Static and dynamic sorption of DOM on Bond Elute PPL and Bondesil PPL sorbents: physical-chemical characteristics

ABSTRACT

The objective of this work was to study sorption of dissolved organic matter (DOM) onto Bondesil PPL and Bond Elut PPL sorbents with particular attention to impact of sorption loading on molecular composition of the DOM isolated with a use of solid phase extraction (SPE). It was shown that the batch sorption isotherms were best fitted with the Langmuir model, the sorption constants were 8.6·10³ L·kg_OC⁻¹ and 10.7·10³ L·kg_OC⁻¹ for Bond Elut PPL and Bondesil PPL, respectively. Breakthrough curves were satisfactorily fitted by a logistic equation; the maximum sorbent loading was 13% (wt. dissolved organic carbon) for both sorbents. The relationship between loading values and optical descriptors of the DOM at the column exit showed preferential sorption of low molecular weight aromatic DOM components in the range of low loading values (up to 4%), the similar trends were observed for size exclusion chromatography (SEC) measurements. Much lesser impact of loading onto molecular composition was observed within the range from 4 to 8% dissolved organic carbon (DOC). Given high recovery values (70–85%) in this loading range, it can be recommended as preferential for conducting DOM isolation from natural waters using SPE PPL-modified sorbents.

KEYWORDS:

• Sorption
• DOM
• SPE
• Bondesil PPL
• Bond Elut PPL

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Statement of novelty

In this work, the sorption characteristics of the sorbents for solid-phase extraction of dissolve organic matter onto Bondesil PPL and Bond Elut PPL sorbents were investigated in detail. The studies were carried out in static and dynamic conditions. We have determined the kinetic parameters and sorption constants of the interaction of DOM with the sorbent. It is shown for the first time that during solid-phase extraction, the molecular weight of DOM in the eluate depends on the degree of sorbent loading. We have suggested optimal conditions for DOM extraction on Bondesil PPL and Bond Elut PPL sorbents.

Additional information

Funding

The research was funded by RFBR and the Moscow City Government - the project No 21-33-70130 (adsorption experiments), and by the Russian Science Foundation grant [#20-63-47070] (size exclusion chromatography).