Mathias Ernst

Mathias Ernst
Technische Universität Hamburg | TUHH · Institute of Water Resources and Water Supply

Prof. Dr.-Ing.

About

87
Publications
15,699
Reads
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2,584
Citations
Introduction
Mathias Ernst currently works at the Institute of Water Resources and Water Supply, Technische Universität Hamburg.
Additional affiliations
October 2012 - present
DVGW-Forschungsstelle TUHH
Position
  • Head of Department
April 2012 - present
Technische Universität Hamburg
Position
  • Professor (Full)
November 2003 - March 2012
Technische Universität Berlin
Position
  • Assistant Prof. / Executive Manager

Publications

Publications (87)
Article
Full-text available
Sudden changes in drinking water quality can cause harmful consequences for end users. Thus, real-time monitoring of drinking water quality can allow early warning and provide crucial gains for securing safe water distribution. This study investigated the advantages of simultaneous real-time measuring of flow cytometry and fluorescence spectroscopy...
Article
Membrane ozonation of bromide-containing, high-color natural organic matter (NOM) containing groundwater was performed using single-tube polydimethylsiloxane (PDMS) and multi-tube polytetrafluoroethylene (PTFE) membrane contactors, and compared to batch ozonation. For membrane ozonation, dissolved ozone concentration, water color (VIS436), ultravio...
Article
Full-text available
Ion adsorbing ultrafiltration membranes provide an interesting possibility to remove toxic ions from water. Furthermore, it is also possible to recover valuable elements. In this work, we demonstrate two easy strategies to modify polyacrylonitrile membranes with anion and cation adsorbing groups. The membranes were modified to have positively charg...
Conference Paper
Full-text available
Micropollutants (MP) are anthropogenic substances such as pharmaceuticals, pesticides, household or industrial chemicals that enter the natural water resources in concentration in the range of µg/L. Due to uncompleted degeneration of MP in municipal wastewater treatment plants (WWTP), relatively high concentrations of MP are present in the effluent...
Article
Full-text available
Arsenic is among the major drinking water contaminants affecting populations in many countries because it causes serious health problems on long-term exposure. Two low-cost micro-sized iron oxyhydroxide-based adsorbents (which are by-products of the industrial production process of granular adsorbents), namely, micro granular ferric hydroxide (μGFH...
Article
Photovoltaic driven decentralized reverse osmosis plants for brackish water desalination offer a sustainable and low-emission solution for water deficiency problems, especially in arid and semi-arid regions. However, the primary challenge for this combination is how a brackish water reverse osmosis desalination (BWRO) plant based on photovoltaics (...
Article
Full-text available
Anion-adsorbing membranes provide an interesting possibility to remove toxic arsenate and chromate from drinking water. A promising way to prepare anion-exchange materials is to introduce positively charged amine groups on polymers. In this study, polyacrylonitrile (PAN) ultrafiltration membranes were modified with amine functionalities on the memb...
Article
Full-text available
Negatively charged electrically conductive ultrafiltration (UF) membranes have been intensively investigated for fouling mitigation and rejection enhancement in recent years. This study reports the novel approach of applying positive charge (+2.5 V cell potential) to a conductive membrane to induce electrosorption of negatively charged substances o...
Article
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BACKGROUND: This study reports the development of a dynamic membrane (DM) adsorber by the pre‐depositing powdered‐sized fraction of iron oxide‐based adsorptive material on the surface of a microfiltration(MF) membrane. The aim is to use the developed DM adsorber for arsenate (As(V)) remediation from water by a combined mechanism of adsorptive and...
Article
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Layer-by-layer (LbL) modification of porous membranes for water filtration has become an active research field in the past few years. Different mechanisms regarding polyelectrolyte film growth, swelling and smoothing, transport through these films, etc., have been studied. Although there are conjectures, it is not yet fully understood where the pol...
Article
Full-text available
The characterization of membranes is suitable to investigate changes in the membrane properties caused by Layer-by-Layer (LbL) modification. Besides permeability, rejection, and molecular-weight cut-off (MWCO), which give information about the modification of the separation behaviour of the membrane, the zeta potential is capable of describing the...
Article
Full-text available
The adsorption of arsenic (V), As(V), on two porous iron oxyhydroxide-based adsorbents, namely, micro-sized tetravalent manganese feroxyhyte (µTMF) and granular ferric hydroxide (µGFH), applied in a submerged microfiltration membrane hybrid system has been investigated and modeled. Batch adsorption tests were carried out to determine adsorption equ...
