with internal P loading or other water quality goals to determine an appropriate DWTR dose. Further recommendations were made about dosing DWTRs for lake restoration, allowing practitioners to use DWTR to inactivate P in lake sediment without conducting individual sorption experiments.

Nyckelord

Algae; Alum sludge; Cyanobacteria; Eutrophication; Langmuir isotherm; Water quality

Publicerad i

Water Research
2023, Volym: 232, artikelnummer: 119677
Utgivare: PERGAMON-ELSEVIER SCIENCE LTD

SLU författare

• Huser, Brian

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    

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UKÄ forskningsämne

Vattenbehandling


Publikationens identifierare

DOI: https://doi.org/10.1016/j.watres.2023.119677

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/121551