Capillary Nanofiltration under Anoxic Conditions as Post-Treatment after Bank Filtration

Jeannette Jährig,Ulf Miehe,Alexander Sperlich,Daniel Wicke,Leo Vredenbregt

doi:10.3390/w10111599

Jeannette Jährig, Ulf Miehe + Show 3 more

Open Access

https://doi.org/10.3390/w10111599

Copy DOI

Abstract

Bank filtration schemes for the production of drinking water are increasingly affected by constituents such as sulphate and organic micropollutants (OMP) in the source water. Within the European project AquaNES, the combination of bank filtration followed by capillary nanofiltration (capNF) is being demonstrated as a potential solution for these challenges at pilot scale. As the bank filtration process reliably reduces total organic carbon and dissolved organic carbon (DOC), biopolymers, algae and particles, membrane fouling is reduced resulting in long term operational stability of capNF systems. Iron and manganese fouling could be reduced with the possibility of anoxic operation of capNF. With the newly developed membrane module HF-TNF a good retention of sulphate (67–71%), selected micropollutants (e.g., EDTA: 84–92%) and hardness (41–55%) was achieved together with further removal of DOC (82–87%). Fouling and scaling could be handled with a good cleaning concept with acid and caustic. With the combination of bank filtration and capNF a possibility for treatment of anoxic well water without further pre-treatment was demonstrated and retention of selected current water pollutants was shown.

Highlights

IntroductionBank filtration schemes for the production of drinking water are increasingly affected worldwide by e.g., organic micropollutants (OMP), pathogens, nitrate or sulphate in the source water, flood and low water or riverbed clogging [1,2,3,4,5,6,7]
The present work was developed within the European project AquaNES
In Berlin, drinking water is produced from 54% bank filtrate, 16% groundwater recharge and

Summary

Introduction

Bank filtration schemes for the production of drinking water are increasingly affected worldwide by e.g., OMP, pathogens, nitrate or sulphate in the source water, flood and low water or riverbed clogging [1,2,3,4,5,6,7]. Within AquaNES new technology components were integrated and monitoring and operating regimes were adopted to further optimize water treatment in bank filtration schemes for these new requirements. In Berlin, drinking water is produced from 54% bank filtrate, 16% groundwater recharge and. Background concentrations for sulphate in ground water of Berlin are mostly >100 mg/L, in the inner city >360 mg/L [9]. Selected wells already exceed the limit for drinking water of 250 mg/L [10], reaching up to 900 mg/L at some eastern locations along the Havel River [11]

Objectives

Methods

Results

Conclusion