Article
Full-text available
Recent studies showed that the application of an electrical potential onto an ultrafiltration membrane surface exhibit several advantages with respect to the fouling and rejection behaviour. Sputter deposition of ultra-thin metal layers onto commercial flat sheet membranes proved to be a simple way of producing conductive metal-polymer-composite me...
Article
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Die Umkehrosmose ist eine sehr energieeffiziente Option zur Meerwasserentsalzung. Da sie nur elektrische Energie nachfragt, bietet sich aus Klimaschutzgründen eine Kombination von Umkehrosmose‐ und Photovoltaik(PV)‐Anlagen an. Deshalb wird hier eine PV‐basierte Umkehrosmose‐Anlage zur Meerwasserentsalzung für einen Standort in Saudi‐Arabien ausgele...
Article
Fluoride, an anionic pollutant, is possibly to be found in excessive concentrations especially in groundwaters and can show detrimental effects on human health, in concentrations higher than the commonly applied legislation limit of 1.5 mg/L The most commonly applied method for water de-fluoridation is performed by Al-based coagulants, which howeve...
Article
Full-text available
Water collection based on groundwater abstraction has a high energy consumption that depends primarily on the operation and performance of submersible well pumps. The fact of the matter is that these machines still work with a global energy efficiency of less than 50%, and further investigations of the energy aspects in well pumps are needed. The p...
Article
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Due to their lower energy consumption, permanent magnet synchronous motor (PMSM) submersible pumps have been introduced in ground water well field operation. Besides direct savings of energy, the introduction of PMSM pumps together with the required variable frequency converters offers new operational scenarios to meet the seasonally varying water...
Article
Full-text available
Next to the pore size distribution, surface charge is considered to be one main factor in the separation performance of ultrafiltration (UF) membranes. By applying an external surface potential onto an electro-conductive UF membrane, electrostatic induced rejection was investigated. This study introduces in a first part a relatively simple but yet...
Article
Full-text available
The small sized powdered ferric oxy-hydroxide, termed Dust Ferric Hydroxide (DFH), was applied in batch adsorption experiments to remove arsenic species from water. The DFH was characterized in terms of zero point charge, zeta potential, surface charge density, particle size and moisture content. Batch adsorption isotherm experiments indicated that...
Article
Full-text available
The present study aims to evaluate changes in the structure-composition of natural organic matter (NOM) that occur after the application of bubbleless ozonation or peroxone treatment of surface waters. The oxidation experiments (using 0.5-2 mg O3/mg DOC, or 2:1 O3:H2O2 molar ratio) were performed in a continuous mode, using a tubular ceramic membra...
Article
Full-text available
Chromium (Cr(VI)) is a very toxic and carcinogenic element, which is widely present in groundwaters, mainly due to geogenic conditions. The limit of Cr(VI) in drinking water is expected to be reduced to 10 μg/L in both the USA and the European Union. Recent literature findings indicated that the most efficient process in reducing Cr(VI) levels to b...
Article
Reproducibility of heterogeneous gypsum scale development on a reverse osmosis membrane was investigated using real-time membrane surface imaging by light microscopy. Temporal scale development in nine identical experiments using virgin membrane samples followed reproducible trends with decreasing rate of detected crystals, linear increase of fract...
Article
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The impact of structural properties of three commercial PACs as well as two mechanically ground PACs on their efficiency in NOM removal and fouling reduction in combined adsorption-ultrafiltration (PAC-UF) of northern German groundwater was investigated. All PACs showed highest adsorption affinity for medium molecular weight NOM fractions. The meso...
Article
Full-text available
Due to its toxicity, Cr(VI) is undesirable in groundwater. Its chemical reduction to Cr(III) species, followed by precipitation is the most widely practiced treatment technique for the removal of Cr(VI) from polluted waters. The resulting Cr(III) species present low solubility, is much less toxic, and can be subsequently removed either by precipita...
Article
Full-text available
The present work focuses on understanding and control of biopolymer fouling in ultrafiltration of a typical surface water and nearby secondary effluent for direct and indirect portable use. Characterization results show that both kinds of biopolymers are of similar molecular weight. Longer than one year water quality monitoring results show that th...
Article
In the present study, several pre-polymerized coagulants of iron and aluminum were tested for their efficiency towards As(V) and As(III) removal from water sources. The results showed that the pre-polymerized coagulants of iron, such as poly-ferric sulfate and poly-ferric silicate chloride, were very efficient for As(V) removal. With regard to As(I...
Article
Reverse osmosis desalination is increasingly applied to address the global challenge of water scarcity and pollution of available water resources. This study investigates interactions of select organic macromolecules - sodium alginate, humic acid and bovine serum albumin – with the inherent operational limitation of membrane scaling caused by gypsu...
Article
The impact of inorganic colloidal water constituents on fouling in low-pressure membrane systems was evaluated by carrying out ultrafiltration (UF) experiments using synthetic waters containing model foulants. Humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA) were chosen as model natural organic matter (NOM) foulants, and silico...
Article
The objective of this work was to compare selective sorption and transport behavior of a Selemion AMV membrane for different anions with a theoretically derived kinetic model describing the Donnan dialysis (DD) process. This analysis resulted in a suggested relation for the diffusivity of small ions through “nanochannels” of ion exchange membranes....
Article
The fouling behavior of different NOM fractions in combination with two micro-particles (0.5-10 mu m and -45 mu m) and one nano-particle (5-15 nm) on UF membrane was investigated. Three NOM models, Aldrich humic acid (HA), bovine serum albumin (BSA) and dextran (DEX) were employed as representatives of humic substances, proteins and polysaccharides...
Article
The interdependencies between water quality parameters and ultrafiltration characteristics (reversible, and irreversible fouling) of surface water (SW) in comparison with treated domestic wastewater (TDW) were systematically investigated. A focus was set to the macromolecular dissolved fraction (“biopolymers”), accounting for about 50% of the full...
Article
KMnO4 pre-oxidation combined with FeCl3 coagulation for membrane fouling reduction was investigated during ultrafiltration (UF) of water samples from an impacted canal river. 0.5 mg/L KMnO4 oxidation alone showed an obvious effect on the decrease of the total membrane fouling and fouling irreversibility, due to the removal of relevant organic membr...
Article
This study was carried out to investigate the effect of monovalent Na+ and divalent Ca2+ on UF membrane fouling behavior of different NOM fractions—humic substances, proteins and polysaccharides, as represented by humic acid (HA), bovine serum albumin (BSA) and dextran (DEX), respectively. The results showed that Na+ was able to reduce the membrane...
Article
Correlations between potential fouling-relevant substances and membrane fouling during ultrafiltration (UF) of different waters were investigated, including water samples from Lake Tegel, from a Berlin canal (Landwehrkanal) and from a wastewater treatment plant (WWTP) secondary effluent. The biopolymers quantified with liquid chromatography-organic...
Article
The present work investigated fouling control and phosphorus removal by applying in-line coagulation prior to ultrafiltration (UF) of treated domestic wastewater. Experiments were conducted in both lab- and pilot-scale under close to neutral pH condition. Lab-scale foulant removal tests showed that increasing the dosage of FeCl3, AlCl3 and polymeri...
Chapter
The potential of MBR systems to remove organic micro-pollutants was investigated at different scales, operational conditions, and locations. MBR effluent quality was compared with that of a conventional activated sludge (CAS) plant, followed by ultrafiltration (UF), operated and tested in parallel. A MBR pilot plant in Israel was operated for over...
Article
The process combination of in-line coagulation and subsequent membrane filtration is a suitable advanced treatment stage to achieve higher quality standards regarding pathogens and phosphorus in biologically treated wastewater prior to its discharge into sensitive water bodies. In this study a membrane pilot installation (capacity of 6 m3/h) was op...
Article
Full-text available
The fates of several macrolide, sulphonamide, and trimethoprim antibiotics contained in the raw sewage of the Tel-Aviv wastewater treatment plant (WWTP) were investigated after the sewage was treated using either a full-scale conventional activated sludge (CAS) system coupled with a subsequent ultrafiltration (UF) step or a pilot membrane bioreacto...
Article
Loss of membrane filtration performance due to organic fouling is still a significant drawback for the application of low-pressure membranes in tertiary wastewater treatment. The present study investigates the relevance of different organic fractions present in secondary effluents in terms of hydraulically reversible and irreversible fouling of hol...
Article
Full-text available
The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were ope...
Article
The present study investigated technical choices controlling fouling development of a pressure-driven ultrafiltration (UF) pilot plant filtering tertiary effluent and its corresponding economical aspects. Experimental results showed that although fouling potential of tertiary effluent (treated by slow sand filtration) is much lower than that of sec...
Article
The utilisation of alternative water sources like reclaimed municipal wastewater is one of the most obvious and promising options in integrated water resources management under water stress conditions. Among the various beneficial uses of reclaimed water Managed Aquifer Recharge (MAR) receives growing attention. It features advantages such as addit...
Article
Ultrafiltration (UF) is considered as a suitable treatment process after conventional wastewater treatment to produce reuse water. Nevertheless, fouling affects the performance of UF to a large extent. As biopolymers (mostly macro polysaccharide-like and protein-like molecules) have been identified as major foulants affecting the filterability of w...
Article
Natural biofiltration processes have been verified as effective pre-treatment choice improving the performance of low-pressure membranes (MF/UF) in wastewater reclamation. In the present work, pilot-scale slow sand filtration (SSF) was used to simulate bank filtration at high filtration rates (from 0.25m/h to 0.5m/h) to filter secondary effluent pr...
Article
In the combined laboratory and pilot plant investigation powder activated carbon dosing and inline coagulation were investigated for surface water from river Spree. The aim was to understand the fouling behaviour of this raw water and to understand and to identify strategies to minimize the irreversible fouling in this application. Trials with acti...
Article
Full-text available
The widespread application of nanofiltration (NF) and reverse osmosis (RO) membranes in wastewater reuse inevitably generates a concentrate stream. Due to high concentrations of phosphate and salts, disposal of membrane concentrates is a problem which seriously constrains the application of this technology, especially in inland applications. There...
Article
Ultrafiltration (UF) of treated municipal wastewater has been used to produce high-quality reuse water for different applications. However, without pre-treatment, secondary treated wastewater effluent shows high fouling potential and reduces the performance of UF membrane filtration significantly. To remove foulants prior to UF, slow sand filtratio...
Article
Application of flux enhancers might be an effective alternative to retard fouling in membrane bioreactors (MBRs). In a comprehensive study, the specific removal of different organic fractions (humic substances, organic acids, biopolymers and SMP) from sludge supernatant and the impact on filtration performance was investigated in lab and pilot scal...
Article
In this study, the fate of carbohydrates, proteins, and humic substances in feedwater, sludge supernatant, and permeate of a pilot-scale membrane bioreactor (MBR) was investigated. Over 10 months, carbohydrates were observed to have a lower bioelimination degree (45%) and higher rejection degree (79%) than those of proteins (81% and 44%, respective...
Conference Paper
Full-text available
Solutions to global water stress problems are urgently needed yet must be sustainable, economical and safe. The utilisation of alternative water sources like reclaimed municipal wastewater is one of the most obvious and promising options in integrated water resources management. Among the various beneficial uses of reclaimed wastewater Managed aqui...
Article
Full-text available
Secondary effluent including different kinds of foulants, e.g. extracellar polymeric substances (EPS), soluble microbial products (SMP), and humic acids was considered as a major barrier for wastewater reuse and reclamation when a membrane was applied to obtain high quality treated water. A new hybrid system of photocatalytic oxidation and non-wove...
Article
Ultrafiltration (UF) membranes can be used after conventional wastewater treatment to produce particle free and hygienically safe water for reuse. However, membrane fouling affects the performance of UF to a large extent. Stirred cell tests with UF membrane show high flux decline filtering treated domestic wastewater. Investigation on the impact of...
Article
Full-text available
The widespread application of nanofiltration (NF) a nd reverse osmosis (RO) membranes in wastewater reuse inevitably generates a concentrate stream. Du e to high concentrations of phosphate and salts, disposal of membrane concentrates is a problem which seriously constrains the application of this technology, especially in inland applications. Ther...
Article
Full-text available
The fouling of two different ultrafiltration membranes by solutions of three globular proteins with different molecular weights and isoelectric points was investigated at low concentrations relevant to secondary effluents (10 mg-L(-1)). The results reveal the increased fouling potential of macromolecules being small enough to enter the membrane por...
Article
Recent investigations indicate the relevance of extracellular polymeric substances (EPS) in terms of fouling of low-pressure membranes in advanced wastewater treatment. In this study, the high impact of the macromolecular fraction of effluent organic matter on fouling was confirmed in cross-flow ultrafiltration experiments using secondary effluent...
Article
In a Sino-German research project, a sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008 in Beijing, China. Results from pilot-scale experiments in Beijing and Berlin show that selective nutrient removal by adsorption onto granular ferric hydroxide (GFH) after a membrane...
Article
Membrane fouling by macromolecular dissolved organic compounds is still a fundamental drawback in low-pressure membrane filtration of secondary effluent. In this study, pre-treatment of secondary effluent by coagulation and/or adsorption was investigated in terms of removal of different dissolved organic carbon (DOC) fractions, especially macromole...